CrOS GMC: Hide action buttons when they're not available.

Bug: 1133026
Change-Id: Id4cc583e1eca14b083d2b22c9ee4b25e857d4175
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2437370Reviewed-by: Tommy Steimel <steimel@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Commit-Queue: Jazz Xu <jazzhsu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811560}

ash/system/media/unified_media_controls_controller_unittest.cc

@@ -202,6 +202,36 @@ TEST_F(UnifiedMediaControlsControllerTest, ActionButtonsTest) {
   EXPECT_EQ(1, media_controller()->resume_count());
 }
 
+TEST_F(UnifiedMediaControlsControllerTest, ActionButtonVisibility) {
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPlaying);
+  EnableAction(MediaSessionAction::kPause);
+  EnableAction(MediaSessionAction::kPlay);
+  EXPECT_EQ(GetActionButton(MediaSessionAction::kPlay), nullptr);
+  EXPECT_TRUE(GetActionButton(MediaSessionAction::kPause)->GetVisible());
+  EXPECT_FALSE(
+      GetActionButton(MediaSessionAction::kPreviousTrack)->GetVisible());
+  EXPECT_FALSE(GetActionButton(MediaSessionAction::kNextTrack)->GetVisible());
+
+  EnableAction(MediaSessionAction::kPreviousTrack);
+  EXPECT_TRUE(GetActionButton(MediaSessionAction::kPause)->GetVisible());
+  EXPECT_TRUE(
+      GetActionButton(MediaSessionAction::kPreviousTrack)->GetVisible());
+  EXPECT_FALSE(GetActionButton(MediaSessionAction::kNextTrack)->GetVisible());
+
+  EnableAction(MediaSessionAction::kNextTrack);
+  DisableAction(MediaSessionAction::kPreviousTrack);
+  EXPECT_TRUE(GetActionButton(MediaSessionAction::kPause)->GetVisible());
+  EXPECT_FALSE(
+      GetActionButton(MediaSessionAction::kPreviousTrack)->GetVisible());
+  EXPECT_TRUE(GetActionButton(MediaSessionAction::kNextTrack)->GetVisible());
+
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPaused);
+  EXPECT_EQ(GetActionButton(MediaSessionAction::kPause), nullptr);
+  EXPECT_TRUE(GetActionButton(MediaSessionAction::kPlay)->GetVisible());
+}
+
 TEST_F(UnifiedMediaControlsControllerTest, MetadataUpdate) {
   media_session::MediaMetadata metadata;
   metadata.title = base::ASCIIToUTF16("title");

ash/system/media/unified_media_controls_view.cc

@@ -105,12 +105,6 @@ void UnifiedMediaControlsView::MediaActionButton::SetAction(
                GetVectorIconForMediaAction(action), kMediaButtonIconSize,
                AshColorProvider::Get()->GetContentLayerColor(
                    AshColorProvider::ContentLayerType::kIconColorPrimary)));
-
-  SetImage(views::Button::STATE_DISABLED,
-           CreateVectorIcon(
-               GetVectorIconForMediaAction(action), kMediaButtonIconSize,
-               AshColorProvider::Get()->GetContentLayerColor(
-                   AshColorProvider::ContentLayerType::kIconColorSecondary)));
 }
 
 UnifiedMediaControlsView::UnifiedMediaControlsView(
@@ -228,12 +222,18 @@ void UnifiedMediaControlsView::SetArtist(const base::string16& artist) {
 
 void UnifiedMediaControlsView::UpdateActionButtonAvailability(
     const base::flat_set<MediaSessionAction>& enabled_actions) {
+  bool should_invalidate = false;
   for (views::View* child : button_row_->children()) {
     views::Button* button = static_cast<views::Button*>(child);
-    button->SetEnabled(
-        base::Contains(enabled_actions,
-                       media_message_center::GetActionFromButtonTag(*button)));
+    bool should_show = base::Contains(
+        enabled_actions, media_message_center::GetActionFromButtonTag(*button));
+
+    should_invalidate |= should_show != button->GetVisible();
+    button->SetVisible(should_show);
   }
+
+  if (should_invalidate)
+    button_row_->InvalidateLayout();
 }
 
 SkPath UnifiedMediaControlsView::GetArtworkClipPath() {