Use mirror layer for minimized windows in overview mode

ash/common/wm/overview/scoped_transform_overview_window.h

 // Copyright 2013 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_COMMON_WM_OVERVIEW_SCOPED_TRANSFORM_OVERVIEW_WINDOW_H_
 #define ASH_COMMON_WM_OVERVIEW_SCOPED_TRANSFORM_OVERVIEW_WINDOW_H_
 
 #include <memory>
 #include <vector>
 
 #include "ash/ash_export.h"
 #include "ash/common/wm/overview/overview_animation_type.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "third_party/skia/include/core/SkColor.h"
+#include "ui/events/event_handler.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/transform.h"
 
 class SkRegion;
 
 namespace gfx {
 class Rect;
 }
 
+namespace views {
+class Widget;
+}
+
 namespace ash {
 
 class ScopedOverviewAnimationSettings;
 class WmWindow;
 
 // Manages a window, and it's transient children, in the overview mode. This
 // class allows transforming the windows with a helper to determine the best
 // fit in certain bounds. The window's state is restored on destruction of this
 // object.
-class ASH_EXPORT ScopedTransformOverviewWindow {
+class ASH_EXPORT ScopedTransformOverviewWindow : public ui::EventHandler {
  public:
   class OverviewContentMask;
   using ScopedAnimationSettings =
       std::vector<std::unique_ptr<ScopedOverviewAnimationSettings>>;
 
   // Calculates and returns an optimal scale ratio. With MD this is only
   // taking into account |size.height()| as the width can vary. Without MD this
   // returns the scale that allows the item to fully fit within |size|.
   static float GetItemScale(const gfx::Size& source,
                             const gfx::Size& target,
                             int top_view_inset,
                             int title_height);
 
   // Returns |rect| having been shrunk to fit within |bounds| (preserving the
   // aspect ratio). Takes into account a window header that is |top_view_inset|
   // tall in the original window getting replaced by a window caption that is
   // |title_height| tall in transformed window.
   static gfx::Rect ShrinkRectToFitPreservingAspectRatio(const gfx::Rect& rect,
                                                         const gfx::Rect& bounds,
                                                         int top_view_inset,
                                                         int title_height);
 
   // Returns the transform turning |src_rect| into |dst_rect|.
   static gfx::Transform GetTransformForRect(const gfx::Rect& src_rect,
                                             const gfx::Rect& dst_rect);
 
   explicit ScopedTransformOverviewWindow(WmWindow* window);
-  ~ScopedTransformOverviewWindow();
+  ~ScopedTransformOverviewWindow() override;
 
   // Starts an animation sequence which will use animation settings specified by
   // |animation_type|. The |animation_settings| container is populated with
   // scoped entities and the container should be destroyed at the end of the
   // animation sequence.
   //
   // Example:
   //  ScopedTransformOverviewWindow overview_window(window);
   //  ScopedTransformOverviewWindow::ScopedAnimationSettings scoped_settings;
   //  overview_window.BeginScopedAnimation(
@@ skipping 23 matching lines @@
   // ancestors in which case returns SK_ColorTRANSPARENT.
   SkColor GetTopColor() const;
 
   // Returns TOP_VIEW_INSET property of |window_| unless there are transient
   // ancestors in which case returns 0.
   int GetTopInset() const;
 
   // Restores and animates the managed window to it's non overview mode state.
   void RestoreWindow();
 
-  // Forces the managed window to be shown (ie not hidden or minimized) when
-  // calling RestoreWindow().
-  void ShowWindowOnExit();
-
   // Informs the ScopedTransformOverviewWindow that the window being watched was
   // destroyed. This resets the internal window pointer.
   void OnWindowDestroyed();
 
   // Prepares for overview mode by doing any necessary actions before entering.
   void PrepareForOverview();
 
   // Applies the |transform| to the overview window and all of its transient
   // children.
   void SetTransform(WmWindow* root_window, const gfx::Transform& transform);
 
   // Set's the opacity of the managed windows.
   void SetOpacity(float opacity);
 
   // Hides the window header whose size is given in |TOP_VIEW_INSET|
   // window property.
   void HideHeader();
 
   // Shows the window header that is hidden by HideHeader().
   void ShowHeader();
 
+  // Creates/Deletes a mirror window for minimized windows.
+  void UpdateMirrorWindowForMinimizedState();
+
   WmWindow* window() const { return window_; }
 
   // Closes the transient root of the window managed by |this|.
   void Close();
 
+  // Returns the window used to show the content in overview mdoe.
+  // For minmiezd window, this will be a window that hosts mirrored layers.
+  WmWindow* GetOverviewWindow() const;
+
+  // Returns the window created for minimized window, or nullptr
+  // if it does not exit.
+  WmWindow* GetOverviewWindowForMinimizedState() const;
+
+  // ui::EventHandler:
+  void OnGestureEvent(ui::GestureEvent* event) override;
+  void OnMouseEvent(ui::MouseEvent* event) override;
+
  private:
   friend class WindowSelectorTest;
 
-  enum OriginalVisibility {
-    ORIGINALLY_VISIBLE,
-    ORIGINALLY_MINIMIZED,
-    ORIGINALLY_DOCKED_MINIMIZED,
-  };
-
-  // Shows the window if it was minimized.
-  void ShowWindowIfMinimized();
-
   // Closes the window managed by |this|.
   void CloseWidget();
 
+  void CreateMirrorWindowForMinimizedState();
+
   // Makes Close() execute synchronously when used in tests.
   static void SetImmediateCloseForTests();
 
   // A weak pointer to the real window in the overview.
   WmWindow* window_;
 
   // Original window shape, if it was set on a window.
   std::unique_ptr<SkRegion> original_window_shape_;
 
   // True after the |original_window_shape_| has been set or after it has
   // been determined that window shape was not originally set on the |window_|.
   bool determined_original_window_shape_;
 
-  // Original visibility of |window_| upon entering overview mode that needs to
-  // be restored unless the window gets selected.
-  OriginalVisibility original_visibility_;
-
   // Tracks if this window was ignored by the shelf.
   bool ignored_by_shelf_;
 
   // True if the window has been transformed for overview mode.
   bool overview_started_;
 
   // The original transform of the window before entering overview mode.
   gfx::Transform original_transform_;
 
-  // The original opacity of the window before entering overview mode.
-  float original_opacity_;
+  // A window that holds the content for minimized window.
+  std::unique_ptr<views::Widget> minimized_;

[varkha, 2016/11/15 20:10:21]

How about minimized_widget_? Longer but we often use minimized_ as a boolean
elsewhere so it was slightly confusing when reading the implementation,
especially since you are actually using it as "if (minimized_)".

[oshima, 2016/11/16 14:58:27]

Done.

 
   base::WeakPtrFactory<ScopedTransformOverviewWindow> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedTransformOverviewWindow);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_OVERVIEW_SCOPED_TRANSFORM_OVERVIEW_WINDOW_H_