Support detaching/attaching panels via inter-strip drags.

chrome/browser/ui/panels/docked_panel_strip.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_PANELS_DOCKED_PANEL_STRIP_H_
 #define CHROME_BROWSER_UI_PANELS_DOCKED_PANEL_STRIP_H_
 #pragma once
 
 #include <list>
 #include <set>
@@ skipping 25 matching lines @@
 
   // Rearranges the positions of the panels in the strip.
   // Handles moving panels to/from overflow area as needed.
   // This is called when the display space has been changed, i.e. working
   // area being changed or a panel being closed.
   virtual void RefreshLayout() OVERRIDE;
 
   // 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(
       Panel* panel,
       const gfx::Size& preferred_window_size) OVERRIDE;
   virtual void OnPanelAttentionStateChanged(Panel* panel) OVERRIDE;
   virtual void ActivatePanel(Panel* panel) OVERRIDE;
   virtual void MinimizePanel(Panel* panel) OVERRIDE;
   virtual void RestorePanel(Panel* panel) OVERRIDE;
   virtual bool CanShowPanelAsActive(const Panel* panel) const OVERRIDE;
@@ skipping 44 matching lines @@
  private:
   enum TitlebarAction {
     NO_ACTION,
     BRING_UP,
     BRING_DOWN
   };
 
   // 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();
 
   // Help functions to drag the given panel.
   void DragLeft(Panel* dragging_panel);
   void DragRight(Panel* dragging_panel);
 
   // Does the real job of bringing up or down the titlebars.
   void DoBringUpOrDownTitlebars(bool bring_up);
   // The callback for a delyed task, checks if it still need to perform
   // the delayed action.
   void DelayedBringUpOrDownTitlebarsCheck();
 
   int GetRightMostAvailablePosition() const;
 
   // Called by AddPanel() after a delay to move a newly created panel from
   // the panel strip to overflow because the panel could not fit
   // within the bounds of the panel strip. New panels are first displayed
   // in the panel strip, then moved to overflow so that all created
   // 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.
 
   // All panels in the panel strip must fit within this area.
   gfx::Rect display_area_;
 
   Panels panels_;
 
   // Stores newly created panels that have a temporary layout until they
   // are moved to overflow after a delay.
   std::set<Panel*> panels_in_temporary_layout_;
 
   int minimized_panel_count_;
   bool are_titlebars_up_;
 
   // |True| to temporarily prevent refreshing panel layout, e.g. while
   // moving panels to overflow area to make room for a panel in this strip.
   bool disable_layout_refresh_;
 
   // Referring to current position in |panels_| where the dragging panel
   // 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.
   TitlebarAction delayed_titlebar_action_;
 
   // Owned by MessageLoop after posting.
   base::WeakPtrFactory<DockedPanelStrip> titlebar_action_factory_;
 
   static const int kPanelsHorizontalSpacing = 4;
 
   // Absolute minimum width and height for panels, including non-client area.
   // Should only be big enough to accomodate a close button on the reasonably
   // recognisable titlebar.
   static const int kPanelMinWidth;
   static const int kPanelMinHeight;
 
   DISALLOW_COPY_AND_ASSIGN(DockedPanelStrip);
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_DOCKED_PANEL_STRIP_H_