Mac: Added a delay before panels go to minimized state from title-only state.

chrome/browser/ui/panels/panel_manager.cc

Index: chrome/browser/ui/panels/panel_manager.cc
diff --git a/chrome/browser/ui/panels/panel_manager.cc b/chrome/browser/ui/panels/panel_manager.cc
index 5bb2bc8d0dc8b9280c3408159ef4e5e4dda75585..ef350aa23d2bb0d805c3b43af383b0631f6f6e3d 100644
--- a/chrome/browser/ui/panels/panel_manager.cc
+++ b/chrome/browser/ui/panels/panel_manager.cc
@@ -32,11 +32,21 @@ const double kPanelMaxHeightFactor = 0.5;
 // After the time expires, we bring up/down the titlebars as planned.
 const int kMaxMillisecondsWaitForBottomBarVisibilityChange = 1000;
 
+// See usage below.
+#if defined (OS_MACOSX)

[jianli, 2011/10/28 01:04:11]

Extra empty space.

[Dmitry Titov, 2011/10/28 20:58:23]

Done.

+const int kMillisecondsBeforeCollapsingFromTitleonlyState = 3000;
+#else
+const int kMillisecondsBeforeCollapsingFromTitleonlyState = 0;
+#endif
+
 // Single instance of PanelManager.
 scoped_refptr<PanelManager> panel_manager_instance;
 }  // namespace
 
 // static
+int PanelManager::sLastTaskIndex = 0;
+
+// static
 PanelManager* PanelManager::GetInstance() {
   if (!panel_manager_instance.get())
     panel_manager_instance = new PanelManager();
@@ -411,22 +421,54 @@ void PanelManager::BringUpOrDownTitlebars(bool bring_up) {
       MessageLoop::current()->PostDelayedTask(
           FROM_HERE,
           method_factory_.NewRunnableMethod(
-              &PanelManager::DelayedBringUpOrDownTitlebarsCheck),
+              &PanelManager::DelayedBringUpOrDownTitlebarsCheck,
+              ++sLastTaskIndex),

[jianli, 2011/10/28 01:04:11]

Where do we reset sLastTaskIndex? What if increasing sLastTaskIndex causes
overflow?

[Dmitry Titov, 2011/10/28 20:58:23]

If we post a task every time user moves the mouse above/below target and user
does it every second, it will take 126 years to overflow 32-bit integer... I
think we can just ignore overflow.

           kMaxMillisecondsWaitForBottomBarVisibilityChange);
 
       return;
     }
   }
 
+  // On some OSes, the interaction with native Taskbars/Docks may be improved
+  // if the panels are not go back to minimized state too fast. For example,

[jianli, 2011/10/28 01:04:11]

are not => do not

[Dmitry Titov, 2011/10/28 20:58:23]

Done.

+  // it makes it possible to hit the titlebar on OSX if Dock has Magnifying
+  // enabled - the panels stay up for a while after Dock magnification effect
+  // stops covering the panels.
+  if (!bring_up) {
+    delayed_titlebar_action_ = BRING_DOWN;
+    MessageLoop::current()->PostDelayedTask(

[jianli, 2011/10/28 01:04:11]

This seems to  be similar to the above PostDelayedTask code. Can they be merged?

[Dmitry Titov, 2011/10/28 20:58:23]

Done.

+        FROM_HERE,
+        method_factory_.NewRunnableMethod(
+            &PanelManager::DelayedBringUpOrDownTitlebarsCheck,
+            ++sLastTaskIndex),
+        kMillisecondsBeforeCollapsingFromTitleonlyState);
+    return;
+  }
+
+
   DoBringUpOrDownTitlebars(bring_up);
 }
 
-void PanelManager::DelayedBringUpOrDownTitlebarsCheck() {
+void PanelManager::DelayedBringUpOrDownTitlebarsCheck(int taskIndex) {

[jianli, 2011/10/28 01:04:11]

taskIndex => task_index

[Dmitry Titov, 2011/10/28 20:58:23]

Done.

+  // task was already processed or cancelled - bail out.

[jianli, 2011/10/28 01:04:11]

task needs to be capitalized.

[Dmitry Titov, 2011/10/28 20:58:23]

Done.

   if (delayed_titlebar_action_ == NO_ACTION)
     return;
 
-  DoBringUpOrDownTitlebars(delayed_titlebar_action_ == BRING_UP);
+  // In case we posted multiple tasks because user was moving mouse back and
+  // forth, ignore all but the last one.
+  if (taskIndex < sLastTaskIndex)
+    return;
+  DCHECK(taskIndex == sLastTaskIndex);
+
+  // We are going to process the task one way or another after this point.
   delayed_titlebar_action_ = NO_ACTION;
+
+  // Check if the action is still needed based on mouse position. In case the
+  // mouse moved and does not call for the titlebars change, cancel.
+  if (are_titlebars_up_ != (delayed_titlebar_action_ == BRING_UP))
+    return;
+
+  DoBringUpOrDownTitlebars(delayed_titlebar_action_ == BRING_UP);
 }
 
 void PanelManager::DoBringUpOrDownTitlebars(bool bring_up) {