[gnome-panel] [panel] Move the toplevel to its configured monitor if it appears

[Vincent Untz <vuntz src gnome org>]

commit 8f342dc0ca8d94f1ce28739ef068d890c82d22c6
Author: Vincent Untz <vuntz gnome org>
Date:   Wed Aug 12 14:07:22 2009 +0200

    [panel] Move the toplevel to its configured monitor if it appears
    
    When a new monitor appears, all toplevels get a size request. So the
    first thing we do during this size request is checking whether the
    monitor of the toplevel is the same as the one it's configured to be on.

 gnome-panel/panel-toplevel.c |   74 +++++++++++++++++++++++++++++++++++++----
 1 files changed, 66 insertions(+), 8 deletions(-)
---
diff --git a/gnome-panel/panel-toplevel.c b/gnome-panel/panel-toplevel.c
index c23a0c0..a223166 100644
--- a/gnome-panel/panel-toplevel.c
+++ b/gnome-panel/panel-toplevel.c
@@ -88,6 +88,10 @@ struct _PanelToplevelPrivate {
 	int                     y_bottom;
 
 	int                     monitor;
+	/* this is used when the configured monitor is missing. We keep it so
+	 * we can move the toplevel to the right monitor when it becomes
+	 * available */
+	int                     missing_monitor;
 
 	int                     hide_delay;
 	int                     unhide_delay;
@@ -232,8 +236,11 @@ static guint         toplevel_signals [LAST_SIGNAL] = { 0 };
 static GSList       *toplevel_list = NULL;
 
 static void panel_toplevel_calculate_animation_end_geometry (PanelToplevel *toplevel);
+
+static void panel_toplevel_update_monitor       (PanelToplevel *toplevel);
 static void panel_toplevel_set_monitor_internal (PanelToplevel *toplevel,
-						 int            monitor);
+						 int            monitor,
+						 gboolean       force_resize);
 
 
 GSList *
@@ -2118,7 +2125,7 @@ panel_toplevel_update_expanded_position (PanelToplevel *toplevel)
 
 	monitor = panel_multiscreen_get_monitor_at_point (screen, x, y);
 
-	panel_toplevel_set_monitor_internal (toplevel, monitor);
+	panel_toplevel_set_monitor_internal (toplevel, monitor, TRUE);
 
 	x -= panel_multiscreen_x (screen, monitor);
 	y -= panel_multiscreen_y (screen, monitor);
@@ -3045,6 +3052,10 @@ panel_toplevel_size_request (GtkWidget      *widget,
 	toplevel = PANEL_TOPLEVEL (widget);
 	bin = GTK_BIN (widget);
 
+	/* we get a size request when there are new monitors, so first try to
+	 * see if we need to move to a new monitor */
+	panel_toplevel_update_monitor (toplevel);
+
 	if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 		gtk_widget_size_request (bin->child, requisition);
 
@@ -4482,6 +4493,7 @@ panel_toplevel_init (PanelToplevel *toplevel)
 	toplevel->priv->x_right         = -1;
 	toplevel->priv->y_bottom        = -1;
 	toplevel->priv->monitor         = 0;
+	toplevel->priv->missing_monitor = -1;
 	toplevel->priv->hide_delay      = DEFAULT_HIDE_DELAY;
 	toplevel->priv->unhide_delay    = DEFAULT_UNHIDE_DELAY;
 	toplevel->priv->auto_hide_size  = DEFAULT_AUTO_HIDE_SIZE;
@@ -4986,15 +4998,59 @@ panel_toplevel_get_y_centered (PanelToplevel *toplevel)
 	return toplevel->priv->y_centered;
 }
 
-/* This is used when we need to change the monitor because of constraints, but
- * not because of the configuration. */
+/**
+ * panel_toplevel_set_monitor_internal:
+ *
+ * Sets the monitor of the toplevel, but only the internal state. We need to
+ * make the difference between the internal state and the configuration of the
+ * user because internal constraints might affect the monitor of the toplevel.
+ *
+ * panel_toplevel_set_monitor_internal() won't update the configuration of the
+ * user.
+ **/
 static void
 panel_toplevel_set_monitor_internal (PanelToplevel *toplevel,
-				     int            monitor)
+				     int            monitor,
+				     gboolean       force_resize)
 {
+	/* if we finally use the missing monitor, then the world is at peace */
+	if (toplevel->priv->missing_monitor == monitor)
+		toplevel->priv->missing_monitor = -1;
+
+	if (toplevel->priv->monitor == monitor)
+		return;
+
 	toplevel->priv->monitor = monitor;
 
-	gtk_widget_queue_resize (GTK_WIDGET (toplevel));
+	if (force_resize)
+		gtk_widget_queue_resize (GTK_WIDGET (toplevel));
+}
+
+/**
+ * panel_toplevel_update_monitor:
+ *
+ * Moves the toplevel to its configured monitor if needed. This generally
+ * happens when the configured monitor was non-existing before, and it appeared
+ * at runtime.
+ *
+ * This must only be called at the beginning of the size request of the
+ * toplevel because it doesn't queue a size request.
+ **/
+static void
+panel_toplevel_update_monitor (PanelToplevel *toplevel)
+{
+	GdkScreen *screen;
+
+	if (toplevel->priv->missing_monitor == -1)
+		return;
+
+	screen = gtk_window_get_screen (GTK_WINDOW (toplevel));
+	if (toplevel->priv->missing_monitor >= panel_multiscreen_monitors (screen))
+		return;
+
+	panel_toplevel_set_monitor_internal (toplevel,
+					     toplevel->priv->missing_monitor,
+					     FALSE);
 }
 
 void
@@ -5013,10 +5069,12 @@ panel_toplevel_set_monitor (PanelToplevel *toplevel,
 	 * We will put the panel on the monitor 0 for this session, and it will
 	 * move back to the right monitor next time. */
 	screen = gtk_window_get_screen (GTK_WINDOW (toplevel));
-	if (monitor >= panel_multiscreen_monitors (screen))
+	if (monitor >= panel_multiscreen_monitors (screen)) {
+		toplevel->priv->missing_monitor = monitor;
 		return;
+	}
 
-	panel_toplevel_set_monitor_internal (toplevel, monitor);
+	panel_toplevel_set_monitor_internal (toplevel, monitor, TRUE);
 
 	g_object_notify (G_OBJECT (toplevel), "monitor");
 }