Full-screen Magnifier: Support warping the cursor on the edge

ash/magnifier/magnification_controller.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 ASH_MAGNIFIER_MAGNIFICATION_CONTROLLER_H_
 #define ASH_MAGNIFIER_MAGNIFICATION_CONTROLLER_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/aura/event_filter.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 
 namespace aura {
 class RootWindow;
 }
 
 namespace ash {
 namespace internal {
 
 class MagnificationController {
  public:
-  MagnificationController();
-
   virtual ~MagnificationController() {}
 
+  // Creates a new MagnificationController. The caller takes ownership of the
+  // returned object.
+  static MagnificationController* CreateInstance();
+
   // Sets the magnification ratio. 1.0f means no magnification.
-  void SetScale(float scale);
+  virtual void SetScale(float scale, bool animate) = 0;
   // Returns the current magnification ratio.
-  float GetScale() const { return scale_; }
+  virtual float GetScale() const = 0;
 
   // Set the top-left point of the magnification window.
-  void MoveWindow(int x, int y);
-  void MoveWindow(const gfx::Point& point);
+  virtual void MoveWindow(int x, int y, bool animate) = 0;
+  virtual void MoveWindow(const gfx::Point& point, bool animate) = 0;
   // Returns the current top-left point of the magnification window.
-  gfx::Point GetWindowPosition() const { return gfx::Point(x_, y_); }
+  virtual gfx::Point GetWindowPosition() const = 0;
 
   // Ensures that the given point/rect is inside the magnification window. If
   // not, the controller moves the window to contain the given point/rect.
-  void EnsureShowRect(const gfx::Rect& rect);
-  void EnsureShowPoint(const gfx::Point& point, bool animation);
+  virtual void EnsureRectIsVisible(const gfx::Rect& rect, bool animate) = 0;
+  virtual void EnsurePointIsVisible(const gfx::Point& point, bool animate) = 0;
 
- private:
-  aura::RootWindow* root_window_;
-
-  // Current scale, position of the magnification window.
-  float scale_;
-  int x_;
-  int y_;
-
-  // Returns the rect of the magnification window.
-  gfx::Rect GetWindowRect();
-  // Moves the magnification window to new scale and position. This method
-  // should be called internally just after the scale and/or the position are
-  // changed.
-  void RedrawScreen(bool animation);
-
-  DISALLOW_COPY_AND_ASSIGN(MagnificationController);
+ protected:
+  MagnificationController() {}
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_MAGNIFIER_MAGNIFICATION_CONTROLLER_H_