[Test]Swiping on system tray bubble.

ash/system/tray/system_tray.cc

Index: ash/system/tray/system_tray.cc
diff --git a/ash/system/tray/system_tray.cc b/ash/system/tray/system_tray.cc
index 66ca2527aa0a3fcbdf222f0f1912912471c14af7..8ff827ebfbdba51e51a171ce28d7ab1892be839f 100644
--- a/ash/system/tray/system_tray.cc
+++ b/ash/system/tray/system_tray.cc
@@ -78,6 +78,9 @@ using views::TrayBubbleView;
 
 namespace ash {
 
+// The velocity of the swiping on the system bubble.
+constexpr float kSwipingVelocity = 100.0;
+
 namespace {
 
 // A tray item that just reserves space in the tray.
@@ -171,8 +174,11 @@ class SystemTray::ActivationObserver : public ::wm::ActivationChangeObserver {
 
     int container_id = wm::GetContainerForWindow(gained_active)->id();
 
-    // Don't close the bubble if a popup notification is activated.
-    if (container_id == kShellWindowId_StatusContainer)
+    // Don't close the bubble if a popup notification is activated and don't
+    // close the the bubble if click the items in the default system tray bubble
+    // on maximize mode.
+    if (container_id == kShellWindowId_StatusContainer ||
+        container_id == kShellWindowId_SettingBubbleContainer)
       return;
 
     views::Widget* bubble_widget =
@@ -198,13 +204,16 @@ class SystemTray::ActivationObserver : public ::wm::ActivationChangeObserver {
 
 // SystemTray
 
-SystemTray::SystemTray(Shelf* shelf) : TrayBackgroundView(shelf) {
+SystemTray::SystemTray(Shelf* shelf)
+    : TrayBackgroundView(shelf), shelf_(shelf) {
   SetInkDropMode(InkDropMode::ON);
 
   // Since user avatar is on the right hand side of System tray of a
   // horizontal shelf and that is sufficient to indicate separation, no
   // separator is required.
   set_separator_visibility(false);
+
+  Shell::Get()->AddShellObserver(this);
 }
 
 SystemTray::~SystemTray() {
@@ -214,6 +223,7 @@ SystemTray::~SystemTray() {
   system_bubble_.reset();
   for (const auto& item : items_)
     item->OnTrayViewDestroyed();
+  Shell::Get()->RemoveShellObserver(this);
 }
 
 void SystemTray::InitializeTrayItems(
@@ -589,6 +599,14 @@ void SystemTray::HideBubble(const TrayBubbleView* bubble_view) {
   HideBubbleWithView(bubble_view);
 }
 
+void SystemTray::OnMaximizeModeStarted() {
+  on_maximize_mode_ = true;
+}
+
+void SystemTray::OnMaximizeModeEnded() {
+  on_maximize_mode_ = false;
+}
+
 void SystemTray::CloseBubble(const ui::KeyEvent& key_event) {
   CloseSystemBubble();
 }
@@ -630,6 +648,10 @@ void SystemTray::ActivateBubble() {
   bubble_view->GetWidget()->Activate();
 }
 
+gfx::Rect SystemTray::GetWorkAreaBoundsInScreen() const {
+  return shelf_->GetUserWorkAreaBounds();
+}
+
 bool SystemTray::PerformAction(const ui::Event& event) {
   // If we're already showing the default view or detailed view in system menu,
   // hide it; otherwise, show it (and hide any popup that's currently shown).
@@ -645,6 +667,108 @@ bool SystemTray::PerformAction(const ui::Event& event) {
   return true;
 }
 
+void SystemTray::OnGestureEvent(ui::GestureEvent* event) {
+  if (on_maximize_mode_ && shelf_->IsHorizontalAlignment() &&
+      ProcessGestureEvent(*event))
+    event->StopPropagation();
+  else
+    CustomButton::OnGestureEvent(event);
+}
+
+bool SystemTray::ProcessGestureEvent(const ui::GestureEvent& event) {
+  if (event.type() == ui::ET_GESTURE_SCROLL_BEGIN) {
+    return StartGestureDrag(event);
+  }
+
+  if (event.type() == ui::ET_GESTURE_SCROLL_UPDATE) {
+    UpdateGestureDrag(event);
+    return true;
+  }
+
+  if (event.type() == ui::ET_GESTURE_SCROLL_END ||
+      event.type() == ui::ET_SCROLL_FLING_START) {
+    CompleteGestureDrag(event);
+    return true;
+  }
+  return false;
+}
+
+bool SystemTray::StartGestureDrag(const ui::GestureEvent& gesture) {
+  if (full_system_tray_menu_ || IsSwipingDownOnShelf(gesture))
+    return false;
+
+  gesture_drag_amount_ = 0.f;
+  ShowDefaultView(BUBBLE_CREATE_NEW);
+  system_tray_bubble_bounds_ =
+      system_bubble_->bubble_view()->GetWidget()->GetWindowBoundsInScreen();
+  system_bubble_->bubble_view()->GetWidget()->Hide();
+  return true;
+}
+
+void SystemTray::UpdateGestureDrag(const ui::GestureEvent& gesture) {
+  gfx::Point gesture_location = gesture.location();
+  View::ConvertPointToScreen(this, &gesture_location);
+
+  // System tray bubble should not be dragged higher than its original height.
+  if (gesture_location.y() < system_tray_bubble_bounds_.y())
+    gesture_location.set_y(system_tray_bubble_bounds_.y());
+  gfx::Rect bounds_on_gesture(
+      system_tray_bubble_bounds_.x(), gesture_location.y(),
+      system_tray_bubble_bounds_.width(), system_tray_bubble_bounds_.height());
+  system_bubble_->bubble_view()->GetWidget()->SetBounds(bounds_on_gesture);
+  system_bubble_->bubble_view()->GetWidget()->Show();
+
+  gesture_drag_amount_ += gesture.details().scroll_y();
+  final_scroll_y_ = gesture.details().scroll_y();
+}
+
+void SystemTray::CompleteGestureDrag(const ui::GestureEvent& gesture) {
+  if (gesture.details().scroll_y())
+    final_scroll_y_ = gesture.details().scroll_y();
+  if (ShouldShowSystemBubbleForSwiping(gesture))
+    system_bubble_->bubble_view()->GetWidget()->SetBounds(
+        system_tray_bubble_bounds_);
+  else
+    system_bubble_->bubble()->Close();
+}
+
+bool SystemTray::IsSwipingDownOnShelf(const ui::GestureEvent& gesture) {
+  gfx::Point gesture_location = gesture.location();
+  View::ConvertPointToScreen(this, &gesture_location);
+
+  if (gesture_location.y() >= shelf_->GetIdealBounds().y() &&
+      gesture.details().scroll_y() > 0) {
+    return true;
+  }
+  return false;
+}
+
+bool SystemTray::ShouldShowSystemBubbleBasedOnPosition() {
+  int system_bubble_height = system_tray_bubble_bounds_.height();
+  float one_third = system_bubble_height / 3.0;
+
+  if (gesture_drag_amount_ > 0)
+    return false;
+
+  if (fabs(gesture_drag_amount_) < one_third)
+    return false;
+  else if (fabs(gesture_drag_amount_) > 2 * one_third)
+    return true;
+  else
+    return final_scroll_y_ < 0;
+}
+
+bool SystemTray::ShouldShowSystemBubbleForSwiping(
+    const ui::GestureEvent& gesture) {
+  if (gesture.type() == ui::ET_GESTURE_SCROLL_END) {
+    return ShouldShowSystemBubbleBasedOnPosition();
+  } else {
+    if (fabs(gesture.details().velocity_y()) > kSwipingVelocity)
+      return gesture.details().velocity_y() < 0;
+    return ShouldShowSystemBubbleBasedOnPosition();
+  }
+}
+
 void SystemTray::CloseSystemBubbleAndDeactivateSystemTray() {
   activation_observer_.reset();
   key_event_watcher_.reset();