ash/wm/workspace/snap_sizer.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_WORKSPACE_SNAP_SIZER_H_
   6 #define ASH_WM_WORKSPACE_SNAP_SIZER_H_
   7
   8 #include <vector>
   9
  10 #include "ash/ash_export.h"
  11 #include "base/basictypes.h"
  12 #include "base/time.h"
  13 #include "ui/gfx/rect.h"
  14
  15 namespace aura {
  16 class Window;
  17 }
  18
  19 namespace ash {
  20 namespace internal {
  21
  22 // SnapSizer is responsible for determining the resulting bounds of a window
  23 // that is being snapped to the left or right side of the screen.
  24 // The bounds used in this class are in the container's coordinates.
  25 class ASH_EXPORT SnapSizer {
  26  public:
  27   enum Edge {
  28     LEFT_EDGE,
  29     RIGHT_EDGE
  30   };
  31
  32   enum InputType {
  33     TOUCH_MAXIMIZE_BUTTON_INPUT,
  34     OTHER_INPUT
  35   };
  36
  37   // Set |input_type| to |TOUCH_MAXIMIZE_BUTTON_INPUT| when called by a touch
  38   // operation by the maximize button. This will allow the user to snap resize
  39   // the window beginning close to the border.
  40   SnapSizer(aura::Window* window,
  41             const gfx::Point& start,
  42             Edge edge,
  43             InputType input_type);
  44   virtual ~SnapSizer();
  45
  46   // Snaps a window left or right.
  47   static void SnapWindow(aura::Window* window, Edge edge);
  48
  49   // Updates the target bounds based on a mouse move.
  50   void Update(const gfx::Point& location);
  51
  52   // Bounds to position the window at.
  53   const gfx::Rect& target_bounds() const { return target_bounds_; }
  54
  55   // Returns the appropriate snap bounds (e.g. if a window is already snapped,
  56   // then it returns the next snap-bounds).
  57   gfx::Rect GetSnapBounds(const gfx::Rect& bounds);
  58
  59   // Set the snap sizer to the button press default size and prevent resizing.
  60   void SelectDefaultSizeAndDisableResize();
  61
  62   // Returns the target bounds based on the edge and the provided |size_index|.
  63   // For unit test purposes this function is not private.
  64   gfx::Rect GetTargetBoundsForSize(size_t size_index) const;
  65
  66  private:
  67   // Calculates the amount to increment by. This returns one of -1, 0 or 1 and
  68   // is intended to by applied to |size_index_|. |x| is the current
  69   // x-coordinate, and |reference_x| is used to determine whether to increase
  70   // or decrease the position. It's one of |last_adjust_x_| or |last_update_x_|.
  71   int CalculateIncrement(int x, int reference_x) const;
  72
  73   // Changes the bounds. |x| is the current x-coordinate and |delta| the amount
  74   // to increase by. |delta| comes from CalculateIncrement() and is applied
  75   // to |size_index_|.
  76   void ChangeBounds(int x, int delta);
  77
  78   // Returns the target bounds based on the edge and |size_index_|.
  79   gfx::Rect GetTargetBounds() const;
  80
  81   // Returns true if the specified point is along the edge of the screen.
  82   bool AlongEdge(int x) const;
  83
  84   // Window being snapped.
  85   aura::Window* window_;
  86
  87   const Edge edge_;
  88
  89   // Current target bounds for the snap.
  90   gfx::Rect target_bounds_;
  91
  92   // Time Update() was last invoked.
  93   base::TimeTicks time_last_update_;
  94
  95   // Index into |kSizes| that dictates the width of the screen the target
  96   // bounds should get.
  97   int size_index_;
  98
  99   // If set, |size_index_| will get ignored and the single button default
 100   // setting will be used instead.
 101   bool resize_disabled_;
 102
 103   // Number of times Update() has been invoked since last ChangeBounds().
 104   int num_moves_since_adjust_;
 105
 106   // X-coordinate the last time ChangeBounds() was invoked.
 107   int last_adjust_x_;
 108
 109   // X-coordinate last supplied to Update().
 110   int last_update_x_;
 111
 112   // Initial x-coordinate.
 113   const int start_x_;
 114
 115   // |TOUCH_MAXIMIZE_BUTTON_INPUT| if the snap sizer was created through a
 116   // touch & drag operation of the maximizer button. It changes the behavior of
 117   // the drag / resize behavior when the dragging starts close to the border.
 118   const InputType input_type_;
 119
 120   // A list of usable window widths for size. This gets created when the
 121   // sizer gets created.
 122   const std::vector<int> usable_width_;
 123
 124   DISALLOW_COPY_AND_ASSIGN(SnapSizer);
 125 };
 126
 127 }  // namespace internal
 128 }  // namespace ash
 129
 130 #endif  // ASH_WM_WORKSPACE_SNAP_SIZER_H_