ambient: add text shadow.

Bug: b/165829625.
Test: manually.
Change-Id: Iabee17198e1887b7498bb01e45c03a133f0df800
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2352518
Commit-Queue: Meilin Wang <meilinw@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800638}

ash/ambient/ui/ambient_background_image_view.cc

@@ -97,6 +97,7 @@ void AmbientBackgroundImageView::InitLayout() {
   details_label_->SetFontList(
       ambient::util::GetDefaultFontlist().DeriveWithSizeDelta(
           kDetailsFontSizeDip - kDefaultFontSizeDip));
+  details_label_->SetShadows(ambient::util::GetTextShadowValues());
   details_label_->SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_LEFT);
   details_label_->SetVerticalAlignment(gfx::VerticalAlignment::ALIGN_BOTTOM);
 }

ash/ambient/ui/glanceable_info_view.cc

@@ -139,6 +139,7 @@ void GlanceableInfoView::InitLayout() {
   time_view_->SetTextFont(GetTimeFontList());
   time_view_->SetTextColor(kTextColor,
                            /*auto_color_readability_enabled=*/false);
+  time_view_->SetTextShadowValues(ambient::util::GetTextShadowValues());
 
   // Inits and layouts the weather info.
   weather_info_ = AddChildView(std::make_unique<views::View>());
@@ -166,6 +167,7 @@ void GlanceableInfoView::InitLayout() {
   temperature_->SetAutoColorReadabilityEnabled(false);
   temperature_->SetEnabledColor(kTextColor);
   temperature_->SetFontList(GetWeatherTemperatureFontList());
+  temperature_->SetShadows(ambient::util::GetTextShadowValues());
 }
 
 }  // namespace ash

ash/ambient/ui/media_string_view.cc

@@ -90,6 +90,7 @@ void MediaStringView::InitLayout() {
   SetEnabledColor(kTextColor);
   SetFontList(ambient::util::GetDefaultFontlist().DeriveWithSizeDelta(
       kMediaStringFontSizeDip - kDefaultFontSizeDip));
+  SetShadows(ambient::util::GetTextShadowValues());
 
   BindMediaControllerObserver();
 }

ash/ambient/util/ambient_util.cc

@@ -6,11 +6,18 @@
 
 #include "ash/public/cpp/ambient/ambient_client.h"
 #include "base/no_destructor.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "ui/gfx/color_palette.h"
+#include "ui/gfx/shadow_value.h"
 
 namespace ash {
 namespace ambient {
 namespace util {
 
+// Appearance of the text shadow.
+constexpr int kTextShadowElevation = 2;
+constexpr SkColor kTextShadowColor = gfx::kGoogleGrey800;
+
 bool IsShowing(LockScreen::ScreenType type) {
   return LockScreen::HasInstance() && LockScreen::Get()->screen_type() == type;
 }
@@ -20,6 +27,11 @@ const gfx::FontList& GetDefaultFontlist() {
   return *font_list;
 }
 
+gfx::ShadowValues GetTextShadowValues() {
+  return gfx::ShadowValue::MakeRefreshShadowValues(kTextShadowElevation,
+                                                   kTextShadowColor);
+}
+
 }  // namespace util
 }  // namespace ambient
 }  // namespace ash

ash/ambient/util/ambient_util.h

@@ -8,6 +8,7 @@
 #include "ash/ash_export.h"
 #include "ash/login/ui/lock_screen.h"
 #include "ui/gfx/font_list.h"
+#include "ui/gfx/shadow_value.h"
 
 namespace ash {
 
@@ -20,6 +21,9 @@ ASH_EXPORT bool IsShowing(LockScreen::ScreenType type);
 // Returns the default fontlist for Ambient Mode.
 ASH_EXPORT const gfx::FontList& GetDefaultFontlist();
 
+// Returns the default static text shadow for Ambient Mode.
+ASH_EXPORT gfx::ShadowValues GetTextShadowValues();
+
 }  // namespace util
 }  // namespace ambient
 }  // namespace ash

ash/system/time/time_view.cc

@@ -106,6 +106,13 @@ void TimeView::SetTextFont(const gfx::FontList& font_list) {
   vertical_label_minutes_->SetFontList(font_list);
 }
 
+void TimeView::SetTextShadowValues(const gfx::ShadowValues& shadows) {
+  horizontal_label_->SetShadows(shadows);
+
+  vertical_label_hours_->SetShadows(shadows);
+  vertical_label_minutes_->SetShadows(shadows);
+}
+
 void TimeView::OnDateFormatChanged() {
   UpdateTimeFormat();
 }

ash/system/time/time_view.h

@@ -16,6 +16,7 @@
 #include "components/session_manager/session_manager_types.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/font_list.h"
+#include "ui/gfx/shadow_value.h"
 #include "ui/views/view.h"
 
 namespace base {
@@ -53,6 +54,9 @@ class ASH_EXPORT TimeView : public ActionableView, public ClockObserver {
   // Updates the time text fontlist.
   void SetTextFont(const gfx::FontList& font_list);
 
+  // Updates the time text shadow values.
+  void SetTextShadowValues(const gfx::ShadowValues& shadows);
+
   // ClockObserver:
   void OnDateFormatChanged() override;
   void OnSystemClockTimeUpdated() override;