vcs.maemo.org Git - hildon/blob - hildon-widgets/hildon-scroll-area.c

   1 /*
   2  * This file is part of hildon-libs
   3  *
   4  * Copyright (C) 2005, 2006 Nokia Corporation, all rights reserved.
   5  *
   6  * Contact: Michael Dominic Kostrzewa <michael.kostrzewa@nokia.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; version 2.1 of
  11  * the License.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  *
  23  */
  24
  25 /**
  26  * SECTION:hildon-scroll-area
  27  * @short_description: A helper to create Maemo specific views,
  28  * which are using scrollable area
  29  *
  30  * #GtkScrollArea combines a large widget that needs scrolling (like a
  31  * text editor or a tree view) and other widgets that wouldn't fit one
  32  * the screen normally without scrolling (like entries, toolbars etc.)
  33  * into one scrollable area.
  34  */
  35
  36 #include "hildon-scroll-area.h"
  37 #include <gtk/gtkscrolledwindow.h>
  38 #include <gtk/gtkfixed.h>
  39 #include <gtk/gtkadjustment.h>
  40 #include <gtk/gtkwidget.h>
  41 #include <string.h>
  42
  43 typedef struct
  44   {
  45     GtkWidget *fixed;
  46
  47     /* Scrolled windows */
  48     GtkWidget *swouter;
  49     GtkWidget *swinner;
  50
  51     /* Widget that's being contained */
  52     GtkWidget *child;
  53
  54     /* Vertical adjustment for scrolled windows */
  55     GtkAdjustment *outadj;
  56     GtkAdjustment *inadj;
  57
  58   } HildonScrollArea;
  59
  60
  61 static void hildon_scroll_area_outer_value_changed (GtkAdjustment *adjustment,
  62                                                     HildonScrollArea *sc);
  63 static void hildon_scroll_area_inner_value_changed (GtkAdjustment *adjustment,
  64                                                     HildonScrollArea *sc);
  65 static void hildon_scroll_area_size_allocate (GtkWidget *widget,
  66                                               GtkAllocation *allocation,
  67                                               HildonScrollArea *sc);
  68 static void hildon_scroll_area_child_requisition (GtkWidget *widget,
  69                                                   GtkRequisition *req,
  70                                                   HildonScrollArea *sc);
  71 static void hildon_scroll_area_fixed_allocate (GtkWidget *widget,
  72                                                GtkAllocation *allocation,
  73                                                HildonScrollArea *sc);
  74
  75 /**
  76  * hildon_scroll_area_new:
  77  * @sw: #GtkWidget - #GtkScrolledWindow
  78  * @child: #GtkWidget - child to be place inside the sw
  79  *
  80  * This is not a widget. It's a helper function to create
  81  * hildon-specific scrolling methods.
  82  * A common situation where the scroll area should be used
  83  * might be following.  A view containing @GtkTreeView based widget,
  84  * (or any similar widget which has built-in @GtkScrolledWindow support)
  85  * and eg. couple buttons.  Normaly @GtkScrolledWindow can not handle
  86  * the situation so that the @GtkTreeView built-in support
  87  * would work.  The scroll area is connecting this built-in system to
  88  * the scrolled window and also noticing the buttons.  To use, one should
  89  * create a box to which pack the buttons and the scroll area.
  90  * The scroll area then contains the problematic widget eg. the @GtkTreeView.
  91  * Then the box should be placed in the @GtkScrolledWindow.
  92  * The function is currently assuming that the newly created scroll area
  93  * hierarchy is not modified in anyway.  Or if it is, it may lead to
  94  * unwanted problems.  Also assumed, that the @child will be packed
  95  * to the @sw.
  96  *
  97  * Returns: a @GtkFixed
  98  */
  99 GtkWidget *hildon_scroll_area_new (GtkWidget *sw, GtkWidget *child)
 100 {
 101   GtkWidget *swi;
 102   GtkWidget *fixed;
 103   HildonScrollArea *sc;
 104
 105   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (sw)
 106                         && GTK_IS_WIDGET (child), NULL);
 107
 108   swi = gtk_scrolled_window_new (NULL, NULL);
 109   fixed = gtk_fixed_new ();
 110   sc = g_malloc (sizeof (HildonScrollArea));
 111   memset (sc, 0, sizeof (HildonScrollArea));
 112
 113   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swi),
 114                                   GTK_POLICY_NEVER, GTK_POLICY_NEVER);
 115
 116   gtk_container_add (GTK_CONTAINER (swi), child);
 117   gtk_fixed_put (GTK_FIXED (fixed), swi, 0, 0);
 118
 119   sc->fixed = fixed;
 120   sc->swouter = sw;
 121   sc->swinner = swi;
 122   sc->child = child;
 123   sc->outadj = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (sw));
 124   sc->inadj = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (swi));
 125
 126   g_signal_connect_after (G_OBJECT (child), "size-request",
 127                           G_CALLBACK (hildon_scroll_area_child_requisition), sc);
 128
 129   g_signal_connect_after (G_OBJECT (sc->outadj), "value_changed",
 130                           G_CALLBACK (hildon_scroll_area_outer_value_changed), sc);
 131   g_signal_connect_after (G_OBJECT (sc->inadj), "value_changed",
 132                           G_CALLBACK (hildon_scroll_area_inner_value_changed), sc);
 133
 134   g_signal_connect_after (G_OBJECT (sw), "size-allocate",
 135                           G_CALLBACK (hildon_scroll_area_size_allocate), sc);
 136   g_signal_connect (G_OBJECT (sc->fixed), "size-allocate",
 137                     G_CALLBACK (hildon_scroll_area_fixed_allocate), sc);
 138   g_signal_connect_swapped (G_OBJECT (sw), "destroy",
 139                     G_CALLBACK (g_free), sc);
 140
 141   gtk_widget_show_all (sw);
 142   return fixed;
 143 }
 144
 145 static void hildon_scroll_area_fixed_allocate (GtkWidget *widget,
 146                                                GtkAllocation *allocation,
 147                                                HildonScrollArea *sc)
 148 {
 149   gtk_widget_set_size_request (sc->swinner, -1,
 150                                MIN (sc->outadj->page_size, allocation->height));
 151 }
 152
 153 static void hildon_scroll_area_child_requisition (GtkWidget *widget,
 154                                                   GtkRequisition *req,
 155                                                   HildonScrollArea *sc)
 156 {
 157   /* Limit height to fixed height */
 158   gint new_req = MAX (req->height, sc->fixed->allocation.height);
 159   gtk_widget_set_size_request (sc->fixed, -1, req->height);
 160   /* Request inner scrolled window at most page size */
 161   gtk_widget_set_size_request (sc->swinner, -1,
 162                                MIN (sc->outadj->page_size, new_req));
 163 }
 164
 165 static void hildon_scroll_area_outer_value_changed (GtkAdjustment *adjustment,
 166                                                     HildonScrollArea *sc)
 167 {
 168   GtkRequisition req;
 169   gtk_widget_size_request (sc->child, &req);
 170
 171   /* Update inner adjustment position based on outer one, update fixed position */
 172   if ((sc->outadj->value + sc->outadj->page_size) > sc->fixed->allocation.y
 173       && sc->outadj->value < (sc->fixed->allocation.y + req.height))
 174     {
 175       gdouble new_pos = 0;
 176
 177       new_pos = MAX (sc->outadj->value - sc->fixed->allocation.y, 0);
 178       new_pos = MIN (new_pos, req.height - sc->inadj->page_size);
 179       new_pos = MAX (new_pos, 0);
 180
 181       gtk_fixed_move (GTK_FIXED (sc->fixed), sc->swinner, 0, new_pos);
 182       gtk_adjustment_set_value (sc->inadj, new_pos);
 183     }
 184 }
 185
 186 static void hildon_scroll_area_inner_value_changed (GtkAdjustment *adjustment,
 187                                                     HildonScrollArea *sc)
 188 {
 189   /* Update outer adjustment based on inner adjustment position */
 190   if (sc->outadj->value != sc->fixed->allocation.y + adjustment->value)
 191     gtk_adjustment_set_value (sc->outadj,
 192                               sc->fixed->allocation.y + adjustment->value);
 193 }
 194
 195 __inline__ static gint calculate_width (HildonScrollArea *sc)
 196 {
 197   GtkScrolledWindow *scwin = GTK_SCROLLED_WINDOW (sc->swouter);
 198   return (scwin->hscrollbar_visible * scwin->hscrollbar->allocation.width);
 199 }
 200
 201 static void hildon_scroll_area_size_allocate (GtkWidget *widget,
 202                                               GtkAllocation *allocation,
 203                                               HildonScrollArea *sc)
 204 {
 205   gtk_widget_set_size_request (sc->fixed, calculate_width (sc), sc->fixed->allocation.height);
 206   gtk_widget_set_size_request (sc->child, sc->fixed->allocation.width, -1);
 207 }