Tablet WM : 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 78f2929147dab3951ce59e4d5e0d922ef7483b9c..3bbdfdb60980346ab4d31065040abdf98aa3fc98 100644
--- a/ash/system/tray/system_tray.cc
+++ b/ash/system/tray/system_tray.cc
@@ -50,6 +50,7 @@
 #include "ash/system/user/tray_user.h"
 #include "ash/system/web_notification/web_notification_tray.h"
 #include "ash/wm/container_finder.h"
+#include "ash/wm/maximize_mode/maximize_mode_controller.h"
 #include "ash/wm/widget_finder.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ -172,8 +173,10 @@ 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)
+    if (container_id == kShellWindowId_StatusContainer ||
+        container_id == kShellWindowId_SettingBubbleContainer) {
       return;
+    }
 
     views::Widget* bubble_widget =
         tray_->GetSystemBubble()->bubble_view()->GetWidget();
@@ -198,7 +201,8 @@ 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
@@ -630,6 +634,21 @@ void SystemTray::ActivateBubble() {
   bubble_view->GetWidget()->Activate();
 }
 
+void SystemTray::OnGestureEvent(ui::GestureEvent* event) {
+  if (Shell::Get()
+          ->maximize_mode_controller()
+          ->IsMaximizeModeWindowManagerEnabled() &&
+      shelf_->IsHorizontalAlignment() && ProcessGestureEvent(*event)) {
+    event->SetHandled();
+  } else {
+    TrayBackgroundView::OnGestureEvent(event);
+  }
+}
+
+gfx::Rect SystemTray::GetWorkAreaBoundsInScreen() const {
+  return shelf_->GetUserWorkAreaBounds();
+}
+
 bool SystemTray::PerformAction(const ui::Event& event) {
   // If we're already showing a full system tray menu, either default or
   // detailed menu, hide it; otherwise, show it (and hide any popup that's
@@ -644,6 +663,95 @@ bool SystemTray::PerformAction(const ui::Event& event) {
   return true;
 }
 
+bool SystemTray::ProcessGestureEvent(const ui::GestureEvent& event) {
+  if (event.type() == ui::ET_GESTURE_SCROLL_BEGIN)
+    return StartGestureDrag(event);
+
+  if (!HasSystemBubble() || !is_in_drag_)
+    return false;
+
+  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) {
+  // Close the system bubble if there is already a full one opened. And return
+  // false to let shelf handle the event.
+  is_in_drag_ = true;

[tdanderson, 2017/06/26 18:13:02]

Should this be placed just above line 703 (past the early returns)? If we hit
any of the early returns then I don't think we should consider ourself as being
in a drag, though I could be missing something here.

[minch1, 2017/06/26 23:26:48]

Yeah, you are right, thanks.

+  if (HasSystemBubble() && full_system_tray_menu_) {
+    system_bubble_->bubble()->Close();
+    return false;
+  }
+
+  // If the scroll sequence begins to scroll downward, return false so that the
+  // event will instead by handled by the shelf.
+  if (gesture.details().scroll_y_hint() > 0)
+    return false;
+
+  ShellPort::Get()->RecordUserMetricsAction(
+      UMA_STATUS_AREA_SYSTEM_TRAY_SWIPE_TO_OPEN);
+
+  gesture_drag_amount_ = 0.f;
+  ShowDefaultView(BUBBLE_CREATE_NEW);
+  system_tray_bubble_bounds_ =
+      system_bubble_->bubble_view()->GetWidget()->GetWindowBoundsInScreen();
+  SetBubbleBounds(gesture.location());
+  return true;
+}
+
+void SystemTray::UpdateGestureDrag(const ui::GestureEvent& gesture) {

[tdanderson, 2017/06/26 18:13:01]

Consider adding DCHECK(is_in_drag_);

+  SetBubbleBounds(gesture.location());
+  gesture_drag_amount_ += gesture.details().scroll_y();
+}
+
+void SystemTray::CompleteGestureDrag(const ui::GestureEvent& gesture) {

[tdanderson, 2017/06/26 18:13:02]

Consider adding DCHECK(is_in_drag_);

+  const bool hide_bubble = !ShouldShowSystemBubbleAfterScrollSequence(gesture);
+  gfx::Rect target_bounds = system_tray_bubble_bounds_;
+
+  if (hide_bubble)
+    target_bounds.set_y(shelf_->GetIdealBounds().y());
+
+  system_bubble_->bubble()->AnimateToTargetBounds(target_bounds, hide_bubble);
+  is_in_drag_ = false;

[tdanderson, 2017/06/26 18:13:02]

What do you think of doing the following:

In StartGestureDrag():
  DCHECK_EQ(gesture_drag_amount_, 0.f);
  is_in_drag_ = true;
  
Then in CompleteGestureDrag():
  is_in_drag_ = false;
  gesture_drag_amount_ = 0.f;


This will trigger the DCHECK in any cases where, for some reason, a previous
drag didn't complete and you're trying to start a new one. Offhand I can't think
of any specific case where this could happen, but I am not 100% certain it's
impossible given the many different types of events we have and the possible
combinations of event streams. (For instance, could you run into a
ET_SCROLL_FLING_CANCEL instead of a ET_SCROLL_FLING_START?)

[minch1, 2017/06/26 23:26:48]

Sorry, I think I made a mistake here. It should always has a SCROLL_END /
FLING_START with a normal dragging sequence. I think it is possible the sequence
ends with like FLING_CANCEL. How about set |is_in_drag_| to false and just close
the bubble in this case? And after this, I think we don't need to
DCHECK(is_in_drag_) in UpdateGestureDrag and CompleteGestureDrag? And also the
|gesture_drag_amount_|?

+}
+
+void SystemTray::SetBubbleBounds(const gfx::Point& location) {
+  gfx::Point location_in_screen_coordinates(location);
+  View::ConvertPointToScreen(this, &location_in_screen_coordinates);
+
+  // System tray bubble should not be dragged higher than its original height.
+  if (location_in_screen_coordinates.y() < system_tray_bubble_bounds_.y())
+    location_in_screen_coordinates.set_y(system_tray_bubble_bounds_.y());
+
+  gfx::Rect bounds_on_location = system_tray_bubble_bounds_;
+  bounds_on_location.set_y(location_in_screen_coordinates.y());
+  system_bubble_->bubble_view()->GetWidget()->SetBounds(bounds_on_location);
+}
+
+bool SystemTray::ShouldShowSystemBubbleAfterScrollSequence(
+    const ui::GestureEvent& gesture) {
+  // If the scroll sequence terminates with a fling, show the system menu if the
+  // fling was fast enough and in the correct direction.
+  if (gesture.type() == ui::ET_SCROLL_FLING_START &&
+      fabs(gesture.details().velocity_y()) > kFlingVelocity) {
+    return gesture.details().velocity_y() < 0;
+  }
+
+  DCHECK(gesture.type() == ui::ET_GESTURE_SCROLL_END ||
+         gesture.type() == ui::ET_SCROLL_FLING_START);
+  // Show the system menu if it is already at least one-third visible.
+  return -gesture_drag_amount_ >= system_tray_bubble_bounds_.height() / 3.0;
+}
+
 void SystemTray::CloseSystemBubbleAndDeactivateSystemTray() {
   activation_observer_.reset();
   key_event_watcher_.reset();