NewMessageListView: Paint corners behind tray.

This CL implements TopCornerBorder hack for NewMessageListView. For the
detail of the hack, please refer https://crrev.com/c/1161710 .

NewUnifiedMessageCenterView will replace UnifiedMessageCenterView.
It's behind a flag: --enable-features=NewMessageListView

TEST=NewUnifiedMessageCenterViewTest
BUG=769219

Change-Id: I24ad795fe118c21ef40be6b4ecc2f8e4a5f85101
Reviewed-on: https://chromium-review.googlesource.com/c/1278068
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599822}

ash/system/message_center/new_unified_message_center_view.cc

@@ -12,7 +12,7 @@
 #include "ash/system/message_center/unified_message_list_view.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/unified/sign_out_button.h"
-#include "ash/system/unified/unified_system_tray_controller.h"
+#include "ash/system/unified/unified_system_tray_view.h"
 #include "base/metrics/user_metrics.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/message_center/message_center.h"
@@ -68,8 +68,10 @@ class ScrollerContentsView : public views::View {
 
 }  // namespace
 
-NewUnifiedMessageCenterView::NewUnifiedMessageCenterView()
-    : stacking_counter_(new StackingNotificationCounterView()),
+NewUnifiedMessageCenterView::NewUnifiedMessageCenterView(
+    UnifiedSystemTrayView* parent)
+    : parent_(parent),
+      stacking_counter_(new StackingNotificationCounterView()),
       scroll_bar_(new MessageCenterScrollBar(this)),
       scroller_(new views::ScrollView()),
       message_list_view_(new UnifiedMessageListView(this)),
@@ -89,7 +91,9 @@ NewUnifiedMessageCenterView::NewUnifiedMessageCenterView()
   UpdateVisibility();
 }
 
-NewUnifiedMessageCenterView::~NewUnifiedMessageCenterView() = default;
+NewUnifiedMessageCenterView::~NewUnifiedMessageCenterView() {
+  RemovedFromWidget();
+}
 
 void NewUnifiedMessageCenterView::SetMaxHeight(int max_height) {
   scroller_->ClipHeightTo(0, max_height);
@@ -110,6 +114,19 @@ void NewUnifiedMessageCenterView::ConfigureMessageView(
   message_view->set_scroller(scroller_);
 }
 
+void NewUnifiedMessageCenterView::AddedToWidget() {
+  focus_manager_ = GetFocusManager();
+  if (focus_manager_)
+    focus_manager_->AddFocusChangeListener(this);
+}
+
+void NewUnifiedMessageCenterView::RemovedFromWidget() {
+  if (!focus_manager_)
+    return;
+  focus_manager_->RemoveFocusChangeListener(this);
+  focus_manager_ = nullptr;
+}
+
 void NewUnifiedMessageCenterView::Layout() {
   stacking_counter_->SetCount(GetStackedNotificationCount());
   if (stacking_counter_->visible()) {
@@ -126,6 +143,7 @@ void NewUnifiedMessageCenterView::Layout() {
   }
 
   ScrollToPositionFromBottom();
+  NotifyHeightBelowScroll();
 }
 
 gfx::Size NewUnifiedMessageCenterView::CalculatePreferredSize() const {
@@ -148,6 +166,8 @@ void NewUnifiedMessageCenterView::OnMessageCenterScrolled() {
     // on-screen position of notification list does not change.
     scroll_bar_->ScrollByContentsOffset(previous_y - scroller_->y());
   }
+
+  NotifyHeightBelowScroll();
 }
 
 void NewUnifiedMessageCenterView::ButtonPressed(views::Button* sender,
@@ -160,6 +180,19 @@ void NewUnifiedMessageCenterView::ButtonPressed(views::Button* sender,
       message_center::MessageCenter::RemoveType::NON_PINNED);
 }
 
+void NewUnifiedMessageCenterView::OnWillChangeFocus(views::View* before,
+                                                    views::View* now) {}
+
+void NewUnifiedMessageCenterView::OnDidChangeFocus(views::View* before,
+                                                   views::View* now) {
+  OnMessageCenterScrolled();
+}
+
+void NewUnifiedMessageCenterView::SetNotificationHeightBelowScroll(
+    int height_below_scroll) {
+  parent_->SetNotificationHeightBelowScroll(height_below_scroll);
+}
+
 void NewUnifiedMessageCenterView::UpdateVisibility() {
   SessionController* session_controller = Shell::Get()->session_controller();
   SetVisible(message_list_view_->child_count() > 0 &&
@@ -203,4 +236,9 @@ int NewUnifiedMessageCenterView::GetStackedNotificationCount() const {
   return message_list_view_->CountNotificationsAboveY(y_offset);
 }
 
+void NewUnifiedMessageCenterView::NotifyHeightBelowScroll() {
+  SetNotificationHeightBelowScroll(std::max(
+      0, message_list_view_->height() - scroller_->GetVisibleRect().bottom()));
+}
+
 }  // namespace ash

ash/system/message_center/new_unified_message_center_view.h

@@ -20,15 +20,17 @@ namespace ash {
 
 class MessageCenterScrollBar;
 class StackingNotificationCounterView;
+class UnifiedSystemTrayView;
 
 // Manages scrolling of notification list.
 // TODO(tetsui): Rename to UnifiedMessageCenterView after old code is removed.
 class ASH_EXPORT NewUnifiedMessageCenterView
     : public views::View,
       public MessageCenterScrollBar::Observer,
-      public views::ButtonListener {
+      public views::ButtonListener,
+      public views::FocusChangeListener {
  public:
-  NewUnifiedMessageCenterView();
+  explicit NewUnifiedMessageCenterView(UnifiedSystemTrayView* parent);
   ~NewUnifiedMessageCenterView() override;
 
   // Sets the maximum height that the view can take.
@@ -42,6 +44,8 @@ class ASH_EXPORT NewUnifiedMessageCenterView
   void ConfigureMessageView(message_center::MessageView* message_view);
 
   // views::View:
+  void AddedToWidget() override;
+  void RemovedFromWidget() override;
   void Layout() override;
   gfx::Size CalculatePreferredSize() const override;
 
@@ -51,6 +55,14 @@ class ASH_EXPORT NewUnifiedMessageCenterView
   // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
+  // views::FocusChangeListener:
+  void OnWillChangeFocus(views::View* before, views::View* now) override;
+  void OnDidChangeFocus(views::View* before, views::View* now) override;
+
+ protected:
+  // Virtual for testing.
+  virtual void SetNotificationHeightBelowScroll(int height_below_scroll);
+
  private:
   friend class NewUnifiedMessageCenterViewTest;
 
@@ -59,9 +71,14 @@ class ASH_EXPORT NewUnifiedMessageCenterView
   // Scroll the notification list to |position_from_bottom_|.
   void ScrollToPositionFromBottom();
 
+  // Notifies height below scroll to |parent_| so that it can update
+  // TopCornerBorder.
+  void NotifyHeightBelowScroll();
+
   // Count number of notifications that are above visible area.
   int GetStackedNotificationCount() const;
 
+  UnifiedSystemTrayView* const parent_;
   StackingNotificationCounterView* const stacking_counter_;
   MessageCenterScrollBar* const scroll_bar_;
   views::ScrollView* const scroller_;
@@ -70,6 +87,8 @@ class ASH_EXPORT NewUnifiedMessageCenterView
   // Position from the bottom of scroll contents in dip.
   int position_from_bottom_;
 
+  views::FocusManager* focus_manager_ = nullptr;
+
   DISALLOW_COPY_AND_ASSIGN(NewUnifiedMessageCenterView);
 };
 

ash/system/message_center/new_unified_message_center_view_unittest.cc

@@ -32,6 +32,24 @@ class DummyEvent : public ui::Event {
   ~DummyEvent() override = default;
 };
 
+class TestNewUnifiedMessageCenterView : public NewUnifiedMessageCenterView {
+ public:
+  TestNewUnifiedMessageCenterView() : NewUnifiedMessageCenterView(nullptr) {}
+
+  ~TestNewUnifiedMessageCenterView() override = default;
+
+  void SetNotificationHeightBelowScroll(int height_below_scroll) override {
+    height_below_scroll_ = height_below_scroll;
+  }
+
+  int height_below_scroll() const { return height_below_scroll_; }
+
+ private:
+  int height_below_scroll_ = -1;
+
+  DISALLOW_COPY_AND_ASSIGN(TestNewUnifiedMessageCenterView);
+};
+
 }  // namespace
 
 class NewUnifiedMessageCenterViewTest : public AshTestBase,
@@ -68,7 +86,7 @@ class NewUnifiedMessageCenterViewTest : public AshTestBase,
   }
 
   void CreateMessageCenterView(int max_height = kDefaultMaxHeight) {
-    message_center_view_ = std::make_unique<NewUnifiedMessageCenterView>();
+    message_center_view_ = std::make_unique<TestNewUnifiedMessageCenterView>();
     message_center_view_->AddObserver(this);
     message_center_view_->SetMaxHeight(max_height);
     OnViewPreferredSizeChanged(message_center_view_.get());
@@ -100,7 +118,7 @@ class NewUnifiedMessageCenterViewTest : public AshTestBase,
     return message_center_view()->stacking_counter_;
   }
 
-  NewUnifiedMessageCenterView* message_center_view() {
+  TestNewUnifiedMessageCenterView* message_center_view() {
     return message_center_view_.get();
   }
 
@@ -110,7 +128,7 @@ class NewUnifiedMessageCenterViewTest : public AshTestBase,
   int id_ = 0;
   int size_changed_count_ = 0;
 
-  std::unique_ptr<NewUnifiedMessageCenterView> message_center_view_;
+  std::unique_ptr<TestNewUnifiedMessageCenterView> message_center_view_;
 
   DISALLOW_COPY_AND_ASSIGN(NewUnifiedMessageCenterViewTest);
 };
@@ -332,4 +350,22 @@ TEST_F(NewUnifiedMessageCenterViewTest,
   EXPECT_FALSE(GetStackingCounter()->visible());
 }
 
+TEST_F(NewUnifiedMessageCenterViewTest, HeightBelowScroll) {
+  for (size_t i = 0; i < 6; ++i)
+    AddNotification();
+  CreateMessageCenterView();
+  EXPECT_TRUE(message_center_view()->visible());
+
+  // MessageCenterView is maxed out.
+  EXPECT_GT(GetMessageListView()->bounds().height(),
+            message_center_view()->bounds().height());
+  message_center_view()->OnMessageCenterScrolled();
+
+  EXPECT_EQ(0, message_center_view()->height_below_scroll());
+
+  GetScroller()->ScrollToPosition(GetScrollBar(), 0);
+  message_center_view()->OnMessageCenterScrolled();
+  EXPECT_LT(0, message_center_view()->height_below_scroll());
+}
+
 }  // namespace ash

ash/system/unified/unified_system_tray_view.cc

@@ -228,7 +228,7 @@ UnifiedSystemTrayView::UnifiedSystemTrayView(
                                      this,
                                      message_center::MessageCenter::Get())),
       new_message_center_view_(features::IsNewMessageListViewEnabled()
-                                   ? new NewUnifiedMessageCenterView()
+                                   ? new NewUnifiedMessageCenterView(this)
                                    : nullptr),
       focus_search_(std::make_unique<FocusSearch>(this)),
       interacted_by_tap_recorder_(