vcs.maemo.org Git - hildon/blob - hildon/hildon-text-view.c

   1 /*
   2  * This file is a part of hildon
   3  *
   4  * Copyright (C) 2008 Nokia Corporation, all rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU Lesser Public License as published by
   8  * the Free Software Foundation; version 2 of the license.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU Lesser Public License for more details.
  14  *
  15  */
  16
  17 /**
  18  * SECTION:hildon-text-view
  19  * @short_description: Text view within the Hildon framework.
  20  *
  21  * The #HildonTextView is a text
  22  * view derived from the #GtkTextView widget that provides
  23  * additional commodities specific to the Hildon framework.
  24  *
  25  * Besides all the features inherited from #GtkTextView, a
  26  * #HildonTextView can also have a placeholder text. This text will be
  27  * shown if the text view is empty and doesn't have the input focus,
  28  * but it's otherwise ignored. Thus, calls to
  29  * hildon_text_view_get_buffer() will never return the placeholder
  30  * text, not even when it's being displayed.
  31  *
  32  * Although #HildonTextView is derived from #GtkTextView,
  33  * gtk_text_view_get_buffer() and gtk_text_view_set_buffer() must
  34  * never be used to get/set the buffer in this
  35  * widget. hildon_text_view_get_buffer() and
  36  * hildon_text_view_set_buffer() must be used instead.
  37  *
  38  * <example>
  39  * <title>Creating a HildonTextView with a placeholder</title>
  40  * <programlisting>
  41  * GtkWidget *
  42  * create_text_view (void)
  43  * {
  44  *     GtkWidget *text_view;
  45  * <!-- -->
  46  *     text_view = hildon_text_view_new ();
  47  *     hildon_text_view_set_placeholder (HILDON_TEXT_VIEW (text_view),
  48  *                                       "Type some text here");
  49  * <!-- -->
  50  *     return text_view;
  51  * }
  52  * </programlisting>
  53  * </example>
  54  */
  55
  56 #include                                        "hildon-text-view.h"
  57 #include                                        "hildon-helper.h"
  58 #include <math.h>
  59
  60 #define HILDON_TEXT_VIEW_DRAG_THRESHOLD 16.0
  61
  62 G_DEFINE_TYPE                                   (HildonTextView, hildon_text_view, GTK_TYPE_TEXT_VIEW);
  63
  64 #define                                         HILDON_TEXT_VIEW_GET_PRIVATE(obj) \
  65                                                 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), \
  66                                                 HILDON_TYPE_TEXT_VIEW, HildonTextViewPrivate));
  67
  68 typedef struct                                  _HildonTextViewPrivate HildonTextViewPrivate;
  69
  70 struct                                          _HildonTextViewPrivate
  71 {
  72     GtkTextBuffer *main_buffer;                   /* Used to show the "real" contents */
  73     GtkTextBuffer *placeholder_buffer;   /* Internal, used to display the placeholder */
  74     gulong changed_id;               /* ID of the main_buffer::changed signal handler */
  75     gdouble x;                                                      /* tap x position */
  76     gdouble y;                                                      /* tap y position */
  77 };
  78
  79 /* Function used to decide whether to show the placeholder or not */
  80 static void
  81 hildon_text_view_refresh_contents               (GtkWidget *text_view)
  82 {
  83     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
  84     gint bufsize = gtk_text_buffer_get_char_count (priv->main_buffer);
  85
  86     if ((bufsize > 0) || GTK_WIDGET_HAS_FOCUS (text_view)) {
  87         /* Display the main buffer if it contains text or the widget is focused */
  88         hildon_helper_set_logical_color (text_view, GTK_RC_TEXT, GTK_STATE_NORMAL, "ReversedTextColor");
  89         gtk_text_view_set_buffer (GTK_TEXT_VIEW (text_view), priv->main_buffer);
  90     } else {
  91         /* Otherwise, display the placeholder */
  92         hildon_helper_set_logical_color (text_view, GTK_RC_TEXT, GTK_STATE_NORMAL, "ReversedSecondaryTextColor");
  93         gtk_text_view_set_buffer (GTK_TEXT_VIEW (text_view), priv->placeholder_buffer);
  94     }
  95 }
  96
  97 /**
  98  * hildon_text_view_set_buffer:
  99  * @text_view: a #HildonTextView
 100  * @buffer: a #GtkTextBuffer
 101  *
 102  * Sets @buffer as the buffer being displayed by @text_view. The
 103  * previous buffer displayed by the text view is unreferenced, and a
 104  * reference is added to @buffer. If you owned a reference to @buffer
 105  * before passing it to this function, you must remove that reference
 106  * yourself
 107  *
 108  * Note that you must never use gtk_text_view_set_buffer() to set the
 109  * buffer of a #HildonTextView.
 110  *
 111  * Since: 2.2
 112  */
 113 void
 114 hildon_text_view_set_buffer                     (HildonTextView *text_view,
 115                                                  GtkTextBuffer  *buffer)
 116 {
 117     HildonTextViewPrivate *priv;
 118
 119     g_return_if_fail (HILDON_IS_TEXT_VIEW (text_view));
 120     g_return_if_fail (GTK_IS_TEXT_BUFFER (buffer));
 121
 122     priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
 123
 124     /* If this is the same buffer, don't do anything */
 125     if (buffer == priv->main_buffer)
 126         return;
 127
 128     /* Disconnect the signal handler from the old buffer */
 129     g_signal_handler_disconnect (priv->main_buffer, priv->changed_id);
 130
 131     /* Replace the old buffer with the new one */
 132     g_object_unref (priv->main_buffer);
 133     priv->main_buffer = g_object_ref (buffer);
 134
 135     /* Attach a callback to the new text buffer */
 136     priv->changed_id =
 137         g_signal_connect_swapped (priv->main_buffer, "changed",
 138                                   G_CALLBACK (hildon_text_view_refresh_contents), text_view);
 139
 140     /* Refresh textview contents */
 141     hildon_text_view_refresh_contents (GTK_WIDGET (text_view));
 142 }
 143
 144 /**
 145  * hildon_text_view_get_buffer:
 146  * @text_view: a #HildonTextView
 147  *
 148  * Returns the text buffer in @text_view. The reference count is not
 149  * incremented; the caller of this function won't own a new reference.
 150  *
 151  * Note that you must never use gtk_text_view_get_buffer() to get the
 152  * buffer from a #HildonTextView.
 153  *
 154  * Also note that placeholder text (set using
 155  * hildon_text_view_set_placeholder()) is never contained in this
 156  * buffer.
 157  *
 158  * Returns: a #GtkTextBuffer
 159  *
 160  * Since: 2.2
 161  */
 162 GtkTextBuffer *
 163 hildon_text_view_get_buffer                     (HildonTextView *text_view)
 164 {
 165     HildonTextViewPrivate *priv;
 166
 167     g_return_val_if_fail (HILDON_IS_TEXT_VIEW (text_view), NULL);
 168
 169     priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
 170
 171     /* Always return priv->main_buffer even if the placeholder is
 172      * being displayed */
 173     return priv->main_buffer;
 174 }
 175
 176 /**
 177  * hildon_text_view_set_placeholder:
 178  * @text_view: a #HildonTextView
 179  * @text: the new text
 180  *
 181  * Sets the placeholder text in @text_view to @text.
 182  *
 183  * Since: 2.2
 184  */
 185 void
 186 hildon_text_view_set_placeholder                (HildonTextView *text_view,
 187                                                  const gchar    *text)
 188 {
 189     HildonTextViewPrivate *priv;
 190
 191     g_return_if_fail (HILDON_IS_TEXT_VIEW (text_view) && text != NULL);
 192
 193     priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
 194
 195     gtk_text_buffer_set_text (priv->placeholder_buffer, text, -1);
 196 }
 197
 198 /**
 199  * hildon_text_view_new:
 200  *
 201  * Creates a new text view.
 202  *
 203  * Returns: a new #HildonTextView
 204  *
 205  * Since: 2.2
 206  */
 207 GtkWidget *
 208 hildon_text_view_new                            (void)
 209 {
 210     GtkWidget *entry = g_object_new (HILDON_TYPE_TEXT_VIEW, NULL);
 211
 212     return entry;
 213 }
 214
 215 static gboolean
 216 hildon_text_view_focus_in_event                 (GtkWidget     *widget,
 217                                                  GdkEventFocus *event)
 218 {
 219     hildon_text_view_refresh_contents (widget);
 220
 221     if (GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_in_event) {
 222         return GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_in_event (widget, event);
 223     } else {
 224         return FALSE;
 225     }
 226 }
 227
 228 static gboolean
 229 hildon_text_view_focus_out_event                (GtkWidget     *widget,
 230                                                  GdkEventFocus *event)
 231 {
 232     hildon_text_view_refresh_contents (widget);
 233
 234     if (GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_out_event) {
 235         return GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_out_event (widget, event);
 236     } else {
 237         return FALSE;
 238     }
 239 }
 240
 241 static gint
 242 hildon_text_view_button_press_event             (GtkWidget        *widget,
 243                                                  GdkEventButton   *event)
 244 {
 245     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (widget);
 246
 247     gtk_widget_grab_focus (widget);
 248
 249     if (GTK_TEXT_VIEW (widget)->editable &&
 250         hildon_gtk_im_context_filter_event (GTK_TEXT_VIEW (widget)->im_context, (GdkEvent*)event)) {
 251         GTK_TEXT_VIEW (widget)->need_im_reset = TRUE;
 252         return TRUE;
 253     }
 254
 255     if (event->button == 1 && event->type == GDK_BUTTON_PRESS) {
 256         priv->x = event->x;
 257         priv->y = event->y;
 258
 259         return TRUE;
 260     }
 261
 262     return FALSE;
 263 }
 264
 265 static gint
 266 hildon_text_view_button_release_event           (GtkWidget        *widget,
 267                                                  GdkEventButton   *event)
 268 {
 269     GtkTextView *text_view = GTK_TEXT_VIEW (widget);
 270     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (widget);
 271     GtkTextIter iter;
 272     gint x, y;
 273
 274     if (text_view->editable &&
 275         hildon_gtk_im_context_filter_event (text_view->im_context, (GdkEvent*)event)) {
 276         text_view->need_im_reset = TRUE;
 277         return TRUE;
 278     }
 279
 280     if (event->button == 1 && event->type == GDK_BUTTON_RELEASE) {
 281         if (fabs (priv->x - event->x) < HILDON_TEXT_VIEW_DRAG_THRESHOLD &&
 282             fabs (priv->y - event->y) < HILDON_TEXT_VIEW_DRAG_THRESHOLD) {
 283             GtkTextWindowType window_type;
 284
 285             window_type = gtk_text_view_get_window_type (text_view, event->window);
 286             gtk_text_view_window_to_buffer_coords (text_view,
 287                                                    window_type,
 288                                                    event->x, event->y,
 289                                                    &x, &y);
 290             gtk_text_view_get_iter_at_location (text_view, &iter, x, y);
 291             if (gtk_text_buffer_get_char_count (priv->main_buffer))
 292                 gtk_text_buffer_place_cursor (priv->main_buffer, &iter);
 293
 294             gtk_widget_grab_focus (GTK_WIDGET (text_view));
 295
 296             return TRUE;
 297         }
 298     }
 299     return FALSE;
 300 }
 301
 302 static void
 303 hildon_text_view_finalize                       (GObject *object)
 304 {
 305     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (object);
 306
 307     g_signal_handler_disconnect (priv->main_buffer, priv->changed_id);
 308     g_object_unref (priv->main_buffer);
 309     g_object_unref (priv->placeholder_buffer);
 310
 311     if (G_OBJECT_CLASS (hildon_text_view_parent_class)->finalize)
 312         G_OBJECT_CLASS (hildon_text_view_parent_class)->finalize (object);
 313 }
 314
 315 static void
 316 hildon_text_view_class_init                     (HildonTextViewClass *klass)
 317 {
 318     GObjectClass *gobject_class = (GObjectClass *)klass;
 319     GtkWidgetClass *widget_class = (GtkWidgetClass *)klass;
 320
 321     gobject_class->finalize = hildon_text_view_finalize;
 322     widget_class->focus_in_event = hildon_text_view_focus_in_event;
 323     widget_class->focus_out_event = hildon_text_view_focus_out_event;
 324     widget_class->motion_notify_event = NULL;
 325     widget_class->button_press_event = hildon_text_view_button_press_event;
 326     widget_class->button_release_event = hildon_text_view_button_release_event;
 327
 328     g_type_class_add_private (klass, sizeof (HildonTextViewPrivate));
 329 }
 330
 331 static void
 332 hildon_text_view_init                           (HildonTextView *self)
 333 {
 334     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (self);
 335
 336     priv->main_buffer = gtk_text_buffer_new (NULL);
 337     priv->placeholder_buffer = gtk_text_buffer_new (NULL);
 338
 339     hildon_text_view_refresh_contents (GTK_WIDGET (self));
 340
 341     priv->changed_id =
 342         g_signal_connect_swapped (priv->main_buffer, "changed",
 343                                   G_CALLBACK (hildon_text_view_refresh_contents), self);
 344 }