This file is indexed.

/usr/share/gtk-2.0/demo/hypertext.c is in gtk2.0-examples 2.24.23-0ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
/* Text Widget/Hypertext
 *
 * Usually, tags modify the appearance of text in the view, e.g. making it 
 * bold or colored or underlined. But tags are not restricted to appearance. 
 * They can also affect the behavior of mouse and key presses, as this demo 
 * shows.
 */

#include <gtk/gtk.h>
#include <gdk/gdkkeysyms.h>

/* Inserts a piece of text into the buffer, giving it the usual
 * appearance of a hyperlink in a web browser: blue and underlined.
 * Additionally, attaches some data on the tag, to make it recognizable
 * as a link. 
 */
static void 
insert_link (GtkTextBuffer *buffer, 
             GtkTextIter   *iter, 
             gchar         *text, 
             gint           page)
{
  GtkTextTag *tag;
  
  tag = gtk_text_buffer_create_tag (buffer, NULL, 
                                    "foreground", "blue", 
                                    "underline", PANGO_UNDERLINE_SINGLE, 
                                    NULL);
  g_object_set_data (G_OBJECT (tag), "page", GINT_TO_POINTER (page));
  gtk_text_buffer_insert_with_tags (buffer, iter, text, -1, tag, NULL);
}

/* Fills the buffer with text and interspersed links. In any real
 * hypertext app, this method would parse a file to identify the links.
 */
static void
show_page (GtkTextBuffer *buffer, 
           gint           page)
{
  GtkTextIter iter;

  gtk_text_buffer_set_text (buffer, "", 0);
  gtk_text_buffer_get_iter_at_offset (buffer, &iter, 0);
  if (page == 1)
    {
      gtk_text_buffer_insert (buffer, &iter, "Some text to show that simple ", -1);
      insert_link (buffer, &iter, "hypertext", 3);
      gtk_text_buffer_insert (buffer, &iter, " can easily be realized with ", -1);
      insert_link (buffer, &iter, "tags", 2);
      gtk_text_buffer_insert (buffer, &iter, ".", -1);
    }
  else if (page == 2)
    {
      gtk_text_buffer_insert (buffer, &iter, 
                              "A tag is an attribute that can be applied to some range of text. "
                              "For example, a tag might be called \"bold\" and make the text inside "
                              "the tag bold. However, the tag concept is more general than that; "
                              "tags don't have to affect appearance. They can instead affect the "
                              "behavior of mouse and key presses, \"lock\" a range of text so the "
                              "user can't edit it, or countless other things.\n", -1);
      insert_link (buffer, &iter, "Go back", 1);
    }
  else if (page == 3) 
    {
      GtkTextTag *tag;
  
      tag = gtk_text_buffer_create_tag (buffer, NULL, 
                                        "weight", PANGO_WEIGHT_BOLD, 
                                        NULL);
      gtk_text_buffer_insert_with_tags (buffer, &iter, "hypertext:\n", -1, tag, NULL);
      gtk_text_buffer_insert (buffer, &iter, 
                              "machine-readable text that is not sequential but is organized "
                              "so that related items of information are connected.\n", -1);
      insert_link (buffer, &iter, "Go back", 1);
    }
}

/* Looks at all tags covering the position of iter in the text view, 
 * and if one of them is a link, follow it by showing the page identified
 * by the data attached to it.
 */
static void
follow_if_link (GtkWidget   *text_view, 
                GtkTextIter *iter)
{
  GSList *tags = NULL, *tagp = NULL;

  tags = gtk_text_iter_get_tags (iter);
  for (tagp = tags;  tagp != NULL;  tagp = tagp->next)
    {
      GtkTextTag *tag = tagp->data;
      gint page = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (tag), "page"));

      if (page != 0)
        {
          show_page (gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view)), page);
          break;
        }
    }

  if (tags) 
    g_slist_free (tags);
}

/* Links can be activated by pressing Enter.
 */
static gboolean
key_press_event (GtkWidget *text_view,
                 GdkEventKey *event)
{
  GtkTextIter iter;
  GtkTextBuffer *buffer;

  switch (event->keyval)
    {
      case GDK_Return: 
      case GDK_KP_Enter:
        buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view));
        gtk_text_buffer_get_iter_at_mark (buffer, &iter, 
                                          gtk_text_buffer_get_insert (buffer));
        follow_if_link (text_view, &iter);
        break;

      default:
        break;
    }

  return FALSE;
}

/* Links can also be activated by clicking.
 */
static gboolean
event_after (GtkWidget *text_view,
             GdkEvent  *ev)
{
  GtkTextIter start, end, iter;
  GtkTextBuffer *buffer;
  GdkEventButton *event;
  gint x, y;

  if (ev->type != GDK_BUTTON_RELEASE)
    return FALSE;

  event = (GdkEventButton *)ev;

  if (event->button != 1)
    return FALSE;

  buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view));

  /* we shouldn't follow a link if the user has selected something */
  gtk_text_buffer_get_selection_bounds (buffer, &start, &end);
  if (gtk_text_iter_get_offset (&start) != gtk_text_iter_get_offset (&end))
    return FALSE;

  gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (text_view), 
                                         GTK_TEXT_WINDOW_WIDGET,
                                         event->x, event->y, &x, &y);

  gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (text_view), &iter, x, y);

  follow_if_link (text_view, &iter);

  return FALSE;
}

static gboolean hovering_over_link = FALSE;
static GdkCursor *hand_cursor = NULL;
static GdkCursor *regular_cursor = NULL;

/* Looks at all tags covering the position (x, y) in the text view, 
 * and if one of them is a link, change the cursor to the "hands" cursor
 * typically used by web browsers.
 */
static void
set_cursor_if_appropriate (GtkTextView    *text_view,
                           gint            x,
                           gint            y)
{
  GSList *tags = NULL, *tagp = NULL;
  GtkTextIter iter;
  gboolean hovering = FALSE;

  gtk_text_view_get_iter_at_location (text_view, &iter, x, y);
  
  tags = gtk_text_iter_get_tags (&iter);
  for (tagp = tags;  tagp != NULL;  tagp = tagp->next)
    {
      GtkTextTag *tag = tagp->data;
      gint page = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (tag), "page"));

      if (page != 0) 
        {
          hovering = TRUE;
          break;
        }
    }

  if (hovering != hovering_over_link)
    {
      hovering_over_link = hovering;

      if (hovering_over_link)
        gdk_window_set_cursor (gtk_text_view_get_window (text_view, GTK_TEXT_WINDOW_TEXT), hand_cursor);
      else
        gdk_window_set_cursor (gtk_text_view_get_window (text_view, GTK_TEXT_WINDOW_TEXT), regular_cursor);
    }

  if (tags) 
    g_slist_free (tags);
}

/* Update the cursor image if the pointer moved. 
 */
static gboolean
motion_notify_event (GtkWidget      *text_view,
                     GdkEventMotion *event)
{
  gint x, y;

  gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (text_view), 
                                         GTK_TEXT_WINDOW_WIDGET,
                                         event->x, event->y, &x, &y);

  set_cursor_if_appropriate (GTK_TEXT_VIEW (text_view), x, y);

  gdk_window_get_pointer (gtk_widget_get_window (text_view), NULL, NULL, NULL);
  return FALSE;
}

/* Also update the cursor image if the window becomes visible
 * (e.g. when a window covering it got iconified).
 */
static gboolean
visibility_notify_event (GtkWidget          *text_view,
                         GdkEventVisibility *event)
{
  gint wx, wy, bx, by;
  
  gdk_window_get_pointer (gtk_widget_get_window (text_view), &wx, &wy, NULL);
  
  gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (text_view), 
                                         GTK_TEXT_WINDOW_WIDGET,
                                         wx, wy, &bx, &by);

  set_cursor_if_appropriate (GTK_TEXT_VIEW (text_view), bx, by);

  return FALSE;
}

GtkWidget *
do_hypertext (GtkWidget *do_widget)
{
  static GtkWidget *window = NULL;

  if (!window)
    {
      GtkWidget *view;
      GtkWidget *sw;
      GtkTextBuffer *buffer;

      hand_cursor = gdk_cursor_new (GDK_HAND2);
      regular_cursor = gdk_cursor_new (GDK_XTERM);
      
      window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
      gtk_window_set_screen (GTK_WINDOW (window),
                             gtk_widget_get_screen (do_widget));
      gtk_window_set_default_size (GTK_WINDOW (window),
                                   450, 450);
      
      g_signal_connect (window, "destroy",
                        G_CALLBACK (gtk_widget_destroyed), &window);

      gtk_window_set_title (GTK_WINDOW (window), "Hypertext");
      gtk_container_set_border_width (GTK_CONTAINER (window), 0);

      view = gtk_text_view_new ();
      gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (view), GTK_WRAP_WORD);
      g_signal_connect (view, "key-press-event", 
                        G_CALLBACK (key_press_event), NULL);
      g_signal_connect (view, "event-after", 
                        G_CALLBACK (event_after), NULL);
      g_signal_connect (view, "motion-notify-event", 
                        G_CALLBACK (motion_notify_event), NULL);
      g_signal_connect (view, "visibility-notify-event", 
                        G_CALLBACK (visibility_notify_event), NULL);

      buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
      
      sw = gtk_scrolled_window_new (NULL, NULL);
      gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                      GTK_POLICY_AUTOMATIC,
                                      GTK_POLICY_AUTOMATIC);
      gtk_container_add (GTK_CONTAINER (window), sw);
      gtk_container_add (GTK_CONTAINER (sw), view);

      show_page (buffer, 1);

      gtk_widget_show_all (sw);
    }

  if (!gtk_widget_get_visible (window))
    {
      gtk_widget_show (window);
    }
  else
    {
      gtk_widget_destroy (window);
      window = NULL;
    }

  return window;
}