ambient: Impl media string animation

This patch adds a transform animation to scroll the long text in the media info.
Text will stop a few seconds before scrolling.

Bug: b/167236615
Test: added new tests
Change-Id: I4c79b5e4a150dbe6d02b5d602af8b2d202e0f065
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2411545
Commit-Queue: Tao Wu <wutao@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810855}

ash/ambient/ambient_constants.h

@@ -49,6 +49,9 @@ constexpr base::TimeDelta kTokenUsageTimeBuffer =
 // Spacing between two portrait images.
 constexpr int kMarginLeftOfRelatedImageDip = 8;
 
+// Media string related.
+constexpr int kMediaStringMaxWidthDip = 280;
+
 }  // namespace ash
 
 #endif  // ASH_AMBIENT_AMBIENT_CONSTANTS_H_

ash/ambient/test/ambient_ash_test_base.cc

@@ -32,6 +32,7 @@
 #include "chromeos/dbus/power_manager/idle.pb.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_unittest_util.h"
+#include "ui/views/controls/label.h"
 
 namespace ash {
 
@@ -197,6 +198,14 @@ void AmbientAshTestBase::SetScreenBrightnessAndWait(double percent) {
   base::RunLoop().RunUntilIdle();
 }
 
+views::View* AmbientAshTestBase::GetMediaStringViewTextContainer() {
+  return GetMediaStringView()->media_text_container_for_testing();
+}
+
+views::Label* AmbientAshTestBase::GetMediaStringViewTextLabel() {
+  return GetMediaStringView()->media_text_label_for_testing();
+}
+
 void AmbientAshTestBase::SimulateMediaMetadataChanged(
     media_session::MediaMetadata metadata) {
   GetMediaStringView()->MediaSessionMetadataChanged(metadata);

ash/ambient/test/ambient_ash_test_base.h

@@ -19,6 +19,10 @@
 #include "services/media_session/public/mojom/media_session.mojom.h"
 #include "ui/views/widget/widget.h"
 
+namespace views {
+class Label;
+}  // namespace views
+
 namespace ash {
 
 class AmbientAccessTokenController;
@@ -62,6 +66,10 @@ class AmbientAshTestBase : public AshTestBase {
   void SimulateSystemSuspendAndWait(
       power_manager::SuspendImminent::Reason reason);
 
+  views::View* GetMediaStringViewTextContainer();
+
+  views::Label* GetMediaStringViewTextLabel();
+
   // Simulates the system starting to resume.
   // Wait until the event has been processed.
   void SimulateSystemResumeAndWait();

ash/ambient/ui/ambient_container_view.cc

@@ -37,9 +37,8 @@ namespace {
 using chromeos::assistant::features::IsAmbientAssistantEnabled;
 
 // Appearance.
-constexpr int kHorizontalMarginDip = 16;
 constexpr int kAssistantPreferredHeightDip = 128;
-constexpr int kMediaStringTopMarginDip = 25;
+constexpr int kMediaStringMarginDip = 32;
 
 // A tolerance threshold used to ignore spurious mouse move.
 constexpr int kMouseMoveErrorTolerancePx = 3;
@@ -185,12 +184,9 @@ void AmbientContainerView::LayoutMediaStringView() {
 
   // The media string view is positioned on the right-top corner of the
   // container.
-  // TODO(meilinw): without a maximum width limit, media string can grow too
-  // long or even overflow the screen. Revisit here to polish the UI once the
-  // spec is available. See b/163398805.
   int x =
-      container_size.width() - kHorizontalMarginDip - preferred_size.width();
-  int y = kMediaStringTopMarginDip;
+      container_size.width() - kMediaStringMarginDip - preferred_size.width();
+  int y = kMediaStringMarginDip;
   media_string_view_->SetBoundsRect(
       gfx::Rect(x, y, preferred_size.width(), preferred_size.height()));
 }

ash/ambient/ui/media_string_view.cc

@@ -5,8 +5,8 @@
 #include "ash/ambient/ui/media_string_view.h"
 
 #include <memory>
-#include <string>
 
+#include "ash/ambient/ambient_constants.h"
 #include "ash/ambient/util/ambient_util.h"
 #include "ash/assistant/ui/assistant_view_ids.h"
 #include "ash/public/cpp/ash_pref_names.h"
@@ -15,23 +15,29 @@
 #include "ash/shell_delegate.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
 #include "components/prefs/pref_service.h"
 #include "services/media_session/public/mojom/media_session.mojom.h"
 #include "services/media_session/public/mojom/media_session_service.mojom.h"
 #include "third_party/skia/include/core/SkColor.h"
+#include "ui/compositor/layer.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/gfx/shadow_value.h"
+#include "ui/gfx/text_constants.h"
+#include "ui/gfx/transform.h"
+#include "ui/views/border.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/box_layout.h"
+#include "ui/views/layout/flex_layout.h"
+#include "ui/views/layout/flex_layout_types.h"
 
 namespace ash {
 
 namespace {
 
 // Typography.
-constexpr SkColor kTextColor = SK_ColorWHITE;
 constexpr char kMiddleDotSeparator[] = " \u00B7 ";
 constexpr char kPreceedingEighthNoteSymbol[] = "\u266A ";
-constexpr int kDefaultFontSizeDip = 64;
-constexpr int kMediaStringFontSizeDip = 16;
 
 // Returns true if we should show media string for ambient mode on lock-screen
 // based on user pref. We should keep the same user policy here as the
@@ -58,6 +64,10 @@ const char* MediaStringView::GetClassName() const {
   return "MediaStringView";
 }
 
+void MediaStringView::VisibilityChanged(View* starting_from, bool is_visible) {
+  media_text_->layer()->GetAnimator()->StopAnimating();
+}
+
 void MediaStringView::MediaSessionInfoChanged(
     media_session::mojom::MediaSessionInfoPtr session_info) {
   if (ambient::util::IsShowing(LockScreen::ScreenType::kLock) &&
@@ -85,18 +95,38 @@ void MediaStringView::MediaSessionMetadataChanged(
       metadata.value_or(media_session::MediaMetadata());
 
   base::string16 media_string;
+  base::string16 middle_dot = base::UTF8ToUTF16(kMiddleDotSeparator);
   if (!session_metadata.title.empty() && !session_metadata.artist.empty()) {
-    media_string = session_metadata.title +
-                   base::UTF8ToUTF16(kMiddleDotSeparator) +
-                   session_metadata.artist;
+    media_string =
+        session_metadata.title + middle_dot + session_metadata.artist;
   } else if (!session_metadata.title.empty()) {
     media_string = session_metadata.title;
   } else {
     media_string = session_metadata.artist;
   }
 
-  // Formats the media string with a preceding music eighth note.
-  SetText(base::UTF8ToUTF16(kPreceedingEighthNoteSymbol) + media_string);
+  // Reset text and stop any ongoing animation.
+  media_text_->SetText(base::string16());
+  media_text_->layer()->GetAnimator()->StopAnimating();
+
+  media_text_->SetText(media_string);
+  media_text_->layer()->SetTransform(gfx::Transform());
+  const auto& text_size = media_text_->GetPreferredSize();
+  const int text_width = text_size.width();
+  media_text_container_->SetPreferredSize(gfx::Size(
+      std::min(kMediaStringMaxWidthDip, text_width), text_size.height()));
+
+  if (NeedToAnimate()) {
+    media_text_->SetText(media_string + middle_dot + media_string + middle_dot);
+    ScheduleScrolling(/*is_initial=*/true);
+  }
+}
+
+void MediaStringView::OnImplicitAnimationsCompleted() {
+  if (!NeedToAnimate())
+    return;
+
+  ScheduleScrolling(/*is_initial=*/false);
 }
 
 void MediaStringView::InitLayout() {
@@ -105,12 +135,44 @@ void MediaStringView::InitLayout() {
   SetPaintToLayer();
   layer()->SetFillsBoundsOpaquely(false);
 
+  auto* layout = SetLayoutManager(std::make_unique<views::BoxLayout>(
+      views::BoxLayout::Orientation::kHorizontal));
+  layout->set_main_axis_alignment(views::BoxLayout::MainAxisAlignment::kStart);
+  layout->set_cross_axis_alignment(
+      views::BoxLayout::CrossAxisAlignment::kCenter);
+
+  icon_ = AddChildView(std::make_unique<views::Label>(
+      base::UTF8ToUTF16(kPreceedingEighthNoteSymbol)));
+
+  media_text_container_ = AddChildView(std::make_unique<views::View>());
+  media_text_container_->SetPaintToLayer();
+  media_text_container_->layer()->SetFillsBoundsOpaquely(false);
+  media_text_container_->layer()->SetMasksToBounds(true);
+  auto* text_layout = media_text_container_->SetLayoutManager(
+      std::make_unique<views::FlexLayout>());
+  text_layout->SetOrientation(views::LayoutOrientation::kHorizontal);
+  text_layout->SetMainAxisAlignment(views::LayoutAlignment::kStart);
+  text_layout->SetCrossAxisAlignment(views::LayoutAlignment::kCenter);
+
+  media_text_ =
+      media_text_container_->AddChildView(std::make_unique<views::Label>());
+  media_text_->SetPaintToLayer();
+  media_text_->layer()->SetFillsBoundsOpaquely(false);
+
   // Defines the appearance.
-  SetAutoColorReadabilityEnabled(false);
-  SetEnabledColor(kTextColor);
-  SetFontList(ambient::util::GetDefaultFontlist().DeriveWithSizeDelta(
+  constexpr SkColor kTextColor = SK_ColorWHITE;
+  constexpr int kDefaultFontSizeDip = 64;
+  constexpr int kMediaStringFontSizeDip = 18;
+  for (auto* view : {icon_, media_text_}) {
+    view->SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_TO_HEAD);
+    view->SetVerticalAlignment(gfx::VerticalAlignment::ALIGN_BOTTOM);
+    view->SetAutoColorReadabilityEnabled(false);
+    view->SetEnabledColor(kTextColor);
+    view->SetFontList(ambient::util::GetDefaultFontlist().DeriveWithSizeDelta(
         kMediaStringFontSizeDip - kDefaultFontSizeDip));
-  SetShadows(ambient::util::GetTextShadowValues());
+    view->SetShadows(ambient::util::GetTextShadowValues());
+    view->SetElideBehavior(gfx::ElideBehavior::NO_ELIDE);
+  }
 
   BindMediaControllerObserver();
 }
@@ -136,4 +198,56 @@ void MediaStringView::BindMediaControllerObserver() {
       observer_receiver_.BindNewPipeAndPassRemote());
 }
 
+bool MediaStringView::NeedToAnimate() const {
+  return media_text_->GetPreferredSize().width() >
+         media_text_container_->GetPreferredSize().width();
+}
+
+gfx::Transform MediaStringView::GetMediaTextTransform(bool is_initial) {
+  gfx::Transform transform;
+  if (is_initial) {
+    // Start animation half way of |media_text_container_|.
+    transform.Translate(kMediaStringMaxWidthDip / 2, 0);
+  }
+  return transform;
+}
+
+void MediaStringView::ScheduleScrolling(bool is_initial) {
+  if (!GetVisible())
+    return;
+
+  base::SequencedTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::BindOnce(&MediaStringView::StartScrolling,
+                                weak_factory_.GetWeakPtr(), is_initial));
+}
+
+void MediaStringView::StartScrolling(bool is_initial) {
+  ui::Layer* text_layer = media_text_->layer();
+  text_layer->SetTransform(GetMediaTextTransform(is_initial));
+  {
+    // Desired speed is 10 seconds for kMediaStringMaxWidthDip.
+    const int text_width = media_text_->GetPreferredSize().width();
+    const int shadow_width =
+        gfx::ShadowValue::GetMargin(ambient::util::GetTextShadowValues())
+            .width();
+    const int start_x = text_layer->GetTargetTransform().To2dTranslation().x();
+    const int end_x = -(text_width + shadow_width) / 2;
+    const int transform_distance = start_x - end_x;
+    const base::TimeDelta kScrollingDuration =
+        base::TimeDelta::FromSeconds(10) * transform_distance /
+        kMediaStringMaxWidthDip;
+
+    ui::ScopedLayerAnimationSettings animation(text_layer->GetAnimator());
+    animation.SetTransitionDuration(kScrollingDuration);
+    animation.SetTweenType(gfx::Tween::LINEAR);
+    animation.SetPreemptionStrategy(
+        ui::LayerAnimator::IMMEDIATELY_SET_NEW_TARGET);
+    animation.AddObserver(this);
+
+    gfx::Transform transform;
+    transform.Translate(end_x, 0);
+    text_layer->SetTransform(transform);
+  }
+}
+
 }  // namespace ash

ash/ambient/ui/media_string_view.h

@@ -5,22 +5,24 @@
 #ifndef ASH_AMBIENT_UI_MEDIA_STRING_VIEW_H_
 #define ASH_AMBIENT_UI_MEDIA_STRING_VIEW_H_
 
-#include <string>
-#include "ash/app_menu/notification_item_view.h"
-#include "ash/public/cpp/ambient/ambient_ui_model.h"
 #include "mojo/public/cpp/bindings/receiver.h"
 #include "mojo/public/cpp/bindings/remote.h"
 #include "services/media_session/public/mojom/media_controller.mojom.h"
-#include "ui/views/controls/image_view.h"
-#include "ui/views/controls/label.h"
+#include "ui/compositor/layer_animation_observer.h"
+#include "ui/views/view.h"
+
+namespace views {
+class Label;
+}  // namespace views
 
 namespace ash {
 
 // Container for displaying ongoing media information, including the name of the
 // media and the artist, formatted with a proceding music note symbol and a
 // middle dot separator.
-class MediaStringView : public views::Label,
-                        public media_session::mojom::MediaControllerObserver {
+class MediaStringView : public views::View,
+                        public media_session::mojom::MediaControllerObserver,
+                        public ui::ImplicitAnimationObserver {
  public:
   MediaStringView();
   MediaStringView(const MediaStringView&) = delete;
@@ -29,6 +31,7 @@ class MediaStringView : public views::Label,
 
   // views::Label:
   const char* GetClassName() const override;
+  void VisibilityChanged(View* starting_from, bool is_visible) override;
 
   // media_session::mojom::MediaControllerObserver:
   void MediaSessionInfoChanged(
@@ -43,15 +46,44 @@ class MediaStringView : public views::Label,
   void MediaSessionPositionChanged(
       const base::Optional<media_session::MediaPosition>& position) override {}
 
+  // ui::ImplicitAnimationObserver:
+  void OnImplicitAnimationsCompleted() override;
+
  private:
+  friend class AmbientAshTestBase;
+
   void InitLayout();
 
   void BindMediaControllerObserver();
 
+  bool NeedToAnimate() const;
+
+  // Get the transform of |media_text_| for scrolling animation.
+  gfx::Transform GetMediaTextTransform(bool is_initial);
+  void ScheduleScrolling(bool is_initial);
+  void StartScrolling(bool is_initial);
+
+  views::View* media_text_container_for_testing() {
+    return media_text_container_;
+  }
+
+  views::Label* media_text_label_for_testing() { return media_text_; }
+
+  // Music eighth note.
+  views::Label* icon_ = nullptr;
+
+  // Container of media info text.
+  views::View* media_text_container_ = nullptr;
+
+  // With an extra copy of media info text for scrolling animation.
+  views::Label* media_text_ = nullptr;
+
   // Used to receive updates to the active media controller.
   mojo::Remote<media_session::mojom::MediaController> media_controller_remote_;
   mojo::Receiver<media_session::mojom::MediaControllerObserver>
       observer_receiver_{this};
+
+  base::WeakPtrFactory<MediaStringView> weak_factory_{this};
 };
 
 }  // namespace ash

ash/ambient/ui/media_string_view_unittest.cc

@@ -4,12 +4,15 @@
 
 #include "ash/ambient/ui/media_string_view.h"
 
+#include "ash/ambient/ambient_constants.h"
 #include "ash/ambient/test/ambient_ash_test_base.h"
 #include "ash/public/cpp/ash_pref_names.h"
 #include "ash/shell.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "services/media_session/public/mojom/media_session.mojom.h"
+#include "ui/compositor/scoped_animation_duration_scale_mode.h"
+#include "ui/views/controls/label.h"
 
 namespace ash {
 
@@ -23,6 +26,10 @@ class MediaStringViewTest : public AmbientAshTestBase {
     AmbientAshTestBase::SetUp();
     GetSessionControllerClient()->set_show_lock_screen_views(true);
   }
+
+  const base::string16& GetText() {
+    return GetMediaStringViewTextLabel()->GetText();
+  }
 };
 
 TEST_F(MediaStringViewTest, ShowMediaTitleAndArtist) {
@@ -35,9 +42,213 @@ TEST_F(MediaStringViewTest, ShowMediaTitleAndArtist) {
 
   SimulateMediaMetadataChanged(metadata);
 
-  const base::string16 expected_text =
-      base::UTF8ToUTF16("\u266A title \u00B7 artist");
-  EXPECT_EQ(GetMediaStringView()->GetText(), expected_text);
+  const base::string16 expected_text = base::UTF8ToUTF16("title \u00B7 artist");
+  EXPECT_EQ(GetMediaStringViewTextLabel()->GetText(), expected_text);
+}
+
+TEST_F(MediaStringViewTest, TextContainerFitsWidthOfShortText) {
+  ShowAmbientScreen();
+
+  // Sets metadata for current session.
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("title");
+  metadata.artist = base::ASCIIToUTF16("artist");
+
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_LT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+  EXPECT_EQ(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            GetMediaStringViewTextContainer()->GetPreferredSize().width());
+}
+
+TEST_F(MediaStringViewTest, TextContainerHasMaxWidthWithLongText) {
+  ShowAmbientScreen();
+
+  // Sets metadata for current session.
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("A super duper long title");
+  metadata.artist = base::ASCIIToUTF16("A super duper long artist name");
+
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_GT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+  EXPECT_EQ(kMediaStringMaxWidthDip,
+            GetMediaStringViewTextContainer()->GetPreferredSize().width());
+}
+
+TEST_F(MediaStringViewTest, HasNoAnimationWithShortText) {
+  ui::ScopedAnimationDurationScaleMode test_duration_mode(
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
+
+  ShowAmbientScreen();
+
+  // Sets metadata for current session.
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("title");
+  metadata.artist = base::ASCIIToUTF16("name");
+
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPlaying);
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_LT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+}
+
+TEST_F(MediaStringViewTest, HasAnimationWithLongText) {
+  ui::ScopedAnimationDurationScaleMode test_duration_mode(
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
+
+  ShowAmbientScreen();
+
+  // Sets metadata for current session.
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("A super duper long title");
+  metadata.artist = base::ASCIIToUTF16("A super duper long artist name");
+
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPlaying);
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_GT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_TRUE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+}
+
+TEST_F(MediaStringViewTest, ShouldStopAndStartAnimationWhenTextChanges) {
+  ui::ScopedAnimationDurationScaleMode test_duration_mode(
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
+
+  ShowAmbientScreen();
+
+  // Sets metadata for current session.
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("A super duper long title");
+  metadata.artist = base::ASCIIToUTF16("A super duper long artist name");
+
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPlaying);
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_GT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_TRUE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+
+  // Change to another long text.
+  metadata.title = base::ASCIIToUTF16("Another super duper long title");
+  metadata.artist = base::ASCIIToUTF16("Another super duper long artist name");
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_GT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_TRUE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+}
+
+TEST_F(MediaStringViewTest, ShouldStartAndStopAnimationWhenTextChanges) {
+  ui::ScopedAnimationDurationScaleMode test_duration_mode(
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
+
+  ShowAmbientScreen();
+
+  // Sets metadata for current session.
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("title");
+  metadata.artist = base::ASCIIToUTF16("name");
+
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPlaying);
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_LT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+
+  // Change to long text.
+  metadata.title = base::ASCIIToUTF16("A super duper long title");
+  metadata.artist = base::ASCIIToUTF16("A super duper long artist name");
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_GT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_TRUE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+
+  // Change to short text.
+  metadata.title = base::ASCIIToUTF16("title");
+  metadata.artist = base::ASCIIToUTF16("name");
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_LT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+}
+
+TEST_F(MediaStringViewTest, PauseMediaWillStopAnimationWithLongText) {
+  ui::ScopedAnimationDurationScaleMode test_duration_mode(
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
+
+  ShowAmbientScreen();
+
+  // Sets metadata for current session.
+  media_session::MediaMetadata metadata;
+  metadata.title = base::ASCIIToUTF16("A super duper long title");
+  metadata.artist = base::ASCIIToUTF16("A super duper long artist name");
+
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPlaying);
+  SimulateMediaMetadataChanged(metadata);
+
+  EXPECT_GT(GetMediaStringViewTextLabel()->GetPreferredSize().width(),
+            kMediaStringMaxWidthDip);
+
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+  task_environment()->FastForwardBy(base::TimeDelta::FromMilliseconds(100));
+  EXPECT_TRUE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
+
+  SimulateMediaPlaybackStateChanged(
+      media_session::mojom::MediaPlaybackState::kPaused);
+  EXPECT_FALSE(GetMediaStringView()->GetVisible());
+  EXPECT_FALSE(
+      GetMediaStringViewTextLabel()->layer()->GetAnimator()->is_animating());
 }
 
 TEST_F(MediaStringViewTest, ShowWhenMediaIsPlaying) {