Only support left/right maximizing at 50% width when the --ash-enable-alternate-caption-button

ash/wm/workspace/snap_sizer.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_WORKSPACE_SNAP_SIZER_H_
-#define ASH_WM_WORKSPACE_SNAP_SIZER_H_
-
-#include <vector>
-
-#include "ash/ash_export.h"
-#include "base/basictypes.h"
-#include "base/time/time.h"
-#include "ui/gfx/rect.h"
-
-namespace aura {
-class Window;
-}
-
-namespace ash {
-namespace internal {
-
-// SnapSizer is responsible for determining the resulting bounds of a window
-// that is being snapped to the left or right side of the screen.
-// The bounds used in this class are in the container's coordinates.
-class ASH_EXPORT SnapSizer {
- public:
-  enum Edge {
-    LEFT_EDGE,
-    RIGHT_EDGE
-  };
-
-  enum InputType {
-    TOUCH_MAXIMIZE_BUTTON_INPUT,
-    OTHER_INPUT
-  };
-
-  // Set |input_type| to |TOUCH_MAXIMIZE_BUTTON_INPUT| when called by a touch
-  // operation by the maximize button. This will allow the user to snap resize
-  // the window beginning close to the border.
-  SnapSizer(aura::Window* window,
-            const gfx::Point& start,
-            Edge edge,
-            InputType input_type);
-  virtual ~SnapSizer();
-
-  // Snaps a window left or right.
-  static void SnapWindow(aura::Window* window, Edge edge);
-
-  // Updates the target bounds based on a mouse move.
-  void Update(const gfx::Point& location);
-
-  // Bounds to position the window at.
-  const gfx::Rect& target_bounds() const { return target_bounds_; }
-
-  // Returns the appropriate snap bounds (e.g. if a window is already snapped,
-  // then it returns the next snap-bounds).
-  gfx::Rect GetSnapBounds(const gfx::Rect& bounds);
-
-  // Set the snap sizer to the button press default size and prevent resizing.
-  void SelectDefaultSizeAndDisableResize();
-
-  // Returns the target bounds based on the edge and the provided |size_index|.
-  // For unit test purposes this function is not private.
-  gfx::Rect GetTargetBoundsForSize(size_t size_index) const;
-
- private:
-  // Calculates the amount to increment by. This returns one of -1, 0 or 1 and
-  // is intended to by applied to |size_index_|. |x| is the current
-  // x-coordinate, and |reference_x| is used to determine whether to increase
-  // or decrease the position. It's one of |last_adjust_x_| or |last_update_x_|.
-  int CalculateIncrement(int x, int reference_x) const;
-
-  // Changes the bounds. |x| is the current x-coordinate and |delta| the amount
-  // to increase by. |delta| comes from CalculateIncrement() and is applied
-  // to |size_index_|.
-  void ChangeBounds(int x, int delta);
-
-  // Returns the target bounds based on the edge and |size_index_|.
-  gfx::Rect GetTargetBounds() const;
-
-  // Returns true if the specified point is along the edge of the screen.
-  bool AlongEdge(int x) const;
-
-  // Window being snapped.
-  aura::Window* window_;
-
-  const Edge edge_;
-
-  // Current target bounds for the snap.
-  gfx::Rect target_bounds_;
-
-  // Time Update() was last invoked.
-  base::TimeTicks time_last_update_;
-
-  // Index into |kSizes| that dictates the width of the screen the target
-  // bounds should get.
-  int size_index_;
-
-  // If set, |size_index_| will get ignored and the single button default
-  // setting will be used instead.
-  bool resize_disabled_;
-
-  // Number of times Update() has been invoked since last ChangeBounds().
-  int num_moves_since_adjust_;
-
-  // X-coordinate the last time ChangeBounds() was invoked.
-  int last_adjust_x_;
-
-  // X-coordinate last supplied to Update().
-  int last_update_x_;
-
-  // Initial x-coordinate.
-  const int start_x_;
-
-  // |TOUCH_MAXIMIZE_BUTTON_INPUT| if the snap sizer was created through a
-  // touch & drag operation of the maximizer button. It changes the behavior of
-  // the drag / resize behavior when the dragging starts close to the border.
-  const InputType input_type_;
-
-  // A list of usable window widths for size. This gets created when the
-  // sizer gets created.
-  const std::vector<int> usable_width_;
-
-  DISALLOW_COPY_AND_ASSIGN(SnapSizer);
-};
-
-}  // namespace internal
-}  // namespace ash
-
-#endif  // ASH_WM_WORKSPACE_SNAP_SIZER_H_