Cros: Add tooltip for scrollable shelf arrows

Bug: 1009413
Change-Id: I96251acc1010789d41e43b3dd1bac5b16b8698cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1863856Reviewed-by: Andrew Xu <andrewxu@chromium.org>
Reviewed-by: Manu Cornet <manucornet@chromium.org>
Commit-Queue: Ana Salazar <anasalazar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706648}

ash/shelf/scrollable_shelf_view.cc

@@ -13,11 +13,13 @@
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "base/numerics/ranges.h"
 #include "chromeos/constants/chromeos_switches.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/paint_recorder.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/vector2d_conversions.h"
 #include "ui/gfx/skia_paint_util.h"
+#include "ui/strings/grit/ui_strings.h"
 #include "ui/views/focus/focus_search.h"
 #include "ui/views/view_targeter_delegate.h"
 
@@ -763,6 +765,9 @@ bool ScrollableShelfView::ShouldShowTooltipForView(
   if (!view || !view->parent())
     return false;
 
+  if (view == left_arrow_ || view == right_arrow_)
+    return true;
+
   if (view->parent() != shelf_view_)
     return false;
 
@@ -799,6 +804,12 @@ base::string16 ScrollableShelfView::GetTitleForView(
   if (view->parent() == shelf_view_)
     return shelf_view_->GetTitleForView(view);
 
+  if (view == left_arrow_)
+    return l10n_util::GetStringUTF16(IDS_SHELF_PREVIOUS);
+
+  if (view == right_arrow_)
+    return l10n_util::GetStringUTF16(IDS_SHELF_NEXT);
+
   return base::string16();
 }
 

ash/shelf/scrollable_shelf_view_unittest.cc

@@ -307,4 +307,37 @@ TEST_F(ScrollableShelfViewTest, VerifyTappableAppIndices) {
   CheckFirstAndLastTappableIconsBounds();
 }
 
+TEST_F(ScrollableShelfViewTest, ShowTooltipForArrowButtons) {
+  AddAppShortcutsUntilOverflow();
+  ASSERT_EQ(ScrollableShelfView::kShowRightArrowButton,
+            scrollable_shelf_view_->layout_strategy_for_test());
+
+  // Check the initial state of |tooltip_manager|.
+  ShelfTooltipManager* tooltip_manager = test_api_->tooltip_manager();
+  EXPECT_FALSE(tooltip_manager->IsVisible());
+
+  // Verifies that tooltip should show for a visible shelf item.
+  views::View* right_arrow = scrollable_shelf_view_->right_arrow();
+  GetEventGenerator()->MoveMouseTo(
+      right_arrow->GetBoundsInScreen().CenterPoint());
+  tooltip_manager->ShowTooltip(right_arrow);
+  EXPECT_TRUE(tooltip_manager->IsVisible());
+
+  // Click right arrow button to scroll the shelf and show left arrow button.
+  GetEventGenerator()->ClickLeftButton();
+  ASSERT_EQ(ScrollableShelfView::kShowLeftArrowButton,
+            scrollable_shelf_view_->layout_strategy_for_test());
+
+  // Reset |tooltip_manager|.
+  GetEventGenerator()->MoveMouseTo(gfx::Point());
+  tooltip_manager->Close();
+  EXPECT_FALSE(tooltip_manager->IsVisible());
+
+  views::View* left_arrow = scrollable_shelf_view_->left_arrow();
+  GetEventGenerator()->MoveMouseTo(
+      left_arrow->GetBoundsInScreen().CenterPoint());
+  tooltip_manager->ShowTooltip(left_arrow);
+  EXPECT_TRUE(tooltip_manager->IsVisible());
+}
+
 }  // namespace ash

ui/strings/ui_strings.grd

@@ -861,6 +861,12 @@ need to be translated for each locale.-->
       <message name="IDS_SHELF_STATE_AUTO_HIDE" desc="Accessibility announcement notifying users that the shelf will now hide itself automatically">
         Shelf auto hidden
       </message>
+      <message name="IDS_SHELF_NEXT" desc="Tooltip for the shelf arrow button that scrolls the shelf forward">
+        Next
+      </message>
+      <message name="IDS_SHELF_PREVIOUS" desc="Tooltip for the shelf arrow button that scrolls the shelf backward">
+        Previous
+      </message>
       <message name="IDS_REMOVE_ZERO_STATE_SUGGESTION_TITLE" desc="Titlebar of removing zero state suggestion confirmation dialog">
         Delete this search from your history?
       </message>