Ports SystemModalContainerLayoutManager to ash/common

ash/wm/system_modal_container_layout_manager.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_SYSTEM_MODAL_CONTAINER_LAYOUT_MANAGER_H_
-#define ASH_WM_SYSTEM_MODAL_CONTAINER_LAYOUT_MANAGER_H_
-
-#include <memory>
-#include <vector>
-
-#include "ash/ash_export.h"
-#include "ash/snap_to_pixel_layout_manager.h"
-#include "base/compiler_specific.h"
-#include "base/macros.h"
-#include "ui/aura/window_observer.h"
-#include "ui/keyboard/keyboard_controller_observer.h"
-
-namespace aura {
-class Window;
-class EventFilter;
-}
-namespace gfx {
-class Rect;
-}
-
-namespace ash {
-class WindowDimmer;
-
-// LayoutManager for the modal window container.
-// System modal windows which are centered on the screen will be kept centered
-// when the container size changes.
-class ASH_EXPORT SystemModalContainerLayoutManager
-    : public SnapToPixelLayoutManager,
-      public aura::WindowObserver,
-      public keyboard::KeyboardControllerObserver {
- public:
-  explicit SystemModalContainerLayoutManager(aura::Window* container);
-  ~SystemModalContainerLayoutManager() override;
-
-  bool has_window_dimmer() const { return window_dimmer_ != nullptr; }
-
-  // Overridden from SnapToPixelLayoutManager:
-  void OnWindowResized() override;
-  void OnWindowAddedToLayout(aura::Window* child) override;
-  void OnWillRemoveWindowFromLayout(aura::Window* child) override;
-  void SetChildBounds(aura::Window* child,
-                      const gfx::Rect& requested_bounds) override;
-
-  // Overridden from aura::WindowObserver:
-  void OnWindowPropertyChanged(aura::Window* window,
-                               const void* key,
-                               intptr_t old) override;
-  void OnWindowVisibilityChanged(aura::Window* window, bool visible) override;
-
-  // Overridden from keyboard::KeyboardControllerObserver:
-  void OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) override;
-
-  // True if the window is either contained by the top most modal window,
-  // or contained by its transient children.
-  bool IsPartOfActiveModalWindow(aura::Window* window);
-
-  // Activates next modal window if any. Returns false if there
-  // are no more modal windows in this layout manager.
-  bool ActivateNextModalWindow();
-
-  // Creates modal background window, which is a partially-opaque
-  // fullscreen window. If there is already a modal background window,
-  // it will bring it the top.
-  void CreateModalBackground();
-
-  void DestroyModalBackground();
-
-  // Is the |window| modal background?
-  static bool IsModalBackground(aura::Window* window);
-
- private:
-  void AddModalWindow(aura::Window* window);
-  void RemoveModalWindow(aura::Window* window);
-
-  // Reposition the dialogs to become visible after the work area changes.
-  void PositionDialogsAfterWorkAreaResize();
-
-  // Get the usable bounds rectangle for enclosed dialogs.
-  gfx::Rect GetUsableDialogArea();
-
-  // Gets the new bounds for a |window| to use which are either centered (if the
-  // window was previously centered) or fitted to the screen.
-  gfx::Rect GetCenteredAndOrFittedBounds(const aura::Window* window);
-
-  // Returns true if |window_bounds| is centered.
-  bool DialogIsCentered(const gfx::Rect& window_bounds);
-
-  aura::Window* modal_window() {
-    return !modal_windows_.empty() ? modal_windows_.back() : NULL;
-  }
-
-  // The container that owns the layout manager.
-  aura::Window* container_;
-
-  // WindowDimmer used to dim windows behind the modal window(s) being shown in
-  // |container_|.
-  std::unique_ptr<WindowDimmer> window_dimmer_;
-
-  // A stack of modal windows. Only the topmost can receive events.
-  std::vector<aura::Window*> modal_windows_;
-
-  DISALLOW_COPY_AND_ASSIGN(SystemModalContainerLayoutManager);
-};
-
-}  // namespace ash
-
-#endif  // ASH_WM_SYSTEM_MODAL_CONTAINER_LAYOUT_MANAGER_H_