Bug 1681691 - Add metrics override descriptors to webidl. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D109288
dothq · Mar 23, 2021 · a7442dc · a7442dc
1 parent 03752c9
commit a7442dc
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Showing 3 changed files with 48 additions and 1 deletion.
diff --git a/dom/webidl/FontFace.webidl b/dom/webidl/FontFace.webidl
@@ -21,6 +21,9 @@ dictionary FontFaceDescriptors {
   UTF8String featureSettings = "normal";
   UTF8String variationSettings = "normal";
   UTF8String display = "auto";
+  UTF8String ascentOverride = "normal";
+  UTF8String descentOverride = "normal";
+  UTF8String lineGapOverride = "normal";
 };
 
 enum FontFaceLoadStatus { "unloaded", "loading", "loaded", "error" };
@@ -44,6 +47,9 @@ interface FontFace {
   [SetterThrows] attribute UTF8String featureSettings;
   [SetterThrows, Pref="layout.css.font-variations.enabled"] attribute UTF8String variationSettings;
   [SetterThrows, Pref="layout.css.font-display.enabled"] attribute UTF8String display;
+  [SetterThrows, Pref="layout.css.font-metrics-overrides.enabled"] attribute UTF8String ascentOverride;
+  [SetterThrows, Pref="layout.css.font-metrics-overrides.enabled"] attribute UTF8String descentOverride;
+  [SetterThrows, Pref="layout.css.font-metrics-overrides.enabled"] attribute UTF8String lineGapOverride;
 
   readonly attribute FontFaceLoadStatus status;
 

diff --git a/layout/style/FontFace.cpp b/layout/style/FontFace.cpp
@@ -303,6 +303,36 @@ void FontFace::SetDisplay(const nsACString& aValue, ErrorResult& aRv) {
   }
 }
 
+void FontFace::GetAscentOverride(nsACString& aResult) {
+  GetDesc(eCSSFontDesc_AscentOverride, aResult);
+}
+
+void FontFace::SetAscentOverride(const nsACString& aValue, ErrorResult& aRv) {
+  if (SetDescriptor(eCSSFontDesc_AscentOverride, aValue, aRv)) {
+    DescriptorUpdated();
+  }
+}
+
+void FontFace::GetDescentOverride(nsACString& aResult) {
+  GetDesc(eCSSFontDesc_DescentOverride, aResult);
+}
+
+void FontFace::SetDescentOverride(const nsACString& aValue, ErrorResult& aRv) {
+  if (SetDescriptor(eCSSFontDesc_DescentOverride, aValue, aRv)) {
+    DescriptorUpdated();
+  }
+}
+
+void FontFace::GetLineGapOverride(nsACString& aResult) {
+  GetDesc(eCSSFontDesc_LineGapOverride, aResult);
+}
+
+void FontFace::SetLineGapOverride(const nsACString& aValue, ErrorResult& aRv) {
+  if (SetDescriptor(eCSSFontDesc_LineGapOverride, aValue, aRv)) {
+    DescriptorUpdated();
+  }
+}
+
 void FontFace::DescriptorUpdated() {
   // If we haven't yet initialized mUserFontEntry, no need to do anything here;
   // we'll respect the updated descriptor when the time comes to create it.
@@ -531,7 +561,12 @@ bool FontFace::SetDescriptors(const nsACString& aFamily,
       (StaticPrefs::layout_css_font_variations_enabled() &&
        !setDesc(eCSSFontDesc_FontVariationSettings,
                 aDescriptors.mVariationSettings)) ||
-      !setDesc(eCSSFontDesc_Display, aDescriptors.mDisplay)) {
+      !setDesc(eCSSFontDesc_Display, aDescriptors.mDisplay) ||
+      (StaticPrefs::layout_css_font_metrics_overrides_enabled() &&
+       (!setDesc(eCSSFontDesc_AscentOverride, aDescriptors.mAscentOverride) ||
+        !setDesc(eCSSFontDesc_DescentOverride, aDescriptors.mDescentOverride) ||
+        !setDesc(eCSSFontDesc_LineGapOverride,
+                 aDescriptors.mLineGapOverride)))) {
     // XXX Handle font-variant once we support it (bug 1055385).
 
     // If any of the descriptors failed to parse, none of them should be set

diff --git a/layout/style/FontFace.h b/layout/style/FontFace.h
@@ -174,6 +174,12 @@ class FontFace final : public nsISupports, public nsWrapperCache {
   void SetVariationSettings(const nsACString& aValue, ErrorResult& aRv);
   void GetDisplay(nsACString& aResult);
   void SetDisplay(const nsACString& aValue, ErrorResult& aRv);
+  void GetAscentOverride(nsACString& aResult);
+  void SetAscentOverride(const nsACString& aValue, ErrorResult& aRv);
+  void GetDescentOverride(nsACString& aResult);
+  void SetDescentOverride(const nsACString& aValue, ErrorResult& aRv);
+  void GetLineGapOverride(nsACString& aResult);
+  void SetLineGapOverride(const nsACString& aValue, ErrorResult& aRv);
 
   FontFaceLoadStatus Status();
   Promise* Load(ErrorResult& aRv);