ash/wm/window_resizer.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef ASH_WM_WINDOW_RESIZER_H_
   6 #define ASH_WM_WINDOW_RESIZER_H_
   7 #pragma once
   8
   9 #include "ash/ash_export.h"
  10 #include "base/basictypes.h"
  11 #include "ui/gfx/rect.h"
  12
  13 namespace aura {
  14 class Window;
  15 }
  16
  17 namespace ash {
  18
  19 namespace internal {
  20 class RootWindowEventFilter;
  21 }
  22
  23 // WindowResizer is used by ToplevelWindowEventFilter to handle dragging,
  24 // moving or resizing a window.
  25 class ASH_EXPORT WindowResizer {
  26  public:
  27   // Constants to identify the type of resize.
  28   static const int kBoundsChange_None;
  29   static const int kBoundsChange_Repositions;
  30   static const int kBoundsChange_Resizes;
  31
  32   // Used to indicate which direction the resize occurs in.
  33   static const int kBoundsChangeDirection_None;
  34   static const int kBoundsChangeDirection_Horizontal;
  35   static const int kBoundsChangeDirection_Vertical;
  36
  37   WindowResizer(aura::Window* window,
  38                 const gfx::Point& location,
  39                 int window_component,
  40                 int grid_size);
  41   ~WindowResizer();
  42
  43   // Returns a bitmask of the kBoundsChange_ values.
  44   static int GetBoundsChangeForWindowComponent(int component);
  45
  46   // Returns a location >= |location| that is aligned to fall on increments of
  47   // |grid_size|.
  48   static int AlignToGrid(int location, int grid_size);
  49
  50   // Invoked to drag/move/resize the window. |location| is in the coordinates
  51   // of the window supplied to the constructor.
  52   void Drag(const gfx::Point& location);
  53
  54   // Invoked to complete the drag.
  55   void CompleteDrag();
  56
  57   // Returns true if the drag will result in changing the window in anyway.
  58   bool is_resizable() const { return is_resizable_; }
  59
  60   // See description above members for details.
  61   const gfx::Rect& initial_bounds() const { return initial_bounds_; }
  62   const gfx::Point& initial_location_in_parent() const {
  63     return initial_location_in_parent_;
  64   }
  65   int window_component() const { return window_component_; }
  66   aura::Window* window() const { return window_; }
  67
  68  private:
  69   // Returns the bounds to give to the window once the mouse has moved to
  70   // |location|.
  71   gfx::Rect GetBoundsForDrag(const gfx::Point& location);
  72
  73   // Returns the new origin of the window. The arguments are the difference
  74   // between the current location and the initial location.
  75   gfx::Point GetOriginForDrag(int delta_x, int delta_y) const;
  76
  77   // Returns the size of the window for the drag.
  78   gfx::Size GetSizeForDrag(int* delta_x, int* delta_y) const;
  79
  80   // Returns the width of the window.
  81   int GetWidthForDrag(int min_width, int* delta_x) const;
  82
  83   // Returns the height of the drag.
  84   int GetHeightForDrag(int min_height, int* delta_y) const;
  85
  86   // The window we're resizing.
  87   aura::Window* window_;
  88
  89   // Initial bounds of the window.
  90   const gfx::Rect initial_bounds_;
  91
  92   // Location passed to the constructor, in |window->parent()|'s coordinates.
  93   const gfx::Point initial_location_in_parent_;
  94
  95   // The component the user pressed on.
  96   const int window_component_;
  97
  98   // Bitmask of the |kBoundsChange_| constants.
  99   const int bounds_change_;
 100
 101   // Bitmask of the |kBoundsChangeDirection_| constants.
 102   const int position_change_direction_;
 103
 104   // Bitmask of the |kBoundsChangeDirection_| constants.
 105   const int size_change_direction_;
 106
 107   // Will the drag actually modify the window?
 108   const bool is_resizable_;
 109
 110   // Size of the grid.
 111   const int grid_size_;
 112
 113   // Set to true once Drag() is invoked and the bounds of the window change.
 114   bool did_move_or_resize_;
 115
 116   internal::RootWindowEventFilter* root_filter_;
 117
 118   DISALLOW_COPY_AND_ASSIGN(WindowResizer);
 119 };
 120
 121 }  // namespace aura
 122
 123 #endif  // ASH_WM_WINDOW_RESIZER_H_