Minor refactoring of window resize code. I wasn't too happy with

ash/wm/default_window_resizer.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_WM_WINDOW_RESIZER_H_
-#define ASH_WM_WINDOW_RESIZER_H_
+#ifndef ASH_WM_DEFAULT_WINDOW_RESIZER_H_
+#define ASH_WM_DEFAULT_WINDOW_RESIZER_H_
 #pragma once
 
-#include "ash/ash_export.h"
-#include "base/basictypes.h"
-#include "ui/gfx/rect.h"
-
-namespace aura {
-class Window;
-}
+#include "ash/wm/window_resizer.h"
+#include "base/compiler_specific.h"
 
 namespace ash {
 
 namespace internal {
 class RootWindowEventFilter;
 }
 
-// WindowResizer is used by ToplevelWindowEventFilter to handle dragging,
-// moving or resizing a window.
-class ASH_EXPORT WindowResizer {
+// WindowResizer is used by ToplevelWindowEventFilter to handle dragging, moving
+// or resizing a window. All coordinates passed to this are in the parent
+// windows coordiantes.
+class ASH_EXPORT DefaultWindowResizer : public WindowResizer {
  public:
   // Constants to identify the type of resize.
   static const int kBoundsChange_None;
   static const int kBoundsChange_Repositions;
   static const int kBoundsChange_Resizes;
 
   // Used to indicate which direction the resize occurs in.
   static const int kBoundsChangeDirection_None;
   static const int kBoundsChangeDirection_Horizontal;
   static const int kBoundsChangeDirection_Vertical;
 
-  WindowResizer(aura::Window* window,
-                const gfx::Point& location,
-                int window_component,
-                int grid_size);
-  virtual ~WindowResizer();
+  virtual ~DefaultWindowResizer();
 
-  // Returns a bitmask of the kBoundsChange_ values.
-  static int GetBoundsChangeForWindowComponent(int component);
-
-  // Returns a location >= |location| that is aligned to fall on increments of
-  // |grid_size|.
-  static int AlignToGrid(int location, int grid_size);
-
-  // Invoked to drag/move/resize the window. |location| is in the coordinates
-  // of the window supplied to the constructor.
-  void Drag(const gfx::Point& location);
-
-  // Invoked to complete the drag.
-  virtual void CompleteDrag();
-
-  // Reverts the drag.
-  virtual void RevertDrag();
+  // Creates a new DefaultWindowResizer. The caller takes ownership of the
+  // returned object. Returns NULL if not resizable.
+  static DefaultWindowResizer* Create(aura::Window* window,
+                                      const gfx::Point& location,
+                                      int window_component,
+                                      int grid_size);
 
   // Returns true if the drag will result in changing the window in anyway.
-  bool is_resizable() const { return is_resizable_; }
+  bool is_resizable() const { return details_.is_resizable; }
 
-  // See description above members for details.
-  const gfx::Rect& initial_bounds() const { return initial_bounds_; }
-  const gfx::Point& initial_location_in_parent() const {
-    return initial_location_in_parent_;
-  }
-  int window_component() const { return window_component_; }
-  aura::Window* window() const { return window_; }
-  int grid_size() const { return grid_size_; }
-  bool did_move_or_resize() const { return did_move_or_resize_; }
-  int bounds_change() const { return bounds_change_; }
-
- protected:
-  // Returns the bounds to give to the window once the mouse has moved to
-  // |location|.
-  virtual gfx::Rect GetBoundsForDrag(const gfx::Point& location);
-
-  // Returns the final bounds. This differs from current bounds if a grid_size
-  // was specified.
-  virtual gfx::Rect GetFinalBounds();
+  // WindowResizer overides:
+  virtual void Drag(const gfx::Point& location) OVERRIDE;
+  virtual void CompleteDrag() OVERRIDE;
+  virtual void RevertDrag() OVERRIDE;
 
  private:
-  // Returns the new origin of the window. The arguments are the difference
-  // between the current location and the initial location.
-  gfx::Point GetOriginForDrag(int delta_x, int delta_y) const;
+  explicit DefaultWindowResizer(const Details& details);
 
-  // Returns the size of the window for the drag.
-  gfx::Size GetSizeForDrag(int* delta_x, int* delta_y) const;
-
-  // Returns the width of the window.
-  int GetWidthForDrag(int min_width, int* delta_x) const;
-
-  // Returns the height of the drag.
-  int GetHeightForDrag(int min_height, int* delta_y) const;
-
-  // The window we're resizing.
-  aura::Window* window_;
-
-  // Initial bounds of the window.
-  const gfx::Rect initial_bounds_;
-
-  // Location passed to the constructor, in |window->parent()|'s coordinates.
-  const gfx::Point initial_location_in_parent_;
-
-  // The component the user pressed on.
-  const int window_component_;
-
-  // Bitmask of the |kBoundsChange_| constants.
-  const int bounds_change_;
-
-  // Bitmask of the |kBoundsChangeDirection_| constants.
-  const int position_change_direction_;
-
-  // Bitmask of the |kBoundsChangeDirection_| constants.
-  const int size_change_direction_;
-
-  // Will the drag actually modify the window?
-  const bool is_resizable_;
-
-  // Size of the grid.
-  const int grid_size_;
+  const Details details_;
 
   // Set to true once Drag() is invoked and the bounds of the window change.
   bool did_move_or_resize_;
 
   internal::RootWindowEventFilter* root_filter_;
 
-  DISALLOW_COPY_AND_ASSIGN(WindowResizer);
+  DISALLOW_COPY_AND_ASSIGN(DefaultWindowResizer);
 };
 
 }  // namespace aura
 
-#endif  // ASH_WM_WINDOW_RESIZER_H_
+#endif  // ASH_WM_DEFAULT_WINDOW_RESIZER_H_