ash/wm/resize_shadow_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_WM_RESIZE_SHADOW_CONTROLLER_H_
#define ASH_WM_RESIZE_SHADOW_CONTROLLER_H_

#include <map>
#include <memory>

#include "ash/ash_export.h"
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "ui/aura/window_observer.h"

namespace aura {
class Window;
}

namespace ash {
class ResizeShadow;

// ResizeShadowController observes changes to resizable windows and shows
// a resize handle visual effect when the cursor is near the edges.
class ASH_EXPORT ResizeShadowController : public aura::WindowObserver {
 public:
  ResizeShadowController();
  ~ResizeShadowController() override;

  // Shows the appropriate shadow for a given |window| and |hit_test| location.
  void ShowShadow(aura::Window* window, int hit_test);

  // Hides the shadow for a |window|, if it has one.
  void HideShadow(aura::Window* window);

  ResizeShadow* GetShadowForWindowForTest(aura::Window* window);

  // aura::WindowObserver overrides:
  void OnWindowDestroying(aura::Window* window) override;
  void OnWindowVisibilityChanging(aura::Window* window, bool visible) override;

 private:
  // Creates a shadow for a given window and returns it.  |window_shadows_|
  // owns the memory.
  ResizeShadow* CreateShadow(aura::Window* window);

  // Returns the resize shadow for |window| or NULL if no shadow exists.
  ResizeShadow* GetShadowForWindow(aura::Window* window);

  std::map<aura::Window*, std::unique_ptr<ResizeShadow>> window_shadows_;

  DISALLOW_COPY_AND_ASSIGN(ResizeShadowController);
};

}  // namespace ash

#endif  // ASH_WM_RESIZE_SHADOW_CONTROLLER_H_