[california] Stop main window from "stuttering" when maximized: Bug #729029

[Jim Nelson <jnelson src gnome org>]

commit 923716e49fcdfb8ffffb0061c72617ec4875ec25
Author: Jim Nelson <jim yorba org>
Date:   Tue Sep 23 18:56:48 2014 -0700

    Stop main window from "stuttering" when maximized: Bug #729029
    
    The GtkStack transition for the month and week views were causing the
    main window to shift strangely on the screen and then return to
    position.  Toolkit.StackModel was using the timer to "guess" when the
    GtkStack transition was completed to balance its cache.  With GTK+
    3.12, a GtkStack property notification does this better, and moving
    the balance call to there seems to have solved the issue.

 src/toolkit/toolkit-stack-model.vala |   22 +++++++++++++---------
 1 files changed, 13 insertions(+), 9 deletions(-)
---
diff --git a/src/toolkit/toolkit-stack-model.vala b/src/toolkit/toolkit-stack-model.vala
index 5eb3afe..aa95dc3 100644
--- a/src/toolkit/toolkit-stack-model.vala
+++ b/src/toolkit/toolkit-stack-model.vala
@@ -34,6 +34,7 @@ public class StackModel<G> : BaseObject {
      * Transition type for spatial transitions according to ordering.
      */
     public enum OrderedTransitionType {
+        NONE,
         CROSSFADE,
         SLIDE_LEFT_RIGHT,
         SLIDE_UP_DOWN;
@@ -51,6 +52,9 @@ public class StackModel<G> : BaseObject {
                 return (this == CROSSFADE) ? Gtk.StackTransitionType.CROSSFADE : 
Gtk.StackTransitionType.NONE;
             
             switch (this) {
+                case NONE:
+                    return Gtk.StackTransitionType.NONE;
+                
                 case CROSSFADE:
                     return Gtk.StackTransitionType.CROSSFADE;
                 
@@ -116,7 +120,6 @@ public class StackModel<G> : BaseObject {
     private Gee.HashMap<G, Gtk.Widget?> items;
     private bool in_balance_cache = false;
     private bool stack_destroyed = false;
-    private Scheduled? scheduled_balance_cache = null;
     
     public StackModel(Gtk.Stack stack,
         OrderedTransitionType ordered_transition_type,
@@ -138,12 +141,14 @@ public class StackModel<G> : BaseObject {
         
         stack.remove.connect(on_stack_removed);
         stack.notify["visible-child"].connect(on_stack_child_visible);
+        stack.notify["transition-running"].connect(on_stack_transition_running);
         stack.destroy.connect(on_stack_destroyed);
     }
     
     ~StackModel() {
         stack.remove.disconnect(on_stack_removed);
         stack.notify["visible-child"].disconnect(on_stack_child_visible);
+        stack.notify["transition-running"].disconnect(on_stack_transition_running);
         stack.destroy.disconnect(on_stack_destroyed);
     }
     
@@ -253,14 +258,6 @@ public class StackModel<G> : BaseObject {
             if (iter.get_value() == stack.visible_child) {
                 visible_item = iter.get_key();
                 
-                // to avoid stutter, only balance the cache when the transition has completed,
-                // which (apparently) it has not when this change is made (probably made at start
-                // of transition, not the end) ... "transition-running" property would be useful
-                // here, but that's not available until GTK 3.12
-                scheduled_balance_cache = new Scheduled.once_at_idle(() => {
-                    balance_cache("on_stack_child_visible");
-                }, Priority.LOW);
-                
                 return;
             }
         }
@@ -269,6 +266,13 @@ public class StackModel<G> : BaseObject {
         visible_item = null;
     }
     
+    // to avoid stutter, only balance the cache when the transition has completed,
+    private void on_stack_transition_running() {
+        // don't care if it is running, want to known when it's not
+        if (!stack.transition_running)
+            balance_cache("!on_stack_transition_running");
+    }
+    
     private void on_stack_destroyed() {
         stack_destroyed = true;
     }