vcs.maemo.org Git - hildon/blob - src/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: Widget representing a text view in the Hildon framework.
  20  *
  21  * The #HildonTextView is a GTK widget which represents a text
  22  * view. It is derived from the #GtkTextView widget and 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 <math.h>
  58
  59 #define HILDON_TEXT_VIEW_DRAG_THRESHOLD 16.0
  60
  61 G_DEFINE_TYPE                                   (HildonTextView, hildon_text_view, GTK_TYPE_TEXT_VIEW);
  62
  63 #define                                         HILDON_TEXT_VIEW_GET_PRIVATE(obj) \
  64                                                 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), \
  65                                                 HILDON_TYPE_TEXT_VIEW, HildonTextViewPrivate));
  66
  67 typedef struct                                  _HildonTextViewPrivate HildonTextViewPrivate;
  68
  69 struct                                          _HildonTextViewPrivate
  70 {
  71     GtkTextBuffer *main_buffer;                   /* Used to show the "real" contents */
  72     GtkTextBuffer *placeholder_buffer;   /* Internal, used to display the placeholder */
  73     gulong changed_id;               /* ID of the main_buffer::changed signal handler */
  74     gdouble x;                                                      /* tap x position */
  75     gdouble y;                                                      /* tap y position */
  76 };
  77
  78 static const gchar *placeholder_widget_name     = "hildon-text-view-placeholder";
  79
  80 /* Function used to decide whether to show the placeholder or not */
  81 static void
  82 hildon_text_view_refresh_contents               (GtkWidget *text_view)
  83 {
  84     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
  85     gint bufsize = gtk_text_buffer_get_char_count (priv->main_buffer);
  86
  87     if ((bufsize > 0) || GTK_WIDGET_HAS_FOCUS (text_view)) {
  88         /* Display the main buffer if it contains text or the widget is focused */
  89         gtk_widget_set_name (text_view, NULL);
  90         gtk_text_view_set_buffer (GTK_TEXT_VIEW (text_view), priv->main_buffer);
  91     } else {
  92         /* Otherwise, display the placeholder */
  93         gtk_widget_set_name (text_view, placeholder_widget_name);
  94         gtk_text_view_set_buffer (GTK_TEXT_VIEW (text_view), priv->placeholder_buffer);
  95     }
  96 }
  97
  98 /**
  99  * hildon_text_view_set_buffer:
 100  * @text_view: a #HildonTextView
 101  * @buffer: a #GtkTextBuffer
 102  *
 103  * Sets @buffer as the buffer being displayed by @text_view. The
 104  * previous buffer displayed by the text view is unreferenced, and a
 105  * reference is added to @buffer. If you owned a reference to @buffer
 106  * before passing it to this function, you must remove that reference
 107  * yourself
 108  *
 109  * Note that you must never use gtk_text_view_set_buffer() to set the
 110  * buffer of a #HildonTextView.
 111  *
 112  * Since: 2.2
 113  */
 114 void
 115 hildon_text_view_set_buffer                     (HildonTextView *text_view,
 116                                                  GtkTextBuffer  *buffer)
 117 {
 118     HildonTextViewPrivate *priv;
 119
 120     g_return_if_fail (HILDON_IS_TEXT_VIEW (text_view));
 121     g_return_if_fail (GTK_IS_TEXT_BUFFER (buffer));
 122
 123     priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
 124
 125     /* If this is the same buffer, don't do anything */
 126     if (buffer == priv->main_buffer)
 127         return;
 128
 129     /* Disconnect the signal handler from the old buffer */
 130     g_signal_handler_disconnect (priv->main_buffer, priv->changed_id);
 131
 132     /* Replace the old buffer with the new one */
 133     g_object_unref (priv->main_buffer);
 134     priv->main_buffer = g_object_ref (buffer);
 135
 136     /* Attach a callback to the new text buffer */
 137     priv->changed_id =
 138         g_signal_connect_swapped (priv->main_buffer, "changed",
 139                                   G_CALLBACK (hildon_text_view_refresh_contents), text_view);
 140
 141     /* Refresh textview contents */
 142     hildon_text_view_refresh_contents (GTK_WIDGET (text_view));
 143 }
 144
 145 /**
 146  * hildon_text_view_get_buffer:
 147  * @text_view: a #HildonTextView
 148  *
 149  * Returns the text buffer in @text_view. The reference count is not
 150  * incremented; the caller of this function won't own a new reference.
 151  *
 152  * Note that you must never use gtk_text_view_get_buffer() to get the
 153  * buffer from a #HildonTextView.
 154  *
 155  * Also note that placeholder text (set using
 156  * hildon_text_view_set_placeholder()) is never contained in this
 157  * buffer.
 158  *
 159  * Returns: a #GtkTextBuffer
 160  *
 161  * Since: 2.2
 162  */
 163 GtkTextBuffer *
 164 hildon_text_view_get_buffer                     (HildonTextView *text_view)
 165 {
 166     HildonTextViewPrivate *priv;
 167
 168     g_return_val_if_fail (HILDON_IS_TEXT_VIEW (text_view), NULL);
 169
 170     priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
 171
 172     /* Always return priv->main_buffer even if the placeholder is
 173      * being displayed */
 174     return priv->main_buffer;
 175 }
 176
 177 /**
 178  * hildon_text_view_set_placeholder:
 179  * @text_view: a #HildonTextView
 180  * @text: the new text
 181  *
 182  * Sets the placeholder text in @text_view to @text.
 183  *
 184  * Since: 2.2
 185  */
 186 void
 187 hildon_text_view_set_placeholder                (HildonTextView *text_view,
 188                                                  const gchar    *text)
 189 {
 190     HildonTextViewPrivate *priv;
 191
 192     g_return_if_fail (HILDON_IS_TEXT_VIEW (text_view) && text != NULL);
 193
 194     priv = HILDON_TEXT_VIEW_GET_PRIVATE (text_view);
 195
 196     gtk_text_buffer_set_text (priv->placeholder_buffer, text, -1);
 197 }
 198
 199 /**
 200  * hildon_text_view_new:
 201  *
 202  * Creates a new text view.
 203  *
 204  * Returns: a new #HildonTextView
 205  *
 206  * Since: 2.2
 207  */
 208 GtkWidget *
 209 hildon_text_view_new                            (void)
 210 {
 211     GtkWidget *entry = g_object_new (HILDON_TYPE_TEXT_VIEW, NULL);
 212
 213     return entry;
 214 }
 215
 216 static gboolean
 217 hildon_text_view_focus_in_event                 (GtkWidget     *widget,
 218                                                  GdkEventFocus *event)
 219 {
 220     hildon_text_view_refresh_contents (widget);
 221
 222     if (GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_in_event) {
 223         return GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_in_event (widget, event);
 224     } else {
 225         return FALSE;
 226     }
 227 }
 228
 229 static gboolean
 230 hildon_text_view_focus_out_event                (GtkWidget     *widget,
 231                                                  GdkEventFocus *event)
 232 {
 233     hildon_text_view_refresh_contents (widget);
 234
 235     if (GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_out_event) {
 236         return GTK_WIDGET_CLASS (hildon_text_view_parent_class)->focus_out_event (widget, event);
 237     } else {
 238         return FALSE;
 239     }
 240 }
 241
 242 static gint
 243 hildon_text_view_button_press_event             (GtkWidget        *widget,
 244                                                  GdkEventButton   *event)
 245 {
 246     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (widget);
 247
 248     if (GTK_TEXT_VIEW (widget)->editable &&
 249         hildon_gtk_im_context_filter_event (GTK_TEXT_VIEW (widget)->im_context, (GdkEvent*)event)) {
 250         GTK_TEXT_VIEW (widget)->need_im_reset = TRUE;
 251         return TRUE;
 252     }
 253
 254     if (event->button == 1 && event->type == GDK_BUTTON_PRESS) {
 255         priv->x = event->x;
 256         priv->y = event->y;
 257
 258         return TRUE;
 259     }
 260
 261     return FALSE;
 262 }
 263
 264 static gint
 265 hildon_text_view_button_release_event           (GtkWidget        *widget,
 266                                                  GdkEventButton   *event)
 267 {
 268     GtkTextView *text_view = GTK_TEXT_VIEW (widget);
 269     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (widget);
 270     GtkTextIter iter;
 271     gint x, y;
 272
 273     if (text_view->editable &&
 274         hildon_gtk_im_context_filter_event (text_view->im_context, (GdkEvent*)event)) {
 275         text_view->need_im_reset = TRUE;
 276         return TRUE;
 277     }
 278
 279     if (event->button == 1 && event->type == GDK_BUTTON_RELEASE) {
 280         if (fabs (priv->x - event->x) < HILDON_TEXT_VIEW_DRAG_THRESHOLD &&
 281             fabs (priv->y - event->y) < HILDON_TEXT_VIEW_DRAG_THRESHOLD) {
 282             GtkTextWindowType window_type;
 283
 284             window_type = gtk_text_view_get_window_type (text_view, event->window);
 285             gtk_text_view_window_to_buffer_coords (text_view,
 286                                                    window_type,
 287                                                    event->x, event->y,
 288                                                    &x, &y);
 289             gtk_text_view_get_iter_at_location (text_view, &iter, x, y);
 290             if (gtk_text_buffer_get_char_count (priv->main_buffer))
 291                 gtk_text_buffer_place_cursor (priv->main_buffer, &iter);
 292
 293             gtk_widget_grab_focus (GTK_WIDGET (text_view));
 294
 295             return TRUE;
 296         }
 297     }
 298     return FALSE;
 299 }
 300
 301 static void
 302 hildon_text_view_finalize                       (GObject *object)
 303 {
 304     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (object);
 305
 306     g_signal_handler_disconnect (priv->main_buffer, priv->changed_id);
 307     g_object_unref (priv->main_buffer);
 308     g_object_unref (priv->placeholder_buffer);
 309
 310     if (G_OBJECT_CLASS (hildon_text_view_parent_class)->finalize)
 311         G_OBJECT_CLASS (hildon_text_view_parent_class)->finalize (object);
 312 }
 313
 314 static void
 315 hildon_text_view_class_init                     (HildonTextViewClass *klass)
 316 {
 317     GObjectClass *gobject_class = (GObjectClass *)klass;
 318     GtkWidgetClass *widget_class = (GtkWidgetClass *)klass;
 319
 320     gobject_class->finalize = hildon_text_view_finalize;
 321     widget_class->focus_in_event = hildon_text_view_focus_in_event;
 322     widget_class->focus_out_event = hildon_text_view_focus_out_event;
 323     widget_class->motion_notify_event = NULL;
 324     widget_class->button_press_event = hildon_text_view_button_press_event;
 325     widget_class->button_release_event = hildon_text_view_button_release_event;
 326
 327     g_type_class_add_private (klass, sizeof (HildonTextViewPrivate));
 328 }
 329
 330 static void
 331 hildon_text_view_init                           (HildonTextView *self)
 332 {
 333     HildonTextViewPrivate *priv = HILDON_TEXT_VIEW_GET_PRIVATE (self);
 334
 335     priv->main_buffer = gtk_text_buffer_new (NULL);
 336     priv->placeholder_buffer = gtk_text_buffer_new (NULL);
 337
 338     hildon_text_view_refresh_contents (GTK_WIDGET (self));
 339
 340     priv->changed_id =
 341         g_signal_connect_swapped (priv->main_buffer, "changed",
 342                                   G_CALLBACK (hildon_text_view_refresh_contents), self);
 343 }