Tablet WM : Swiping on system tray bubble.

ash/system/tray/system_tray.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_SYSTEM_TRAY_SYSTEM_TRAY_H_
 #define ASH_SYSTEM_TRAY_SYSTEM_TRAY_H_
 
 #include <map>
 #include <memory>
 #include <vector>
@@ skipping 29 matching lines @@
 
 // There are different methods for creating bubble views.
 enum BubbleCreationType {
   BUBBLE_CREATE_NEW,    // Closes any existing bubble and creates a new one.
   BUBBLE_USE_EXISTING,  // Uses any existing bubble, or creates a new one.
 };
 
 class ASH_EXPORT SystemTray : public TrayBackgroundView,
                               public views::TrayBubbleView::Delegate {
  public:
+  // The threshold of the velocity of the fling event.
+  static constexpr float kFlingVelocity = 100.0f;
+
   explicit SystemTray(Shelf* shelf);
   ~SystemTray() override;
 
   TrayUpdate* tray_update() { return tray_update_; }
 
   TrayNightLight* tray_night_light() { return tray_night_light_; }
 
   // Calls TrayBackgroundView::Initialize(), creates the tray items, and
   // adds them to SystemTrayNotifier.
   void InitializeTrayItems(SystemTrayDelegate* delegate,
@@ skipping 75 matching lines @@
   void OnMouseExitedView() override;
   base::string16 GetAccessibleNameForBubble() override;
   void HideBubble(const views::TrayBubbleView* bubble_view) override;
 
   ScreenTrayItem* GetScreenShareItem() { return screen_share_tray_item_; }
   ScreenTrayItem* GetScreenCaptureItem() { return screen_capture_tray_item_; }
 
   // Activates the system tray bubble.
   void ActivateBubble();
 
+  // ui::EventHandler:
+  void OnGestureEvent(ui::GestureEvent* event) override;
+
+  gfx::Rect GetWorkAreaBoundsInScreen() const;
+
  private:
   friend class SystemTrayTestApi;
   class ActivationObserver;
 
   // Closes the bubble. Used to bind as a KeyEventWatcher::KeyEventCallback.
   void CloseBubble(const ui::KeyEvent& key_event);
 
   // Activates the bubble and starts key navigation with the |key_event|.
   void ActivateAndStartNavigation(const ui::KeyEvent& key_event);
 
@@ skipping 31 matching lines @@
   // Deactivate the system tray in the shelf if it was active before.
   void CloseSystemBubbleAndDeactivateSystemTray();
 
   // Records UMA metrics for the number of user-visible rows in the system menu
   // and the percentage of the work area height covered by the system menu.
   void RecordSystemMenuMetrics();
 
   // Overridden from ActionableView.
   bool PerformAction(const ui::Event& event) override;
 
+  // Gesture related functions:
+  bool ProcessGestureEvent(const ui::GestureEvent& event);
+  bool StartGestureDrag(const ui::GestureEvent& gesture);
+  void UpdateGestureDrag(const ui::GestureEvent& gesture);
+  void CompleteGestureDrag(const ui::GestureEvent& gesture);
+
+  // Update the bounds of the system tray bubble according to |location|. Note
+  // that |location| is in the local coordinate space of |this|.
+  void SetBubbleBounds(const gfx::Point& location);
+
+  // Return true if the system bubble should be shown (i.e., animated upward to
+  // be made fully visible) after a sequence of scroll events terminated by
+  // |sequence_end|. Otherwise return false, indicating that the
+  // partially-visible system bubble should be animated downward and made fully
+  // hidden.
+  bool ShouldShowSystemBubbleAfterScrollSequence(
+      const ui::GestureEvent& sequence_end);
+
+  // Shelf the system tray is in.
+  Shelf* const shelf_;
+
+  // The original bounds of the system tray bubble.
+  gfx::Rect system_tray_bubble_bounds_;
+
+  // Tracks the amount of the drag.

[tdanderson, 2017/06/27 17:58:13]

nit: Add "Only valid if |is_in_drag_| is true".

+  float gesture_drag_amount_ = 0.f;
+
+  // True if the user is in the process of gesture-dragging to open the system
+  // tray bubble, false otherwise.
+  bool is_in_drag_ = false;
+
   // The web notification tray view that appears adjacent to this view.
   WebNotificationTray* web_notification_tray_ = nullptr;
 
   // Items.
   std::vector<std::unique_ptr<SystemTrayItem>> items_;
 
   // Pointers to members of |items_|.
   SystemTrayItem* detailed_item_ = nullptr;
 
   // Bubble for default and detailed views.
@@ skipping 29 matching lines @@
   std::unique_ptr<KeyEventWatcher> key_event_watcher_;
 
   std::unique_ptr<ActivationObserver> activation_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_SYSTEM_TRAY_H_