highlight intermediate tabs

chrome/browser/ui/views/ash/tab_scrubber.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_VIEWS_ASH_TAB_SCRUBBER_H_
 #define CHROME_BROWSER_UI_VIEWS_ASH_TAB_SCRUBBER_H_
 
+#include "base/timer.h"
+#include "chrome/browser/ui/views/tabs/tab_strip_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "ui/base/animation/animation_delegate.h"
 #include "ui/base/events/event_handler.h"
 
 class Browser;
-class Tab;
+class TabStrip;
+
+namespace gfx {
+class Point;
+}
 
 // Class to enable quick tab switching via Ctrl-left-drag.
 // Notes: this is experimental, and disables ctrl-clicks. It should not be
 // enabled other than through flags until we implement 3 finger drag as the
 // mechanism to invoke it. At that point we will add test coverage.
 class TabScrubber : public ui::EventHandler,
-                    public content::NotificationObserver {
+                    public content::NotificationObserver,
+                    public TabStripObserver {
  public:
+  enum Direction {LEFT, RIGHT};
+
+  // Returns a the single instance of a TabScrubber.
   static TabScrubber* GetInstance();
 
+  // Returns the virtual position of a swipe starting in the tab at |index|,
+  // base on the |direction|.
+  static gfx::Point GetStartPoint(TabStrip* tab_strip,
+                                  int index,
+                                  TabScrubber::Direction direction);
+
+  void set_activation_delay(base::TimeDelta activation_delay) {
+    activation_delay_ = activation_delay;
+  }
+  base::TimeDelta activation_delay() const { return activation_delay_; }
+  int highlighted_tab() const { return highlighted_tab_; }
+  bool IsActivationPending();
+
  private:
   TabScrubber();
   virtual ~TabScrubber();
 
   // ui::EventHandler overrides:
   virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
 
   // content::NotificationObserver overrides:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // TabStripObserver overrides.
+  virtual void TabStripAddedTabAt(TabStrip* tab_strip, int index);
+  virtual void TabStripMovedTab(TabStrip* tab_strip,
+                                int from_index,
+                                int to_index);
+  virtual void TabStripRemovedTabAt(TabStrip* tab_strip, int index);
+  virtual void TabStripDeleted(TabStrip* tab_strip);
+
   Browser* GetActiveBrowser();
-  void StartScrubbing();
-  void StopScrubbing();
+  void FinishScrub(bool activate);
+  void CancelImmersiveReveal();
 
-  // Indicates that we are currently scrubbing.
+  // Are we currently scrubbing?.
   bool scrubbing_;
-  // The browser that we are scrubbing.
+  // The last browser we used for scrubbing, NULL if |scrubbing_| is
+  // false and there is no pending work.
   Browser* browser_;
-  // The x value of the event that initiated scrubbing.
-  float scroll_x_;
-  float scroll_y_;
+  // The current accumulated x and y positions of a swipe, in
+  // the coordinates of the TabStrip of |browser_|
+  float swipe_x_;
+  float swipe_y_;
+  // The direction the current swipe is headed.
+  Direction swipe_direction_;
+  // The index of the tab that is currently highlighted.
+  int highlighted_tab_;
+  // Timer to control a delayed activation of the |highlighted_tab_|.
+  base::Timer activate_timer_;
+  // Time to wait before newly selected tab becomes active.
+  base::TimeDelta activation_delay_;
+  // Indicates if we were in immersive mode and forced the tabs to be
+  // revealed.
+  bool should_cancel_immersive_reveal_;
+  // Timer to control the cancel of an immersive reveal.
+  base::Timer cancel_immersive_reveal_timer_;
 
   content::NotificationRegistrar registrar_;
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate its weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<TabScrubber> weak_ptr_factory_;

[sky, 2013/02/06 22:55:16]

I would recommend explicitly doing this first in the destructor. It's easy to
miss a comment like this here, but harder when there is something explicit in
the destructor.

 
   DISALLOW_COPY_AND_ASSIGN(TabScrubber);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_ASH_TAB_SCRUBBER_H_