indexing
	description: "."
	copyright: "[
					Copyright (C) 2006 Paolo Redaelli, GTK+ team
					
					This library is free software; you can redistribute it and/or
					modify it under the terms of the GNU Lesser General Public License
					as published by the Free Software Foundation; either version 2.1 of
					the License, or (at your option) any later version.
					
					This library is distributed in the hope that it will be useful, but
					WITHOUT ANY WARRANTY; without even the implied warranty of
					MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
					Lesser General Public License for more details.

					You should have received a copy of the GNU Lesser General Public
					License along with this library; if not, write to the Free Software
					Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
					02110-1301 USA
			]"

class CHANGEDISPLAY

creation make

feature
-- /* Change Display
--  * 
--  * Demonstrates migrating a window between different displays and
--  * screens. A display is a mouse and keyboard with some number of
--  * associated monitors. A screen is a set of monitors grouped
--  * into a single physical work area. The neat thing about having
--  * multiple displays is that they can be on a completely separate
--  * computers, as long as there is a network connection to the
--  * computer where the application is running.
--  *
--  * Only some of the windowing systems where GTK+ runs have the
--  * concept of multiple displays and screens. (The X Window System
--  * is the main example.) Other windowing systems can only
--  * handle one keyboard and mouse, and combine all monitors into
--  * a single screen.
--  *
--  * This is a moderately complex example, and demonstrates:
--  *
--  *  - Tracking the currently open displays and screens
--  *
--  *  - Changing the screen for a window
--  *
--  *  - Letting the user choose a window by clicking on it
--  * 
--  *  - Using GtkListStore and GtkTreeView
--  *
--  *  - Using GtkDialog
--  */
-- #include <string.h>
-- #include <gtk/gtk.h>
-- #include "demo-common.h"

-- /* The ChangeDisplayInfo structure corresponds to a toplevel window and
--  * holds pointers to widgets inside the toplevel window along with other
--  * information about the contents of the window.
--  * This is a common organizational structure in real applications.
--  */
-- typedef struct _ChangeDisplayInfo ChangeDisplayInfo;

-- struct _ChangeDisplayInfo
-- {
--   GtkWidget *window;
--   GtkSizeGroup *size_group;

--   GtkTreeModel *display_model;
--   GtkTreeModel *screen_model;
--   GtkTreeSelection *screen_selection;
  
--   GdkDisplay *current_display;
--   GdkScreen *current_screen;
-- };

-- /* These enumerations provide symbolic names for the columns
--  * in the two GtkListStore models.
--  */
-- enum
-- {
--   DISPLAY_COLUMN_NAME,
--   DISPLAY_COLUMN_DISPLAY,
--   DISPLAY_NUM_COLUMNS
-- };

-- enum
-- {
--   SCREEN_COLUMN_NUMBER,
--   SCREEN_COLUMN_SCREEN,
--   SCREEN_NUM_COLUMNS
-- };

-- /* Finds the toplevel window under the mouse pointer, if any.
--  */
-- static GtkWidget *
-- find_toplevel_at_pointer (GdkDisplay *display)
-- {
--   GdkWindow *pointer_window;
--   GtkWidget *widget = NULL;

--   pointer_window = gdk_display_get_window_at_pointer (display, NULL, NULL);

--   /* The user data field of a GdkWindow is used to store a pointer
--    * to the widget that created it.
--    */
--   if (pointer_window)
--     gdk_window_get_user_data (pointer_window, (gpointer*) &widget);

--   return widget ? gtk_widget_get_toplevel (widget) : NULL;
-- }

-- static gboolean
-- button_release_event_cb (GtkWidget       *widget,
-- 			 GdkEventButton  *event,
-- 			 gboolean        *clicked)
-- {
--   *clicked = TRUE;
--   return TRUE;
-- }

-- /* Asks the user to click on a window, then waits for them click
--  * the mouse. When the mouse is released, returns the toplevel
--  * window under the pointer, or NULL, if there is none.
--  */
-- static GtkWidget *
-- query_for_toplevel (GdkScreen  *screen,
-- 		    const char *prompt)
-- {
--   GdkDisplay *display = gdk_screen_get_display (screen);
--   GtkWidget *popup, *label, *frame;
--   GdkCursor *cursor;
--   GtkWidget *toplevel = NULL;
  
--   popup = gtk_window_new (GTK_WINDOW_POPUP);
--   gtk_window_set_screen (GTK_WINDOW (popup), screen);
--   gtk_window_set_modal (GTK_WINDOW (popup), TRUE);
--   gtk_window_set_position (GTK_WINDOW (popup), GTK_WIN_POS_CENTER);
  
--   frame = gtk_frame_new (NULL);
--   gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_OUT);
--   gtk_container_add (GTK_CONTAINER (popup), frame);
  
--   label = gtk_label_new (prompt);
--   gtk_misc_set_padding (GTK_MISC (label), 10, 10);
--   gtk_container_add (GTK_CONTAINER (frame), label);
  
--   gtk_widget_show_all (popup);
--   cursor = gdk_cursor_new_for_display (display, GDK_CROSSHAIR);
  
--   if (gdk_pointer_grab (popup->window, FALSE,
-- 			GDK_BUTTON_RELEASE_MASK,
-- 			NULL,
-- 			cursor,
-- 			GDK_CURRENT_TIME) == GDK_GRAB_SUCCESS)
--     {
--       gboolean clicked = FALSE;
		
--       g_signal_connect (popup, "button-release-event",
-- 			G_CALLBACK (button_release_event_cb), &clicked);
		
--       /* Process events until clicked is set by button_release_event_cb.
--        * We pass in may_block=TRUE since we want to wait if there
--        * are no events currently.
--        */
--       while (!clicked)
-- 	g_main_context_iteration (NULL, TRUE);
		
--       toplevel = find_toplevel_at_pointer (gdk_screen_get_display (screen));
--       if (toplevel == popup)
-- 	toplevel = NULL;
--     }
		
--   gdk_cursor_unref (cursor);
--   gtk_widget_destroy (popup);
--   gdk_flush ();			/* Really release the grab */
  
--   return toplevel;
-- }

-- /* Prompts the user for a toplevel window to move, and then moves
--  * that window to the currently selected display
--  */
-- static void
-- query_change_display (ChangeDisplayInfo *info)
-- {
--   GdkScreen *screen = gtk_widget_get_screen (info->window);
--   GtkWidget *toplevel;

--   toplevel = query_for_toplevel (screen,
-- 				 "Please select the toplevel\n"
-- 				 "to move to the new screen");

--   if (toplevel)
--     gtk_window_set_screen (GTK_WINDOW (toplevel), info->current_screen);
--   else
--     gdk_display_beep (gdk_screen_get_display (screen));
-- }

-- /* Fills in the screen list based on the current display
--  */
-- static void
-- fill_screens (ChangeDisplayInfo *info)
-- {
--   gtk_list_store_clear (GTK_LIST_STORE (info->screen_model));

--   if (info->current_display)
--     {
--       gint n_screens = gdk_display_get_n_screens (info->current_display);
--       gint i;
		
--       for (i = 0; i < n_screens; i++)
-- 	{
-- 	  GdkScreen *screen = gdk_display_get_screen (info->current_display, i);
-- 	  GtkTreeIter iter;
	
-- 	  gtk_list_store_append (GTK_LIST_STORE (info->screen_model), &iter);
-- 	  gtk_list_store_set (GTK_LIST_STORE (info->screen_model), &iter,
-- 			      SCREEN_COLUMN_NUMBER, i,
-- 			      SCREEN_COLUMN_SCREEN, screen,
-- 			      -1);

-- 	  if (i == 0)
-- 	    gtk_tree_selection_select_iter (info->screen_selection, &iter);
-- 	}
--     }
-- }

-- /* Called when the user clicks on a button in our dialog or
--  * closes the dialog through the window manager. Unless the
--  * "Change" button was clicked, we destroy the dialog.
--  */
-- static void
-- response_cb (GtkDialog         *dialog,
-- 	     gint               response_id,
-- 	     ChangeDisplayInfo *info)
-- {
--   if (response_id == GTK_RESPONSE_OK)
--     query_change_display (info);
--   else
--     gtk_widget_destroy (GTK_WIDGET (dialog));
-- }

-- /* Called when the user clicks on "Open..." in the display
--  * frame. Prompts for a new display, and then opens a connection
--  * to that display.
--  */
-- static void
-- open_display_cb (GtkWidget         *button,
-- 		 ChangeDisplayInfo *info)
-- {
--   GtkWidget *dialog;
--   GtkWidget *display_entry;
--   GtkWidget *dialog_label;
--   gchar *new_screen_name = NULL;
--   GdkDisplay *result = NULL;
  
--   dialog = gtk_dialog_new_with_buttons ("Open Display",
-- 					GTK_WINDOW (info->window),
-- 					GTK_DIALOG_MODAL,
-- 					GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
-- 					GTK_STOCK_OK, GTK_RESPONSE_OK,
-- 					NULL);

--   gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_OK);
--   display_entry = gtk_entry_new ();
--   gtk_entry_set_activates_default (GTK_ENTRY (display_entry), TRUE);
--   dialog_label =
--     gtk_label_new ("Please enter the name of\nthe new display\n");

--   gtk_container_add (GTK_CONTAINER (GTK_DIALOG (dialog)->vbox), dialog_label);
--   gtk_container_add (GTK_CONTAINER (GTK_DIALOG (dialog)->vbox), display_entry);

--   gtk_widget_grab_focus (display_entry);
--   gtk_widget_show_all (GTK_BIN (dialog)->child);
  
--   while (!result)
--     {
--       gint response_id = gtk_dialog_run (GTK_DIALOG (dialog));
--       if (response_id != GTK_RESPONSE_OK)
-- 	break;
		
--       new_screen_name = gtk_editable_get_chars (GTK_EDITABLE (display_entry),
-- 						0, -1);

--       if (strcmp (new_screen_name, "") != 0)
-- 	{
-- 	  result = gdk_display_open (new_screen_name);
-- 	  if (!result)
-- 	    {
-- 	      gchar *error_msg =
-- 		g_strdup_printf  ("Can't open display :\n\t%s\nplease try another one\n",
-- 				  new_screen_name);
-- 	      gtk_label_set_text (GTK_LABEL (dialog_label), error_msg);
-- 	      g_free (error_msg);
-- 	    }

-- 	  g_free (new_screen_name);
-- 	}
--     }
  
--   gtk_widget_destroy (dialog);
-- }

-- /* Called when the user clicks on the "Close" button in the
--  * "Display" frame. Closes the selected display.
--  */
-- static void
-- close_display_cb (GtkWidget         *button,
-- 		  ChangeDisplayInfo *info)
-- {
--   if (info->current_display)
--     gdk_display_close (info->current_display);
-- }

-- /* Called when the selected row in the display list changes.
--  * Updates info->current_display, then refills the list of
--  * screens.
--  */
-- static void
-- display_changed_cb (GtkTreeSelection  *selection,
-- 		    ChangeDisplayInfo *info)
-- {
--   GtkTreeModel *model;
--   GtkTreeIter iter;

--   if (gtk_tree_selection_get_selected (selection, &model, &iter))
--     gtk_tree_model_get (model, &iter,
-- 			DISPLAY_COLUMN_DISPLAY, &info->current_display,
-- 			-1);
--   else
--     info->current_display = NULL;

--   fill_screens (info);
-- }

-- /* Called when the selected row in the sceen list changes.
--  * Updates info->current_screen.
--  */
-- static void
-- screen_changed_cb (GtkTreeSelection  *selection,
-- 		   ChangeDisplayInfo *info)
-- {
--   GtkTreeModel *model;
--   GtkTreeIter iter;

--   if (gtk_tree_selection_get_selected (selection, &model, &iter))
--     gtk_tree_model_get (model, &iter,
-- 			SCREEN_COLUMN_SCREEN, &info->current_screen,
-- 			-1);
--   else
--     info->current_screen = NULL;
-- }

-- /* This function is used both for creating the "Display" and
--  * "Screen" frames, since they have a similar structure. The
--  * caller hooks up the right context for the value returned
--  * in tree_view, and packs any relevant buttons into button_vbox.
--  */
-- static void
-- create_frame (ChangeDisplayInfo *info,
-- 	      const char        *title,
-- 	      GtkWidget        **frame,
-- 	      GtkWidget        **tree_view,
-- 	      GtkWidget        **button_vbox)
-- {
--   GtkTreeSelection *selection;
--   GtkWidget *scrollwin;
--   GtkWidget *hbox;
  
--   *frame = gtk_frame_new (title);

--   hbox = gtk_hbox_new (FALSE, 8);
--   gtk_container_set_border_width (GTK_CONTAINER (hbox), 8);
--   gtk_container_add (GTK_CONTAINER (*frame), hbox);

--   scrollwin = gtk_scrolled_window_new (NULL, NULL);
--   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrollwin),
-- 				  GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
--   gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (scrollwin),
-- 				       GTK_SHADOW_IN);
--   gtk_box_pack_start (GTK_BOX (hbox), scrollwin, TRUE, TRUE, 0);

--   *tree_view = gtk_tree_view_new ();
--   gtk_tree_view_set_headers_visible (GTK_TREE_VIEW (*tree_view), FALSE);
--   gtk_container_add (GTK_CONTAINER (scrollwin), *tree_view);

--   selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (*tree_view));
--   gtk_tree_selection_set_mode (selection, GTK_SELECTION_BROWSE);

--   *button_vbox = gtk_vbox_new (FALSE, 5);
--   gtk_box_pack_start (GTK_BOX (hbox), *button_vbox, FALSE, FALSE, 0);

--   if (!info->size_group)
--     info->size_group = gtk_size_group_new (GTK_SIZE_GROUP_HORIZONTAL);
  
--   gtk_size_group_add_widget (GTK_SIZE_GROUP (info->size_group), *button_vbox);
-- }

-- /* If we have a stack of buttons, it often looks better if their contents
--  * are left-aligned, rather than centered. This function creates a button
--  * and left-aligns it contents.
--  */
-- GtkWidget *
-- left_align_button_new (const char *label)
-- {
--   GtkWidget *button = gtk_button_new_with_mnemonic (label);
--   GtkWidget *child = gtk_bin_get_child (GTK_BIN (button));

--   gtk_misc_set_alignment (GTK_MISC (child), 0., 0.5);

--   return button;
-- }

-- /* Creates the "Display" frame in the main window.
--  */
-- GtkWidget *
-- create_display_frame (ChangeDisplayInfo *info)
-- {
--   GtkWidget *frame;
--   GtkWidget *tree_view;
--   GtkWidget *button_vbox;
--   GtkTreeViewColumn *column;
--   GtkTreeSelection *selection;
--   GtkWidget *button;

--   create_frame (info, "Display", &frame, &tree_view, &button_vbox);

--   button = left_align_button_new ("_Open...");
--   g_signal_connect (button, "clicked",  G_CALLBACK (open_display_cb), info);
--   gtk_box_pack_start (GTK_BOX (button_vbox), button, FALSE, FALSE, 0);
  
--   button = left_align_button_new ("_Close");
--   g_signal_connect (button, "clicked",  G_CALLBACK (close_display_cb), info);
--   gtk_box_pack_start (GTK_BOX (button_vbox), button, FALSE, FALSE, 0);

--   info->display_model = (GtkTreeModel *)gtk_list_store_new (DISPLAY_NUM_COLUMNS,
-- 							    G_TYPE_STRING,
-- 							    GDK_TYPE_DISPLAY);

--   gtk_tree_view_set_model (GTK_TREE_VIEW (tree_view), info->display_model);

--   column = gtk_tree_view_column_new_with_attributes ("Name",
-- 						     gtk_cell_renderer_text_new (),
-- 						     "text", DISPLAY_COLUMN_NAME,
-- 						     NULL);
--   gtk_tree_view_append_column (GTK_TREE_VIEW (tree_view), column);

--   selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (tree_view));
--   g_signal_connect (selection, "changed",
-- 		    G_CALLBACK (display_changed_cb), info);

--   return frame;
-- }

-- /* Creates the "Screen" frame in the main window.
--  */
-- GtkWidget *
-- create_screen_frame (ChangeDisplayInfo *info)
-- {
--   GtkWidget *frame;
--   GtkWidget *tree_view;
--   GtkWidget *button_vbox;
--   GtkTreeViewColumn *column;

--   create_frame (info, "Screen", &frame, &tree_view, &button_vbox);

--   info->screen_model = (GtkTreeModel *)gtk_list_store_new (SCREEN_NUM_COLUMNS,
-- 							   G_TYPE_INT,
-- 							   GDK_TYPE_SCREEN);

--   gtk_tree_view_set_model (GTK_TREE_VIEW (tree_view), info->screen_model);

--   column = gtk_tree_view_column_new_with_attributes ("Number",
-- 						     gtk_cell_renderer_text_new (),
-- 						     "text", SCREEN_COLUMN_NUMBER,
-- 						     NULL);
--   gtk_tree_view_append_column (GTK_TREE_VIEW (tree_view), column);

--   info->screen_selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (tree_view));
--   g_signal_connect (info->screen_selection, "changed",
-- 		    G_CALLBACK (screen_changed_cb), info);

--   return frame;
-- }

-- /* Called when one of the currently open displays is closed.
--  * Remove it from our list of displays.
--  */
-- static void
-- display_closed_cb (GdkDisplay        *display,
-- 		   gboolean           is_error,
-- 		   ChangeDisplayInfo *info)
-- {
--   GtkTreeIter iter;
--   gboolean valid;

--   for (valid = gtk_tree_model_get_iter_first (info->display_model, &iter);
--        valid;
--        valid = gtk_tree_model_iter_next (info->display_model, &iter))
--     {
--       GdkDisplay *tmp_display;
		
--       gtk_tree_model_get (info->display_model, &iter,
-- 			  DISPLAY_COLUMN_DISPLAY, &tmp_display,
-- 			  -1);
--       if (tmp_display == display)
-- 	{
-- 	  gtk_list_store_remove (GTK_LIST_STORE (info->display_model), &iter);
-- 	  break;
-- 	}
--     }
-- }

-- /* Adds a new display to our list of displays, and connects
--  * to the "closed" signal so that we can remove it from the
--  * list of displays again.
--  */
-- static void
-- add_display (ChangeDisplayInfo *info,
-- 	     GdkDisplay        *display)
-- {
--   const gchar *name = gdk_display_get_name (display);
--   GtkTreeIter iter;
  
--   gtk_list_store_append (GTK_LIST_STORE (info->display_model), &iter);
--   gtk_list_store_set (GTK_LIST_STORE (info->display_model), &iter,
-- 		      DISPLAY_COLUMN_NAME, name,
-- 		      DISPLAY_COLUMN_DISPLAY, display,
-- 		      -1);

--   g_signal_connect (display, "closed",
-- 		    G_CALLBACK (display_closed_cb), info); 
-- }

-- /* Called when a new display is opened
--  */
-- static void
-- display_opened_cb (GdkDisplayManager *manager,
-- 		   GdkDisplay        *display,
-- 		   ChangeDisplayInfo *info)
-- {
--   add_display (info, display);
-- }

-- /* Adds all currently open displays to our list of displays,
--  * and set up a signal connection so that we'll be notified
--  * when displays are opened in the future as well.
--  */
-- static void
-- initialize_displays (ChangeDisplayInfo *info)
-- {
--   GdkDisplayManager *manager = gdk_display_manager_get ();
--   GSList *displays = gdk_display_manager_list_displays (manager);
--   GSList *tmp_list;

--   for (tmp_list = displays; tmp_list; tmp_list = tmp_list->next)
--     add_display (info, tmp_list->data);

--   g_slist_free (tmp_list);

--   g_signal_connect (manager, "display_opened",
-- 		    G_CALLBACK (display_opened_cb), info);
-- }

-- /* Cleans up when the toplevel is destroyed; we remove the
--  * connections we use to track currently open displays, then
--  * free the ChangeDisplayInfo structure.
--  */
-- static void
-- destroy_info (ChangeDisplayInfo *info)
-- {
--   GdkDisplayManager *manager = gdk_display_manager_get ();
--   GSList *displays = gdk_display_manager_list_displays (manager);
--   GSList *tmp_list;

--   g_signal_handlers_disconnect_by_func (manager,
-- 					display_opened_cb,
-- 					info);

--   for (tmp_list = displays; tmp_list; tmp_list = tmp_list->next)
--     g_signal_handlers_disconnect_by_func (tmp_list->data,
-- 					  display_closed_cb,
-- 					  info);
  
--   g_slist_free (tmp_list);

--   g_object_unref (info->size_group);
--   g_free (info);
-- }

-- static void
-- destroy_cb (GtkObject          *object,
-- 	    ChangeDisplayInfo **info)
-- {
--   destroy_info (*info);
--   *info = NULL;
-- }

-- /* Main entry point. If the dialog for this demo doesn't yet exist, creates
--  * it. Otherwise, destroys it.
--  */
-- GtkWidget *
-- do_changedisplay (GtkWidget *do_widget)
-- {
--   static ChangeDisplayInfo *info = NULL;

--   if (!info)
--     {
--       GtkWidget *vbox;
--       GtkWidget *frame;

--       info = g_new0 (ChangeDisplayInfo, 1);

--       info->window = gtk_dialog_new_with_buttons ("Change Screen or display",
-- 					    GTK_WINDOW (do_widget), 
-- 					    GTK_DIALOG_NO_SEPARATOR,
-- 					    GTK_STOCK_CLOSE,  GTK_RESPONSE_CLOSE,
-- 					    "Change",         GTK_RESPONSE_OK,
-- 					    NULL);

--       gtk_window_set_default_size (GTK_WINDOW (info->window), 300, 400);

--       g_signal_connect (info->window, "response",
-- 			G_CALLBACK (response_cb), info);
--       g_signal_connect (info->window, "destroy",
-- 			G_CALLBACK (destroy_cb), &info);

--       vbox = gtk_vbox_new (FALSE, 5);
--       gtk_container_set_border_width (GTK_CONTAINER (vbox), 8);
	
--       gtk_box_pack_start (GTK_BOX (GTK_DIALOG (info->window)->vbox), vbox,
-- 			  TRUE, TRUE, 0);

--       frame = create_display_frame (info);
--       gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);
		
--       frame = create_screen_frame (info);
--       gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);

--       initialize_displays (info);

--       gtk_widget_show_all (info->window);
--       return info->window;
--     }
--   else
--     {
--       gtk_widget_destroy (info->window);
--       return NULL;
--     }
-- }
end