Support detaching/attaching panels via inter-strip drags.

chrome/browser/ui/panels/docked_panel_strip.h

Index: chrome/browser/ui/panels/docked_panel_strip.h
diff --git a/chrome/browser/ui/panels/docked_panel_strip.h b/chrome/browser/ui/panels/docked_panel_strip.h
index 2fb002943a84d77ae1a730dd4bf1c3e73b0a1e1a..8f81ee952c49bd1028e890fd8ff7b45bd7f43c6e 100644
--- a/chrome/browser/ui/panels/docked_panel_strip.h
+++ b/chrome/browser/ui/panels/docked_panel_strip.h
@@ -43,6 +43,8 @@ class DockedPanelStrip : public PanelStrip,
   // Adds a panel to the strip. The panel may be a newly created panel or one
   // that is transitioning from another grouping of panels.
   virtual void AddPanel(Panel* panel) OVERRIDE;
+  virtual void AddPanelAtPosition(Panel* panel,
+                                  const gfx::Point& position) OVERRIDE;
   virtual bool RemovePanel(Panel* panel) OVERRIDE;
   virtual void CloseAll() OVERRIDE;
   virtual void ResizePanelWindow(
@@ -107,6 +109,11 @@ class DockedPanelStrip : public PanelStrip,
   // Overridden from PanelMouseWatcherObserver:
   virtual void OnMouseMove(const gfx::Point& mouse_position) OVERRIDE;
 
+  // Ensures that there is sufficient space in the strip to add a panel with
+  // the specified width. We might need to bump panels in the strip to make
+  // room for this panel.
+  void EnsureEnoughSpaceForPanel(int width);
+
   // Keep track of the minimized panels to control mouse watching.
   void IncrementMinimizedPanels();
   void DecrementMinimizedPanels();
@@ -130,6 +137,10 @@ class DockedPanelStrip : public PanelStrip,
   // panels are (at least briefly) visible before entering overflow.
   void DelayedMovePanelToOverflow(Panel* panel);
 
+  // Returns next panel in the list that is placed after the given iterator.
+  // Returns NULL if the given iterator refers to the last panel in the list.
+  Panel* GetNextPanel(const Panels::iterator& iter) const;

[jennb, 2012/03/01 00:33:38]

Is this just a wrapper for iter++?

[jianli, 2012/03/02 22:42:43]

Yes. I removed it since it is not needed.

+
   Panel* dragging_panel() const;
 
   PanelManager* panel_manager_;  // Weak, owns us.
@@ -154,9 +165,10 @@ class DockedPanelStrip : public PanelStrip,
   // resides.
   Panels::iterator dragging_panel_current_iterator_;
 
-  // Referring to original position in |panels_| where the dragging panel
-  // resides.
-  Panels::iterator dragging_panel_original_iterator_;
+  // Panel to restore after when the drag is cancelled and the dragging panel
+  // needs to get back to its original position. If NULL, the panel will be
+  // restored at the end of the list.
+  Panel* panel_to_restore_after_on_drag_cancelled_;

[jennb, 2012/03/01 00:33:38]

I don't understand the comment for this var. 

[jianli, 2012/03/02 22:42:43]

Per discussion, removed.

 
   // Delayed transitions support. Sometimes transitions between minimized and
   // title-only states are delayed, for better usability with Taskbars/Docks.