Select the RANDR output which contains the configuration window

2008-12-15  Federico Mena Quintero  <federico@novell.com>

	* xrandr-capplet.c (select_current_output_from_dialog_position):
	New function.
	(dialog_map_event_cb): New GtkWidget::map-event handler for the
	toplevel dialog.  When the dialog gets mapped, we make the current
	output be the one which actually contains the dialog window, so
	that the user can edit the monitor which he's looking at.

Signed-off-by: Federico Mena Quintero <federico@novell.com>

svn path=/trunk/; revision=9170

capplets/display/ChangeLog

@@ -1,3 +1,12 @@
+2008-12-15  Federico Mena Quintero  <federico@novell.com>
+
+	* xrandr-capplet.c (select_current_output_from_dialog_position):
+	New function.
+	(dialog_map_event_cb): New GtkWidget::map-event handler for the
+	toplevel dialog.  When the dialog gets mapped, we make the current
+	output be the one which actually contains the dialog window, so
+	that the user can edit the monitor which he's looking at.
+
 2008-12-15  Federico Mena Quintero  <federico@novell.com>
 
 	* display-capplet.glade: Put the "Monitor" label inside an event

capplets/display/xrandr-capplet.c

@@ -1721,6 +1721,134 @@ on_show_icon_toggled (GtkWidget *widget, gpointer data)
 			   gtk_toggle_button_get_active (tb), NULL);
 }
 
+static GnomeOutputInfo *
+get_nearest_output (GnomeRRConfig *configuration, int x, int y)
+{
+    int i;
+    int nearest_index;
+    int nearest_dist;
+
+    nearest_index = -1;
+    nearest_dist = G_MAXINT;
+
+    for (i = 0; configuration->outputs[i] != NULL; i++)
+    {
+	GnomeOutputInfo *output;
+	int dist_x, dist_y;
+
+	output = configuration->outputs[i];
+
+	if (!(output->connected && output->on))
+	    continue;
+
+	if (x < output->x)
+	    dist_x = output->x - x;
+	else if (x >= output->x + output->width)
+	    dist_x = x - (output->x + output->width) + 1;
+	else
+	    dist_x = 0;
+
+	if (y < output->y)
+	    dist_y = output->y - y;
+	else if (y >= output->y + output->height)
+	    dist_y = y - (output->y + output->height) + 1;
+	else
+	    dist_y = 0;
+
+	if (MIN (dist_x, dist_y) < nearest_dist)
+	{
+	    nearest_dist = MIN (dist_x, dist_y);
+	    nearest_index = i;
+	}
+    }
+
+    if (nearest_index != -1)
+	return configuration->outputs[nearest_index];
+    else
+	return NULL;
+		
+}
+
+/* Gets the output that contains the largest intersection with the window.
+ * Logic stolen from gdk_screen_get_monitor_at_window().
+ */
+static GnomeOutputInfo *
+get_output_for_window (GnomeRRConfig *configuration, GdkWindow *window)
+{
+    GdkRectangle win_rect;
+    int i;
+    int largest_area;
+    int largest_index;
+
+    gdk_window_get_geometry (window, &win_rect.x, &win_rect.y, &win_rect.width, &win_rect.height, NULL);
+    gdk_window_get_origin (window, &win_rect.x, &win_rect.y);
+
+    largest_area = 0;
+    largest_index = -1;
+
+    for (i = 0; configuration->outputs[i] != NULL; i++)
+    {
+	GnomeOutputInfo *output;
+	GdkRectangle output_rect, intersection;
+
+	output = configuration->outputs[i];
+
+	output_rect.x	   = output->x;
+	output_rect.y	   = output->y;
+	output_rect.width  = output->width;
+	output_rect.height = output->height;
+
+	if (output->connected && output->on && gdk_rectangle_intersect (&win_rect, &output_rect, &intersection))
+	{
+	    int area;
+
+	    area = intersection.width * intersection.height;
+	    if (area > largest_area)
+	    {
+		largest_area = area;
+		largest_index = i;
+	    }
+	}
+    }
+
+    if (largest_index != -1)
+	return configuration->outputs[largest_index];
+    else
+	return get_nearest_output (configuration,
+				   win_rect.x + win_rect.width / 2,
+				   win_rect.y + win_rect.height / 2);
+}
+
+/* We select the current output, i.e. select the one being edited, based on
+ * which output is showing the configuration dialog.
+ */
+static void
+select_current_output_from_dialog_position (App *app)
+{
+    GnomeOutputInfo *output;
+
+    output = get_output_for_window (app->current_configuration, app->dialog->window);
+
+    if (output)
+    {
+	app->current_output = output;
+	rebuild_gui (app);
+    }
+}
+
+/* This is a GtkWidget::map-event handler.  We wait for the display-properties
+ * dialog to be mapped, and then we select the output which corresponds to the
+ * monitor on which the dialog is being shown.
+ */
+static gboolean
+dialog_map_event_cb (GtkWidget *widget, GdkEventAny *event, gpointer data)
+{
+    App *app = data;
+
+    select_current_output_from_dialog_position (app);
+    return FALSE;
+}
+
 static void
 run_application (App *app)
 {
@@ -1753,6 +1881,8 @@ run_application (App *app)
     app->client = gconf_client_get_default ();
 
     app->dialog = glade_xml_get_widget (xml, "dialog");
+    g_signal_connect_after (app->dialog, "map-event",
+			    G_CALLBACK (dialog_map_event_cb), app);
 
     gtk_window_set_default_icon_name ("gnome-display-properties");
     gtk_window_set_icon_name (GTK_WINDOW (app->dialog),