Refactor PanelManager to create PanelStrip.

chrome/browser/ui/panels/panel_strip.h

 // Copyright (c) 2011 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_PANEL_MANAGER_H_
-#define CHROME_BROWSER_UI_PANELS_PANEL_MANAGER_H_
+#ifndef CHROME_BROWSER_UI_PANELS_PANEL_STRIP_H_
+#define CHROME_BROWSER_UI_PANELS_PANEL_STRIP_H_
 #pragma once
 
 #include <vector>
 #include "base/basictypes.h"
-#include "base/lazy_instance.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/ui/panels/auto_hiding_desktop_bar.h"
+#include "chrome/browser/ui/panels/panel_mouse_watcher_observer.h"
 #include "chrome/browser/ui/panels/panel.h"
-#include "chrome/browser/ui/panels/panel_mouse_watcher_observer.h"
 #include "ui/gfx/rect.h"
 
 class Browser;
-class Panel;
-class PanelMouseWatcher;
+class PanelManager;
 
-// This class manages a set of panels.
-// Note that the ref count is needed by using PostTask in the implementation.
-class PanelManager : public PanelMouseWatcherObserver,
-                     public AutoHidingDesktopBar::Observer {
+// This class manages a group of panels displayed in a strip.

[jianli, 2011/11/30 19:27:01]

Probably more detail to the comment like:
  in a strip attached to the bottom of the screen.

[jennb, 2011/11/30 19:55:12]

Added more details, but I purposely avoided limiting this to being docked along
the bottom of the screen. The strip merely positions panels within its bounds.
Exception that I want to cleanup in a separate patch is the title-only panels
appearing above an auto-hiding taskbar. Then this becomes a generic strip of
panels for minimized/title-only/expanded state. We could even dock it to the top
of the screen. Eventually, we could allow the entire strip to be positioned by
the user and perhaps even oriented vertically. Would be nice if the overflow
strip could be managed likewise.

+class PanelStrip : public PanelMouseWatcherObserver {
  public:
   typedef std::vector<Panel*> Panels;
 
-  // Returns a single instance.
-  static PanelManager* GetInstance();
+  explicit PanelStrip(PanelManager* panel_manager);
+  virtual ~PanelStrip();
 
-  // Called when the display is changed, i.e. work area is updated.
-  void OnDisplayChanged();
+  // Sets the bounds of the panel strip.
+  // |bounds| is in screen coordinates.
+  void SetBounds(const gfx::Rect bounds);
 
-  // Creates a panel and returns it. The panel might be queued for display
-  // later.
-  Panel* CreatePanel(Browser* browser);
+  // Adds a panel to the strip. The panel may be a newly created panel or one
+  // that is transitioning from another grouping of panels.
+  void AddPanel(Panel* panel);
 
-  void Remove(Panel* panel);
+  // Returns |false| if the panel is not in the strip.
+  bool Remove(Panel* panel);
   void RemoveAll();
 
   // Drags the given panel.
   void StartDragging(Panel* panel);
   void Drag(int delta_x);
   void EndDragging(bool cancelled);
 
   // Invoked when a panel's expansion state changes.
   void OnPanelExpansionStateChanged(Panel::ExpansionState old_state,
                                     Panel::ExpansionState new_state);
 
   // Invoked when the preferred window size of the given panel might need to
   // get changed.
   void OnPreferredWindowSizeChanged(
       Panel* panel, const gfx::Size& preferred_window_size);
 
   // 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;
 
-  // Returns the next browser window which could be either panel window or
-  // tabbed window, to switch to if the given panel is going to be deactivated.
-  // Returns NULL if such window cannot be found.
-  BrowserWindow* GetNextBrowserWindowToActivate(Panel* panel) const;
-
   int num_panels() const { return panels_.size(); }
   bool is_dragging_panel() const;
   const Panels& panels() const { return panels_; }
 
   int GetMaxPanelWidth() const;
   int GetMaxPanelHeight() const;
   int StartingRightPosition() const;
 
-  // Moves a panel to the panel strip. The panel does not currently
-  // belong in any other strip. This may cause other panels to be
-  // bumped out of the panel strip.
-  void MoveToPanelStrip(Panel* panel);
-
-  // Moves a panel to the overflow strip. The panel does not currently
-  // belong in any other strip.
-  // |is_new| is true if the panel was just created.
-  void MoveToOverflowStrip(Panel* panel, bool is_new);
-
   // Overridden from PanelMouseWatcherObserver:
   virtual void OnMouseMove(const gfx::Point& mouse_position) OVERRIDE;
 
+  void OnAutoHidingDesktopBarVisibilityChanged(
+      AutoHidingDesktopBar::Alignment alignment,
+      AutoHidingDesktopBar::Visibility visibility);
+
 #ifdef UNIT_TEST
   static int horizontal_spacing() { return kPanelsHorizontalSpacing; }
 
-  const gfx::Rect& work_area() const {
-    return work_area_;
-  }
-
-  void set_auto_hiding_desktop_bar(
-      AutoHidingDesktopBar* auto_hiding_desktop_bar) {
-    auto_hiding_desktop_bar_ = auto_hiding_desktop_bar;
-  }
-
-  void enable_auto_sizing(bool enabled) {
-    auto_sizing_enabled_ = enabled;
-  }
-
-  void SetWorkAreaForTesting(const gfx::Rect& work_area) {
-    SetWorkArea(work_area);
-  }
-
   void remove_delays_for_testing() {
     remove_delays_for_testing_ = true;
   }
 
   int minimized_panel_count() {
     return minimized_panel_count_;
   }
-
-  // Tests should disable mouse watching if mouse movements will be simulated.
-  void disable_mouse_watching() {
-    mouse_watching_disabled_ = true;
-  }
 #endif
 
  private:
-  friend struct base::DefaultLazyInstanceTraits<PanelManager>;
-  FRIEND_TEST_ALL_PREFIXES(PanelBrowserTest, SizeClamping);
-
   enum TitlebarAction {
     NO_ACTION,
     BRING_UP,
     BRING_DOWN
   };
 
-  PanelManager();
-  virtual ~PanelManager();
-
-  // Overridden from AutoHidingDesktopBar::Observer:
-  virtual void OnAutoHidingDesktopBarThicknessChanged() OVERRIDE;
-  virtual void OnAutoHidingDesktopBarVisibilityChanged(
-      AutoHidingDesktopBar::Alignment alignment,
-      AutoHidingDesktopBar::Visibility visibility) OVERRIDE;
-
-  // Applies the new work area. This is called by OnDisplayChanged and the test
-  // code.
-  void SetWorkArea(const gfx::Rect& work_area);
-
-  // Adjusts the work area to exclude the influence of auto-hiding desktop bars.
-  void AdjustWorkAreaForAutoHidingDesktopBars();
+  // Helper functions to add a panel to the strip.
+  void AddNewPanel(Panel* panel);
+  void AddExistingPanel(Panel* panel);
 
   // Keep track of the minimized panels to control mouse watching.
   void IncrementMinimizedPanels();
   void DecrementMinimizedPanels();
 
   // Handles all the panels that're delayed to be removed.
   void DelayedRemove();
 
   // Does the remove. Called from Remove and DelayedRemove.
   void DoRemove(Panel* panel);
 
   // Rearranges the positions of the panels starting from the given iterator.
   // This is called when the display space has been changed, i.e. working
   // area being changed or a panel being closed.
   void Rearrange(Panels::iterator iter_to_start, int rightmost_position);
 
   // Help functions to drag the given panel.
   void DragLeft();
   void DragRight();
 
   // 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;
 
+  PanelManager* panel_manager_;  // Weak, owns us.
+
+  // All panels in the panel strip must fit within this area.
+  gfx::Rect strip_bounds_;

[jianli, 2011/11/30 19:27:01]

Would strip_area_ sounds better? The suffix |bounds| reminds me the bounds for a
window or control.

[jennb, 2011/11/30 19:55:12]

I think of the strip like a containing view and the panels are subviews within
its bounds.

+
   Panels panels_;
 
   // Stores the panels that are pending to remove. We want to delay the removal
   // when we're in the process of the dragging.
   Panels panels_pending_to_remove_;
 
-  // Use a mouse watcher to know when to bring up titlebars to "peek" at
-  // minimized panels. Mouse movement is only tracked when there is a minimized
-  // panel.
-  scoped_ptr<PanelMouseWatcher> panel_mouse_watcher_;
   int minimized_panel_count_;
   bool are_titlebars_up_;
 
-  // The maximum work area avaialble. This area does not include the area taken
-  // by the always-visible (non-auto-hiding) desktop bars.
-  gfx::Rect work_area_;
-
-  // The useable work area for computing the panel bounds. This area excludes
-  // the potential area that could be taken by the auto-hiding desktop
-  // bars (we only consider those bars that are aligned to bottom, left, and
-  // right of the screen edges) when they become fully visible.
-  gfx::Rect adjusted_work_area_;
-
   // Panel to drag.
   size_t dragging_panel_index_;
 
   // 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_;
 
-  scoped_refptr<AutoHidingDesktopBar> auto_hiding_desktop_bar_;
-
   // Delayed transitions support. Sometimes transitions between minimized and
   // title-only states are delayed, for better usability with Taskbars/Docks.
   TitlebarAction delayed_titlebar_action_;
   bool remove_delays_for_testing_;
   // Owned by MessageLoop after posting.
-  base::WeakPtrFactory<PanelManager> titlebar_action_factory_;
-
-  // Whether or not bounds will be updated when the preferred content size is
-  // changed. The testing code could set this flag to false so that other tests
-  // will not be affected.
-  bool auto_sizing_enabled_;
-
-  bool mouse_watching_disabled_;  // For tests to simulate mouse movements.
+  base::WeakPtrFactory<PanelStrip> 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(PanelManager);
+  DISALLOW_COPY_AND_ASSIGN(PanelStrip);
 };
 
-#endif  // CHROME_BROWSER_UI_PANELS_PANEL_MANAGER_H_
+#endif  // CHROME_BROWSER_UI_PANELS_PANEL_STRIP_H_