Fix feature pods focus traversal

Always ensure the focused view is visible by switching pages
when needed.

Bug: 1013722
Change-Id: I27e561dabc43daea32167ff68d84ba710821d902
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1856852
Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
Reviewed-by: Tim Song <tengs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705768}

ash/system/unified/feature_pods_container_view.cc

@@ -163,6 +163,23 @@ int FeaturePodsContainerView::GetVisibleCount() const {
       });
 }
 
+void FeaturePodsContainerView::EnsurePageWithButton(FeaturePodButton* button) {
+  int index = visible_buttons_.GetIndexOfView(button->parent());
+  if (index < 0)
+    return;
+
+  int tiles_per_page = GetTilesPerPage();
+  int first_index = pagination_model_->selected_page() * tiles_per_page;
+  int last_index =
+      ((pagination_model_->selected_page() + 1) * tiles_per_page) - 1;
+  if (index < first_index || index > last_index) {
+    int page = ((index + 1) / tiles_per_page) +
+               ((index + 1) % tiles_per_page ? 1 : 0) - 1;
+
+    pagination_model_->SelectPage(page, true /*animate*/);
+  }
+}
+
 gfx::Point FeaturePodsContainerView::GetButtonPosition(
     int visible_index) const {
   int row = visible_index / kUnifiedFeaturePodItemsInRow;

ash/system/unified/feature_pods_container_view.h

@@ -50,6 +50,9 @@ class ASH_EXPORT FeaturePodsContainerView : public views::View,
   // Returns the number of children that prefer to be visible.
   int GetVisibleCount() const;
 
+  // Make sure button is visible by switching page if needed.
+  void EnsurePageWithButton(FeaturePodButton* button);
+
   // views::View:
   gfx::Size CalculatePreferredSize() const override;
   void ChildVisibilityChanged(View* child) override;

ash/system/unified/unified_system_tray_view.cc

@@ -565,20 +565,26 @@ void UnifiedSystemTrayView::OnWillChangeFocus(views::View* before,
 
 void UnifiedSystemTrayView::OnDidChangeFocus(views::View* before,
                                              views::View* now) {
-  if (features::IsUnifiedMessageCenterRefactorEnabled()) {
-    views::View* first_view = GetFirstFocusableChild();
-    views::View* last_view = GetLastFocusableChild();
-
-    bool focused_out = false;
-    if (before == last_view && now == first_view)
-      focused_out = controller_->FocusOut(false);
-    else if (before == first_view && now == last_view)
-      focused_out = controller_->FocusOut(true);
-
-    if (focused_out) {
-      GetFocusManager()->ClearFocus();
-      GetFocusManager()->SetStoredFocusView(nullptr);
-    }
+  if (!features::IsUnifiedMessageCenterRefactorEnabled())
+    return;
+
+  if (feature_pods_container_->Contains(now)) {
+    feature_pods_container_->EnsurePageWithButton(
+        static_cast<FeaturePodButton*>(now));
+  }
+
+  views::View* first_view = GetFirstFocusableChild();
+  views::View* last_view = GetLastFocusableChild();
+
+  bool focused_out = false;
+  if (before == last_view && now == first_view)
+    focused_out = controller_->FocusOut(false);
+  else if (before == first_view && now == last_view)
+    focused_out = controller_->FocusOut(true);
+
+  if (focused_out) {
+    GetFocusManager()->ClearFocus();
+    GetFocusManager()->SetStoredFocusView(nullptr);
   }
 }