Dark mode manifest parsing.

Parses the user_preferences field from the manifest and sets dark_mode_theme_color and dark_mode_background_color in WebApplicationInfo. This is based off the proposal in this comment: w3c/manifest#975 (comment) There is no explainer yet. This is the same format as the translations member. Intent to prototype: https://groups.google.com/a/chromium.org/g/blink-dev/c/Y6zNtG0f-6A Bug: 1271804 Change-Id: I9764f300159d35041323d4a1602e06ba7f80afd8 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3292905 Commit-Queue: Louise Brett <[email protected]> Reviewed-by: Kentaro Hara <[email protected]> Reviewed-by: Dominick Ng <[email protected]> Cr-Commit-Position: refs/heads/main@{#945184} NOKEYCHECK=True GitOrigin-RevId: b076313fcbacd0be2f2b663f7d16083a19555e07
mjfroman · Nov 25, 2021 · 1572deb · 1572deb
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diff --git a/blink/common/features.cc b/blink/common/features.cc
@@ -798,6 +798,11 @@ const base::Feature kLogUnexpectedIPCPostedToBackForwardCachedDocuments{
     "LogUnexpectedIPCPostedToBackForwardCachedDocuments",
     base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enables web apps to provide theme color and background color overrides for
+// dark mode.
+const base::Feature kWebAppEnableDarkMode{"WebAppEnableDarkMode",
+                                          base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables the "handle_links" manifest field for web apps.
 // Explainer:
 // https://github.com/WICG/pwa-url-handler/blob/main/handle_links/explainer.md

diff --git a/blink/public/common/features.h b/blink/public/common/features.h
@@ -319,6 +319,8 @@ BLINK_COMMON_EXPORT extern const base::Feature kPreferCompositingToLCDText;
 BLINK_COMMON_EXPORT extern const base::Feature
     kLogUnexpectedIPCPostedToBackForwardCachedDocuments;
 
+BLINK_COMMON_EXPORT extern const base::Feature kWebAppEnableDarkMode;
+
 BLINK_COMMON_EXPORT extern const base::Feature kWebAppEnableHandleLinks;
 
 BLINK_COMMON_EXPORT extern const base::Feature kWebAppEnableIsolatedStorage;

diff --git a/blink/public/mojom/manifest/manifest.mojom b/blink/public/mojom/manifest/manifest.mojom
@@ -109,6 +109,11 @@ struct Manifest {
   // https://github.com/WICG/manifest-incubations/blob/gh-pages/translations-explainer.md
   // A mapping of locales to their translations.
   map<mojo_base.mojom.String16, ManifestTranslationItem> translations;
+
+  // TODO(crbug.com/1271804): This field is non-standard and part of a Chrome
+  // experiment. See:
+  // https://github.com/w3c/manifest/issues/975#issuecomment-960222756
+  ManifestUserPreferences? user_preferences;
 };
 
 // Structure representing a Shortcut Item per the Manifest specification, see:
@@ -290,6 +295,21 @@ struct ManifestTranslationItem {
   mojo_base.mojom.String16? description;
 };
 
+// Structure representing overrides for certain user preferences.
+struct ManifestUserPreferences {
+  ManifestUserPreferenceOverrides? color_scheme_dark;
+};
+
+// Structure representing manifest fields that can be overridden given certain
+// user preferences (eg. dark mode). All fields are optional.
+struct ManifestUserPreferenceOverrides {
+  bool has_theme_color;
+  uint32 theme_color;
+
+  bool has_background_color;
+  uint32 background_color;
+};
+
 // Debug information for a parsed manifest.
 struct ManifestDebugInfo {
   array<ManifestError> errors;

diff --git a/blink/renderer/modules/manifest/manifest_parser.cc b/blink/renderer/modules/manifest/manifest_parser.cc
@@ -172,6 +172,10 @@ bool ManifestParser::Parse() {
     manifest_->translations = ParseTranslations(root_object.get());
   }
 
+  if (RuntimeEnabledFeatures::WebAppDarkModeEnabled(feature_context_)) {
+    manifest_->user_preferences = ParseUserPreferences(root_object.get());
+  }
+
   ManifestUmaUtil::ParseSucceeded(manifest_);
 
   return has_comments;
@@ -1547,6 +1551,60 @@ ManifestParser::ParseTranslations(const JSONObject* object) {
   return result;
 }
 
+mojom::blink::ManifestUserPreferenceOverridesPtr
+ManifestParser::ParsePreferenceOverrides(const JSONObject* object,
+                                         const String& preference) {
+  auto user_preference_overrides =
+      mojom::blink::ManifestUserPreferenceOverrides::New();
+
+  if (!object->Get(preference))
+    return nullptr;
+
+  JSONObject* overrides = object->GetJSONObject(preference);
+  if (!overrides) {
+    AddErrorInfo("preference '" + preference + "' ignored, object expected.");
+    return nullptr;
+  }
+
+  absl::optional<RGBA32> theme_color = ParseThemeColor(overrides);
+  user_preference_overrides->has_theme_color = theme_color.has_value();
+  if (user_preference_overrides->has_theme_color)
+    user_preference_overrides->theme_color = *theme_color;
+
+  absl::optional<RGBA32> background_color = ParseBackgroundColor(overrides);
+  user_preference_overrides->has_background_color =
+      background_color.has_value();
+  if (user_preference_overrides->has_background_color)
+    user_preference_overrides->background_color = *background_color;
+
+  // All of the fields that can be overridden by user_preferences are
+  // optional. If no overrides are supplied, skip the preference.
+  if (!user_preference_overrides->has_theme_color &&
+      !user_preference_overrides->has_background_color) {
+    return nullptr;
+  }
+  return user_preference_overrides;
+}
+
+mojom::blink::ManifestUserPreferencesPtr ManifestParser::ParseUserPreferences(
+    const JSONObject* object) {
+  auto result = mojom::blink::ManifestUserPreferences::New();
+
+  if (!object->Get("user_preferences"))
+    return nullptr;
+
+  JSONObject* user_preferences_map = object->GetJSONObject("user_preferences");
+  if (!user_preferences_map) {
+    AddErrorInfo("property 'user_preferences' ignored, object expected.");
+    return nullptr;
+  }
+
+  result->color_scheme_dark =
+      ParsePreferenceOverrides(user_preferences_map, "color_scheme_dark");
+
+  return result;
+}
+
 void ManifestParser::AddErrorInfo(const String& error_msg,
                                   bool critical,
                                   int error_line,

diff --git a/blink/renderer/modules/manifest/manifest_parser.h b/blink/renderer/modules/manifest/manifest_parser.h
@@ -441,6 +441,18 @@ class MODULES_EXPORT ManifestParser {
   HashMap<String, mojom::blink::ManifestTranslationItemPtr> ParseTranslations(
       const JSONObject* object);
 
+  // Parses individual preferences from the 'user_preferences' field.
+  // Returns nullptr if not present or parsing failed.
+  mojom::blink::ManifestUserPreferenceOverridesPtr ParsePreferenceOverrides(
+      const JSONObject* object,
+      const String& preference);
+
+  // Parse the 'user_preferences' field of the manifest as defined in:
+  // https://github.com/w3c/manifest/issues/975#issuecomment-960222756
+  // Returns nullptr if parsing fails.
+  mojom::blink::ManifestUserPreferencesPtr ParseUserPreferences(
+      const JSONObject* object);
+
   void AddErrorInfo(const String& error_msg,
                     bool critical = false,
                     int error_line = 0,

diff --git a/blink/renderer/modules/manifest/manifest_parser_unittest.cc b/blink/renderer/modules/manifest/manifest_parser_unittest.cc
@@ -5117,4 +5117,101 @@ TEST_F(ManifestParserTest, TranslationsStringsParseRules) {
   }
 }
 
+TEST_F(ManifestParserTest, UserPreferencesParseRules) {
+  {
+    ScopedWebAppDarkModeForTest feature(false);
+
+    // Feature not enabled, should not be parsed.
+    auto& manifest = ParseManifest(
+        R"({ "user_preferences":
+        {"color_scheme_dark": {"theme_color": "#FF0000"}} })");
+    EXPECT_TRUE(manifest->user_preferences.is_null());
+    EXPECT_EQ(0u, GetErrorCount());
+  }
+  {
+    ScopedWebAppDarkModeForTest feature(true);
+
+    // Manifest does not contain a 'user_preferences' field.
+    {
+      auto& manifest = ParseManifest(R"({ })");
+      EXPECT_TRUE(manifest->user_preferences.is_null());
+      EXPECT_EQ(0u, GetErrorCount());
+    }
+
+    // user_preferences object is empty.
+    {
+      auto& manifest = ParseManifest(R"({ "user_preferences": {} })");
+      EXPECT_FALSE(manifest->user_preferences.is_null());
+      EXPECT_TRUE(manifest->user_preferences->color_scheme_dark.is_null());
+      EXPECT_EQ(0u, GetErrorCount());
+    }
+
+    // Empty preference is ignored.
+    {
+      auto& manifest =
+          ParseManifest(R"({ "user_preferences": {"color_scheme_dark": {}} })");
+      EXPECT_FALSE(manifest->user_preferences.is_null());
+      EXPECT_TRUE(manifest->user_preferences->color_scheme_dark.is_null());
+      EXPECT_EQ(0u, GetErrorCount());
+    }
+
+    // Valid theme_color and background_color should be parsed
+    {
+      auto& manifest = ParseManifest(
+          R"({ "user_preferences": {"color_scheme_dark":
+          {"theme_color": "#FF0000", "background_color": "#FFF"}} })");
+      EXPECT_FALSE(manifest->user_preferences.is_null());
+      EXPECT_FALSE(manifest->user_preferences->color_scheme_dark.is_null());
+      EXPECT_EQ(manifest->user_preferences->color_scheme_dark->theme_color,
+                0xFFFF0000u);
+      EXPECT_EQ(manifest->user_preferences->color_scheme_dark->background_color,
+                0xFFFFFFFFu);
+      EXPECT_EQ(0u, GetErrorCount());
+    }
+
+    // Don't parse if the property isn't an object.
+    {
+      auto& manifest = ParseManifest(R"({ "user_preferences": [] })");
+      EXPECT_TRUE(manifest->user_preferences.is_null());
+      EXPECT_EQ(1u, GetErrorCount());
+      EXPECT_EQ("property 'user_preferences' ignored, object expected.",
+                errors()[0]);
+    }
+
+    // Ignore preference if it isn't an object.
+    {
+      auto& manifest =
+          ParseManifest(R"({ "user_preferences": {"color_scheme_dark": []} })");
+      EXPECT_FALSE(manifest->user_preferences.is_null());
+      EXPECT_TRUE(manifest->user_preferences->color_scheme_dark.is_null());
+      EXPECT_EQ(1u, GetErrorCount());
+      EXPECT_EQ("preference 'color_scheme_dark' ignored, object expected.",
+                errors()[0]);
+    }
+
+    // Preferences overriding a single value should be parsed.
+    {
+      auto& manifest = ParseManifest(
+          R"({ "user_preferences":
+          {"color_scheme_dark": {"theme_color": "#FF0000"}} })");
+      EXPECT_FALSE(manifest->user_preferences.is_null());
+      EXPECT_FALSE(manifest->user_preferences->color_scheme_dark.is_null());
+      EXPECT_EQ(manifest->user_preferences->color_scheme_dark->theme_color,
+                0xFFFF0000u);
+      EXPECT_FALSE(
+          manifest->user_preferences->color_scheme_dark->has_background_color);
+      EXPECT_EQ(0u, GetErrorCount());
+    }
+
+    // Unknown preference string should be ignored.
+    {
+      auto& manifest = ParseManifest(
+          R"({ "user_preferences": {"something": {"theme_color": "#FF0000"}} })");
+      EXPECT_FALSE(manifest->user_preferences.is_null());
+      EXPECT_TRUE(manifest->user_preferences->color_scheme_dark.is_null());
+      EXPECT_EQ(0u, GetErrorCount());
+    }
+  }
+}
+
 }  // namespace blink
diff --git a/blink/renderer/platform/runtime_enabled_features.json5 b/blink/renderer/platform/runtime_enabled_features.json5
@@ -2406,6 +2406,10 @@
       name: "WebAnimationsSVG",
       status: "experimental",
     },
+    {
+      name: "WebAppDarkMode",
+      status: "experimental",
+    },
     {
       name: "WebAppHandleLinks",
       status: "experimental",