[Tab Groups] Add animation for tab group headers.

Bug: 1021689

Change-Id: Ida4f922471b9e53684acfc683623150b82e2a7cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1906873
Commit-Queue: Charlene Yan <cyan@chromium.org>
Reviewed-by: Connie Wan <connily@chromium.org>
Reviewed-by: Taylor Bergquist <tbergquist@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721269}

chrome/browser/ui/views/tabs/tab_strip.cc

@@ -1273,6 +1273,7 @@ void TabStrip::OnGroupVisualsChanged(TabGroupId group) {
 }
 
 void TabStrip::OnGroupDeleted(TabGroupId group) {
+  bounds_animator_.StopAnimatingView(group_header(group));
   layout_helper_->RemoveGroupHeader(group);
   UpdateIdealBounds();
   AnimateToIdealBounds();
@@ -2452,6 +2453,15 @@ void TabStrip::AnimateToIdealBounds(ClosingTabsBehavior closing_tabs_behavior) {
                         : std::make_unique<TabAnimationDelegate>(this, tab));
   }
 
+  std::map<TabGroupId, TabGroupHeader*> group_headers = GetGroupHeaders();
+  std::map<TabGroupId, gfx::Rect> group_headers_bounds =
+      layout_helper_->group_header_ideal_bounds();
+
+  for (const auto& header_pair : group_headers) {
+    bounds_animator_.AnimateViewTo(header_pair.second,
+                                   group_headers_bounds.at(header_pair.first));
+  }
+
   if (bounds_animator_.GetTargetBounds(new_tab_button_) !=
       new_tab_button_ideal_bounds_) {
     bounds_animator_.AnimateViewTo(new_tab_button_,
@@ -2631,8 +2641,6 @@ void TabStrip::StoppedDraggingView(TabSlotView* view, bool* is_first_view) {
     // Ensure the drag status is updated even if the view is not a valid tab.
     // This is primarily to make sure group headers are updated correctly.
     // Otherwise, tab drag status is only updated in PrepareForAnimation().
-    // TODO(crbug.com/1021689): Incorporate group headers in the normal
-    // animation flow instead of handling it here and then ignoring it.
     if (view)
       view->set_dragging(false);
 

chrome/browser/ui/views/tabs/tab_strip_layout_helper.cc

@@ -242,7 +242,6 @@ void TabStripLayoutHelper::InsertGroupHeader(
     TabGroupId group,
     TabGroupHeader* header,
     base::OnceClosure header_removed_callback) {
-  // TODO(958173): Animate open.
   std::vector<int> tabs_in_group = controller_->ListTabsInGroup(group);
   const int header_slot_index =
       GetSlotIndexForTabModelIndex(tabs_in_group[0], group);
@@ -250,6 +249,11 @@ void TabStripLayoutHelper::InsertGroupHeader(
       slots_.begin() + header_slot_index,
       TabSlot::CreateForGroupHeader(group, header, TabPinned::kUnpinned,
                                     std::move(header_removed_callback)));
+
+  // Set the starting location of the header to something reasonable for the
+  // animation.
+  slots_[header_slot_index].view->SetBoundsRect(
+      GetTabs()[tabs_in_group[0]]->bounds());
 }
 
 void TabStripLayoutHelper::RemoveGroupHeader(TabGroupId group) {
@@ -357,7 +361,7 @@ void TabStripLayoutHelper::UpdateIdealBounds(int available_width) {
         }
         break;
       case ViewType::kGroupHeader:
-        slot.view->SetBoundsRect(bounds[i]);
+        group_header_ideal_bounds_[slot.view->group().value()] = bounds[i];
         break;
     }
   }

chrome/browser/ui/views/tabs/tab_strip_layout_helper.h

@@ -54,6 +54,11 @@ class TabStripLayoutHelper {
   // Returns the number of pinned tabs in the tabstrip.
   int GetPinnedTabCount() const;
 
+  // Returns a map of all tab groups and their bounds.
+  const std::map<TabGroupId, gfx::Rect>& group_header_ideal_bounds() const {
+    return group_header_ideal_bounds_;
+  }
+
   // Inserts a new tab at |index|, without animation. |tab_removed_callback|
   // will be invoked if the tab is removed at the end of a remove animation.
   void InsertTabAtNoAnimation(int model_index,
@@ -205,6 +210,9 @@ class TabStripLayoutHelper {
   // run layout and animations for those Views.
   std::vector<TabSlot> slots_;
 
+  // Contains the ideal bounds of tab group headers.
+  std::map<TabGroupId, gfx::Rect> group_header_ideal_bounds_;
+
   // When in tab closing mode, if we want the next tab to the right to end up
   // under the cursor, each tab needs to stay the same size. When defined,
   // this specifies that size.

chrome/browser/ui/views/tabs/tab_strip_unittest.cc

@@ -1123,6 +1123,7 @@ TEST_P(TabStripTest, GroupHeaderMovesOnRegrouping) {
   // Change groups in a way so that the header should swap with the tab, without
   // an explicit MoveTab call.
   controller_->MoveTabIntoGroup(1, group0);
+  CompleteAnimationAndLayout();
 
   // Header is now right of tab 1.
   EXPECT_LT(tab_strip_->tab_at(1)->x(), header1->x());