Draggable peeking/fullscreen launcher with transparent background.

ui/app_list/views/app_list_view.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 UI_APP_LIST_VIEWS_APP_LIST_VIEW_H_
 #define UI_APP_LIST_VIEWS_APP_LIST_VIEW_H_
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "ui/app_list/app_list_export.h"
 #include "ui/app_list/speech_ui_model_observer.h"
+#include "ui/display/display_observer.h"
 #include "ui/views/bubble/bubble_dialog_delegate.h"
 #include "ui/views/widget/widget.h"
 
 namespace app_list {
 class ApplicationDragAndDropHost;
 class AppListMainView;
 class AppListModel;
 class AppListViewDelegate;
 class HideViewAnimationObserver;
 class PaginationModel;
 class SearchBoxView;
 class SpeechView;
 
 namespace test {
 class AppListViewTestApi;
 }
 
 // AppListView is the top-level view and controller of app list UI. It creates
 // and hosts a AppsGridView and passes AppListModel to it for display.
 class APP_LIST_EXPORT AppListView : public views::BubbleDialogDelegateView,
-                                    public SpeechUIModelObserver {
+                                    public SpeechUIModelObserver,
+                                    public display::DisplayObserver {
  public:
   // Does not take ownership of |delegate|.
   explicit AppListView(AppListViewDelegate* delegate);
   ~AppListView() override;
 
   // Initializes the widget as a bubble or fullscreen view depending on the
   // presence of a cmd line switch. parent and initial_apps_page are used for
   // both the bubble and fullscreen initialization.
   void Initialize(gfx::NativeView parent, int initial_apps_page);
 
@@ skipping 33 matching lines @@
       gfx::NativeView child,
       const gfx::Point& location) override;
 
   AppListMainView* app_list_main_view() { return app_list_main_view_; }
 
   // Gets the PaginationModel owned by this view's apps grid.
   PaginationModel* GetAppsPaginationModel();
 
   // Overridden from views::View:
   bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
+
+  void ComputeConstants();

[vadimt, 2017/05/22 23:36:58]

Please don't place it between views::View overrides.

[newcomer, 2017/05/25 23:10:53]

Done.

+
   void Layout() override;
   void SchedulePaintInRect(const gfx::Rect& rect) override;
 
+  // Changes the view to the peeking state or to the fullscreen state.
+  void ToFullscreen();
+  void ToPeeking();
+
+  bool IsFullscreen();

[vadimt, 2017/05/22 23:36:58]

I assume there are 2 states Fullscreen and peeking. Then we need to have a
matching SetFullScreen(bool), not ToFullScreen/ToPeeking pair.

[newcomer, 2017/05/25 23:10:53]

In the next CL there will be five states (INITIAL, PEEKING, HALF,
FULLSCREEN_ALL_APPS, and FULLSCREEN_SEARCH). Can I push this to the next CL? It
will have to get refactored in the next CL anyways.

[vadimt, 2017/05/26 01:27:56]

Acknowledged.

+
  private:
   friend class test::AppListViewTestApi;
 
   void InitContents(gfx::NativeView parent, int initial_apps_page);
 
   void InitChildWidgets();
 
   // Initializes the widget for fullscreen mode.
   void InitializeFullscreen(gfx::NativeView parent, int initial_apps_page);
 
   // Initializes the widget as a bubble.
   void InitializeBubble(gfx::NativeView parent, int initial_apps_page);
 
   // Overridden from views::BubbleDialogDelegateView:
   void OnBeforeBubbleWidgetInit(views::Widget::InitParams* params,
                                 views::Widget* widget) const override;
   int GetDialogButtons() const override;
 
   // Overridden from views::WidgetDelegateView:
   views::View* GetInitiallyFocusedView() override;
   bool WidgetHasHitTestMask() const override;
   void GetWidgetHitTestMask(gfx::Path* mask) const override;
 
+  // Both OnMouseEvent and OnGestureEvent check to see if their events are
+  // drag events, if so the events are sent to HandleDrag which holds all
+  // AppListView drag logic.
+  void OnMouseEvent(ui::MouseEvent* event) override;

[vadimt, 2017/05/22 23:36:58]

You don't need comments for overrides. BTW are they overrides for
views::WidgetDelegateView?

[newcomer, 2017/05/25 23:10:53]

They are ui::EventHandler overrides. Done!

+  void OnGestureEvent(ui::GestureEvent* event) override;
+
+  // Handles all drag logic for the app list view. Touch and Click events are
+  // filtered through OnMouseEvent and OnGestureEvent before being passed to
+  // HandleDrag.
+  void HandleDrag(gfx::Point location, ui::EventType type);

[vadimt, 2017/05/22 23:36:58]

Is this override? If so, add override keyword; else, move.

[newcomer, 2017/05/25 23:10:53]

Done.

+
   // Overridden from views::WidgetObserver:
   void OnWidgetDestroying(views::Widget* widget) override;
   void OnWidgetVisibilityChanged(views::Widget* widget, bool visible) override;
 
   // Overridden from SpeechUIModelObserver:
   void OnSpeechRecognitionStateChanged(
       SpeechRecognitionState new_state) override;
 
+  // Overridden from DisplayObserver:
+  void OnDisplayMetricsChanged(const display::Display& display,
+                               uint32_t changed_metrics) override;
+
   AppListViewDelegate* delegate_;  // Weak. Owned by AppListService.
 
   AppListMainView* app_list_main_view_;
   SpeechView* speech_view_;
+  views::Widget* fullscreen_widget_;
 
   views::View* search_box_focus_host_;  // Owned by the views hierarchy.
   views::Widget* search_box_widget_;    // Owned by the app list's widget.
   SearchBoxView* search_box_view_;      // Owned by |search_box_widget_|.
+  views::View* launcher_background_shield_;  // Owned by the app list's widget.

[vadimt, 2017/05/22 23:36:58]

I assume all added fields can't be made const fields?

[xiyuan, 2017/05/24 18:28:18]

Initialize it to nullptr,

i.e.
  views::View* launcher_background_shield_ = nullptr

So that we can use |launcher_background_shield_| in Layout etc instead of
checking fullscreen feature everywhere.

[newcomer, 2017/05/25 23:10:53]

Correct.

[newcomer, 2017/05/25 23:10:53]

Done.

+
+  int initial_drag_separation_;

[vadimt, 2017/05/22 23:36:58]

I know that other fields don't have comments, but it's hard to deduce the
meaning from the name. Please add comments for all added fields.

[newcomer, 2017/05/25 23:10:53]

Done.

+  float last_fling_velocity_;
+  int default_peeking_launcher_y_;
+  int launcher_threshold_;
+  bool is_fullscreen_launcher_;
+  gfx::Rect display_work_area_bounds_;
+  gfx::Rect fullscreen_widget_bounds_;
 
   // A semi-transparent white overlay that covers the app list while dialogs are
   // open.
   views::View* overlay_view_;
 
   std::unique_ptr<HideViewAnimationObserver> animation_observer_;
 
   // For UMA and testing. If non-null, triggered when the app list is painted.
   base::Closure next_paint_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(AppListView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_APP_LIST_VIEW_H_