3 * Demonstrates migrating a window between different displays and
4 * screens. A display is a mouse and keyboard with some number of
5 * associated monitors. A screen is a set of monitors grouped
6 * into a single physical work area. The neat thing about having
7 * multiple displays is that they can be on a completely separate
8 * computers, as long as there is a network connection to the
9 * computer where the application is running.
11 * Only some of the windowing systems where GTK+ runs have the
12 * concept of multiple displays and screens. (The X Window System
13 * is the main example.) Other windowing systems can only
14 * handle one keyboard and mouse, and combine all monitors into
17 * This is a moderately complex example, and demonstrates:
19 * - Tracking the currently open displays and screens
21 * - Changing the screen for a window
23 * - Letting the user choose a window by clicking on it
25 * - Using GtkListStore and GtkTreeView
31 #include "demo-common.h"
33 /* The ChangeDisplayInfo structure corresponds to a toplevel window and
34 * holds pointers to widgets inside the toplevel window along with other
35 * information about the contents of the window.
36 * This is a common organizational structure in real applications.
38 typedef struct _ChangeDisplayInfo ChangeDisplayInfo;
40 struct _ChangeDisplayInfo
43 GtkSizeGroup *size_group;
45 GtkTreeModel *display_model;
46 GtkTreeModel *screen_model;
47 GtkTreeSelection *screen_selection;
49 GdkDisplay *current_display;
50 GdkScreen *current_screen;
53 /* These enumerations provide symbolic names for the columns
54 * in the two GtkListStore models.
59 DISPLAY_COLUMN_DISPLAY,
70 /* Finds the toplevel window under the mouse pointer, if any.
73 find_toplevel_at_pointer (GdkDisplay *display)
75 GdkWindow *pointer_window;
76 GtkWidget *widget = NULL;
78 pointer_window = gdk_display_get_window_at_pointer (display, NULL, NULL);
80 /* The user data field of a GdkWindow is used to store a pointer
81 * to the widget that created it.
84 gdk_window_get_user_data (pointer_window, (gpointer*) &widget);
86 return widget ? gtk_widget_get_toplevel (widget) : NULL;
90 button_release_event_cb (GtkWidget *widget,
91 GdkEventButton *event,
98 /* Asks the user to click on a window, then waits for them click
99 * the mouse. When the mouse is released, returns the toplevel
100 * window under the pointer, or NULL, if there is none.
103 query_for_toplevel (GdkScreen *screen,
106 GdkDisplay *display = gdk_screen_get_display (screen);
107 GtkWidget *popup, *label, *frame;
109 GtkWidget *toplevel = NULL;
111 popup = gtk_window_new (GTK_WINDOW_POPUP);
112 gtk_window_set_screen (GTK_WINDOW (popup), screen);
113 gtk_window_set_modal (GTK_WINDOW (popup), TRUE);
114 gtk_window_set_position (GTK_WINDOW (popup), GTK_WIN_POS_CENTER);
116 frame = gtk_frame_new (NULL);
117 gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_OUT);
118 gtk_container_add (GTK_CONTAINER (popup), frame);
120 label = gtk_label_new (prompt);
121 gtk_misc_set_padding (GTK_MISC (label), 10, 10);
122 gtk_container_add (GTK_CONTAINER (frame), label);
124 gtk_widget_show_all (popup);
125 cursor = gdk_cursor_new_for_display (display, GDK_CROSSHAIR);
127 if (gdk_pointer_grab (popup->window, FALSE,
128 GDK_BUTTON_RELEASE_MASK,
131 GDK_CURRENT_TIME) == GDK_GRAB_SUCCESS)
133 gboolean clicked = FALSE;
135 g_signal_connect (popup, "button-release-event",
136 G_CALLBACK (button_release_event_cb), &clicked);
138 /* Process events until clicked is set by button_release_event_cb.
139 * We pass in may_block=TRUE since we want to wait if there
140 * are no events currently.
143 g_main_context_iteration (NULL, TRUE);
145 toplevel = find_toplevel_at_pointer (gdk_screen_get_display (screen));
146 if (toplevel == popup)
150 gdk_cursor_unref (cursor);
151 gtk_widget_destroy (popup);
152 gdk_flush (); /* Really release the grab */
157 /* Prompts the user for a toplevel window to move, and then moves
158 * that window to the currently selected display
161 query_change_display (ChangeDisplayInfo *info)
163 GdkScreen *screen = gtk_widget_get_screen (info->window);
166 toplevel = query_for_toplevel (screen,
167 "Please select the toplevel\n"
168 "to move to the new screen");
171 gtk_window_set_screen (GTK_WINDOW (toplevel), info->current_screen);
173 gdk_display_beep (gdk_screen_get_display (screen));
176 /* Fills in the screen list based on the current display
179 fill_screens (ChangeDisplayInfo *info)
181 gtk_list_store_clear (GTK_LIST_STORE (info->screen_model));
183 if (info->current_display)
185 gint n_screens = gdk_display_get_n_screens (info->current_display);
188 for (i = 0; i < n_screens; i++)
190 GdkScreen *screen = gdk_display_get_screen (info->current_display, i);
193 gtk_list_store_append (GTK_LIST_STORE (info->screen_model), &iter);
194 gtk_list_store_set (GTK_LIST_STORE (info->screen_model), &iter,
195 SCREEN_COLUMN_NUMBER, i,
196 SCREEN_COLUMN_SCREEN, screen,
200 gtk_tree_selection_select_iter (info->screen_selection, &iter);
205 /* Called when the user clicks on a button in our dialog or
206 * closes the dialog through the window manager. Unless the
207 * "Change" button was clicked, we destroy the dialog.
210 response_cb (GtkDialog *dialog,
212 ChangeDisplayInfo *info)
214 if (response_id == GTK_RESPONSE_OK)
215 query_change_display (info);
217 gtk_widget_destroy (GTK_WIDGET (dialog));
220 /* Called when the user clicks on "Open..." in the display
221 * frame. Prompts for a new display, and then opens a connection
225 open_display_cb (GtkWidget *button,
226 ChangeDisplayInfo *info)
229 GtkWidget *display_entry;
230 GtkWidget *dialog_label;
231 gchar *new_screen_name = NULL;
232 GdkDisplay *result = NULL;
234 dialog = gtk_dialog_new_with_buttons ("Open Display",
235 GTK_WINDOW (info->window),
237 GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
238 GTK_STOCK_OK, GTK_RESPONSE_OK,
241 gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_OK);
242 display_entry = gtk_entry_new ();
243 gtk_entry_set_activates_default (GTK_ENTRY (display_entry), TRUE);
245 gtk_label_new ("Please enter the name of\nthe new display\n");
247 gtk_container_add (GTK_CONTAINER (GTK_DIALOG (dialog)->vbox), dialog_label);
248 gtk_container_add (GTK_CONTAINER (GTK_DIALOG (dialog)->vbox), display_entry);
250 gtk_widget_grab_focus (display_entry);
251 gtk_widget_show_all (GTK_BIN (dialog)->child);
255 gint response_id = gtk_dialog_run (GTK_DIALOG (dialog));
256 if (response_id != GTK_RESPONSE_OK)
259 new_screen_name = gtk_editable_get_chars (GTK_EDITABLE (display_entry),
262 if (strcmp (new_screen_name, "") != 0)
264 result = gdk_display_open (new_screen_name);
268 g_strdup_printf ("Can't open display :\n\t%s\nplease try another one\n",
270 gtk_label_set_text (GTK_LABEL (dialog_label), error_msg);
274 g_free (new_screen_name);
278 gtk_widget_destroy (dialog);
281 /* Called when the user clicks on the "Close" button in the
282 * "Display" frame. Closes the selected display.
285 close_display_cb (GtkWidget *button,
286 ChangeDisplayInfo *info)
288 if (info->current_display)
289 gdk_display_close (info->current_display);
292 /* Called when the selected row in the display list changes.
293 * Updates info->current_display, then refills the list of
297 display_changed_cb (GtkTreeSelection *selection,
298 ChangeDisplayInfo *info)
303 if (gtk_tree_selection_get_selected (selection, &model, &iter))
304 gtk_tree_model_get (model, &iter,
305 DISPLAY_COLUMN_DISPLAY, &info->current_display,
308 info->current_display = NULL;
313 /* Called when the selected row in the sceen list changes.
314 * Updates info->current_screen.
317 screen_changed_cb (GtkTreeSelection *selection,
318 ChangeDisplayInfo *info)
323 if (gtk_tree_selection_get_selected (selection, &model, &iter))
324 gtk_tree_model_get (model, &iter,
325 SCREEN_COLUMN_SCREEN, &info->current_screen,
328 info->current_screen = NULL;
331 /* This function is used both for creating the "Display" and
332 * "Screen" frames, since they have a similar structure. The
333 * caller hooks up the right context for the value returned
334 * in tree_view, and packs any relevant buttons into button_vbox.
337 create_frame (ChangeDisplayInfo *info,
340 GtkWidget **tree_view,
341 GtkWidget **button_vbox)
343 GtkTreeSelection *selection;
344 GtkWidget *scrollwin;
347 *frame = gtk_frame_new (title);
349 hbox = gtk_hbox_new (FALSE, 8);
350 gtk_container_set_border_width (GTK_CONTAINER (hbox), 8);
351 gtk_container_add (GTK_CONTAINER (*frame), hbox);
353 scrollwin = gtk_scrolled_window_new (NULL, NULL);
354 gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrollwin),
355 GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
356 gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (scrollwin),
358 gtk_box_pack_start (GTK_BOX (hbox), scrollwin, TRUE, TRUE, 0);
360 *tree_view = gtk_tree_view_new ();
361 gtk_tree_view_set_headers_visible (GTK_TREE_VIEW (*tree_view), FALSE);
362 gtk_container_add (GTK_CONTAINER (scrollwin), *tree_view);
364 selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (*tree_view));
365 gtk_tree_selection_set_mode (selection, GTK_SELECTION_BROWSE);
367 *button_vbox = gtk_vbox_new (FALSE, 5);
368 gtk_box_pack_start (GTK_BOX (hbox), *button_vbox, FALSE, FALSE, 0);
370 if (!info->size_group)
371 info->size_group = gtk_size_group_new (GTK_SIZE_GROUP_HORIZONTAL);
373 gtk_size_group_add_widget (GTK_SIZE_GROUP (info->size_group), *button_vbox);
376 /* If we have a stack of buttons, it often looks better if their contents
377 * are left-aligned, rather than centered. This function creates a button
378 * and left-aligns it contents.
381 left_align_button_new (const char *label)
383 GtkWidget *button = gtk_button_new_with_mnemonic (label);
384 GtkWidget *child = gtk_bin_get_child (GTK_BIN (button));
386 gtk_misc_set_alignment (GTK_MISC (child), 0., 0.5);
391 /* Creates the "Display" frame in the main window.
394 create_display_frame (ChangeDisplayInfo *info)
397 GtkWidget *tree_view;
398 GtkWidget *button_vbox;
399 GtkTreeViewColumn *column;
400 GtkTreeSelection *selection;
403 create_frame (info, "Display", &frame, &tree_view, &button_vbox);
405 button = left_align_button_new ("_Open...");
406 g_signal_connect (button, "clicked", G_CALLBACK (open_display_cb), info);
407 gtk_box_pack_start (GTK_BOX (button_vbox), button, FALSE, FALSE, 0);
409 button = left_align_button_new ("_Close");
410 g_signal_connect (button, "clicked", G_CALLBACK (close_display_cb), info);
411 gtk_box_pack_start (GTK_BOX (button_vbox), button, FALSE, FALSE, 0);
413 info->display_model = (GtkTreeModel *)gtk_list_store_new (DISPLAY_NUM_COLUMNS,
417 gtk_tree_view_set_model (GTK_TREE_VIEW (tree_view), info->display_model);
419 column = gtk_tree_view_column_new_with_attributes ("Name",
420 gtk_cell_renderer_text_new (),
421 "text", DISPLAY_COLUMN_NAME,
423 gtk_tree_view_append_column (GTK_TREE_VIEW (tree_view), column);
425 selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (tree_view));
426 g_signal_connect (selection, "changed",
427 G_CALLBACK (display_changed_cb), info);
432 /* Creates the "Screen" frame in the main window.
435 create_screen_frame (ChangeDisplayInfo *info)
438 GtkWidget *tree_view;
439 GtkWidget *button_vbox;
440 GtkTreeViewColumn *column;
442 create_frame (info, "Screen", &frame, &tree_view, &button_vbox);
444 info->screen_model = (GtkTreeModel *)gtk_list_store_new (SCREEN_NUM_COLUMNS,
448 gtk_tree_view_set_model (GTK_TREE_VIEW (tree_view), info->screen_model);
450 column = gtk_tree_view_column_new_with_attributes ("Number",
451 gtk_cell_renderer_text_new (),
452 "text", SCREEN_COLUMN_NUMBER,
454 gtk_tree_view_append_column (GTK_TREE_VIEW (tree_view), column);
456 info->screen_selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (tree_view));
457 g_signal_connect (info->screen_selection, "changed",
458 G_CALLBACK (screen_changed_cb), info);
463 /* Called when one of the currently open displays is closed.
464 * Remove it from our list of displays.
467 display_closed_cb (GdkDisplay *display,
469 ChangeDisplayInfo *info)
474 for (valid = gtk_tree_model_get_iter_first (info->display_model, &iter);
476 valid = gtk_tree_model_iter_next (info->display_model, &iter))
478 GdkDisplay *tmp_display;
480 gtk_tree_model_get (info->display_model, &iter,
481 DISPLAY_COLUMN_DISPLAY, &tmp_display,
483 if (tmp_display == display)
485 gtk_list_store_remove (GTK_LIST_STORE (info->display_model), &iter);
491 /* Adds a new display to our list of displays, and connects
492 * to the "closed" signal so that we can remove it from the
493 * list of displays again.
496 add_display (ChangeDisplayInfo *info,
499 const gchar *name = gdk_display_get_name (display);
502 gtk_list_store_append (GTK_LIST_STORE (info->display_model), &iter);
503 gtk_list_store_set (GTK_LIST_STORE (info->display_model), &iter,
504 DISPLAY_COLUMN_NAME, name,
505 DISPLAY_COLUMN_DISPLAY, display,
508 g_signal_connect (display, "closed",
509 G_CALLBACK (display_closed_cb), info);
512 /* Called when a new display is opened
515 display_opened_cb (GdkDisplayManager *manager,
517 ChangeDisplayInfo *info)
519 add_display (info, display);
522 /* Adds all currently open displays to our list of displays,
523 * and set up a signal connection so that we'll be notified
524 * when displays are opened in the future as well.
527 initialize_displays (ChangeDisplayInfo *info)
529 GdkDisplayManager *manager = gdk_display_manager_get ();
530 GSList *displays = gdk_display_manager_list_displays (manager);
533 for (tmp_list = displays; tmp_list; tmp_list = tmp_list->next)
534 add_display (info, tmp_list->data);
536 g_slist_free (tmp_list);
538 g_signal_connect (manager, "display_opened",
539 G_CALLBACK (display_opened_cb), info);
542 /* Cleans up when the toplevel is destroyed; we remove the
543 * connections we use to track currently open displays, then
544 * free the ChangeDisplayInfo structure.
547 destroy_info (ChangeDisplayInfo *info)
549 GdkDisplayManager *manager = gdk_display_manager_get ();
550 GSList *displays = gdk_display_manager_list_displays (manager);
553 g_signal_handlers_disconnect_by_func (manager,
557 for (tmp_list = displays; tmp_list; tmp_list = tmp_list->next)
558 g_signal_handlers_disconnect_by_func (tmp_list->data,
562 g_slist_free (tmp_list);
564 g_object_unref (info->size_group);
569 destroy_cb (GtkObject *object,
570 ChangeDisplayInfo **info)
572 destroy_info (*info);
576 /* Main entry point. If the dialog for this demo doesn't yet exist, creates
577 * it. Otherwise, destroys it.
580 do_changedisplay (GtkWidget *do_widget)
582 static ChangeDisplayInfo *info = NULL;
589 info = g_new0 (ChangeDisplayInfo, 1);
591 info->window = gtk_dialog_new_with_buttons ("Change Screen or display",
592 GTK_WINDOW (do_widget),
593 GTK_DIALOG_NO_SEPARATOR,
594 GTK_STOCK_CLOSE, GTK_RESPONSE_CLOSE,
595 "Change", GTK_RESPONSE_OK,
598 gtk_window_set_default_size (GTK_WINDOW (info->window), 300, 400);
600 g_signal_connect (info->window, "response",
601 G_CALLBACK (response_cb), info);
602 g_signal_connect (info->window, "destroy",
603 G_CALLBACK (destroy_cb), &info);
605 vbox = gtk_vbox_new (FALSE, 5);
606 gtk_container_set_border_width (GTK_CONTAINER (vbox), 8);
608 gtk_box_pack_start (GTK_BOX (GTK_DIALOG (info->window)->vbox), vbox,
611 frame = create_display_frame (info);
612 gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);
614 frame = create_screen_frame (info);
615 gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);
617 initialize_displays (info);
619 gtk_widget_show_all (info->window);
624 gtk_widget_destroy (info->window);