vcs.maemo.org Git - hildon/blob - hildon/hildon-pannable-area.c

   1 /*
   2  * This file is a part of hildon
   3  *
   4  * Copyright (C) 2008 Nokia Corporation, all rights reserved.
   5  *
   6  * Contact: Rodrigo Novo <rodrigo.novo@nokia.com>
   7  *
   8  * This widget is based on MokoFingerScroll from libmokoui
   9  * OpenMoko Application Framework UI Library
  10  * Authored by Chris Lord <chris@openedhand.com>
  11  * Copyright (C) 2006-2007 OpenMoko Inc.
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU Lesser Public License as published by
  15  * the Free Software Foundation; version 2 of the license.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Lesser Public License for more details.
  21  *
  22  */
  23
  24 /**
  25  * SECTION: hildon-pannable-area
  26  * @short_description: A scrolling widget designed for touch screens
  27  * @see_also: #GtkScrolledWindow
  28  *
  29  * #HildonPannableArea is a container widget that can be "panned" (scrolled)
  30  * up and down using the touchscreen with fingers. The widget has no scrollbars,
  31  * but it rather shows small scroll indicators to give an idea of the part of the
  32  * content that is visible at a time. The scroll indicators appear when a dragging
  33  * motion is started on the pannable area.
  34  *
  35  * The scrolling is "kinetic", meaning the motion can be "flicked" and it will
  36  * continue from the initial motion by gradually slowing down to an eventual stop.
  37  * The motion can also be stopped immediately by pressing the touchscreen over the
  38  * pannable area.
  39  */
  40
  41 #undef HILDON_DISABLE_DEPRECATED
  42
  43 #include <math.h>
  44 #if USE_CAIRO_SCROLLBARS == 1
  45 #include <cairo.h>
  46 #endif
  47 #include <gdk/gdkx.h>
  48
  49 #include "hildon-pannable-area.h"
  50 #include "hildon-marshalers.h"
  51 #include "hildon-enum-types.h"
  52
  53 #define USE_CAIRO_SCROLLBARS 0
  54
  55 #define SCROLL_BAR_MIN_SIZE 5
  56 #define RATIO_TOLERANCE 0.000001
  57 #define SCROLL_FADE_TIMEOUT 100
  58 #define MOTION_EVENTS_PER_SECOND 25
  59 #define CURSOR_STOPPED_TIMEOUT 80
  60 #define MAX_SPEED_THRESHOLD 500
  61 #define PANNABLE_MAX_WIDTH 788
  62 #define PANNABLE_MAX_HEIGHT 378
  63
  64 G_DEFINE_TYPE (HildonPannableArea, hildon_pannable_area, GTK_TYPE_BIN)
  65
  66 #define PANNABLE_AREA_PRIVATE(o)                                \
  67   (G_TYPE_INSTANCE_GET_PRIVATE ((o), HILDON_TYPE_PANNABLE_AREA, \
  68                                 HildonPannableAreaPrivate))
  69
  70 struct _HildonPannableAreaPrivate {
  71   HildonPannableAreaMode mode;
  72   HildonMovementMode mov_mode;
  73   GdkWindow *event_window;
  74   gdouble x;            /* Used to store mouse co-ordinates of the first or */
  75   gdouble y;            /* previous events in a press-motion pair */
  76   gdouble ex;           /* Used to store mouse co-ordinates of the last */
  77   gdouble ey;           /* motion event in acceleration mode */
  78   gboolean enabled;
  79   gboolean button_pressed;
  80   guint32 last_time;    /* Last event time, to stop infinite loops */
  81   gint last_type;
  82   gboolean last_in;
  83   gboolean moved;
  84   gdouble vmin;
  85   gdouble vmax;
  86   gdouble vmax_overshooting;
  87   gdouble vfast_factor;
  88   gdouble decel;
  89   gdouble drag_inertia;
  90   gdouble scroll_time;
  91   gdouble vel_factor;
  92   guint sps;
  93   guint panning_threshold;
  94   guint scrollbar_fade_delay;
  95   guint bounce_steps;
  96   guint force;
  97   guint direction_error_margin;
  98   gdouble vel_x;
  99   gdouble vel_y;
 100   GdkWindow *child;
 101   gint child_width;
 102   gint child_height;
 103   gint ix;                      /* Initial click mouse co-ordinates */
 104   gint iy;
 105   gint cx;                      /* Initial click child window mouse co-ordinates */
 106   gint cy;
 107   guint idle_id;
 108   gdouble scroll_to_x;
 109   gdouble scroll_to_y;
 110   gdouble motion_x;
 111   gdouble motion_y;
 112   gint overshot_dist_x;
 113   gint overshot_dist_y;
 114   gint overshooting_y;
 115   gint overshooting_x;
 116   gdouble scroll_indicator_alpha;
 117   gint motion_event_scroll_timeout;
 118   gint scroll_indicator_timeout;
 119   gint scroll_indicator_event_interrupt;
 120   gint scroll_delay_counter;
 121   gint vovershoot_max;
 122   gint hovershoot_max;
 123   gboolean initial_hint;
 124   gboolean initial_effect;
 125   gboolean low_friction_mode;
 126   gboolean first_drag;
 127
 128   gboolean size_request_policy;
 129   gboolean hscroll_visible;
 130   gboolean vscroll_visible;
 131   GdkRectangle hscroll_rect;
 132   GdkRectangle vscroll_rect;
 133   guint indicator_width;
 134
 135   GtkAdjustment *hadjust;
 136   GtkAdjustment *vadjust;
 137   gint x_offset;
 138   gint y_offset;
 139
 140   GtkPolicyType vscrollbar_policy;
 141   GtkPolicyType hscrollbar_policy;
 142
 143   GdkGC *scrollbars_gc;
 144   GdkColor scroll_color;
 145
 146   gboolean center_on_child_focus;
 147   gboolean center_on_child_focus_pending;
 148 };
 149
 150 /*signals*/
 151 enum {
 152   HORIZONTAL_MOVEMENT,
 153   VERTICAL_MOVEMENT,
 154   PANNING_STARTED,
 155   PANNING_FINISHED,
 156   LAST_SIGNAL
 157 };
 158
 159 static guint pannable_area_signals [LAST_SIGNAL] = { 0 };
 160
 161 enum {
 162   PROP_ENABLED = 1,
 163   PROP_MODE,
 164   PROP_MOVEMENT_MODE,
 165   PROP_VELOCITY_MIN,
 166   PROP_VELOCITY_MAX,
 167   PROP_VEL_MAX_OVERSHOOTING,
 168   PROP_VELOCITY_FAST_FACTOR,
 169   PROP_DECELERATION,
 170   PROP_DRAG_INERTIA,
 171   PROP_SPS,
 172   PROP_PANNING_THRESHOLD,
 173   PROP_SCROLLBAR_FADE_DELAY,
 174   PROP_BOUNCE_STEPS,
 175   PROP_FORCE,
 176   PROP_DIRECTION_ERROR_MARGIN,
 177   PROP_VSCROLLBAR_POLICY,
 178   PROP_HSCROLLBAR_POLICY,
 179   PROP_VOVERSHOOT_MAX,
 180   PROP_HOVERSHOOT_MAX,
 181   PROP_SCROLL_TIME,
 182   PROP_INITIAL_HINT,
 183   PROP_LOW_FRICTION_MODE,
 184   PROP_SIZE_REQUEST_POLICY,
 185   PROP_HADJUSTMENT,
 186   PROP_VADJUSTMENT,
 187   PROP_CENTER_ON_CHILD_FOCUS,
 188   PROP_LAST
 189 };
 190
 191 static void hildon_pannable_area_class_init (HildonPannableAreaClass * klass);
 192 static void hildon_pannable_area_init (HildonPannableArea * area);
 193 static void hildon_pannable_area_get_property (GObject * object,
 194                                                guint property_id,
 195                                                GValue * value,
 196                                                GParamSpec * pspec);
 197 static void hildon_pannable_area_set_property (GObject * object,
 198                                                guint property_id,
 199                                                const GValue * value,
 200                                                GParamSpec * pspec);
 201 static void hildon_pannable_area_remove_timeouts (GtkWidget * widget);
 202 static void hildon_pannable_area_dispose (GObject * object);
 203 static void hildon_pannable_area_realize (GtkWidget * widget);
 204 static void hildon_pannable_area_unrealize (GtkWidget * widget);
 205 static void hildon_pannable_area_size_request (GtkWidget * widget,
 206                                                GtkRequisition * requisition);
 207 static void hildon_pannable_area_size_allocate (GtkWidget * widget,
 208                                                 GtkAllocation * allocation);
 209 static void hildon_pannable_area_child_allocate_calculate (GtkWidget * widget,
 210                                                            GtkAllocation * allocation,
 211                                                            GtkAllocation * child_allocation);
 212 static void hildon_pannable_area_style_set (GtkWidget * widget,
 213                                             GtkStyle * previous_style);
 214 static void hildon_pannable_area_map (GtkWidget * widget);
 215 static void hildon_pannable_area_unmap (GtkWidget * widget);
 216 static void hildon_pannable_area_grab_notify (GtkWidget *widget,
 217                                               gboolean was_grabbed,
 218                                               gpointer user_data);
 219 #if USE_CAIRO_SCROLLBARS == 1
 220 static void rgb_from_gdkcolor (GdkColor *color, gdouble *r, gdouble *g, gdouble *b);
 221 #else /* USE_CAIRO_SCROLLBARS */
 222 static void tranparency_color (GdkColor *color,
 223                                GdkColor colora,
 224                                GdkColor colorb,
 225                                gdouble transparency);
 226 #endif /* USE_CAIRO_SCROLLBARS */
 227 static void hildon_pannable_draw_vscroll (GtkWidget * widget,
 228                                           GdkColor *back_color,
 229                                           GdkColor *scroll_color);
 230 static void hildon_pannable_draw_hscroll (GtkWidget * widget,
 231                                           GdkColor *back_color,
 232                                           GdkColor *scroll_color);
 233 static void hildon_pannable_area_initial_effect (GtkWidget * widget);
 234 static void hildon_pannable_area_redraw (HildonPannableArea * area);
 235 static void hildon_pannable_area_launch_fade_timeout (HildonPannableArea * area,
 236                                                       gdouble alpha);
 237 static void hildon_pannable_area_adjust_value_changed (HildonPannableArea * area,
 238                                                        gpointer data);
 239 static void hildon_pannable_area_adjust_changed (HildonPannableArea * area,
 240                                                  gpointer data);
 241 static gboolean hildon_pannable_area_scroll_indicator_fade(HildonPannableArea * area);
 242 static gboolean hildon_pannable_area_expose_event (GtkWidget * widget,
 243                                                    GdkEventExpose * event);
 244 static GdkWindow * hildon_pannable_area_get_topmost (GdkWindow * window,
 245                                                      gint x, gint y,
 246                                                      gint * tx, gint * ty,
 247                                                      GdkEventMask mask);
 248 static void synth_crossing (GdkWindow * child,
 249                             gint x, gint y,
 250                             gint x_root, gint y_root,
 251                             guint32 time, gboolean in);
 252 static gboolean hildon_pannable_area_button_press_cb (GtkWidget * widget,
 253                                                       GdkEventButton * event);
 254 static void hildon_pannable_area_refresh (HildonPannableArea * area);
 255 static gboolean hildon_pannable_area_check_scrollbars (HildonPannableArea * area);
 256 static void hildon_pannable_axis_scroll (HildonPannableArea *area,
 257                                          GtkAdjustment *adjust,
 258                                          gdouble *vel,
 259                                          gdouble inc,
 260                                          gint *overshooting,
 261                                          gint *overshot_dist,
 262                                          gdouble *scroll_to,
 263                                          gint overshoot_max,
 264                                          gboolean *s);
 265 static void hildon_pannable_area_scroll (HildonPannableArea *area,
 266                                          gdouble x, gdouble y);
 267 static gboolean hildon_pannable_area_timeout (HildonPannableArea * area);
 268 static void hildon_pannable_area_calculate_velocity (gdouble *vel,
 269                                                      gdouble delta,
 270                                                      gdouble dist,
 271                                                      gdouble vmax,
 272                                                      gdouble drag_inertia,
 273                                                      gdouble force,
 274                                                      guint sps);
 275 static gboolean hildon_pannable_area_motion_event_scroll_timeout (HildonPannableArea *area);
 276 static void hildon_pannable_area_motion_event_scroll (HildonPannableArea *area,
 277                                                       gdouble x, gdouble y);
 278 static void hildon_pannable_area_check_move (HildonPannableArea *area,
 279                                              GdkEventMotion * event,
 280                                              gdouble *x,
 281                                              gdouble *y);
 282 static void hildon_pannable_area_handle_move (HildonPannableArea *area,
 283                                               GdkEventMotion * event,
 284                                               gdouble *x,
 285                                               gdouble *y);
 286 static gboolean hildon_pannable_area_motion_notify_cb (GtkWidget * widget,
 287                                                        GdkEventMotion * event);
 288 static gboolean hildon_pannable_leave_notify_event (GtkWidget *widget,
 289                                                     GdkEventCrossing *event);
 290 static gboolean hildon_pannable_area_button_release_cb (GtkWidget * widget,
 291                                                         GdkEventButton * event);
 292 static gboolean hildon_pannable_area_scroll_cb (GtkWidget *widget,
 293                                                 GdkEventScroll *event);
 294 static void hildon_pannable_area_child_mapped (GtkWidget *widget,
 295                                                GdkEvent  *event,
 296                                                gpointer user_data);
 297 static void hildon_pannable_area_add (GtkContainer *container, GtkWidget *child);
 298 static void hildon_pannable_area_remove (GtkContainer *container, GtkWidget *child);
 299 static void hildon_pannable_calculate_vel_factor (HildonPannableArea * self);
 300 static void hildon_pannable_area_set_focus_child (GtkContainer *container,
 301                                                  GtkWidget *child);
 302 static void hildon_pannable_area_center_on_child_focus (HildonPannableArea *area);
 303
 304
 305 static void
 306 hildon_pannable_area_class_init (HildonPannableAreaClass * klass)
 307 {
 308   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 309   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
 310   GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
 311
 312
 313   g_type_class_add_private (klass, sizeof (HildonPannableAreaPrivate));
 314
 315   object_class->get_property = hildon_pannable_area_get_property;
 316   object_class->set_property = hildon_pannable_area_set_property;
 317   object_class->dispose = hildon_pannable_area_dispose;
 318
 319   widget_class->realize = hildon_pannable_area_realize;
 320   widget_class->unrealize = hildon_pannable_area_unrealize;
 321   widget_class->map = hildon_pannable_area_map;
 322   widget_class->unmap = hildon_pannable_area_unmap;
 323   widget_class->size_request = hildon_pannable_area_size_request;
 324   widget_class->size_allocate = hildon_pannable_area_size_allocate;
 325   widget_class->expose_event = hildon_pannable_area_expose_event;
 326   widget_class->style_set = hildon_pannable_area_style_set;
 327   widget_class->button_press_event = hildon_pannable_area_button_press_cb;
 328   widget_class->button_release_event = hildon_pannable_area_button_release_cb;
 329   widget_class->motion_notify_event = hildon_pannable_area_motion_notify_cb;
 330   widget_class->leave_notify_event = hildon_pannable_leave_notify_event;
 331   widget_class->scroll_event = hildon_pannable_area_scroll_cb;
 332
 333   container_class->add = hildon_pannable_area_add;
 334   container_class->remove = hildon_pannable_area_remove;
 335   container_class->set_focus_child = hildon_pannable_area_set_focus_child;
 336
 337   klass->horizontal_movement = NULL;
 338   klass->vertical_movement = NULL;
 339
 340   g_object_class_install_property (object_class,
 341                                    PROP_ENABLED,
 342                                    g_param_spec_boolean ("enabled",
 343                                                          "Enabled",
 344                                                          "Enable or disable finger-scroll.",
 345                                                          TRUE,
 346                                                          G_PARAM_READWRITE |
 347                                                          G_PARAM_CONSTRUCT));
 348
 349   g_object_class_install_property (object_class,
 350                                    PROP_VSCROLLBAR_POLICY,
 351                                    g_param_spec_enum ("vscrollbar_policy",
 352                                                       "vscrollbar policy",
 353                                                       "Visual policy of the vertical scrollbar",
 354                                                       GTK_TYPE_POLICY_TYPE,
 355                                                       GTK_POLICY_AUTOMATIC,
 356                                                       G_PARAM_READWRITE |
 357                                                       G_PARAM_CONSTRUCT));
 358
 359   g_object_class_install_property (object_class,
 360                                    PROP_HSCROLLBAR_POLICY,
 361                                    g_param_spec_enum ("hscrollbar_policy",
 362                                                       "hscrollbar policy",
 363                                                       "Visual policy of the horizontal scrollbar",
 364                                                       GTK_TYPE_POLICY_TYPE,
 365                                                       GTK_POLICY_AUTOMATIC,
 366                                                       G_PARAM_READWRITE |
 367                                                       G_PARAM_CONSTRUCT));
 368
 369   g_object_class_install_property (object_class,
 370                                    PROP_MODE,
 371                                    g_param_spec_enum ("mode",
 372                                                       "Scroll mode",
 373                                                       "Change the finger-scrolling mode.",
 374                                                       HILDON_TYPE_PANNABLE_AREA_MODE,
 375                                                       HILDON_PANNABLE_AREA_MODE_AUTO,
 376                                                       G_PARAM_READWRITE |
 377                                                       G_PARAM_CONSTRUCT));
 378
 379   g_object_class_install_property (object_class,
 380                                    PROP_MOVEMENT_MODE,
 381                                    g_param_spec_flags ("mov_mode",
 382                                                        "Scroll movement mode",
 383                                                        "Controls if the widget can scroll vertically, horizontally or both",
 384                                                        HILDON_TYPE_MOVEMENT_MODE,
 385                                                        HILDON_MOVEMENT_MODE_VERT,
 386                                                        G_PARAM_READWRITE |
 387                                                        G_PARAM_CONSTRUCT));
 388
 389   g_object_class_install_property (object_class,
 390                                    PROP_VELOCITY_MIN,
 391                                    g_param_spec_double ("velocity_min",
 392                                                         "Minimum scroll velocity",
 393                                                         "Minimum distance the child widget should scroll "
 394                                                         "per 'frame', in pixels per frame.",
 395                                                         0, G_MAXDOUBLE, 10,
 396                                                         G_PARAM_READWRITE |
 397                                                         G_PARAM_CONSTRUCT));
 398
 399   g_object_class_install_property (object_class,
 400                                    PROP_VELOCITY_MAX,
 401                                    g_param_spec_double ("velocity_max",
 402                                                         "Maximum scroll velocity",
 403                                                         "Maximum distance the child widget should scroll "
 404                                                         "per 'frame', in pixels per frame.",
 405                                                         0, G_MAXDOUBLE, 2000,
 406                                                         G_PARAM_READWRITE |
 407                                                         G_PARAM_CONSTRUCT));
 408
 409   g_object_class_install_property (object_class,
 410                                    PROP_VEL_MAX_OVERSHOOTING,
 411                                    g_param_spec_double ("velocity_overshooting_max",
 412                                                         "Maximum scroll velocity when overshooting",
 413                                                         "Maximum distance the child widget should scroll "
 414                                                         "per 'frame', in pixels per frame when it overshoots after hitting the edge.",
 415                                                         0, G_MAXDOUBLE, 130,
 416                                                         G_PARAM_READWRITE |
 417                                                         G_PARAM_CONSTRUCT));
 418
 419   g_object_class_install_property (object_class,
 420                                    PROP_VELOCITY_FAST_FACTOR,
 421                                    g_param_spec_double ("velocity_fast_factor",
 422                                                         "Fast velocity factor",
 423                                                         "Minimum velocity that is considered 'fast': "
 424                                                         "children widgets won't receive button presses. "
 425                                                         "Expressed as a fraction of the maximum velocity.",
 426                                                         0, 1, 0.02,
 427                                                         G_PARAM_READWRITE |
 428                                                         G_PARAM_CONSTRUCT));
 429
 430   g_object_class_install_property (object_class,
 431                                    PROP_DECELERATION,
 432                                    g_param_spec_double ("deceleration",
 433                                                         "Deceleration multiplier",
 434                                                         "The multiplier used when decelerating when in "
 435                                                         "acceleration scrolling mode.",
 436                                                         0, 1.0, 0.93,
 437                                                         G_PARAM_READWRITE |
 438                                                         G_PARAM_CONSTRUCT));
 439
 440   g_object_class_install_property (object_class,
 441                                    PROP_DRAG_INERTIA,
 442                                    g_param_spec_double ("drag_inertia",
 443                                                         "Inertia of the cursor dragging",
 444                                                         "Percentage of the calculated speed in each moment we are are going to use"
 445                                                         "to calculate the launch speed, the other part would be the speed"
 446                                                         "calculated previously",
 447                                                         0, 1.0, 0.85,
 448                                                         G_PARAM_READWRITE |
 449                                                         G_PARAM_CONSTRUCT));
 450
 451   g_object_class_install_property (object_class,
 452                                    PROP_SPS,
 453                                    g_param_spec_uint ("sps",
 454                                                       "Scrolls per second",
 455                                                       "Amount of scroll events to generate per second.",
 456                                                       0, G_MAXUINT, 20,
 457                                                       G_PARAM_READWRITE |
 458                                                       G_PARAM_CONSTRUCT));
 459
 460   g_object_class_install_property (object_class,
 461                                    PROP_PANNING_THRESHOLD,
 462                                    g_param_spec_uint ("panning_threshold",
 463                                                       "Threshold to consider a motion event an scroll",
 464                                                       "Amount of pixels to consider a motion event an scroll, if it is less"
 465                                                       "it is a click detected incorrectly by the touch screen.",
 466                                                       0, G_MAXUINT, 25,
 467                                                       G_PARAM_READWRITE |
 468                                                       G_PARAM_CONSTRUCT));
 469
 470   g_object_class_install_property (object_class,
 471                                    PROP_SCROLLBAR_FADE_DELAY,
 472                                    g_param_spec_uint ("scrollbar_fade_delay",
 473                                                       "Time before starting to fade the scrollbar",
 474                                                       "Time the scrollbar is going to be visible if the widget is not in"
 475                                                       "action in miliseconds",
 476                                                       0, G_MAXUINT, 3000,
 477                                                       G_PARAM_READWRITE |
 478                                                       G_PARAM_CONSTRUCT));
 479
 480   g_object_class_install_property (object_class,
 481                                    PROP_BOUNCE_STEPS,
 482                                    g_param_spec_uint ("bounce_steps",
 483                                                       "Bounce steps",
 484                                                       "Number of steps that is going to be used to bounce when hitting the"
 485                                                       "edge, the rubberband effect depends on it",
 486                                                       0, G_MAXUINT, 3,
 487                                                       G_PARAM_READWRITE |
 488                                                       G_PARAM_CONSTRUCT));
 489
 490   g_object_class_install_property (object_class,
 491                                    PROP_FORCE,
 492                                    g_param_spec_uint ("force",
 493                                                       "Multiplier of the calculated speed",
 494                                                       "Force applied to the movement, multiplies the calculated speed of the"
 495                                                       "user movement the cursor in the screen",
 496                                                       0, G_MAXUINT, 80,
 497                                                       G_PARAM_READWRITE |
 498                                                       G_PARAM_CONSTRUCT));
 499
 500   g_object_class_install_property (object_class,
 501                                    PROP_DIRECTION_ERROR_MARGIN,
 502                                    g_param_spec_uint ("direction_error_margin",
 503                                                       "Margin in the direction detection",
 504                                                       "After detecting the direction of the movement (horizontal or"
 505                                                       "vertical), we can add this margin of error to allow the movement in"
 506                                                       "the other direction even apparently it is not",
 507                                                       0, G_MAXUINT, 10,
 508                                                       G_PARAM_READWRITE |
 509                                                       G_PARAM_CONSTRUCT));
 510
 511   g_object_class_install_property (object_class,
 512                                    PROP_VOVERSHOOT_MAX,
 513                                    g_param_spec_int ("vovershoot_max",
 514                                                      "Vertical overshoot distance",
 515                                                      "Space we allow the widget to pass over its vertical limits when"
 516                                                      "hitting the edges, set 0 in order to deactivate overshooting.",
 517                                                      0, G_MAXINT, 150,
 518                                                      G_PARAM_READWRITE |
 519                                                      G_PARAM_CONSTRUCT));
 520
 521   g_object_class_install_property (object_class,
 522                                    PROP_HOVERSHOOT_MAX,
 523                                    g_param_spec_int ("hovershoot_max",
 524                                                      "Horizontal overshoot distance",
 525                                                      "Space we allow the widget to pass over its horizontal limits when"
 526                                                      "hitting the edges, set 0 in order to deactivate overshooting.",
 527                                                      0, G_MAXINT, 150,
 528                                                      G_PARAM_READWRITE |
 529                                                      G_PARAM_CONSTRUCT));
 530
 531   g_object_class_install_property (object_class,
 532                                    PROP_SCROLL_TIME,
 533                                    g_param_spec_double ("scroll_time",
 534                                                         "Time to scroll to a position",
 535                                                         "The time to scroll to a position when calling the hildon_pannable_scroll_to function",
 536                                                         0.0, 20.0, 1.0,
 537                                                         G_PARAM_READWRITE |
 538                                                         G_PARAM_CONSTRUCT));
 539
 540   g_object_class_install_property (object_class,
 541                                    PROP_INITIAL_HINT,
 542                                    g_param_spec_boolean ("initial-hint",
 543                                                          "Initial hint",
 544                                                          "Whether to hint the user about the pannability of the container.",
 545                                                          TRUE,
 546                                                          G_PARAM_READWRITE |
 547                                                          G_PARAM_CONSTRUCT));
 548
 549   g_object_class_install_property (object_class,
 550                                    PROP_LOW_FRICTION_MODE,
 551                                    g_param_spec_boolean ("low-friction-mode",
 552                                                          "Do not decelerate the initial velocity",
 553                                                          "Avoid decelerating the panning movement, like no friction, the widget"
 554                                                          "will stop in the edges or if the user clicks.",
 555                                                          FALSE,
 556                                                          G_PARAM_READWRITE |
 557                                                          G_PARAM_CONSTRUCT));
 558
 559   g_object_class_install_property (object_class,
 560                                    PROP_SIZE_REQUEST_POLICY,
 561                                    g_param_spec_enum ("size-request-policy",
 562                                                       "Size Requisition policy",
 563                                                       "Controls the size request policy of the widget",
 564                                                       HILDON_TYPE_SIZE_REQUEST_POLICY,
 565                                                       HILDON_SIZE_REQUEST_MINIMUM,
 566                                                       G_PARAM_READWRITE|
 567                                                       G_PARAM_CONSTRUCT));
 568
 569   g_object_class_install_property (object_class,
 570                                    PROP_HADJUSTMENT,
 571                                    g_param_spec_object ("hadjustment",
 572                                                         "Horizontal Adjustment",
 573                                                         "The GtkAdjustment for the horizontal position",
 574                                                         GTK_TYPE_ADJUSTMENT,
 575                                                         G_PARAM_READABLE));
 576   g_object_class_install_property (object_class,
 577                                    PROP_VADJUSTMENT,
 578                                    g_param_spec_object ("vadjustment",
 579                                                         "Vertical Adjustment",
 580                                                         "The GtkAdjustment for the vertical position",
 581                                                         GTK_TYPE_ADJUSTMENT,
 582                                                         G_PARAM_READABLE));
 583
 584   g_object_class_install_property (object_class,
 585                                    PROP_CENTER_ON_CHILD_FOCUS,
 586                                    g_param_spec_boolean ("center-on-child-focus",
 587                                                          "Center on the child with the focus",
 588                                                          "Whether to center the pannable on the child that receives the focus.",
 589                                                          FALSE,
 590                                                          G_PARAM_READWRITE |
 591                                                          G_PARAM_CONSTRUCT));
 592
 593
 594   gtk_widget_class_install_style_property (widget_class,
 595                                            g_param_spec_uint
 596                                            ("indicator-width",
 597                                             "Width of the scroll indicators",
 598                                             "Pixel width used to draw the scroll indicators.",
 599                                             0, G_MAXUINT, 8,
 600                                             G_PARAM_READWRITE));
 601
 602  /**
 603    * HildonPannableArea::horizontal-movement:
 604    * @hildonpannable: the object which received the signal
 605    * @direction: the direction of the movement #HILDON_MOVEMENT_LEFT or #HILDON_MOVEMENT_RIGHT
 606    * @initial_x: the x coordinate of the point where the user clicked to start the movement
 607    * @initial_y: the y coordinate of the point where the user clicked to start the movement
 608    *
 609    * The horizontal-movement signal is emitted when the pannable area
 610    * detects a horizontal movement. The detection does not mean the
 611    * widget is going to move (i.e. maybe the children are smaller
 612    * horizontally than the screen).
 613    *
 614    * Since: 2.2
 615    */
 616   pannable_area_signals[HORIZONTAL_MOVEMENT] =
 617     g_signal_new ("horizontal_movement",
 618                   G_TYPE_FROM_CLASS (object_class),
 619                   G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
 620                   G_STRUCT_OFFSET (HildonPannableAreaClass, horizontal_movement),
 621                   NULL, NULL,
 622                   _hildon_marshal_VOID__INT_DOUBLE_DOUBLE,
 623                   G_TYPE_NONE, 3,
 624                   G_TYPE_INT,
 625                   G_TYPE_DOUBLE,
 626                   G_TYPE_DOUBLE);
 627
 628   /**
 629    * HildonPannableArea::vertical-movement:
 630    * @hildonpannable: the object which received the signal
 631    * @direction: the direction of the movement #HILDON_MOVEMENT_UP or #HILDON_MOVEMENT_DOWN
 632    * @initial_x: the x coordinate of the point where the user clicked to start the movement
 633    * @initial_y: the y coordinate of the point where the user clicked to start the movement
 634    *
 635    * The vertical-movement signal is emitted when the pannable area
 636    * detects a vertical movement. The detection does not mean the
 637    * widget is going to move (i.e. maybe the children are smaller
 638    * vertically than the screen).
 639    *
 640    * Since: 2.2
 641    */
 642   pannable_area_signals[VERTICAL_MOVEMENT] =
 643     g_signal_new ("vertical_movement",
 644                   G_TYPE_FROM_CLASS (object_class),
 645                   G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
 646                   G_STRUCT_OFFSET (HildonPannableAreaClass, vertical_movement),
 647                   NULL, NULL,
 648                   _hildon_marshal_VOID__INT_DOUBLE_DOUBLE,
 649                   G_TYPE_NONE, 3,
 650                   G_TYPE_INT,
 651                   G_TYPE_DOUBLE,
 652                   G_TYPE_DOUBLE);
 653
 654  /**
 655    * HildonPannableArea::panning-started:
 656    * @hildonpannable: the pannable area object that is going to start
 657    * the panning
 658    *
 659    * This signal is emitted before the panning starts. Applications
 660    * can return %TRUE to avoid the panning. The main difference with
 661    * the vertical-movement and horizontal-movement signals is those
 662    * gesture signals are launched no matter if the widget is going to
 663    * move, this signal means the widget is going to start moving. It
 664    * could even happen that the widget moves and there was no gesture
 665    * (i.e. click meanwhile the pannable is overshooting).
 666    *
 667    * Returns: %TRUE to stop the panning launch. %FALSE to continue
 668    * with it.
 669    *
 670    * Since: 2.2
 671    */
 672   pannable_area_signals[PANNING_STARTED] =
 673     g_signal_new ("panning-started",
 674                   G_TYPE_FROM_CLASS (object_class),
 675                   0,
 676                   0,
 677                   NULL, NULL,
 678                   _hildon_marshal_BOOLEAN__VOID,
 679                   G_TYPE_BOOLEAN, 0);
 680
 681  /**
 682    * HildonPannableArea::panning-finished:
 683    * @hildonpannable: the pannable area object that finished the
 684    * panning
 685    *
 686    * This signal is emitted after the kinetic panning has
 687    * finished.
 688    *
 689    * Since: 2.2
 690    */
 691   pannable_area_signals[PANNING_FINISHED] =
 692     g_signal_new ("panning-finished",
 693                   G_TYPE_FROM_CLASS (object_class),
 694                   0,
 695                   0,
 696                   NULL, NULL,
 697                   _hildon_marshal_VOID__VOID,
 698                   G_TYPE_NONE, 0);
 699
 700 }
 701
 702 static void
 703 hildon_pannable_area_init (HildonPannableArea * area)
 704 {
 705   HildonPannableAreaPrivate *priv = PANNABLE_AREA_PRIVATE (area);
 706
 707   GTK_WIDGET_UNSET_FLAGS (area, GTK_NO_WINDOW);
 708
 709   area->priv = priv;
 710
 711   priv->moved = FALSE;
 712   priv->button_pressed = FALSE;
 713   priv->last_time = 0;
 714   priv->last_type = 0;
 715   priv->vscroll_visible = TRUE;
 716   priv->hscroll_visible = TRUE;
 717   priv->indicator_width = 6;
 718   priv->overshot_dist_x = 0;
 719   priv->overshot_dist_y = 0;
 720   priv->overshooting_y = 0;
 721   priv->overshooting_x = 0;
 722   priv->idle_id = 0;
 723   priv->vel_x = 0;
 724   priv->vel_y = 0;
 725   priv->scroll_indicator_alpha = 0.0;
 726   priv->scroll_indicator_timeout = 0;
 727   priv->motion_event_scroll_timeout = 0;
 728   priv->scroll_indicator_event_interrupt = 0;
 729   priv->scroll_delay_counter = 0;
 730   priv->scrollbar_fade_delay = 0;
 731   priv->scroll_to_x = -1;
 732   priv->scroll_to_y = -1;
 733   priv->first_drag = TRUE;
 734   priv->initial_effect = TRUE;
 735   priv->child_width = 0;
 736   priv->child_height = 0;
 737   priv->last_in = TRUE;
 738   priv->x_offset = 0;
 739   priv->y_offset = 0;
 740   priv->center_on_child_focus_pending = FALSE;
 741
 742   gtk_style_lookup_color (GTK_WIDGET (area)->style,
 743                           "SecondaryTextColor", &priv->scroll_color);
 744
 745   priv->hadjust =
 746     GTK_ADJUSTMENT (gtk_adjustment_new (0.0, 0.0, 0.0, 0.0, 0.0, 0.0));
 747   priv->vadjust =
 748     GTK_ADJUSTMENT (gtk_adjustment_new (0.0, 0.0, 0.0, 0.0, 0.0, 0.0));
 749
 750   g_object_ref_sink (G_OBJECT (priv->hadjust));
 751   g_object_ref_sink (G_OBJECT (priv->vadjust));
 752
 753   g_signal_connect_swapped (priv->hadjust, "value-changed",
 754                             G_CALLBACK (hildon_pannable_area_adjust_value_changed), area);
 755   g_signal_connect_swapped (priv->vadjust, "value-changed",
 756                             G_CALLBACK (hildon_pannable_area_adjust_value_changed), area);
 757   g_signal_connect_swapped (priv->hadjust, "changed",
 758                             G_CALLBACK (hildon_pannable_area_adjust_changed), area);
 759   g_signal_connect_swapped (priv->vadjust, "changed",
 760                             G_CALLBACK (hildon_pannable_area_adjust_changed), area);
 761   g_signal_connect (area, "grab-notify",
 762                     G_CALLBACK (hildon_pannable_area_grab_notify), NULL);
 763 }
 764
 765 static void
 766 hildon_pannable_area_get_property (GObject * object,
 767                                    guint property_id,
 768                                    GValue * value,
 769                                    GParamSpec * pspec)
 770 {
 771   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (object)->priv;
 772
 773   switch (property_id) {
 774   case PROP_ENABLED:
 775     g_value_set_boolean (value, priv->enabled);
 776     break;
 777   case PROP_MODE:
 778     g_value_set_enum (value, priv->mode);
 779     break;
 780   case PROP_MOVEMENT_MODE:
 781     g_value_set_flags (value, priv->mov_mode);
 782     break;
 783   case PROP_VELOCITY_MIN:
 784     g_value_set_double (value, priv->vmin);
 785     break;
 786   case PROP_VELOCITY_MAX:
 787     g_value_set_double (value, priv->vmax);
 788     break;
 789   case PROP_VEL_MAX_OVERSHOOTING:
 790     g_value_set_double (value, priv->vmax_overshooting);
 791     break;
 792   case PROP_VELOCITY_FAST_FACTOR:
 793     g_value_set_double (value, priv->vfast_factor);
 794     break;
 795   case PROP_DECELERATION:
 796     g_value_set_double (value, priv->decel);
 797     break;
 798   case PROP_DRAG_INERTIA:
 799     g_value_set_double (value, priv->drag_inertia);
 800     break;
 801   case PROP_SPS:
 802     g_value_set_uint (value, priv->sps);
 803     break;
 804   case PROP_PANNING_THRESHOLD:
 805     g_value_set_uint (value, priv->panning_threshold);
 806     break;
 807   case PROP_SCROLLBAR_FADE_DELAY:
 808     /* convert to miliseconds */
 809     g_value_set_uint (value, priv->scrollbar_fade_delay * SCROLL_FADE_TIMEOUT);
 810     break;
 811   case PROP_BOUNCE_STEPS:
 812     g_value_set_uint (value, priv->bounce_steps);
 813     break;
 814   case PROP_FORCE:
 815     g_value_set_uint (value, priv->force);
 816     break;
 817   case PROP_DIRECTION_ERROR_MARGIN:
 818     g_value_set_uint (value, priv->direction_error_margin);
 819     break;
 820   case PROP_VSCROLLBAR_POLICY:
 821     g_value_set_enum (value, priv->vscrollbar_policy);
 822     break;
 823   case PROP_HSCROLLBAR_POLICY:
 824     g_value_set_enum (value, priv->hscrollbar_policy);
 825     break;
 826   case PROP_VOVERSHOOT_MAX:
 827     g_value_set_int (value, priv->vovershoot_max);
 828     break;
 829   case PROP_HOVERSHOOT_MAX:
 830     g_value_set_int (value, priv->hovershoot_max);
 831     break;
 832   case PROP_SCROLL_TIME:
 833     g_value_set_double (value, priv->scroll_time);
 834     break;
 835   case PROP_INITIAL_HINT:
 836     g_value_set_boolean (value, priv->initial_hint);
 837     break;
 838   case PROP_LOW_FRICTION_MODE:
 839     g_value_set_boolean (value, priv->low_friction_mode);
 840     break;
 841   case PROP_SIZE_REQUEST_POLICY:
 842     g_value_set_enum (value, priv->size_request_policy);
 843     break;
 844   case PROP_HADJUSTMENT:
 845     g_value_set_object (value,
 846                         hildon_pannable_area_get_hadjustment
 847                         (HILDON_PANNABLE_AREA (object)));
 848     break;
 849   case PROP_VADJUSTMENT:
 850     g_value_set_object (value,
 851                         hildon_pannable_area_get_vadjustment
 852                         (HILDON_PANNABLE_AREA (object)));
 853     break;
 854   case PROP_CENTER_ON_CHILD_FOCUS:
 855     g_value_set_boolean (value, priv->center_on_child_focus);
 856     break;
 857   default:
 858     G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
 859   }
 860 }
 861
 862 static void
 863 hildon_pannable_area_set_property (GObject * object,
 864                                    guint property_id,
 865                                    const GValue * value,
 866                                    GParamSpec * pspec)
 867 {
 868   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (object)->priv;
 869   gboolean enabled;
 870
 871   switch (property_id) {
 872   case PROP_ENABLED:
 873     enabled = g_value_get_boolean (value);
 874
 875     if ((priv->enabled != enabled) && (GTK_WIDGET_REALIZED (object))) {
 876       if (enabled)
 877         gdk_window_raise (priv->event_window);
 878       else
 879         gdk_window_lower (priv->event_window);
 880     }
 881
 882     priv->enabled = enabled;
 883     break;
 884   case PROP_MODE:
 885     priv->mode = g_value_get_enum (value);
 886     break;
 887   case PROP_MOVEMENT_MODE:
 888     priv->mov_mode = g_value_get_flags (value);
 889     break;
 890   case PROP_VELOCITY_MIN:
 891     priv->vmin = g_value_get_double (value);
 892     break;
 893   case PROP_VELOCITY_MAX:
 894     priv->vmax = g_value_get_double (value);
 895     break;
 896   case PROP_VEL_MAX_OVERSHOOTING:
 897     priv->vmax_overshooting = g_value_get_double (value);
 898     break;
 899   case PROP_VELOCITY_FAST_FACTOR:
 900     priv->vfast_factor = g_value_get_double (value);
 901     break;
 902   case PROP_DECELERATION:
 903     priv->decel = g_value_get_double (value);
 904     hildon_pannable_calculate_vel_factor (HILDON_PANNABLE_AREA (object));
 905     break;
 906   case PROP_DRAG_INERTIA:
 907     priv->drag_inertia = g_value_get_double (value);
 908     break;
 909   case PROP_SPS:
 910     priv->sps = g_value_get_uint (value);
 911     break;
 912   case PROP_PANNING_THRESHOLD:
 913     {
 914       GtkSettings *settings = gtk_settings_get_default ();
 915       GtkSettingsValue svalue = { NULL, { 0, }, };
 916
 917       priv->panning_threshold = g_value_get_uint (value);
 918
 919       /* insure gtk dnd is the same we are using, not allowed
 920          different thresholds in the same application */
 921       svalue.origin = "panning_threshold";
 922       g_value_init (&svalue.value, G_TYPE_LONG);
 923       g_value_set_long (&svalue.value, priv->panning_threshold);
 924       gtk_settings_set_property_value (settings, "gtk-dnd-drag-threshold", &svalue);
 925       g_value_unset (&svalue.value);
 926     }
 927     break;
 928   case PROP_SCROLLBAR_FADE_DELAY:
 929     /* convert to miliseconds */
 930     priv->scrollbar_fade_delay = g_value_get_uint (value)/(SCROLL_FADE_TIMEOUT);
 931     break;
 932   case PROP_BOUNCE_STEPS:
 933     priv->bounce_steps = g_value_get_uint (value);
 934     break;
 935   case PROP_FORCE:
 936     priv->force = g_value_get_uint (value);
 937     break;
 938   case PROP_DIRECTION_ERROR_MARGIN:
 939     priv->direction_error_margin = g_value_get_uint (value);
 940     break;
 941   case PROP_VSCROLLBAR_POLICY:
 942     priv->vscrollbar_policy = g_value_get_enum (value);
 943
 944     gtk_widget_queue_resize (GTK_WIDGET (object));
 945     break;
 946   case PROP_HSCROLLBAR_POLICY:
 947     priv->hscrollbar_policy = g_value_get_enum (value);
 948
 949     gtk_widget_queue_resize (GTK_WIDGET (object));
 950     break;
 951   case PROP_VOVERSHOOT_MAX:
 952     priv->vovershoot_max = g_value_get_int (value);
 953     break;
 954   case PROP_HOVERSHOOT_MAX:
 955     priv->hovershoot_max = g_value_get_int (value);
 956     break;
 957   case PROP_SCROLL_TIME:
 958     priv->scroll_time = g_value_get_double (value);
 959
 960     hildon_pannable_calculate_vel_factor (HILDON_PANNABLE_AREA (object));
 961     break;
 962   case PROP_INITIAL_HINT:
 963     priv->initial_hint = g_value_get_boolean (value);
 964     break;
 965   case PROP_LOW_FRICTION_MODE:
 966     priv->low_friction_mode = g_value_get_boolean (value);
 967     break;
 968   case PROP_SIZE_REQUEST_POLICY:
 969     hildon_pannable_area_set_size_request_policy (HILDON_PANNABLE_AREA (object),
 970                                                   g_value_get_enum (value));
 971     break;
 972   case PROP_CENTER_ON_CHILD_FOCUS:
 973     priv->center_on_child_focus = g_value_get_boolean (value);
 974     break;
 975
 976   default:
 977     G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
 978   }
 979 }
 980
 981 static void
 982 hildon_pannable_area_dispose (GObject * object)
 983 {
 984   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (object)->priv;
 985   GtkWidget *child = gtk_bin_get_child (GTK_BIN (object));
 986
 987   hildon_pannable_area_remove_timeouts (GTK_WIDGET (object));
 988
 989   if (child) {
 990     g_signal_handlers_disconnect_by_func (child,
 991                                           hildon_pannable_area_child_mapped,
 992                                           object);
 993   }
 994
 995   g_signal_handlers_disconnect_by_func (object,
 996                                         hildon_pannable_area_grab_notify,
 997                                         NULL);
 998
 999   if (priv->hadjust) {
1000     g_signal_handlers_disconnect_by_func (priv->hadjust,
1001                                           hildon_pannable_area_adjust_value_changed,
1002                                           object);
1003     g_signal_handlers_disconnect_by_func (priv->hadjust,
1004                                           hildon_pannable_area_adjust_changed,
1005                                           object);
1006     g_object_unref (priv->hadjust);
1007     priv->hadjust = NULL;
1008   }
1009
1010   if (priv->vadjust) {
1011     g_signal_handlers_disconnect_by_func (priv->vadjust,
1012                                           hildon_pannable_area_adjust_value_changed,
1013                                           object);
1014     g_signal_handlers_disconnect_by_func (priv->vadjust,
1015                                           hildon_pannable_area_adjust_changed,
1016                                           object);
1017     g_object_unref (priv->vadjust);
1018     priv->vadjust = NULL;
1019   }
1020
1021   if (G_OBJECT_CLASS (hildon_pannable_area_parent_class)->dispose)
1022     G_OBJECT_CLASS (hildon_pannable_area_parent_class)->dispose (object);
1023 }
1024
1025 static void
1026 hildon_pannable_area_realize (GtkWidget * widget)
1027 {
1028   GdkWindowAttr attributes;
1029   gint attributes_mask;
1030   gint border_width;
1031   HildonPannableAreaPrivate *priv;
1032
1033   priv = HILDON_PANNABLE_AREA (widget)->priv;
1034
1035   GTK_WIDGET_SET_FLAGS (widget, GTK_REALIZED);
1036
1037   border_width = GTK_CONTAINER (widget)->border_width;
1038
1039   attributes.x = widget->allocation.x + border_width;
1040   attributes.y = widget->allocation.y + border_width;
1041   attributes.width = MAX (widget->allocation.width - 2 * border_width, 0);
1042   attributes.height = MAX (widget->allocation.height - 2 * border_width, 0);
1043   attributes.window_type = GDK_WINDOW_CHILD;
1044
1045   /* avoid using the hildon_window */
1046   attributes.visual = gtk_widget_get_visual (widget);
1047   attributes.colormap = gtk_widget_get_colormap (widget);
1048   attributes.event_mask = gtk_widget_get_events (widget) | GDK_EXPOSURE_MASK;
1049   attributes.wclass = GDK_INPUT_OUTPUT;
1050
1051   attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
1052
1053   widget->window = gdk_window_new (gtk_widget_get_parent_window (widget),
1054                                    &attributes, attributes_mask);
1055   gdk_window_set_user_data (widget->window, widget);
1056
1057   /* create the events window */
1058   attributes.x = 0;
1059   attributes.y = 0;
1060   attributes.event_mask = gtk_widget_get_events (widget)
1061     | GDK_BUTTON_MOTION_MASK
1062     | GDK_BUTTON_PRESS_MASK
1063     | GDK_BUTTON_RELEASE_MASK
1064     | GDK_SCROLL_MASK
1065     | GDK_POINTER_MOTION_HINT_MASK
1066     | GDK_EXPOSURE_MASK | GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK;
1067   attributes.wclass = GDK_INPUT_ONLY;
1068
1069   attributes_mask = GDK_WA_X | GDK_WA_Y;
1070
1071   priv->event_window = gdk_window_new (widget->window,
1072                                        &attributes, attributes_mask);
1073   gdk_window_set_user_data (priv->event_window, widget);
1074
1075   widget->style = gtk_style_attach (widget->style, widget->window);
1076   gtk_style_set_background (widget->style, widget->window, GTK_STATE_NORMAL);
1077
1078   priv->scrollbars_gc = gdk_gc_new (GDK_DRAWABLE (widget->window));
1079   gdk_gc_copy (priv->scrollbars_gc, widget->style->fg_gc[GTK_STATE_INSENSITIVE]);
1080 }
1081
1082
1083 static void
1084 hildon_pannable_area_remove_timeouts (GtkWidget * widget)
1085 {
1086   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1087
1088   if (priv->idle_id) {
1089     g_signal_emit (widget, pannable_area_signals[PANNING_FINISHED], 0);
1090     g_source_remove (priv->idle_id);
1091     priv->idle_id = 0;
1092   }
1093
1094   if (priv->scroll_indicator_timeout){
1095     g_source_remove (priv->scroll_indicator_timeout);
1096     priv->scroll_indicator_timeout = 0;
1097   }
1098
1099   if (priv->motion_event_scroll_timeout){
1100     g_source_remove (priv->motion_event_scroll_timeout);
1101     priv->motion_event_scroll_timeout = 0;
1102   }
1103 }
1104
1105 static void
1106 hildon_pannable_area_unrealize (GtkWidget * widget)
1107 {
1108   HildonPannableAreaPrivate *priv;
1109
1110   priv = HILDON_PANNABLE_AREA (widget)->priv;
1111
1112   hildon_pannable_area_remove_timeouts (widget);
1113
1114   if (priv->event_window != NULL) {
1115     gdk_window_set_user_data (priv->event_window, NULL);
1116     gdk_window_destroy (priv->event_window);
1117     priv->event_window = NULL;
1118   }
1119
1120   gdk_gc_unref (priv->scrollbars_gc);
1121
1122   if (GTK_WIDGET_CLASS (hildon_pannable_area_parent_class)->unrealize)
1123     (*GTK_WIDGET_CLASS (hildon_pannable_area_parent_class)->unrealize)(widget);
1124 }
1125
1126 static void
1127 hildon_pannable_area_size_request (GtkWidget * widget,
1128                                    GtkRequisition * requisition)
1129 {
1130   GtkRequisition child_requisition = {0};
1131   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1132   GtkWidget *child = gtk_bin_get_child (GTK_BIN (widget));
1133
1134   if (child && GTK_WIDGET_VISIBLE (child))
1135     {
1136       gtk_widget_size_request (child, &child_requisition);
1137     }
1138
1139   if (priv->hscrollbar_policy == GTK_POLICY_NEVER) {
1140     requisition->width = child_requisition.width;
1141   } else {
1142     switch (priv->size_request_policy) {
1143       case HILDON_SIZE_REQUEST_CHILDREN:
1144         requisition->width = MIN (PANNABLE_MAX_WIDTH,
1145                                   child_requisition.width);
1146         break;
1147       case HILDON_SIZE_REQUEST_MINIMUM:
1148       default:
1149         requisition->width = priv->indicator_width;
1150       }
1151   }
1152
1153   if (priv->vscrollbar_policy == GTK_POLICY_NEVER) {
1154     requisition->height = child_requisition.height;
1155   } else {
1156     switch (priv->size_request_policy) {
1157       case HILDON_SIZE_REQUEST_CHILDREN:
1158         requisition->height = MIN (PANNABLE_MAX_HEIGHT,
1159                                    child_requisition.height);
1160         break;
1161       case HILDON_SIZE_REQUEST_MINIMUM:
1162       default:
1163         requisition->height = priv->indicator_width;
1164       }
1165   }
1166
1167   requisition->width += 2 * GTK_CONTAINER (widget)->border_width;
1168   requisition->height += 2 * GTK_CONTAINER (widget)->border_width;
1169 }
1170
1171 static void
1172 hildon_pannable_area_child_allocate_calculate (GtkWidget * widget,
1173                                                GtkAllocation * allocation,
1174                                                GtkAllocation * child_allocation)
1175 {
1176   gint border_width;
1177   HildonPannableAreaPrivate *priv;
1178
1179   border_width = GTK_CONTAINER (widget)->border_width;
1180
1181   priv = HILDON_PANNABLE_AREA (widget)->priv;
1182
1183   child_allocation->x = 0;
1184   child_allocation->y = 0;
1185   child_allocation->width = MAX (allocation->width - 2 * border_width -
1186                                  (priv->vscroll_visible ? priv->vscroll_rect.width : 0), 0);
1187   child_allocation->height = MAX (allocation->height - 2 * border_width -
1188                                   (priv->hscroll_visible ? priv->hscroll_rect.height : 0), 0);
1189
1190   if (priv->overshot_dist_y > 0) {
1191     child_allocation->y = MIN (child_allocation->y + priv->overshot_dist_y,
1192                                child_allocation->height);
1193     child_allocation->height = MAX (child_allocation->height - priv->overshot_dist_y, 0);
1194   } else if (priv->overshot_dist_y < 0) {
1195     child_allocation->height = MAX (child_allocation->height + priv->overshot_dist_y, 0);
1196   }
1197
1198   if (priv->overshot_dist_x > 0) {
1199     child_allocation->x = MIN (child_allocation->x + priv->overshot_dist_x,
1200                                child_allocation->width);
1201     child_allocation->width = MAX (child_allocation->width - priv->overshot_dist_x, 0);
1202   } else if (priv->overshot_dist_x < 0) {
1203     child_allocation->width = MAX (child_allocation->width + priv->overshot_dist_x, 0);
1204   }
1205 }
1206
1207 static void
1208 hildon_pannable_area_size_allocate (GtkWidget * widget,
1209                                     GtkAllocation * allocation)
1210 {
1211   GtkAllocation child_allocation;
1212   HildonPannableAreaPrivate *priv;
1213   GtkWidget *child = gtk_bin_get_child (GTK_BIN (widget));
1214   gint border_width;
1215   gdouble hv, vv;
1216
1217   border_width = GTK_CONTAINER (widget)->border_width;
1218
1219   widget->allocation = *allocation;
1220
1221   priv = HILDON_PANNABLE_AREA (widget)->priv;
1222
1223   if (GTK_WIDGET_REALIZED (widget)) {
1224       gdk_window_move_resize (widget->window,
1225                               allocation->x + border_width,
1226                               allocation->y  + border_width,
1227                               allocation->width  - border_width * 2,
1228                               allocation->height - border_width * 2);
1229       gdk_window_move_resize (priv->event_window,
1230                               0,
1231                               0,
1232                               allocation->width  - border_width * 2,
1233                               allocation->height - border_width * 2);
1234   }
1235
1236   if (child && GTK_WIDGET_VISIBLE (child)) {
1237
1238     hildon_pannable_area_check_scrollbars (HILDON_PANNABLE_AREA (widget));
1239
1240     hildon_pannable_area_child_allocate_calculate (widget,
1241                                                    allocation,
1242                                                    &child_allocation);
1243
1244     gtk_widget_size_allocate (child, &child_allocation);
1245
1246     if (hildon_pannable_area_check_scrollbars (HILDON_PANNABLE_AREA (widget))) {
1247       hildon_pannable_area_child_allocate_calculate (widget,
1248                                                      allocation,
1249                                                      &child_allocation);
1250
1251       gtk_widget_size_allocate (child, &child_allocation);
1252     }
1253
1254     hv = priv->hadjust->value;
1255     vv = priv->vadjust->value;
1256
1257     /* we have to do this after child size_allocate because page_size is
1258      * changed when we allocate the size of the children */
1259     if (priv->overshot_dist_y < 0) {
1260       priv->vadjust->value = priv->vadjust->upper - priv->vadjust->page_size;
1261     }
1262
1263     if (priv->overshot_dist_x < 0) {
1264       priv->hadjust->value = priv->hadjust->upper - priv->hadjust->page_size;
1265     }
1266
1267     if (hv != priv->hadjust->value)
1268       gtk_adjustment_value_changed (priv->hadjust);
1269
1270     if (vv != priv->vadjust->value)
1271       gtk_adjustment_value_changed (priv->vadjust);
1272
1273   } else {
1274     hildon_pannable_area_check_scrollbars (HILDON_PANNABLE_AREA (widget));
1275   }
1276 }
1277
1278 static void
1279 hildon_pannable_area_style_set (GtkWidget * widget,
1280                                 GtkStyle * previous_style)
1281 {
1282   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1283
1284   GTK_WIDGET_CLASS (hildon_pannable_area_parent_class)->
1285     style_set (widget, previous_style);
1286
1287   gtk_style_lookup_color (widget->style, "SecondaryTextColor", &priv->scroll_color);
1288   gtk_widget_style_get (widget, "indicator-width", &priv->indicator_width, NULL);
1289 }
1290
1291 static void
1292 hildon_pannable_area_map (GtkWidget * widget)
1293 {
1294   HildonPannableAreaPrivate *priv;
1295
1296   priv = HILDON_PANNABLE_AREA (widget)->priv;
1297
1298   gdk_window_show (widget->window);
1299
1300   if (priv->event_window != NULL && !priv->enabled)
1301     gdk_window_show (priv->event_window);
1302
1303   (*GTK_WIDGET_CLASS (hildon_pannable_area_parent_class)->map) (widget);
1304
1305   if (priv->event_window != NULL && priv->enabled)
1306     gdk_window_show (priv->event_window);
1307 }
1308
1309 static void
1310 hildon_pannable_area_unmap (GtkWidget * widget)
1311 {
1312   HildonPannableAreaPrivate *priv;
1313
1314   priv = HILDON_PANNABLE_AREA (widget)->priv;
1315
1316   if (priv->event_window != NULL)
1317     gdk_window_hide (priv->event_window);
1318
1319   gdk_window_hide (widget->window);
1320
1321   (*GTK_WIDGET_CLASS (hildon_pannable_area_parent_class)->unmap) (widget);
1322 }
1323
1324 static void
1325 hildon_pannable_area_grab_notify (GtkWidget *widget,
1326                                   gboolean was_grabbed,
1327                                   gpointer user_data)
1328 {
1329   /* an internal widget has grabbed the focus and now has returned it,
1330      we have to do some release actions */
1331   if (was_grabbed) {
1332     HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1333
1334     priv->scroll_indicator_event_interrupt = 0;
1335
1336     if ((!priv->scroll_indicator_timeout)&&(priv->scroll_indicator_alpha)>0.1) {
1337       priv->scroll_delay_counter = priv->scrollbar_fade_delay;
1338
1339       hildon_pannable_area_launch_fade_timeout (HILDON_PANNABLE_AREA (widget),
1340                                                 priv->scroll_indicator_alpha);
1341     }
1342
1343     priv->last_type = 3;
1344     priv->moved = FALSE;
1345   }
1346 }
1347
1348 #if USE_CAIRO_SCROLLBARS == 1
1349
1350 static void
1351 rgb_from_gdkcolor (GdkColor *color, gdouble *r, gdouble *g, gdouble *b)
1352 {
1353   *r = (color->red >> 8) / 255.0;
1354   *g = (color->green >> 8) / 255.0;
1355   *b = (color->blue >> 8) / 255.0;
1356 }
1357
1358 static void
1359 hildon_pannable_draw_vscroll (GtkWidget * widget,
1360                               GdkColor *back_color,
1361                               GdkColor *scroll_color)
1362 {
1363   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1364   gfloat y, height;
1365   cairo_t *cr;
1366   cairo_pattern_t *pattern;
1367   gdouble r, g, b;
1368   gint radius = (priv->vscroll_rect.width/2) - 1;
1369
1370   cr = gdk_cairo_create(widget->window);
1371
1372   /* Draw the background */
1373   rgb_from_gdkcolor (back_color, &r, &g, &b);
1374   cairo_set_source_rgb (cr, r, g, b);
1375   cairo_rectangle(cr, priv->vscroll_rect.x, priv->vscroll_rect.y,
1376                   priv->vscroll_rect.width,
1377                   priv->vscroll_rect.height);
1378   cairo_fill_preserve (cr);
1379   cairo_clip (cr);
1380
1381   /* Calculate the scroll bar height and position */
1382   y = ((priv->vadjust->value - priv->vadjust->lower) / (priv->vadjust->upper - priv->vadjust->lower)) *
1383     (widget->allocation.height -
1384      (priv->hscroll_visible ? priv->indicator_width : 0));
1385   height = ((((priv->vadjust->value - priv->vadjust->lower) +
1386               priv->vadjust->page_size) /
1387              (priv->vadjust->upper - priv->vadjust->lower)) *
1388             (widget->allocation.height -
1389              (priv->hscroll_visible ? priv->indicator_width : 0))) - y;
1390
1391   /* Set a minimum height */
1392   height = MAX (SCROLL_BAR_MIN_SIZE, height);
1393
1394   /* Check the max y position */
1395   y = MIN (y, widget->allocation.height -
1396            (priv->hscroll_visible ? priv->hscroll_rect.height : 0) -
1397            height);
1398
1399   /* Draw the scrollbar */
1400   rgb_from_gdkcolor (scroll_color, &r, &g, &b);
1401
1402   pattern = cairo_pattern_create_linear(radius+1, y, radius+1,y + height);
1403   cairo_pattern_add_color_stop_rgb(pattern, 0, r, g, b);
1404   cairo_pattern_add_color_stop_rgb(pattern, 1, r/2, g/2, b/2);
1405   cairo_set_source(cr, pattern);
1406   cairo_fill(cr);
1407   cairo_pattern_destroy(pattern);
1408
1409   cairo_arc(cr, priv->vscroll_rect.x + radius + 1, y + radius + 1, radius, G_PI, 0);
1410   cairo_line_to(cr, priv->vscroll_rect.x + (radius * 2) + 1, y + height - radius);
1411   cairo_arc(cr, priv->vscroll_rect.x + radius + 1, y + height - radius, radius, 0, G_PI);
1412   cairo_line_to(cr, priv->vscroll_rect.x + 1, y + height - radius);
1413   cairo_clip (cr);
1414
1415   cairo_paint_with_alpha(cr, priv->scroll_indicator_alpha);
1416
1417   cairo_destroy(cr);
1418 }
1419
1420 static void
1421 hildon_pannable_draw_hscroll (GtkWidget * widget,
1422                               GdkColor *back_color,
1423                               GdkColor *scroll_color)
1424 {
1425   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1426   gfloat x, width;
1427   cairo_t *cr;
1428   cairo_pattern_t *pattern;
1429   gdouble r, g, b;
1430   gint radius = (priv->hscroll_rect.height/2) - 1;
1431
1432   cr = gdk_cairo_create(widget->window);
1433
1434   /* Draw the background */
1435   rgb_from_gdkcolor (back_color, &r, &g, &b);
1436   cairo_set_source_rgb (cr, r, g, b);
1437   cairo_rectangle(cr, priv->hscroll_rect.x, priv->hscroll_rect.y,
1438                   priv->hscroll_rect.width,
1439                   priv->hscroll_rect.height);
1440   cairo_fill_preserve (cr);
1441   cairo_clip (cr);
1442
1443   /* calculate the scrollbar width and position */
1444   x = ((priv->hadjust->value - priv->hadjust->lower) / (priv->hadjust->upper - priv->hadjust->lower)) *
1445     (widget->allocation.width - (priv->vscroll_visible ? priv->indicator_width : 0));
1446   width =((((priv->hadjust->value - priv->hadjust->lower) +
1447             priv->hadjust->page_size) / (priv->hadjust->upper - priv->hadjust->lower)) *
1448           (widget->allocation.width -
1449            (priv->vscroll_visible ? priv->indicator_width : 0))) - x;
1450
1451   /* Set a minimum width */
1452   width = MAX (SCROLL_BAR_MIN_SIZE, width);
1453
1454   /* Check the max x position */
1455   x = MIN (x, widget->allocation.width -
1456            (priv->vscroll_visible ? priv->vscroll_rect.width : 0) -
1457            width);
1458
1459   /* Draw the scrollbar */
1460   rgb_from_gdkcolor (scroll_color, &r, &g, &b);
1461
1462   pattern = cairo_pattern_create_linear(x, radius+1, x+width, radius+1);
1463   cairo_pattern_add_color_stop_rgb(pattern, 0, r, g, b);
1464   cairo_pattern_add_color_stop_rgb(pattern, 1, r/2, g/2, b/2);
1465   cairo_set_source(cr, pattern);
1466   cairo_fill(cr);
1467   cairo_pattern_destroy(pattern);
1468
1469   cairo_arc_negative(cr, x + radius + 1, priv->hscroll_rect.y + radius + 1, radius, 3*G_PI_2, G_PI_2);
1470   cairo_line_to(cr, x + width - radius, priv->hscroll_rect.y + (radius * 2) + 1);
1471   cairo_arc_negative(cr, x + width - radius, priv->hscroll_rect.y + radius + 1, radius, G_PI_2, 3*G_PI_2);
1472   cairo_line_to(cr, x + width - radius, priv->hscroll_rect.y + 1);
1473   cairo_clip (cr);
1474
1475   cairo_paint_with_alpha(cr, priv->scroll_indicator_alpha);
1476
1477   cairo_destroy(cr);
1478 }
1479
1480 #else /* USE_CAIRO_SCROLLBARS */
1481
1482 static void
1483 tranparency_color (GdkColor *color,
1484                    GdkColor colora,
1485                    GdkColor colorb,
1486                    gdouble transparency)
1487 {
1488   gdouble diff;
1489
1490   diff = colora.red - colorb.red;
1491   color->red = colora.red-diff*transparency;
1492
1493   diff = colora.green - colorb.green;
1494   color->green = colora.green-diff*transparency;
1495
1496   diff = colora.blue - colorb.blue;
1497   color->blue = colora.blue-diff*transparency;
1498 }
1499
1500 static void
1501 hildon_pannable_draw_vscroll (GtkWidget *widget,
1502                               GdkColor *back_color,
1503                               GdkColor *scroll_color)
1504 {
1505   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1506   gfloat y, height;
1507   GdkColor transp_color;
1508   GdkGC *gc = priv->scrollbars_gc;
1509
1510   gdk_draw_rectangle (widget->window,
1511                       widget->style->bg_gc[GTK_STATE_NORMAL],
1512                       TRUE,
1513                        priv->vscroll_rect.x, priv->vscroll_rect.y,
1514                       priv->vscroll_rect.width,
1515                       priv->vscroll_rect.height);
1516
1517   y = ((priv->vadjust->value - priv->vadjust->lower) / (priv->vadjust->upper - priv->vadjust->lower)) *
1518     (widget->allocation.height - (priv->hscroll_visible ? priv->indicator_width : 0));
1519   height = ((((priv->vadjust->value - priv->vadjust->lower) + priv->vadjust->page_size) /
1520              (priv->vadjust->upper - priv->vadjust->lower)) *
1521             (widget->allocation.height -
1522              (priv->hscroll_visible ? priv->indicator_width : 0))) - y;
1523
1524   /* Set a minimum height */
1525   height = MAX (SCROLL_BAR_MIN_SIZE, height);
1526
1527   /* Check the max y position */
1528   y = MIN (y, widget->allocation.height -
1529            (priv->hscroll_visible ? priv->hscroll_rect.height : 0) -
1530            height);
1531
1532   if (priv->scroll_indicator_alpha == 1.0) {
1533     transp_color = priv->scroll_color;
1534   } else if (priv->scroll_indicator_alpha < 1.0) {
1535     tranparency_color (&transp_color, *back_color, *scroll_color,
1536                        priv->scroll_indicator_alpha);
1537   }
1538   gdk_gc_set_rgb_fg_color (gc, &transp_color);
1539
1540   gdk_draw_rectangle (widget->window, gc,
1541                       TRUE, priv->vscroll_rect.x, y,
1542                       priv->vscroll_rect.width, height);
1543 }
1544
1545 static void
1546 hildon_pannable_draw_hscroll (GtkWidget *widget,
1547                               GdkColor *back_color,
1548                               GdkColor *scroll_color)
1549 {
1550   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1551   gfloat x, width;
1552   GdkColor transp_color;
1553   GdkGC *gc = priv->scrollbars_gc;
1554
1555   gdk_draw_rectangle (widget->window,
1556                       widget->style->bg_gc[GTK_STATE_INSENSITIVE],
1557                       TRUE,
1558                       priv->hscroll_rect.x, priv->hscroll_rect.y,
1559                       priv->hscroll_rect.width,
1560                       priv->hscroll_rect.height);
1561
1562   /* calculate the scrollbar width and position */
1563   x = ((priv->hadjust->value - priv->hadjust->lower) / (priv->hadjust->upper - priv->hadjust->lower)) *
1564     (widget->allocation.width - (priv->vscroll_visible ? priv->indicator_width : 0));
1565   width =((((priv->hadjust->value - priv->hadjust->lower) +
1566             priv->hadjust->page_size) / (priv->hadjust->upper - priv->hadjust->lower)) *
1567           (widget->allocation.width -
1568            (priv->vscroll_visible ? priv->indicator_width : 0))) - x;
1569
1570   /* Set a minimum width */
1571   width = MAX (SCROLL_BAR_MIN_SIZE, width);
1572
1573   /* Check the max x position */
1574   x = MIN (x, widget->allocation.width -
1575            (priv->vscroll_visible ? priv->vscroll_rect.width : 0) -
1576            width);
1577
1578   if (priv->scroll_indicator_alpha == 1.0) {
1579     transp_color = priv->scroll_color;
1580   } else if (priv->scroll_indicator_alpha < 1.0) {
1581     tranparency_color (&transp_color, *back_color, *scroll_color,
1582                        priv->scroll_indicator_alpha);
1583   }
1584   gdk_gc_set_rgb_fg_color (gc, &transp_color);
1585
1586   gdk_draw_rectangle (widget->window, gc,
1587                       TRUE, x, priv->hscroll_rect.y, width,
1588                       priv->hscroll_rect.height);
1589 }
1590
1591 #endif /* USE_CAIRO_SCROLLBARS */
1592
1593 static void
1594 hildon_pannable_area_initial_effect (GtkWidget * widget)
1595 {
1596   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1597
1598   if (priv->initial_hint) {
1599     if (priv->vscroll_visible || priv->hscroll_visible) {
1600
1601       priv->scroll_indicator_event_interrupt = 0;
1602       priv->scroll_delay_counter = priv->scrollbar_fade_delay;
1603
1604       hildon_pannable_area_launch_fade_timeout (HILDON_PANNABLE_AREA (widget), 1.0);
1605     }
1606   }
1607 }
1608
1609 static void
1610 hildon_pannable_area_launch_fade_timeout (HildonPannableArea * area,
1611                                           gdouble alpha)
1612 {
1613   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (area)->priv;
1614
1615   priv->scroll_indicator_alpha = alpha;
1616
1617   if (!priv->scroll_indicator_timeout)
1618     priv->scroll_indicator_timeout =
1619       gdk_threads_add_timeout (SCROLL_FADE_TIMEOUT,
1620                                (GSourceFunc) hildon_pannable_area_scroll_indicator_fade,
1621                                area);
1622 }
1623
1624 static void
1625 hildon_pannable_area_adjust_changed (HildonPannableArea * area,
1626                                      gpointer data)
1627 {
1628   if (GTK_WIDGET_REALIZED (area))
1629     hildon_pannable_area_refresh (area);
1630 }
1631
1632 static void
1633 hildon_pannable_area_adjust_value_changed (HildonPannableArea * area,
1634                                            gpointer data)
1635 {
1636   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (area)->priv;
1637   gint xdiff, ydiff;
1638   gint x = priv->x_offset;
1639   gint y = priv->y_offset;
1640
1641   priv->x_offset = priv->hadjust->value;
1642   xdiff = x - priv->x_offset;
1643   priv->y_offset = priv->vadjust->value;
1644   ydiff = y - priv->y_offset;
1645
1646   if ((xdiff || ydiff) && GTK_WIDGET_DRAWABLE (area)) {
1647     hildon_pannable_area_redraw (area);
1648
1649     if ((priv->vscroll_visible) || (priv->hscroll_visible)) {
1650       priv->scroll_indicator_event_interrupt = 0;
1651       priv->scroll_delay_counter = priv->scrollbar_fade_delay;
1652
1653       hildon_pannable_area_launch_fade_timeout (area, 1.0);
1654     }
1655   }
1656 }
1657
1658 static void
1659 hildon_pannable_area_redraw (HildonPannableArea * area)
1660 {
1661   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (area)->priv;
1662
1663   /* Redraw scroll indicators */
1664   if (GTK_WIDGET_DRAWABLE (area)) {
1665       if (priv->hscroll_visible) {
1666         gdk_window_invalidate_rect (GTK_WIDGET (area)->window,
1667                                     &priv->hscroll_rect, FALSE);
1668       }
1669
1670       if (priv->vscroll_visible) {
1671         gdk_window_invalidate_rect (GTK_WIDGET (area)->window,
1672                                     &priv->vscroll_rect, FALSE);
1673       }
1674   }
1675 }
1676
1677 static gboolean
1678 hildon_pannable_area_scroll_indicator_fade(HildonPannableArea * area)
1679 {
1680   HildonPannableAreaPrivate *priv = area->priv;
1681
1682   /* if moving do not fade out */
1683   if (((ABS (priv->vel_y)>priv->vmin)||
1684        (ABS (priv->vel_x)>priv->vmin))&&(!priv->button_pressed)) {
1685
1686     return TRUE;
1687   }
1688
1689   if (priv->scroll_indicator_event_interrupt) {
1690     /* Stop a fade out, and fade back in */
1691     if (priv->scroll_indicator_alpha > 0.9) {
1692       priv->scroll_indicator_alpha = 1.0;
1693       priv->scroll_indicator_timeout = 0;
1694
1695       return FALSE;
1696     } else {
1697       priv->scroll_indicator_alpha += 0.2;
1698       hildon_pannable_area_redraw (area);
1699
1700       return TRUE;
1701     }
1702   }
1703
1704   if ((priv->scroll_indicator_alpha > 0.9) &&
1705       (priv->scroll_delay_counter > 0)) {
1706     priv->scroll_delay_counter--;
1707
1708     return TRUE;
1709   }
1710
1711   if (!priv->scroll_indicator_event_interrupt) {
1712     /* Continue fade out */
1713     if (priv->scroll_indicator_alpha < 0.1) {
1714       priv->scroll_indicator_timeout = 0;
1715       priv->scroll_indicator_alpha = 0.0;
1716
1717       return FALSE;
1718     } else {
1719       priv->scroll_indicator_alpha -= 0.2;
1720       hildon_pannable_area_redraw (area);
1721
1722       return TRUE;
1723     }
1724   }
1725
1726   return TRUE;
1727 }
1728
1729 static gboolean
1730 hildon_pannable_area_expose_event (GtkWidget * widget,
1731                                    GdkEventExpose * event)
1732 {
1733
1734   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
1735 #if USE_CAIRO_SCROLLBARS == 1
1736   GdkColor back_color = widget->style->bg[GTK_STATE_NORMAL];
1737   GdkColor scroll_color = widget->style->base[GTK_STATE_SELECTED];
1738 #else /* USE_CAIRO_SCROLLBARS */
1739   GdkColor back_color = widget->style->bg[GTK_STATE_NORMAL];
1740   GdkColor scroll_color = priv->scroll_color;
1741 #endif
1742
1743   if (G_UNLIKELY (priv->initial_effect)) {
1744     hildon_pannable_area_initial_effect (widget);
1745
1746     priv->initial_effect = FALSE;
1747   }
1748
1749   if (gtk_bin_get_child (GTK_BIN (widget))) {
1750
1751     if (priv->scroll_indicator_alpha > 0.1) {
1752       if (priv->vscroll_visible) {
1753         hildon_pannable_draw_vscroll (widget, &back_color, &scroll_color);
1754       }
1755       if (priv->hscroll_visible) {
1756         hildon_pannable_draw_hscroll (widget, &back_color, &scroll_color);
1757       }
1758     }
1759
1760     /* draw overshooting rectangles */
1761     if (priv->overshot_dist_y > 0) {
1762       gint overshot_height;
1763
1764       overshot_height = MIN (priv->overshot_dist_y, widget->allocation.height -
1765                              (priv->hscroll_visible ? priv->hscroll_rect.height : 0));
1766
1767       gdk_draw_rectangle (widget->window,
1768                           widget->style->bg_gc[GTK_STATE_NORMAL],
1769                           TRUE,
1770                           0,
1771                           0,
1772                           widget->allocation.width -
1773                           (priv->vscroll_visible ? priv->vscroll_rect.width : 0),
1774                           overshot_height);
1775     } else if (priv->overshot_dist_y < 0) {
1776       gint overshot_height;
1777       gint overshot_y;
1778
1779       overshot_height =
1780         MAX (priv->overshot_dist_y,
1781              -(widget->allocation.height -
1782                (priv->hscroll_visible ? priv->hscroll_rect.height : 0)));
1783
1784       overshot_y = MAX (widget->allocation.height +
1785                         overshot_height -
1786                         (priv->hscroll_visible ? priv->hscroll_rect.height : 0), 0);
1787
1788       gdk_draw_rectangle (widget->window,
1789                           widget->style->bg_gc[GTK_STATE_NORMAL],
1790                           TRUE,
1791                           0,
1792                           overshot_y,
1793                           widget->allocation.width -
1794                           priv->vscroll_rect.width,
1795                           -overshot_height);
1796     }
1797
1798     if (priv->overshot_dist_x > 0) {
1799       gint overshot_width;
1800
1801       overshot_width = MIN (priv->overshot_dist_x, widget->allocation.width -
1802                              (priv->vscroll_visible ? priv->vscroll_rect.width : 0));
1803
1804       gdk_draw_rectangle (widget->window,
1805                           widget->style->bg_gc[GTK_STATE_NORMAL],
1806                           TRUE,
1807                           0,
1808                           0,
1809                           overshot_width,
1810                           widget->allocation.height -
1811                           (priv->hscroll_visible ? priv->hscroll_rect.height : 0));
1812     } else if (priv->overshot_dist_x < 0) {
1813       gint overshot_width;
1814       gint overshot_x;
1815
1816       overshot_width =
1817         MAX (priv->overshot_dist_x,
1818              -(widget->allocation.width -
1819                (priv->vscroll_visible ? priv->vscroll_rect.width : 0)));
1820
1821       overshot_x = MAX (widget->allocation.width +
1822                         overshot_width -
1823                         (priv->vscroll_visible ? priv->vscroll_rect.width : 0), 0);
1824
1825       gdk_draw_rectangle (widget->window,
1826                           widget->style->bg_gc[GTK_STATE_NORMAL],
1827                           TRUE,
1828                           overshot_x,
1829                           0,
1830                           -overshot_width,
1831                           widget->allocation.height -
1832                           priv->hscroll_rect.height);
1833     }
1834
1835   }
1836
1837   return GTK_WIDGET_CLASS (hildon_pannable_area_parent_class)->expose_event (widget, event);
1838 }
1839
1840 static GdkWindow *
1841 hildon_pannable_area_get_topmost (GdkWindow * window,
1842                                   gint x, gint y,
1843                                   gint * tx, gint * ty,
1844                                   GdkEventMask mask)
1845 {
1846   /* Find the GdkWindow at the given point, by recursing from a given
1847    * parent GdkWindow. Optionally return the co-ordinates transformed
1848    * relative to the child window.
1849    */
1850   gint width, height;
1851   GList *c, *children;
1852   GdkWindow *selected_window = NULL;
1853
1854   gdk_drawable_get_size (GDK_DRAWABLE (window), &width, &height);
1855   if ((x < 0) || (x >= width) || (y < 0) || (y >= height))
1856     return NULL;
1857
1858   children = gdk_window_peek_children (window);
1859
1860   if (!children) {
1861     if (tx)
1862       *tx = x;
1863     if (ty)
1864       *ty = y;
1865     selected_window = window;
1866   }
1867
1868   for (c = children; c; c = c->next) {
1869     GdkWindow *child = (GdkWindow *) c->data;
1870     gint wx, wy;
1871
1872     gdk_drawable_get_size (GDK_DRAWABLE (child), &width, &height);
1873     gdk_window_get_position (child, &wx, &wy);
1874
1875     if ((x >= wx) && (x < (wx + width)) && (y >= wy) && (y < (wy + height)) &&
1876         (gdk_window_is_visible (child))) {
1877
1878       if (gdk_window_peek_children (child)) {
1879         selected_window = hildon_pannable_area_get_topmost (child, x-wx, y-wy,
1880                                                             tx, ty, mask);
1881         if (!selected_window) {
1882           if (tx)
1883             *tx = x-wx;
1884           if (ty)
1885             *ty = y-wy;
1886           selected_window = child;
1887         }
1888       } else {
1889         if ((gdk_window_get_events (child)&mask)) {
1890           if (tx)
1891             *tx = x-wx;
1892           if (ty)
1893             *ty = y-wy;
1894           selected_window = child;
1895         }
1896       }
1897     }
1898   }
1899
1900   return selected_window;
1901 }
1902
1903 static void
1904 synth_crossing (GdkWindow * child,
1905                 gint x, gint y,
1906                 gint x_root, gint y_root,
1907                 guint32 time, gboolean in)
1908 {
1909   GdkEventCrossing *crossing_event;
1910   GdkEventType type = in ? GDK_ENTER_NOTIFY : GDK_LEAVE_NOTIFY;
1911
1912   /* Send synthetic enter event */
1913   crossing_event = (GdkEventCrossing *) gdk_event_new (type);
1914   ((GdkEventAny *) crossing_event)->type = type;
1915   ((GdkEventAny *) crossing_event)->window = g_object_ref (child);
1916   ((GdkEventAny *) crossing_event)->send_event = FALSE;
1917   crossing_event->subwindow = g_object_ref (child);
1918   crossing_event->time = time;
1919   crossing_event->x = x;
1920   crossing_event->y = y;
1921   crossing_event->x_root = x_root;
1922   crossing_event->y_root = y_root;
1923   crossing_event->mode = GDK_CROSSING_NORMAL;
1924   crossing_event->detail = GDK_NOTIFY_UNKNOWN;
1925   crossing_event->focus = FALSE;
1926   crossing_event->state = 0;
1927   gdk_event_put ((GdkEvent *) crossing_event);
1928   gdk_event_free ((GdkEvent *) crossing_event);
1929 }
1930
1931 static gboolean
1932 hildon_pannable_area_button_press_cb (GtkWidget * widget,
1933                                       GdkEventButton * event)
1934 {
1935   gint x, y;
1936   HildonPannableArea *area = HILDON_PANNABLE_AREA (widget);
1937   HildonPannableAreaPrivate *priv = area->priv;
1938
1939   if ((!priv->enabled) || (event->button != 1) ||
1940       ((event->time == priv->last_time) &&
1941        (priv->last_type == 1)) || (gtk_bin_get_child (GTK_BIN (widget)) == NULL))
1942     return TRUE;
1943
1944   priv->scroll_indicator_event_interrupt = 1;
1945
1946   hildon_pannable_area_launch_fade_timeout (area,
1947                                             priv->scroll_indicator_alpha);
1948
1949   priv->last_time = event->time;
1950   priv->last_type = 1;
1951
1952   priv->scroll_to_x = -1;
1953   priv->scroll_to_y = -1;
1954
1955   if (priv->button_pressed && priv->child) {
1956     /* Widget stole focus on last click, send crossing-out event */
1957     synth_crossing (priv->child, 0, 0, event->x_root, event->y_root,
1958                     event->time, FALSE);
1959   }
1960
1961   priv->x = event->x;
1962   priv->y = event->y;
1963   priv->ix = priv->x;
1964   priv->iy = priv->y;
1965
1966   /* Don't allow a click if we're still moving fast */
1967   if ((ABS (priv->vel_x) <= (priv->vmax * priv->vfast_factor)) &&
1968       (ABS (priv->vel_y) <= (priv->vmax * priv->vfast_factor)))
1969     priv->child =
1970       hildon_pannable_area_get_topmost (gtk_bin_get_child (GTK_BIN (widget))->window,
1971                                         event->x, event->y, &x, &y, GDK_BUTTON_PRESS_MASK);
1972   else
1973     priv->child = NULL;
1974
1975   priv->button_pressed = TRUE;
1976
1977   /* Stop scrolling on mouse-down (so you can flick, then hold to stop) */
1978   priv->vel_x = 0;
1979   priv->vel_y = 0;
1980   if (priv->idle_id) {
1981     g_source_remove (priv->idle_id);
1982     priv->idle_id = 0;
1983     g_signal_emit (area, pannable_area_signals[PANNING_FINISHED], 0);
1984   }
1985
1986   if (priv->child) {
1987
1988     gdk_drawable_get_size (priv->child, &priv->child_width,
1989                            &priv->child_height);
1990     priv->last_in = TRUE;
1991
1992     g_object_add_weak_pointer ((GObject *) priv->child,
1993                                (gpointer) & priv->child);
1994
1995     event = (GdkEventButton *) gdk_event_copy ((GdkEvent *) event);
1996     /* remove the reference we added with the copy */
1997     g_object_unref (priv->event_window);
1998     event->x = x;
1999     event->y = y;
2000     priv->cx = x;
2001     priv->cy = y;
2002
2003     synth_crossing (priv->child, x, y, event->x_root,
2004                     event->y_root, event->time, TRUE);
2005
2006     /* Send synthetic click (button press/release) event */
2007     ((GdkEventAny *) event)->window = g_object_ref (priv->child);
2008
2009     gdk_event_put ((GdkEvent *) event);
2010     gdk_event_free ((GdkEvent *) event);
2011   } else
2012     priv->child = NULL;
2013
2014   return TRUE;
2015 }
2016
2017 static gboolean
2018 hildon_pannable_area_check_scrollbars (HildonPannableArea * area)
2019 {
2020   HildonPannableAreaPrivate *priv = area->priv;
2021   gboolean prev_hscroll_visible, prev_vscroll_visible;
2022
2023   prev_hscroll_visible = priv->hscroll_visible;
2024   prev_vscroll_visible = priv->vscroll_visible;
2025
2026   if (!gtk_bin_get_child (GTK_BIN (area))) {
2027     priv->vscroll_visible = FALSE;
2028     priv->hscroll_visible = FALSE;
2029   } else {
2030     switch (priv->hscrollbar_policy) {
2031     case GTK_POLICY_ALWAYS:
2032       priv->hscroll_visible = TRUE;
2033       break;
2034     case GTK_POLICY_NEVER:
2035       priv->hscroll_visible = FALSE;
2036       break;
2037     default:
2038       priv->hscroll_visible = (priv->hadjust->upper - priv->hadjust->lower >
2039                                priv->hadjust->page_size);
2040     }
2041
2042     switch (priv->vscrollbar_policy) {
2043     case GTK_POLICY_ALWAYS:
2044       priv->vscroll_visible = TRUE;
2045       break;
2046     case GTK_POLICY_NEVER:
2047       priv->vscroll_visible = FALSE;
2048       break;
2049     default:
2050       priv->vscroll_visible = (priv->vadjust->upper - priv->vadjust->lower >
2051                                priv->vadjust->page_size);
2052     }
2053
2054     /* Store the vscroll/hscroll areas for redrawing */
2055     if (priv->vscroll_visible) {
2056       GtkAllocation *allocation = &GTK_WIDGET (area)->allocation;
2057       priv->vscroll_rect.x = allocation->width - priv->indicator_width;
2058       priv->vscroll_rect.y = 0;
2059       priv->vscroll_rect.width = priv->indicator_width;
2060       priv->vscroll_rect.height = allocation->height -
2061         (priv->hscroll_visible ? priv->indicator_width : 0);
2062     }
2063     if (priv->hscroll_visible) {
2064       GtkAllocation *allocation = &GTK_WIDGET (area)->allocation;
2065       priv->hscroll_rect.y = allocation->height - priv->indicator_width;
2066       priv->hscroll_rect.x = 0;
2067       priv->hscroll_rect.height = priv->indicator_width;
2068       priv->hscroll_rect.width = allocation->width -
2069         (priv->vscroll_visible ? priv->indicator_width : 0);
2070     }
2071   }
2072
2073   return ((priv->hscroll_visible != prev_hscroll_visible) ||
2074           (priv->vscroll_visible != prev_vscroll_visible));
2075 }
2076
2077 static void
2078 hildon_pannable_area_refresh (HildonPannableArea * area)
2079 {
2080   if (GTK_WIDGET_DRAWABLE (area) &&
2081       hildon_pannable_area_check_scrollbars (area)) {
2082     HildonPannableAreaPrivate *priv = area->priv;
2083
2084     gtk_widget_queue_resize (GTK_WIDGET (area));
2085
2086     if ((priv->vscroll_visible) || (priv->hscroll_visible)) {
2087       priv->scroll_indicator_event_interrupt = 0;
2088       priv->scroll_delay_counter = area->priv->scrollbar_fade_delay;
2089
2090       hildon_pannable_area_launch_fade_timeout (area, 1.0);
2091     }
2092   } else {
2093     hildon_pannable_area_redraw (area);
2094   }
2095 }
2096
2097 /* Scroll by a particular amount (in pixels). Optionally, return if
2098  * the scroll on a particular axis was successful.
2099  */
2100 static void
2101 hildon_pannable_axis_scroll (HildonPannableArea *area,
2102                              GtkAdjustment *adjust,
2103                              gdouble *vel,
2104                              gdouble inc,
2105                              gint *overshooting,
2106                              gint *overshot_dist,
2107                              gdouble *scroll_to,
2108                              gint overshoot_max,
2109                              gboolean *s)
2110 {
2111   gdouble dist;
2112   HildonPannableAreaPrivate *priv = area->priv;
2113
2114   dist = gtk_adjustment_get_value (adjust) - inc;
2115
2116   /* Overshooting
2117    * We use overshot_dist to define the distance of the current overshoot,
2118    * and overshooting to define the direction/whether or not we are overshot
2119    */
2120   if (!(*overshooting)) {
2121
2122     /* Initiation of the overshoot happens when the finger is released
2123      * and the current position of the pannable contents are out of range
2124      */
2125     if (dist < adjust->lower) {
2126       if (s) *s = FALSE;
2127
2128       dist = adjust->lower;
2129
2130       if (overshoot_max!=0) {
2131         *overshooting = 1;
2132         *scroll_to = -1;
2133         *overshot_dist = CLAMP (*overshot_dist + *vel, 0, overshoot_max);
2134         *vel = MIN (priv->vmax_overshooting, *vel);
2135         gtk_widget_queue_resize (GTK_WIDGET (area));
2136       } else {
2137         *vel = 0.0;
2138       }
2139     } else if (dist > adjust->upper - adjust->page_size) {
2140       if (s) *s = FALSE;
2141
2142       dist = adjust->upper - adjust->page_size;
2143
2144       if (overshoot_max!=0) {
2145         *overshooting = 1;
2146         *scroll_to = -1;
2147         *overshot_dist = CLAMP (*overshot_dist + *vel, -overshoot_max, 0);
2148         *vel = MAX (-priv->vmax_overshooting, *vel);
2149         gtk_widget_queue_resize (GTK_WIDGET (area));
2150       } else {
2151         *vel = 0.0;
2152       }
2153     } else {
2154       if ((*scroll_to) != -1) {
2155         if (((inc < 0)&&(*scroll_to <= dist))||
2156             ((inc > 0)&&(*scroll_to >= dist))) {
2157           dist = *scroll_to;
2158           *scroll_to = -1;
2159           *vel = 0;
2160         }
2161       }
2162     }
2163
2164     adjust->value = dist;
2165   } else {
2166     if (!priv->button_pressed) {
2167
2168       /* When the overshoot has started we continue for
2169        * PROP_BOUNCE_STEPS more steps into the overshoot before we
2170        * reverse direction. The deceleration factor is calculated
2171        * based on the percentage distance from the first item with
2172        * each iteration, therefore always returning us to the
2173        * top/bottom most element
2174        */
2175       if (*overshot_dist > 0) {
2176
2177         if ((*overshooting < priv->bounce_steps) && (*vel > 0)) {
2178           (*overshooting)++;
2179           *vel = (((gdouble)*overshot_dist)/overshoot_max) * (*vel);
2180         } else if ((*overshooting >= priv->bounce_steps) && (*vel > 0)) {
2181           *vel *= -1;
2182         } else if ((*overshooting > 1) && (*vel < 0)) {
2183           /* we add the MIN in order to avoid very small speeds */
2184           *vel = MIN (((((gdouble)*overshot_dist)*0.8) * -1), -10.0);
2185         }
2186
2187         *overshot_dist = CLAMP (*overshot_dist + *vel, 0, overshoot_max);
2188
2189         gtk_widget_queue_resize (GTK_WIDGET (area));
2190
2191       } else if (*overshot_dist < 0) {
2192
2193         if ((*overshooting < priv->bounce_steps) && (*vel < 0)) {
2194           (*overshooting)++;
2195           *vel = (((gdouble)*overshot_dist)/overshoot_max) * (*vel) * -1;
2196         } else if ((*overshooting >= priv->bounce_steps) && (*vel < 0)) {
2197           *vel *= -1;
2198         } else if ((*overshooting > 1) && (*vel > 0)) {
2199           /* we add the MAX in order to avoid very small speeds */
2200           *vel = MAX (((((gdouble)*overshot_dist)*0.8) * -1), 10.0);
2201         }
2202
2203         *overshot_dist = CLAMP (*overshot_dist + (*vel), -overshoot_max, 0);
2204
2205         gtk_widget_queue_resize (GTK_WIDGET (area));
2206
2207       } else {
2208         *overshooting = 0;
2209         *vel = 0;
2210         gtk_widget_queue_resize (GTK_WIDGET (area));
2211       }
2212     } else {
2213
2214       gint overshot_dist_old = *overshot_dist;
2215
2216       if (*overshot_dist > 0) {
2217         *overshot_dist = CLAMP ((*overshot_dist) + inc, 0, overshoot_max);
2218       } else if (*overshot_dist < 0) {
2219         *overshot_dist = CLAMP ((*overshot_dist) + inc, -1 * overshoot_max, 0);
2220       } else {
2221         *overshooting = 0;
2222         adjust->value = CLAMP (dist,
2223                                adjust->lower,
2224                                adjust->upper -
2225                                adjust->page_size);
2226       }
2227
2228       if (*overshot_dist != overshot_dist_old)
2229         gtk_widget_queue_resize (GTK_WIDGET (area));
2230     }
2231   }
2232 }
2233
2234 static void
2235 hildon_pannable_area_scroll (HildonPannableArea *area,
2236                              gdouble x, gdouble y)
2237 {
2238   gboolean sx, sy;
2239   HildonPannableAreaPrivate *priv = area->priv;
2240   gboolean hscroll_visible, vscroll_visible;
2241   gdouble hv, vv;
2242
2243   if (gtk_bin_get_child (GTK_BIN (area)) == NULL)
2244     return;
2245
2246   vscroll_visible = (priv->vadjust->upper - priv->vadjust->lower >
2247              priv->vadjust->page_size);
2248   hscroll_visible = (priv->hadjust->upper - priv->hadjust->lower >
2249              priv->hadjust->page_size);
2250
2251   sx = TRUE;
2252   sy = TRUE;
2253
2254   hv = priv->hadjust->value;
2255   vv = priv->vadjust->value;
2256
2257   if (vscroll_visible) {
2258     hildon_pannable_axis_scroll (area, priv->vadjust, &priv->vel_y, y,
2259                                  &priv->overshooting_y, &priv->overshot_dist_y,
2260                                  &priv->scroll_to_y, priv->vovershoot_max, &sy);
2261   } else {
2262     priv->vel_y = 0;
2263   }
2264
2265   if (hscroll_visible) {
2266     hildon_pannable_axis_scroll (area, priv->hadjust, &priv->vel_x, x,
2267                                  &priv->overshooting_x, &priv->overshot_dist_x,
2268                                  &priv->scroll_to_x, priv->hovershoot_max, &sx);
2269   } else {
2270     priv->vel_x = 0;
2271   }
2272
2273   if (hv != priv->hadjust->value)
2274     gtk_adjustment_value_changed (priv->hadjust);
2275
2276   if (vv != priv->vadjust->value)
2277     gtk_adjustment_value_changed (priv->vadjust);
2278
2279   /* If the scroll on a particular axis wasn't succesful, reset the
2280    * initial scroll position to the new mouse co-ordinate. This means
2281    * when you get to the top of the page, dragging down works immediately.
2282    */
2283   if (priv->mode == HILDON_PANNABLE_AREA_MODE_ACCEL) {
2284       if (!sx) {
2285         priv->x = priv->ex;
2286       }
2287
2288       if (!sy) {
2289         priv->y = priv->ey;
2290       }
2291     }
2292 }
2293
2294 static gboolean
2295 hildon_pannable_area_timeout (HildonPannableArea * area)
2296 {
2297   HildonPannableAreaPrivate *priv = area->priv;
2298
2299   if ((!priv->enabled) || (priv->mode == HILDON_PANNABLE_AREA_MODE_PUSH)) {
2300     priv->idle_id = 0;
2301     g_signal_emit (area, pannable_area_signals[PANNING_FINISHED], 0);
2302
2303     return FALSE;
2304   }
2305
2306   if (!priv->button_pressed) {
2307     /* Decelerate gradually when pointer is raised */
2308     if ((!priv->overshot_dist_y) &&
2309         (!priv->overshot_dist_x)) {
2310
2311       /* in case we move to a specific point do not decelerate when arriving */
2312       if ((priv->scroll_to_x != -1)||(priv->scroll_to_y != -1)) {
2313
2314         if (ABS (priv->vel_x) >= 1.5) {
2315           priv->vel_x *= priv->decel;
2316         }
2317
2318         if (ABS (priv->vel_y) >= 1.5) {
2319           priv->vel_y *= priv->decel;
2320         }
2321
2322       } else {
2323         if ((!priv->low_friction_mode) ||
2324             ((priv->mov_mode&HILDON_MOVEMENT_MODE_HORIZ) &&
2325              (ABS (priv->vel_x) < 0.8*priv->vmax)))
2326           priv->vel_x *= priv->decel;
2327
2328         if ((!priv->low_friction_mode) ||
2329             ((priv->mov_mode&HILDON_MOVEMENT_MODE_VERT) &&
2330              (ABS (priv->vel_y) < 0.8*priv->vmax)))
2331           priv->vel_y *= priv->decel;
2332
2333         if ((ABS (priv->vel_x) < 1.0) && (ABS (priv->vel_y) < 1.0)) {
2334           priv->vel_x = 0;
2335           priv->vel_y = 0;
2336           priv->idle_id = 0;
2337
2338           g_signal_emit (area, pannable_area_signals[PANNING_FINISHED], 0);
2339
2340           return FALSE;
2341         }
2342       }
2343     }
2344   } else if (priv->mode == HILDON_PANNABLE_AREA_MODE_AUTO) {
2345     priv->idle_id = 0;
2346
2347     return FALSE;
2348   }
2349
2350   hildon_pannable_area_scroll (area, priv->vel_x, priv->vel_y);
2351
2352   gdk_window_process_updates (GTK_WIDGET (area)->window, FALSE);
2353
2354   return TRUE;
2355 }
2356
2357 static void
2358 hildon_pannable_area_calculate_velocity (gdouble *vel,
2359                                          gdouble delta,
2360                                          gdouble dist,
2361                                          gdouble vmax,
2362                                          gdouble drag_inertia,
2363                                          gdouble force,
2364                                          guint sps)
2365 {
2366   gdouble rawvel;
2367
2368   if (ABS (dist) >= RATIO_TOLERANCE) {
2369     rawvel = (dist / ABS (delta)) * force;
2370     *vel = *vel * (1 - drag_inertia) +
2371       rawvel * drag_inertia;
2372     *vel = *vel > 0 ? MIN (*vel, vmax)
2373       : MAX (*vel, -1 * vmax);
2374   }
2375 }
2376
2377 static gboolean
2378 hildon_pannable_area_motion_event_scroll_timeout (HildonPannableArea *area)
2379 {
2380   HildonPannableAreaPrivate *priv = area->priv;
2381
2382   if ((priv->motion_x != 0)||(priv->motion_y != 0))
2383     hildon_pannable_area_scroll (area, priv->motion_x, priv->motion_y);
2384
2385   priv->motion_event_scroll_timeout = 0;
2386
2387   return FALSE;
2388 }
2389
2390 static void
2391 hildon_pannable_area_motion_event_scroll (HildonPannableArea *area,
2392                                           gdouble x, gdouble y)
2393 {
2394   HildonPannableAreaPrivate *priv = area->priv;
2395
2396   if (priv->motion_event_scroll_timeout) {
2397
2398     priv->motion_x += x;
2399     priv->motion_y += y;
2400
2401   } else {
2402
2403   /* we do not delay the first event but the next ones */
2404     hildon_pannable_area_scroll (area, x, y);
2405
2406     priv->motion_x = 0;
2407     priv->motion_y = 0;
2408
2409     priv->motion_event_scroll_timeout = gdk_threads_add_timeout
2410       ((gint) (1000.0 / (gdouble) MOTION_EVENTS_PER_SECOND),
2411        (GSourceFunc) hildon_pannable_area_motion_event_scroll_timeout, area);
2412   }
2413 }
2414
2415 static void
2416 hildon_pannable_area_check_move (HildonPannableArea *area,
2417                                  GdkEventMotion * event,
2418                                  gdouble *x,
2419                                  gdouble *y)
2420 {
2421   HildonPannableAreaPrivate *priv = area->priv;
2422
2423   if (priv->first_drag && (!priv->moved) &&
2424       ((ABS (*x) > (priv->panning_threshold))
2425        || (ABS (*y) > (priv->panning_threshold)))) {
2426     priv->moved = TRUE;
2427     *x = 0;
2428     *y = 0;
2429
2430     if (priv->first_drag) {
2431         gboolean vscroll_visible;
2432         gboolean hscroll_visible;
2433
2434       if (ABS (priv->iy - event->y) >=
2435           ABS (priv->ix - event->x)) {
2436
2437         g_signal_emit (area,
2438                        pannable_area_signals[VERTICAL_MOVEMENT],
2439                        0, (priv->iy > event->y) ?
2440                        HILDON_MOVEMENT_UP :
2441                        HILDON_MOVEMENT_DOWN,
2442                        (gdouble)priv->ix, (gdouble)priv->iy);
2443
2444         vscroll_visible = (priv->vadjust->upper - priv->vadjust->lower >
2445                    priv->vadjust->page_size);
2446
2447         if (!((vscroll_visible)&&
2448               (priv->mov_mode&HILDON_MOVEMENT_MODE_VERT))) {
2449
2450           hscroll_visible = (priv->hadjust->upper - priv->hadjust->lower >
2451                              priv->hadjust->page_size);
2452
2453           /* even in case we do not have to move we check if this
2454              could be a fake horizontal movement */
2455           if (!((hscroll_visible)&&
2456                 (priv->mov_mode&HILDON_MOVEMENT_MODE_HORIZ)) ||
2457               (ABS (priv->iy - event->y) -
2458                ABS (priv->ix - event->x) >= priv->direction_error_margin))
2459             priv->moved = FALSE;
2460         }
2461       } else {
2462
2463         g_signal_emit (area,
2464                        pannable_area_signals[HORIZONTAL_MOVEMENT],
2465                        0, (priv->ix > event->x) ?
2466                        HILDON_MOVEMENT_LEFT :
2467                        HILDON_MOVEMENT_RIGHT,
2468                        (gdouble)priv->ix, (gdouble)priv->iy);
2469
2470         hscroll_visible = (priv->hadjust->upper - priv->hadjust->lower >
2471                            priv->hadjust->page_size);
2472
2473         if (!((hscroll_visible)&&
2474               (priv->mov_mode&HILDON_MOVEMENT_MODE_HORIZ))) {
2475
2476           vscroll_visible = (priv->vadjust->upper - priv->vadjust->lower >
2477                              priv->vadjust->page_size);
2478
2479           /* even in case we do not have to move we check if this
2480              could be a fake vertical movement */
2481           if (!((vscroll_visible) &&
2482                 (priv->mov_mode&HILDON_MOVEMENT_MODE_VERT)) ||
2483               (ABS (priv->ix - event->x) -
2484                ABS (priv->iy - event->y) >= priv->direction_error_margin))
2485             priv->moved = FALSE;
2486         }
2487       }
2488
2489       if ((priv->moved)&&(priv->child)) {
2490         gint pos_x, pos_y;
2491
2492         pos_x = priv->cx + (event->x - priv->ix);
2493         pos_y = priv->cy + (event->y - priv->iy);
2494
2495         synth_crossing (priv->child, pos_x, pos_y, event->x_root,
2496                         event->y_root, event->time, FALSE);
2497       }
2498
2499       if (priv->moved) {
2500         gboolean result_val;
2501
2502         g_signal_emit (area,
2503                        pannable_area_signals[PANNING_STARTED],
2504                        0, &result_val);
2505
2506         priv->moved = !result_val;
2507       }
2508     }
2509
2510     priv->first_drag = FALSE;
2511
2512     if ((priv->mode != HILDON_PANNABLE_AREA_MODE_PUSH) &&
2513         (priv->mode != HILDON_PANNABLE_AREA_MODE_AUTO)) {
2514
2515       if (!priv->idle_id)
2516         priv->idle_id = gdk_threads_add_timeout ((gint)
2517                                                  (1000.0 / (gdouble) priv->sps),
2518                                                  (GSourceFunc)
2519                                                  hildon_pannable_area_timeout, area);
2520     }
2521   }
2522 }
2523
2524 static void
2525 hildon_pannable_area_handle_move (HildonPannableArea *area,
2526                                   GdkEventMotion * event,
2527                                   gdouble *x,
2528                                   gdouble *y)
2529 {
2530   HildonPannableAreaPrivate *priv = area->priv;
2531   gdouble delta;
2532
2533   switch (priv->mode) {
2534   case HILDON_PANNABLE_AREA_MODE_PUSH:
2535     /* Scroll by the amount of pixels the cursor has moved
2536      * since the last motion event.
2537      */
2538     hildon_pannable_area_motion_event_scroll (area, *x, *y);
2539     priv->x = event->x;
2540     priv->y = event->y;
2541     break;
2542   case HILDON_PANNABLE_AREA_MODE_ACCEL:
2543     /* Set acceleration relative to the initial click */
2544     priv->ex = event->x;
2545     priv->ey = event->y;
2546     priv->vel_x = ((*x > 0) ? 1 : -1) *
2547       (((ABS (*x) /
2548          (gdouble) GTK_WIDGET (area)->allocation.width) *
2549         (priv->vmax - priv->vmin)) + priv->vmin);
2550     priv->vel_y = ((*y > 0) ? 1 : -1) *
2551       (((ABS (*y) /
2552          (gdouble) GTK_WIDGET (area)->allocation.height) *
2553         (priv->vmax - priv->vmin)) + priv->vmin);
2554     break;
2555   case HILDON_PANNABLE_AREA_MODE_AUTO:
2556
2557     delta = event->time - priv->last_time;
2558
2559     if (priv->mov_mode&HILDON_MOVEMENT_MODE_VERT) {
2560       gdouble dist = event->y - priv->y;
2561
2562       hildon_pannable_area_calculate_velocity (&priv->vel_y,
2563                                                delta,
2564                                                dist,
2565                                                priv->vmax,
2566                                                priv->drag_inertia,
2567                                                priv->force,
2568                                                priv->sps);
2569     } else {
2570       *y = 0;
2571       priv->vel_y = 0;
2572     }
2573
2574     if (priv->mov_mode&HILDON_MOVEMENT_MODE_HORIZ) {
2575       gdouble dist = event->x - priv->x;
2576
2577       hildon_pannable_area_calculate_velocity (&priv->vel_x,
2578                                                delta,
2579                                                dist,
2580                                                priv->vmax,
2581                                                priv->drag_inertia,
2582                                                priv->force,
2583                                                priv->sps);
2584     } else {
2585       *x = 0;
2586       priv->vel_x = 0;
2587     }
2588
2589     hildon_pannable_area_motion_event_scroll (area, *x, *y);
2590
2591     if (priv->mov_mode&HILDON_MOVEMENT_MODE_HORIZ)
2592       priv->x = event->x;
2593     if (priv->mov_mode&HILDON_MOVEMENT_MODE_VERT)
2594       priv->y = event->y;
2595
2596     break;
2597   default:
2598     break;
2599   }
2600 }
2601
2602 static gboolean
2603 hildon_pannable_area_motion_notify_cb (GtkWidget * widget,
2604                                        GdkEventMotion * event)
2605 {
2606   HildonPannableArea *area = HILDON_PANNABLE_AREA (widget);
2607   HildonPannableAreaPrivate *priv = area->priv;
2608   gdouble x, y;
2609
2610   if (gtk_bin_get_child (GTK_BIN (widget)) == NULL)
2611     return TRUE;
2612
2613   if ((!priv->enabled) || (!priv->button_pressed) ||
2614       ((event->time == priv->last_time) && (priv->last_type == 2))) {
2615     gdk_window_get_pointer (widget->window, NULL, NULL, 0);
2616     return TRUE;
2617   }
2618
2619   if (priv->last_type == 1) {
2620     priv->first_drag = TRUE;
2621   }
2622
2623   x = event->x - priv->x;
2624   y = event->y - priv->y;
2625
2626   if (!priv->moved) {
2627     hildon_pannable_area_check_move (area, event, &x, &y);
2628   }
2629
2630   if (priv->moved) {
2631     hildon_pannable_area_handle_move (area, event, &x, &y);
2632   } else if (priv->child) {
2633     gboolean in;
2634     gint pos_x, pos_y;
2635
2636     pos_x = priv->cx + (event->x - priv->ix);
2637     pos_y = priv->cy + (event->y - priv->iy);
2638
2639     in = (((0 <= pos_x)&&(priv->child_width >= pos_x)) &&
2640           ((0 <= pos_y)&&(priv->child_height >= pos_y)));
2641
2642     if (((!priv->last_in)&&in)||((priv->last_in)&&(!in))) {
2643
2644       synth_crossing (priv->child, pos_x, pos_y, event->x_root,
2645                       event->y_root, event->time, in);
2646
2647       priv->last_in = in;
2648     }
2649   }
2650
2651   priv->last_time = event->time;
2652   priv->last_type = 2;
2653
2654   if (priv->child) {
2655     /* Send motion notify to child */
2656     event = (GdkEventMotion *) gdk_event_copy ((GdkEvent *) event);
2657     /* remove the reference we added with the copy */
2658     g_object_unref (priv->event_window);
2659     event->x = priv->cx + (event->x - priv->ix);
2660     event->y = priv->cy + (event->y - priv->iy);
2661     event->window = g_object_ref (priv->child);
2662     gdk_event_put ((GdkEvent *) event);
2663     gdk_event_free ((GdkEvent *) event);
2664   }
2665
2666   gdk_window_get_pointer (widget->window, NULL, NULL, 0);
2667
2668   return TRUE;
2669 }
2670
2671 static gboolean
2672 hildon_pannable_leave_notify_event (GtkWidget *widget,
2673                                     GdkEventCrossing *event)
2674 {
2675   HildonPannableArea *area = HILDON_PANNABLE_AREA (widget);
2676   HildonPannableAreaPrivate *priv = area->priv;
2677
2678   if ((priv->child)&&(priv->last_in)) {
2679     priv->last_in = FALSE;
2680
2681     synth_crossing (priv->child, 0, 0, event->x_root,
2682                     event->y_root, event->time, FALSE);
2683   }
2684
2685   return FALSE;
2686 }
2687
2688 static gboolean
2689 hildon_pannable_area_button_release_cb (GtkWidget * widget,
2690                                         GdkEventButton * event)
2691 {
2692   HildonPannableArea *area = HILDON_PANNABLE_AREA (widget);
2693   HildonPannableAreaPrivate *priv = area->priv;
2694   gint x, y;
2695   gdouble dx, dy;
2696   GdkWindow *child;
2697
2698   if  (((event->time == priv->last_time) && (priv->last_type == 3))
2699        || (gtk_bin_get_child (GTK_BIN (widget)) == NULL)
2700        || (!priv->button_pressed) || (!priv->enabled) || (event->button != 1))
2701     return TRUE;
2702
2703   /* if last event was a motion-notify we have to check the movement
2704      and launch the animation */
2705   if (priv->last_type == 2) {
2706
2707     dx = event->x - priv->x;
2708     dy = event->y - priv->y;
2709
2710     hildon_pannable_area_check_move (area, (GdkEventMotion *) event, &dx, &dy);
2711
2712     if (priv->moved) {
2713       gdouble delta = event->time - priv->last_time;
2714
2715       hildon_pannable_area_handle_move (area, (GdkEventMotion *) event, &dx, &dy);
2716
2717       /* move all the way to the last position now */
2718       if (priv->motion_event_scroll_timeout) {
2719         g_source_remove (priv->motion_event_scroll_timeout);
2720         hildon_pannable_area_motion_event_scroll_timeout (HILDON_PANNABLE_AREA (widget));
2721         priv->motion_x = 0;
2722         priv->motion_y = 0;
2723       }
2724
2725       if ((ABS (dx) < 4.0) && (delta >= CURSOR_STOPPED_TIMEOUT))
2726         priv->vel_x = 0;
2727
2728       if ((ABS (dy) < 4.0) && (delta >= CURSOR_STOPPED_TIMEOUT))
2729         priv->vel_y = 0;
2730     }
2731   }
2732
2733   /* If overshoot has been initiated with a finger down, on release set max speed */
2734   if (priv->overshot_dist_y != 0) {
2735     priv->overshooting_y = priv->bounce_steps; /* Hack to stop a bounce in the finger down case */
2736     priv->vel_y = priv->overshot_dist_y * 0.9;
2737   }
2738
2739   if (priv->overshot_dist_x != 0) {
2740     priv->overshooting_x = priv->bounce_steps; /* Hack to stop a bounce in the finger down case */
2741     priv->vel_x = priv->overshot_dist_x * 0.9;
2742   }
2743
2744   priv->button_pressed = FALSE;
2745
2746   if  ((ABS (priv->vel_y) >= priv->vmin) ||
2747        (ABS (priv->vel_x) >= priv->vmin)) {
2748
2749     /* we have to move because we are in overshooting position*/
2750     if (!priv->moved) {
2751       gboolean result_val;
2752
2753       g_signal_emit (area,
2754                      pannable_area_signals[PANNING_STARTED],
2755                      0, &result_val);
2756     }
2757
2758     priv->scroll_indicator_alpha = 1.0;
2759
2760     if (ABS (priv->vel_x) > MAX_SPEED_THRESHOLD)
2761       priv->vel_x = (priv->vel_x > 0) ? priv->vmax : -priv->vmax;
2762
2763     if (ABS (priv->vel_y) > MAX_SPEED_THRESHOLD)
2764       priv->vel_y = (priv->vel_y > 0) ? priv->vmax : -priv->vmax;
2765
2766     if (!priv->idle_id)
2767       priv->idle_id = gdk_threads_add_timeout ((gint) (1000.0 / (gdouble) priv->sps),
2768                                                (GSourceFunc)
2769                                                hildon_pannable_area_timeout, widget);
2770   } else {
2771     if (priv->center_on_child_focus_pending) {
2772       hildon_pannable_area_center_on_child_focus (area);
2773     }
2774
2775     if (priv->moved)
2776       g_signal_emit (widget, pannable_area_signals[PANNING_FINISHED], 0);
2777   }
2778
2779   area->priv->center_on_child_focus_pending = FALSE;
2780
2781   priv->scroll_indicator_event_interrupt = 0;
2782   priv->scroll_delay_counter = priv->scrollbar_fade_delay;
2783
2784   hildon_pannable_area_launch_fade_timeout (HILDON_PANNABLE_AREA (widget),
2785                                             priv->scroll_indicator_alpha);
2786
2787   priv->last_time = event->time;
2788   priv->last_type = 3;
2789
2790   if (!priv->child) {
2791     priv->moved = FALSE;
2792     return TRUE;
2793   }
2794
2795   child =
2796     hildon_pannable_area_get_topmost (gtk_bin_get_child (GTK_BIN (widget))->window,
2797                                       event->x, event->y, &x, &y, GDK_BUTTON_RELEASE_MASK);
2798
2799   event = (GdkEventButton *) gdk_event_copy ((GdkEvent *) event);
2800   /* remove the reference we added with the copy */
2801   g_object_unref (priv->event_window);
2802   event->x = x;
2803   event->y = y;
2804
2805   /* Leave the widget if we've moved - This doesn't break selection,
2806    * but stops buttons from being clicked.
2807    */
2808   if ((child != priv->child) || (priv->moved)) {
2809     /* Send synthetic leave event */
2810     synth_crossing (priv->child, x, y, event->x_root,
2811                     event->y_root, event->time, FALSE);
2812     /* insure no click will happen for widgets that do not handle
2813        leave-notify */
2814     event->x = -16384;
2815     event->y = -16384;
2816     /* Send synthetic button release event */
2817     ((GdkEventAny *) event)->window = g_object_ref (priv->child);
2818     gdk_event_put ((GdkEvent *) event);
2819   } else {
2820     /* Send synthetic button release event */
2821     ((GdkEventAny *) event)->window = g_object_ref (child);
2822     gdk_event_put ((GdkEvent *) event);
2823     /* Send synthetic leave event */
2824     synth_crossing (priv->child, x, y, event->x_root,
2825                     event->y_root, event->time, FALSE);
2826   }
2827   g_object_remove_weak_pointer ((GObject *) priv->child,
2828                                 (gpointer) & priv->child);
2829
2830   priv->moved = FALSE;
2831   gdk_event_free ((GdkEvent *) event);
2832
2833   return TRUE;
2834 }
2835
2836 /* utility event handler */
2837 static gboolean
2838 hildon_pannable_area_scroll_cb (GtkWidget *widget,
2839                                 GdkEventScroll *event)
2840 {
2841   GtkAdjustment *adj = NULL;
2842   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (widget)->priv;
2843
2844   if ((!priv->enabled) ||
2845       (gtk_bin_get_child (GTK_BIN (widget)) == NULL))
2846     return TRUE;
2847
2848   priv->scroll_indicator_event_interrupt = 0;
2849   priv->scroll_delay_counter = priv->scrollbar_fade_delay + 20;
2850
2851   hildon_pannable_area_launch_fade_timeout (HILDON_PANNABLE_AREA (widget), 1.0);
2852
2853   /* Stop inertial scrolling */
2854   if (priv->idle_id) {
2855     priv->vel_x = 0.0;
2856     priv->vel_y = 0.0;
2857     priv->overshooting_x = 0;
2858     priv->overshooting_y = 0;
2859
2860     if ((priv->overshot_dist_x>0)||(priv->overshot_dist_y>0)) {
2861       priv->overshot_dist_x = 0;
2862       priv->overshot_dist_y = 0;
2863
2864       gtk_widget_queue_resize (GTK_WIDGET (widget));
2865     }
2866
2867     g_signal_emit (widget, pannable_area_signals[PANNING_FINISHED], 0);
2868
2869     g_source_remove (priv->idle_id);
2870     priv->idle_id = 0;
2871   }
2872
2873   if (event->direction == GDK_SCROLL_UP || event->direction == GDK_SCROLL_DOWN)
2874     adj = priv->vadjust;
2875   else
2876     adj = priv->hadjust;
2877
2878   if (adj)
2879     {
2880       gdouble delta, new_value;
2881
2882       /* from gtkrange.c calculate delta*/
2883       delta = pow (adj->page_size, 2.0 / 3.0);
2884
2885       if (event->direction == GDK_SCROLL_UP ||
2886           event->direction == GDK_SCROLL_LEFT)
2887         delta = - delta;
2888
2889       new_value = CLAMP (adj->value + delta, adj->lower, adj->upper - adj->page_size);
2890
2891       gtk_adjustment_set_value (adj, new_value);
2892     }
2893
2894   return TRUE;
2895 }
2896
2897 static void
2898 hildon_pannable_area_child_mapped (GtkWidget *widget,
2899                                    GdkEvent  *event,
2900                                    gpointer user_data)
2901 {
2902   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (user_data)->priv;
2903
2904   if (priv->event_window != NULL && priv->enabled)
2905     gdk_window_raise (priv->event_window);
2906 }
2907
2908 static void
2909 hildon_pannable_area_add (GtkContainer *container, GtkWidget *child)
2910 {
2911   HildonPannableAreaPrivate *priv = HILDON_PANNABLE_AREA (container)->priv;
2912
2913   g_return_if_fail (gtk_bin_get_child (GTK_BIN (container)) == NULL);
2914
2915   gtk_widget_set_parent (child, GTK_WIDGET (container));
2916   GTK_BIN (container)->child = child;
2917
2918   g_signal_connect_after (child, "map-event",
2919                           G_CALLBACK (hildon_pannable_area_child_mapped),
2920                           container);
2921
2922   if (!gtk_widget_set_scroll_adjustments (child, priv->hadjust, priv->vadjust)) {
2923     g_warning ("%s: cannot add non scrollable widget, "
2924                "wrap it in a viewport", __FUNCTION__);
2925   }
2926 }
2927
2928 /* call this function if you are not panning */
2929 static void
2930 hildon_pannable_area_center_on_child_focus      (HildonPannableArea *area)
2931 {
2932   GtkWidget *focused_child = NULL;
2933   GtkWidget *window = NULL;
2934
2935   window = gtk_widget_get_toplevel (GTK_WIDGET (area));
2936
2937   if (GTK_WIDGET_TOPLEVEL (window)) {
2938     focused_child = gtk_window_get_focus (GTK_WINDOW (window));
2939   }
2940
2941   if (focused_child) {
2942     hildon_pannable_area_scroll_to_child (area, focused_child);
2943   }
2944 }
2945
2946 static void
2947 hildon_pannable_area_set_focus_child            (GtkContainer     *container,
2948                                                  GtkWidget        *child)
2949 {
2950   HildonPannableArea *area = HILDON_PANNABLE_AREA (container);
2951
2952   if (!area->priv->center_on_child_focus) {
2953     return;
2954   }
2955
2956   if (GTK_IS_WIDGET (child)) {
2957     area->priv->center_on_child_focus_pending = TRUE;
2958   }
2959 }
2960
2961 static void
2962 hildon_pannable_area_remove (GtkContainer *container, GtkWidget *child)
2963 {
2964   g_return_if_fail (HILDON_IS_PANNABLE_AREA (container));
2965   g_return_if_fail (child != NULL);
2966   g_return_if_fail (gtk_bin_get_child (GTK_BIN (container)) == child);
2967
2968   gtk_widget_set_scroll_adjustments (child, NULL, NULL);
2969
2970   g_signal_handlers_disconnect_by_func (child,
2971                                         hildon_pannable_area_child_mapped,
2972                                         container);
2973
2974   /* chain parent class handler to remove child */
2975   GTK_CONTAINER_CLASS (hildon_pannable_area_parent_class)->remove (container, child);
2976 }
2977
2978 /*
2979  * This method calculates a factor necessary to determine the initial distance
2980  * to jump in hildon_pannable_area_scroll_to(). For fixed time and frames per
2981  * second, we know in how many frames 'n' we need to reach the destination
2982  * point. We know that, for a distance d,
2983  *
2984  *   d = d_0 + d_1 + ... + d_n
2985  *
2986  * where d_i is the distance travelled in the i-th frame and decel_factor is
2987  * the deceleration factor. This can be rewritten as
2988  *
2989  *   d = d_0 + (d_0 * decel_factor) + ... + (d_n-1 * decel_factor),
2990  *
2991  * since the distance travelled on each frame is the distance travelled in the
2992  * previous frame reduced by the deceleration factor. Reducing this and
2993  * factoring d_0 out, we get
2994  *
2995  *   d = d_0 (1 + decel_factor + ... + decel_factor^(n-1)).
2996  *
2997  * Since the sum is independent of the distance to be travelled, we can define
2998  * vel_factor as
2999  *
3000  *   vel_factor = 1 + decel_factor + ... + decel_factor^(n-1).
3001  *
3002  * That's the gem we calculate in this method.
3003  */
3004 static void
3005 hildon_pannable_calculate_vel_factor (HildonPannableArea * self)
3006 {
3007   HildonPannableAreaPrivate *priv = self->priv;
3008   gfloat fct = 1;
3009   gfloat fct_i = 1;
3010   gint i, n;
3011
3012   n = ceil (priv->sps * priv->scroll_time);
3013
3014   for (i = 1; i < n && fct_i >= RATIO_TOLERANCE; i++) {
3015     fct_i *= priv->decel;
3016     fct += fct_i;
3017   }
3018
3019     priv->vel_factor = fct;
3020 }
3021
3022 /**
3023  * hildon_pannable_area_new:
3024  *
3025  * Create a new pannable area widget
3026  *
3027  * Returns: the newly created #HildonPannableArea
3028  *
3029  * Since: 2.2
3030  */
3031
3032 GtkWidget *
3033 hildon_pannable_area_new (void)
3034 {
3035   return g_object_new (HILDON_TYPE_PANNABLE_AREA, NULL);
3036 }
3037
3038 /**
3039  * hildon_pannable_area_new_full:
3040  * @mode: #HildonPannableAreaMode
3041  * @enabled: Value for the enabled property
3042  * @vel_min: Value for the velocity-min property
3043  * @vel_max: Value for the velocity-max property
3044  * @decel: Value for the deceleration property
3045  * @sps: Value for the sps property
3046  *
3047  * Create a new #HildonPannableArea widget and set various properties
3048  *
3049  * returns: the newly create #HildonPannableArea
3050  *
3051  * Since: 2.2
3052  */
3053
3054 GtkWidget *
3055 hildon_pannable_area_new_full (gint mode, gboolean enabled,
3056                                gdouble vel_min, gdouble vel_max,
3057                                gdouble decel, guint sps)
3058 {
3059   return g_object_new (HILDON_TYPE_PANNABLE_AREA,
3060                        "mode", mode,
3061                        "enabled", enabled,
3062                        "velocity_min", vel_min,
3063                        "velocity_max", vel_max,
3064                        "deceleration", decel, "sps", sps, NULL);
3065 }
3066
3067 /**
3068  * hildon_pannable_area_add_with_viewport:
3069  * @area: A #HildonPannableArea
3070  * @child: Child widget to add to the viewport
3071  *
3072  * Convenience function used to add a child to a #GtkViewport, and add the
3073  * viewport to the scrolled window.
3074  *
3075  * Since: 2.2
3076  */
3077
3078 void
3079 hildon_pannable_area_add_with_viewport (HildonPannableArea * area,
3080                                         GtkWidget * child)
3081 {
3082   GtkBin *bin;
3083   GtkWidget *viewport;
3084
3085   g_return_if_fail (HILDON_IS_PANNABLE_AREA (area));
3086   g_return_if_fail (GTK_IS_WIDGET (child));
3087   g_return_if_fail (child->parent == NULL);
3088
3089   bin = GTK_BIN (area);
3090
3091   if (bin->child != NULL)
3092     {
3093       g_return_if_fail (GTK_IS_VIEWPORT (bin->child));
3094       g_return_if_fail (GTK_BIN (bin->child)->child == NULL);
3095
3096       viewport = bin->child;
3097     }
3098   else
3099     {
3100       HildonPannableAreaPrivate *priv = area->priv;
3101
3102       viewport = gtk_viewport_new (priv->hadjust,
3103                                    priv->vadjust);
3104       gtk_viewport_set_shadow_type (GTK_VIEWPORT (viewport), GTK_SHADOW_NONE);
3105       gtk_container_add (GTK_CONTAINER (area), viewport);
3106     }
3107
3108   gtk_widget_show (viewport);
3109   gtk_container_add (GTK_CONTAINER (viewport), child);
3110 }
3111
3112 /**
3113  * hildon_pannable_area_scroll_to:
3114  * @area: A #HildonPannableArea.
3115  * @x: The x coordinate of the destination point or -1 to ignore this axis.
3116  * @y: The y coordinate of the destination point or -1 to ignore this axis.
3117  *
3118  * Smoothly scrolls @area to ensure that (@x, @y) is a visible point
3119  * on the widget. To move in only one coordinate, you must set the other one
3120  * to -1. Notice that, in %HILDON_PANNABLE_AREA_MODE_PUSH mode, this function
3121  * works just like hildon_pannable_area_jump_to().
3122  *
3123  * This function is useful if you need to present the user with a particular
3124  * element inside a scrollable widget, like #GtkTreeView. For instance,
3125  * the following example shows how to scroll inside a #GtkTreeView to
3126  * make visible an item, indicated by the #GtkTreeIter @iter.
3127  *
3128  * <example>
3129  * <programlisting>
3130  *  GtkTreePath *path;
3131  *  GdkRectangle *rect;
3132  *  <!-- -->
3133  *  path = gtk_tree_model_get_path (model, &amp;iter);
3134  *  gtk_tree_view_get_background_area (GTK_TREE_VIEW (treeview),
3135  *                                     path, NULL, &amp;rect);
3136  *  gtk_tree_view_convert_bin_window_to_tree_coords (GTK_TREE_VIEW (treeview),
3137  *                                                   0, rect.y, NULL, &amp;y);
3138  *  hildon_pannable_area_scroll_to (panarea, -1, y);
3139  *  gtk_tree_path_free (path);
3140  * </programlisting>
3141  * </example>
3142  *
3143  * If you want to present a child widget in simpler scenarios,
3144  * use hildon_pannable_area_scroll_to_child() instead.
3145  *
3146  * There is a precondition to this function: the widget must be
3147  * already realized. Check the hildon_pannable_area_jump_to_child() for
3148  * more tips regarding how to call this function during
3149  * initialization.
3150  *
3151  * Since: 2.2
3152  **/
3153 void
3154 hildon_pannable_area_scroll_to (HildonPannableArea *area,
3155                                 const gint x, const gint y)
3156 {
3157   HildonPannableAreaPrivate *priv;
3158   gint width, height;
3159   gint dist_x, dist_y;
3160   gboolean hscroll_visible, vscroll_visible;
3161
3162   g_return_if_fail (GTK_WIDGET_REALIZED (area));
3163   g_return_if_fail (HILDON_IS_PANNABLE_AREA (area));
3164
3165   priv = area->priv;
3166
3167   vscroll_visible = (priv->vadjust->upper - priv->vadjust->lower >
3168              priv->vadjust->page_size);
3169   hscroll_visible = (priv->hadjust->upper - priv->hadjust->lower >
3170              priv->hadjust->page_size);
3171
3172   if (((!vscroll_visible)&&(!hscroll_visible)) ||
3173       (x == -1 && y == -1)) {
3174     return;
3175   }
3176
3177   if (priv->mode == HILDON_PANNABLE_AREA_MODE_PUSH)
3178     hildon_pannable_area_jump_to (area, x, y);
3179
3180   width = priv->hadjust->upper - priv->hadjust->lower;
3181   height = priv->vadjust->upper - priv->vadjust->lower;
3182
3183   g_return_if_fail (x < width || y < height);
3184
3185   if ((x > -1)&&(hscroll_visible)) {
3186     priv->scroll_to_x = CLAMP (x - priv->hadjust->page_size/2,
3187                                priv->hadjust->lower,
3188                                priv->hadjust->upper - priv->hadjust->page_size);
3189     dist_x = priv->scroll_to_x - priv->hadjust->value;
3190     if (dist_x == 0) {
3191       priv->scroll_to_x = -1;
3192     } else {
3193       priv->vel_x = - dist_x/priv->vel_factor;
3194     }
3195   } else {
3196     priv->scroll_to_x = -1;
3197   }
3198
3199   if ((y > -1)&&(vscroll_visible)) {
3200     priv->scroll_to_y = CLAMP (y - priv->vadjust->page_size/2,
3201                                priv->vadjust->lower,
3202                                priv->vadjust->upper - priv->vadjust->page_size);
3203     dist_y = priv->scroll_to_y - priv->vadjust->value;
3204     if (dist_y == 0) {
3205       priv->scroll_to_y = -1;
3206     } else {
3207       priv->vel_y = - dist_y/priv->vel_factor;
3208     }
3209   } else {
3210     priv->scroll_to_y = y;
3211   }
3212
3213   if ((priv->scroll_to_y == -1) && (priv->scroll_to_x == -1)) {
3214     return;
3215   }
3216
3217   hildon_pannable_area_launch_fade_timeout (area, 1.0);
3218
3219   if (!priv->idle_id)
3220     priv->idle_id = gdk_threads_add_timeout ((gint) (1000.0 / (gdouble) priv->sps),
3221                                              (GSourceFunc)
3222                                              hildon_pannable_area_timeout, area);
3223 }
3224
3225 /**
3226  * hildon_pannable_area_jump_to:
3227  * @area: A #HildonPannableArea.
3228  * @x: The x coordinate of the destination point or -1 to ignore this axis.
3229  * @y: The y coordinate of the destination point or -1 to ignore this axis.
3230  *
3231  * Jumps the position of @area to ensure that (@x, @y) is a visible
3232  * point in the widget. In order to move in only one coordinate, you
3233  * must set the other one to -1. See hildon_pannable_area_scroll_to()
3234  * function for an example of how to calculate the position of
3235  * children in scrollable widgets like #GtkTreeview.
3236  *
3237  * There is a precondition to this function: the widget must be
3238  * already realized. Check the hildon_pannable_area_jump_to_child() for
3239  * more tips regarding how to call this function during
3240  * initialization.
3241  *
3242  * Since: 2.2
3243  **/
3244 void
3245 hildon_pannable_area_jump_to (HildonPannableArea *area,
3246                               const gint x, const gint y)
3247 {
3248   HildonPannableAreaPrivate *priv;
3249   gint width, height;
3250   gdouble hv, vv;
3251
3252   g_return_if_fail (HILDON_IS_PANNABLE_AREA (area));
3253   g_return_if_fail (GTK_WIDGET_REALIZED (area));
3254   g_return_if_fail (x >= -1 && y >= -1);
3255
3256   if (x == -1 && y == -1) {
3257     return;
3258   }
3259
3260   priv = area->priv;
3261
3262   width = priv->hadjust->upper - priv->hadjust->lower;
3263   height = priv->vadjust->upper - priv->vadjust->lower;
3264
3265   g_return_if_fail (x < width || y < height);
3266
3267   hv = priv->hadjust->value;
3268   vv = priv->vadjust->value;
3269
3270   if (x != -1) {
3271     gdouble jump_to = x - priv->hadjust->page_size/2;
3272
3273     priv->hadjust->value = CLAMP (jump_to,
3274                                   priv->hadjust->lower,
3275                                   priv->hadjust->upper -
3276                                   priv->hadjust->page_size);
3277   }
3278
3279   if (y != -1) {
3280     gdouble jump_to =  y - priv->vadjust->page_size/2;
3281
3282     priv->vadjust->value = CLAMP (jump_to,
3283                                   priv->vadjust->lower,
3284                                   priv->vadjust->upper -
3285                                   priv->vadjust->page_size);
3286   }
3287
3288   if (hv != priv->hadjust->value)
3289     gtk_adjustment_value_changed (priv->hadjust);
3290
3291   if (vv != priv->vadjust->value)
3292     gtk_adjustment_value_changed (priv->vadjust);
3293
3294   priv->scroll_indicator_alpha = 1.0;
3295
3296   if (priv->scroll_indicator_timeout) {
3297     g_source_remove (priv->scroll_indicator_timeout);
3298     priv->scroll_indicator_timeout = 0;
3299   }
3300
3301   if (priv->idle_id) {
3302     priv->vel_x = 0.0;
3303     priv->vel_y = 0.0;
3304     priv->overshooting_x = 0;
3305     priv->overshooting_y = 0;
3306
3307     if ((priv->overshot_dist_x>0)||(priv->overshot_dist_y>0)) {
3308       priv->overshot_dist_x = 0;
3309       priv->overshot_dist_y = 0;
3310
3311       gtk_widget_queue_resize (GTK_WIDGET (area));
3312     }
3313
3314     g_signal_emit (area, pannable_area_signals[PANNING_FINISHED], 0);
3315     g_source_remove (priv->idle_id);
3316     priv->idle_id = 0;
3317   }
3318 }
3319
3320 /**
3321  * hildon_pannable_area_scroll_to_child:
3322  * @area: A #HildonPannableArea.
3323  * @child: A #GtkWidget, descendant of @area.
3324  *
3325  * Smoothly scrolls until @child is visible inside @area. @child must
3326  * be a descendant of @area. If you need to scroll inside a scrollable
3327  * widget, e.g., #GtkTreeview, see hildon_pannable_area_scroll_to().
3328  *
3329  * There is a precondition to this function: the widget must be
3330  * already realized. Check the hildon_pannable_area_jump_to_child() for
3331  * more tips regarding how to call this function during
3332  * initialization.
3333  *
3334  * Since: 2.2
3335  **/
3336 void
3337 hildon_pannable_area_scroll_to_child (HildonPannableArea *area, GtkWidget *child)
3338 {
3339   GtkWidget *bin_child;
3340   gint x, y;
3341
3342   g_return_if_fail (GTK_WIDGET_REALIZED (area));
3343   g_return_if_fail (HILDON_IS_PANNABLE_AREA (area));
3344   g_return_if_fail (GTK_IS_WIDGET (child));
3345   g_return_if_fail (gtk_widget_is_ancestor (child, GTK_WIDGET (area)));
3346
3347   if (GTK_BIN (area)->child == NULL)
3348     return;
3349
3350   /* We need to get to check the child of the inside the area */
3351   bin_child = GTK_BIN (area)->child;
3352
3353   /* we check if we added a viewport */
3354   if (GTK_IS_VIEWPORT (bin_child)) {
3355     bin_child = GTK_BIN (bin_child)->child;
3356   }
3357
3358   if (gtk_widget_translate_coordinates (child, bin_child, 0, 0, &x, &y))
3359     hildon_pannable_area_scroll_to (area, x, y);
3360 }
3361
3362 /**
3363  * hildon_pannable_area_jump_to_child:
3364  * @area: A #HildonPannableArea.
3365  * @child: A #GtkWidget, descendant of @area.
3366  *
3367  * Jumps to make sure @child is visible inside @area. @child must
3368  * be a descendant of @area. If you want to move inside a scrollable
3369  * widget, like, #GtkTreeview, see hildon_pannable_area_scroll_to().
3370  *
3371  * There is a precondition to this function: the widget must be
3372  * already realized. You can control if the widget is ready with the
3373  * GTK_WIDGET_REALIZED macro. If you want to call this function during
3374  * the initialization process of the widget do it inside a callback to
3375  * the ::realize signal, using g_signal_connect_after() function.
3376  *
3377  * Since: 2.2
3378  **/
3379 void
3380 hildon_pannable_area_jump_to_child (HildonPannableArea *area, GtkWidget *child)
3381 {
3382   GtkWidget *bin_child;
3383   gint x, y;
3384
3385   g_return_if_fail (GTK_WIDGET_REALIZED (area));
3386   g_return_if_fail (HILDON_IS_PANNABLE_AREA (area));
3387   g_return_if_fail (GTK_IS_WIDGET (child));
3388   g_return_if_fail (gtk_widget_is_ancestor (child, GTK_WIDGET (area)));
3389
3390   if (gtk_bin_get_child (GTK_BIN (area)) == NULL)
3391     return;
3392
3393   /* We need to get to check the child of the inside the area */
3394   bin_child = gtk_bin_get_child (GTK_BIN (area));
3395
3396   /* we check if we added a viewport */
3397   if (GTK_IS_VIEWPORT (bin_child)) {
3398     bin_child = gtk_bin_get_child (GTK_BIN (bin_child));
3399   }
3400
3401   if (gtk_widget_translate_coordinates (child, bin_child, 0, 0, &x, &y))
3402     hildon_pannable_area_jump_to (area, x, y);
3403 }
3404
3405 /**
3406  * hildon_pannable_get_child_widget_at:
3407  * @area: A #HildonPannableArea.
3408  * @x: horizontal coordinate of the point
3409  * @y: vertical coordinate of the point
3410  *
3411  * Get the widget at the point (x, y) inside the pannable area. In
3412  * case no widget found it returns NULL.
3413  *
3414  * returns: the #GtkWidget if we find a widget, NULL in any other case
3415  *
3416  * Since: 2.2
3417  **/
3418 GtkWidget*
3419 hildon_pannable_get_child_widget_at (HildonPannableArea *area,
3420                                      gdouble x, gdouble y)
3421 {
3422   GdkWindow *window = NULL;
3423   GtkWidget *child_widget = NULL;
3424
3425   window = hildon_pannable_area_get_topmost
3426     (gtk_bin_get_child (GTK_BIN (area))->window,
3427      x, y, NULL, NULL, GDK_ALL_EVENTS_MASK);
3428
3429   gdk_window_get_user_data (window, (gpointer) &child_widget);
3430
3431   return child_widget;
3432 }
3433
3434
3435 /**
3436  * hildon_pannable_area_get_hadjustment:
3437  * @area: A #HildonPannableArea.
3438  *
3439  * Returns the horizontal adjustment. This adjustment is the internal
3440  * widget adjustment used to control the animations. Do not modify it
3441  * directly to change the position of the pannable, to do that use the
3442  * pannable API. If you modify the object directly it could cause
3443  * artifacts in the animations.
3444  *
3445  * returns: The horizontal #GtkAdjustment
3446  *
3447  * Since: 2.2
3448  **/
3449 GtkAdjustment*
3450 hildon_pannable_area_get_hadjustment            (HildonPannableArea *area)
3451 {
3452
3453   g_return_val_if_fail (HILDON_IS_PANNABLE_AREA (area), NULL);
3454
3455   return area->priv->hadjust;
3456 }
3457
3458 /**
3459  * hildon_pannable_area_get_vadjustment:
3460  * @area: A #HildonPannableArea.
3461  *
3462  * Returns the vertical adjustment. This adjustment is the internal
3463  * widget adjustment used to control the animations. Do not modify it
3464  * directly to change the position of the pannable, to do that use the
3465  * pannable API. If you modify the object directly it could cause
3466  * artifacts in the animations.
3467  *
3468  * returns: The vertical #GtkAdjustment
3469  *
3470  * Since: 2.2
3471  **/
3472 GtkAdjustment*
3473 hildon_pannable_area_get_vadjustment            (HildonPannableArea *area)
3474 {
3475   g_return_val_if_fail (HILDON_IS_PANNABLE_AREA (area), NULL);
3476
3477   return area->priv->vadjust;
3478 }
3479
3480
3481 /**
3482  * hildon_pannable_area_get_size_request_policy:
3483  * @area: A #HildonPannableArea.
3484  *
3485  * This function returns the current size request policy of the
3486  * widget. That policy controls the way the size_request is done in
3487  * the pannable area. Check
3488  * hildon_pannable_area_set_size_request_policy() for a more detailed
3489  * explanation.
3490  *
3491  * returns: the policy is currently being used in the widget
3492  * #HildonSizeRequestPolicy.
3493  *
3494  * Since: 2.2
3495  **/
3496 HildonSizeRequestPolicy
3497 hildon_pannable_area_get_size_request_policy (HildonPannableArea *area)
3498 {
3499   HildonPannableAreaPrivate *priv;
3500
3501   g_return_val_if_fail (HILDON_IS_PANNABLE_AREA (area), FALSE);
3502
3503   priv = area->priv;
3504
3505   return priv->size_request_policy;
3506 }
3507
3508 /**
3509  * hildon_pannable_area_set_size_request_policy:
3510  * @area: A #HildonPannableArea.
3511  * @size_request_policy: One of the allowed #HildonSizeRequestPolicy
3512  *
3513  * This function sets the pannable area size request policy. That
3514  * policy controls the way the size_request is done in the pannable
3515  * area. Pannable can use the size request of its children
3516  * (#HILDON_SIZE_REQUEST_CHILDREN) or the minimum size required for
3517  * the area itself (#HILDON_SIZE_REQUEST_MINIMUM), the latter is the
3518  * default. Recall this size depends on the scrolling policy you are
3519  * requesting to the pannable area, if you set #GTK_POLICY_NEVER this
3520  * parameter will not have any effect with
3521  * #HILDON_SIZE_REQUEST_MINIMUM set.
3522  *
3523  * Since: 2.2
3524  *
3525  * Deprecated: This method and the policy request is deprecated, DO
3526  * NOT use it in future code, the only policy properly supported in
3527  * gtk+ nowadays is the minimum size. Use #gtk_window_set_default_size
3528  * or #gtk_window_set_geometry_hints with the proper size in your case
3529  * to define the height of your dialogs.
3530  **/
3531 void
3532 hildon_pannable_area_set_size_request_policy (HildonPannableArea *area,
3533                                               HildonSizeRequestPolicy size_request_policy)
3534 {
3535   HildonPannableAreaPrivate *priv;
3536
3537   g_return_if_fail (HILDON_IS_PANNABLE_AREA (area));
3538
3539   priv = area->priv;
3540
3541   if (priv->size_request_policy == size_request_policy)
3542     return;
3543
3544   priv->size_request_policy = size_request_policy;
3545
3546   gtk_widget_queue_resize (GTK_WIDGET (area));
3547
3548   g_object_notify (G_OBJECT (area), "size-request-policy");
3549 }
3550
3551 /**
3552  * hildon_pannable_area_get_center_on_child_focus
3553  * @area: A #HildonPannableArea
3554  *
3555  * Gets the @area #HildonPannableArea:center-on-child-focus property
3556  * value.
3557  *
3558  * See #HildonPannableArea:center-on-child-focus for more information.
3559  *
3560  * Returns: the @area #HildonPannableArea:center-on-child-focus value
3561  *
3562  * Since: 2.2
3563  **/
3564 gboolean
3565 hildon_pannable_area_get_center_on_child_focus  (HildonPannableArea *area)
3566 {
3567   g_return_val_if_fail (HILDON_IS_PANNABLE_AREA (area), FALSE);
3568
3569   return area->priv->center_on_child_focus;
3570 }
3571
3572 /**
3573  * hildon_pannable_area_set_center_on_child_focus
3574  * @area: A #HildonPannableArea
3575  * @value: the new value
3576  *
3577  * Sets the @area #HildonPannableArea:center-on-child-focus property
3578  * to @value.
3579  *
3580  * See #HildonPannableArea:center-on-child-focus for more information.
3581  *
3582  * Since: 2.2
3583  **/
3584 void
3585 hildon_pannable_area_set_center_on_child_focus  (HildonPannableArea *area,
3586                                                  gboolean value)
3587 {
3588   g_return_if_fail (HILDON_IS_PANNABLE_AREA (area));
3589
3590   area->priv->center_on_child_focus = value;
3591 }