Move notifications down when lower notifications fade out

Need to move notifications down whenever there is free space below.

Bug: 920110
Change-Id: Ib49a4e22ee1cbb287095125fc29c623e47d20339
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1638142Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Tim Song <tengs@chromium.org>
Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#668427}

ui/message_center/views/message_popup_collection.cc

@@ -239,18 +239,15 @@ void MessagePopupCollection::TransitionFromAnimation() {
     // If the animation is finished, transition to IDLE.
     state_ = State::IDLE;
   } else if (state_ == State::FADE_OUT && !popup_items_.empty()) {
-    if ((HasAddedPopup() && CollapseAllPopups()) || !inverse_) {
-      // If FADE_OUT animation is finished and we still have remaining popups,
-      // we have to MOVE_DOWN them.
       // If we're going to add a new popup after this MOVE_DOWN, do the collapse
       // animation at the same time. Otherwise it will take another MOVE_DOWN.
+      if (HasAddedPopup())
+        CollapseAllPopups();
+
+      // If FADE_OUT animation is finished and we still have remaining popups,
+      // we have to MOVE_DOWN them.
       state_ = State::MOVE_DOWN;
       MoveDownPopups();
-    } else {
-      // If there's no collapsable popups and |inverse_| is on, there's nothing
-      // to do after FADE_OUT.
-      state_ = State::IDLE;
-    }
   } else if (state_ == State::MOVE_UP_FOR_INVERSE) {
     for (auto& item : popup_items_)
       item.is_animating = item.will_fade_in;

ui/message_center/views/message_popup_collection_unittest.cc

@@ -585,6 +585,9 @@ TEST_F(MessagePopupCollectionTest, NotificationsMoveUpForInverse) {
   EXPECT_EQ(ids[1], GetPopup(ids[1])->id());
   EXPECT_TRUE(IsAnimating());
 
+  // MOVE_DOWN
+  AnimateToEnd();
+
   gfx::Rect before = GetPopup(ids[1])->GetBoundsInScreen();
 
   // MOVE_UP_FOR_INVERSE
@@ -610,6 +613,44 @@ TEST_F(MessagePopupCollectionTest, NotificationsMoveUpForInverse) {
   EXPECT_FALSE(IsAnimating());
 }
 
+TEST_F(MessagePopupCollectionTest, NotificationsMoveDownForEmptySpace) {
+  popup_collection()->set_inverse();
+
+  std::vector<std::string> ids;
+  for (size_t i = 0; i < kMaxVisiblePopupNotifications; ++i)
+    ids.push_back(AddNotification());
+
+  AnimateUntilIdle();
+
+  EXPECT_EQ(kMaxVisiblePopupNotifications, GetPopupCounts());
+  EXPECT_FALSE(IsAnimating());
+
+  // Dismiss bottom most notification
+  gfx::Rect dismissed = GetPopup(ids.back())->GetBoundsInScreen();
+  MessageCenter::Get()->MarkSinglePopupAsShown(ids.back(), false);
+
+  // FADE_OUT
+  AnimateToMiddle();
+  EXPECT_GT(1.0f, GetPopup(ids.back())->GetOpacity());
+  EXPECT_EQ(ids[2], GetPopup(ids.back())->id());
+
+  AnimateToEnd();
+  EXPECT_EQ(ids[1], GetPopup(ids[1])->id());
+
+  gfx::Rect before = GetPopup(ids[1])->GetBoundsInScreen();
+
+  // MOVE_DOWN
+  AnimateToMiddle();
+  gfx::Rect moving = GetPopup(ids[1])->GetBoundsInScreen();
+  EXPECT_GT(moving.bottom(), before.bottom());
+  EXPECT_GT(dismissed.bottom(), moving.bottom());
+
+  AnimateToEnd();
+  gfx::Rect after = GetPopup(ids[1])->GetBoundsInScreen();
+  EXPECT_EQ(after, dismissed);
+  EXPECT_FALSE(IsAnimating());
+}
+
 TEST_F(MessagePopupCollectionTest, PopupResized) {
   std::vector<std::string> ids;
   for (size_t i = 0; i < kMaxVisiblePopupNotifications; ++i)