Tablet WM : Swiping on system tray bubble.

ash/system/tray/system_tray.h

Index: ash/system/tray/system_tray.h
diff --git a/ash/system/tray/system_tray.h b/ash/system/tray/system_tray.h
index fa16c53f74067aaee8e1eacaccff91add8d1d17d..9790a7fbf7d2683980e4ec1e803eca0ee6156bfb 100644
--- a/ash/system/tray/system_tray.h
+++ b/ash/system/tray/system_tray.h
@@ -38,6 +38,9 @@ class TrayTiles;
 class TrayUpdate;
 class WebNotificationTray;
 
+// The threshold of the velocity of the fling event.
+const float kFlingVelocity = 100.0f;

[tdanderson, 2017/06/22 20:21:43]

as-is, this constant is being exposed to the entire ash namespace. Instead
consider placing inside the SystemTray class. Have a look at 'static const int
kDesktopBorderSize' in ash/wm/window_positioner.h as an example.

[minch1, 2017/06/23 22:39:57]

Done.

+
 // There are different methods for creating bubble views.
 enum BubbleCreationType {
   BUBBLE_CREATE_NEW,    // Closes any existing bubble and creates a new one.
@@ -142,6 +145,11 @@ class ASH_EXPORT SystemTray : public TrayBackgroundView,
   // 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;
@@ -193,6 +201,32 @@ class ASH_EXPORT SystemTray : public TrayBackgroundView,
   // 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 the location.

[tdanderson, 2017/06/22 20:21:42]

nit: also specify that |location| is in the local coordinate space of |this|.

[minch1, 2017/06/23 22:39:57]

Done.

+  void SetBubbleBounds(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& gesture);
+
+  // 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.
+  float gesture_drag_amount_ = 0.f;
+
   // The web notification tray view that appears adjacent to this view.
   WebNotificationTray* web_notification_tray_ = nullptr;