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