Refactor intra-strip panel drags by introducing PanelDragController.

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 35 matching lines @@
   virtual void AddPanel(Panel* panel) 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;
-
-  // Drags the given panel.
-  void StartDragging(Panel* panel);
-  void Drag(int delta_x);
-  void EndDragging(bool cancelled);
+  virtual bool CanDragPanel(const Panel* panel) const OVERRIDE;
+  virtual void StartDraggingPanel(Panel* panel) OVERRIDE;
+  virtual void DragPanel(Panel* panel, int delta_x, int delta_y) OVERRIDE;
+  virtual void EndDraggingPanel(Panel* panel, bool cancelled) OVERRIDE;
 
   // Invoked when a panel's expansion state changes.
   void OnPanelExpansionStateChanged(Panel* panel);
 
   // Returns true if we should bring up the titlebars, given the current mouse
   // point.
   bool ShouldBringUpTitlebars(int mouse_x, int mouse_y) const;
 
   // Brings up or down the titlebars for all minimized panels.
   void BringUpOrDownTitlebars(bool bring_up);
 
   // Returns the bottom position for the panel per its expansion state. If auto-
   // hide bottom bar is present, we want to move the minimized panel to the
   // bottom of the screen, not the bottom of the work area.
   int GetBottomPositionForExpansionState(
       Panel::ExpansionState expansion_state) const;
 
   // num_panels() and panels() only includes panels in the panel strip that
   // do NOT have a temporary layout.
   int num_panels() const { return panels_.size(); }
   const Panels& panels() const { return panels_; }
 
-  bool is_dragging_panel() const;
   gfx::Rect display_area() const { return display_area_; }
 
   int GetMaxPanelWidth() const;
   int GetMaxPanelHeight() const;
   int StartingRightPosition() const;
 
   void OnAutoHidingDesktopBarVisibilityChanged(
       AutoHidingDesktopBar::Alignment alignment,
       AutoHidingDesktopBar::Visibility visibility);
 
@@ skipping 21 matching lines @@
 
   // Handles all the panels that're delayed to be removed.
   void DelayedRemove();
 
   // Does the actual remove. Caller is responsible for rearranging
   // the panel strip if necessary.
   // Returns |false| if panel is not in the strip.
   bool DoRemove(Panel* panel);
 
   // Help functions to drag the given panel.
-  void DragLeft();
-  void DragRight();
+  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
@@ skipping 18 matching lines @@
   // 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_;
 
-  // Panel to drag.
-  Panel* dragging_panel_;
+  // Iterator of panel being dragged.
   Panels::iterator dragging_panel_iterator_;
 
   // Original x coordinate of the panel to drag. This is used to get back to
   // the original position when we cancel the dragging.
   int dragging_panel_original_x_;
 
   // Bounds of the panel to drag. It is first set to the original bounds when
   // the dragging happens. Then it is updated to the position that will be set
   // to when the dragging ends.
   gfx::Rect dragging_panel_bounds_;
@@ skipping 10 matching lines @@
   // 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_