[IFC][Ruby] Add support for non-normal line-height values

https://bugs.webkit.org/show_bug.cgi?id=264205

Reviewed by Antti Koivisto.

* Source/WebCore/layout/formattingContexts/inline/InlineLevelBox.h:
* Source/WebCore/layout/formattingContexts/inline/InlineLineBoxBuilder.cpp:
(WebCore::Layout::LineBoxBuilder::setLayoutBoundsForInlineBox const):
(WebCore::Layout::LineBoxBuilder::setVerticalPropertiesForInlineLevelBox const):
* Source/WebCore/layout/formattingContexts/inline/ruby/RubyFormattingContext.cpp:
(WebCore::Layout::RubyFormattingContext::applyAnnotationContributionToLayoutBounds const):
(WebCore::Layout::RubyFormattingContext::annotationContributionToLayoutBounds): Deleted.
* Source/WebCore/layout/formattingContexts/inline/ruby/RubyFormattingContext.h:

Canonical link: https://commits.webkit.org/270244@main

Source/WebCore/layout/formattingContexts/inline/InlineLevelBox.h

@@ -125,6 +125,7 @@ class InlineLevelBox {
     friend class LineBoxBuilder;
     friend class LineBoxVerticalAligner;
     friend class InlineFormattingUtils;
+    friend class RubyFormattingContext;
 
     const InlineRect& logicalRect() const { return m_logicalRect; }
     InlineLayoutUnit logicalTop() const { return m_logicalRect.top(); }

Source/WebCore/layout/formattingContexts/inline/InlineLineBoxBuilder.cpp

@@ -218,11 +218,6 @@ void LineBoxBuilder::setLayoutBoundsForInlineBox(InlineLevelBox& inlineBox, Font
                 descent += halfLeading;
             }
         }
-        if (inlineBox.layoutBox().isRubyBase()) {
-            auto [over, under] = RubyFormattingContext { formattingContext() }.annotationContributionToLayoutBounds(inlineBox.layoutBox());
-            ascent += over;
-            descent += under;
-        }
         return { ascent, descent };
     }();
 
@@ -275,6 +270,8 @@ void LineBoxBuilder::setVerticalPropertiesForInlineLevelBox(const LineBox& lineB
         // With text-box-trim, the inline box top is not always where the content starts.
         auto fontMetricBasedAscent = primaryFontMetricsForInlineBox(inlineLevelBox, lineBox.baselineType()).ascent;
         inlineLevelBox.setInlineBoxContentOffsetForTextBoxTrim(fontMetricBasedAscent - ascentAndDescent.ascent);
+        if (inlineLevelBox.layoutBox().isRubyBase())
+            RubyFormattingContext { formattingContext() }.applyAnnotationContributionToLayoutBounds(inlineLevelBox);
         return;
     }
     if (inlineLevelBox.isLineBreakBox()) {

Source/WebCore/layout/formattingContexts/inline/ruby/RubyFormattingContext.cpp

@@ -226,15 +226,41 @@ InlineLayoutSize RubyFormattingContext::sizeAnnotationBox(const Box& rubyBaseLay
     return { logicalAnnotationBoxGeometry.contentBoxHeight(), logicalAnnotationBoxGeometry.marginBoxWidth() };
 }
 
-RubyFormattingContext::OverUnder RubyFormattingContext::annotationContributionToLayoutBounds(const Box& rubyBaseLayoutBox)
+void RubyFormattingContext::applyAnnotationContributionToLayoutBounds(InlineLevelBox& rubyBaseInlineBox) const
 {
+    // In order to ensure consistent spacing of lines, documents with ruby typically ensure that the line-height is
+    // large enough to accommodate ruby between lines of text. Therefore, ordinarily, ruby annotation containers and ruby annotation
+    // boxes do not contribute to the measured height of a line’s inline contents;
+    // line-height calculations are performed using only the ruby base container, exactly as if it were a normal inline.
+    // However, if the line-height specified on the ruby container is less than the distance between the top of the top ruby annotation
+    // container and the bottom of the bottom ruby annotation container, then additional leading is added on the appropriate side(s).
+
+    auto& rubyBaseLayoutBox = rubyBaseInlineBox.layoutBox();
+    ASSERT(rubyBaseLayoutBox.isRubyBase());
     auto* annotationBox = rubyBaseLayoutBox.associatedRubyAnnotationBox();
     if (!isInterlinearAnnotation(annotationBox))
-        return { };
+        return;
+
+    auto over = InlineLayoutUnit { };
+    auto under = InlineLayoutUnit { };
     auto annotationBoxLogicalHeight = InlineLayoutUnit { parentFormattingContext().geometryForBox(*annotationBox).marginBoxHeight() };
     if (annotationBox->style().rubyPosition() == RubyPosition::Before)
-        return { annotationBoxLogicalHeight, { } };
-    return { { }, annotationBoxLogicalHeight };
+        over = annotationBoxLogicalHeight;
+    else
+        under = annotationBoxLogicalHeight;
+
+    auto layoutBounds = rubyBaseInlineBox.layoutBounds();
+    if (rubyBaseInlineBox.isPreferredLineHeightFontMetricsBased()) {
+        layoutBounds.ascent += over;
+        layoutBounds.descent += under;
+    } else {
+        auto& fontMetrics = rubyBaseLayoutBox.style().metricsOfPrimaryFont();
+        auto ascent = fontMetrics.floatAscent() + over;
+        auto descent = fontMetrics.floatDescent() + under;
+        if (layoutBounds.height() < ascent + descent)
+            layoutBounds = { ascent , descent };
+    }
+    rubyBaseInlineBox.setLayoutBounds(layoutBounds);
 }
 
 static inline InlineLayoutUnit halfOfAFullWidthCharacter(const Box& annotationBox)

Source/WebCore/layout/formattingContexts/inline/ruby/RubyFormattingContext.h

@@ -46,11 +46,7 @@ class RubyFormattingContext {
     };
     InlineLayoutResult layoutInlineAxis(const InlineItemRange&, const InlineItemList&, Line&, InlineLayoutUnit availableWidth);
 
-    struct OverUnder {
-        InlineLayoutUnit over { 0.f };
-        InlineLayoutUnit under { 0.f };
-    };
-    OverUnder annotationContributionToLayoutBounds(const Box& rubyBaseLayoutBox);
+    void applyAnnotationContributionToLayoutBounds(InlineLevelBox& rubyBaseInlineBox) const;
     InlineLayoutPoint placeAnnotationBox(const Box& rubyBaseLayoutBox);
     InlineLayoutSize sizeAnnotationBox(const Box& rubyBaseLayoutBox);