Changeset 273815 in webkit

Timestamp:

Mar 3, 2021, 8:34:03 AM (6 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Enable simplified vertical alignment for empty inline boxes
​https://bugs.webkit.org/show_bug.cgi?id=222630

Reviewed by Antti Koivisto.

This patch enables the simplified vertical alignment for cases when the line has non-stretching empty inline boxes.
e.g.
<div>text<span></span>content</div>
but not
<div>text<span style="font-size: 100px"></span>content</div> (in standards mode the empty inline box starts with a strut, so this would be stretching the root inline box to ~100px).

• layout/inlineformatting/InlineFormattingContextGeometry.cpp:

(WebCore::Layout::LineBoxBuilder::constructAndAlignInlineLevelBoxes):
(WebCore::Layout::LineBoxBuilder::SimplifiedVerticalAlignment::canUseSimplifiedAlignment):
(WebCore::Layout::LineBoxBuilder::SimplifiedVerticalAlignment::align):

• layout/inlineformatting/InlineLineBox.h:

(WebCore::Layout::LineBox::InlineLevelBox::LayoutBounds::operator== const):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/inlineformatting/InlineFormattingContextGeometry.cpp (modified) (4 diffs)
• layout/inlineformatting/InlineLineBox.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-03-03  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Enable simplified vertical alignment for empty inline boxes
+        https://bugs.webkit.org/show_bug.cgi?id=222630
+
+        Reviewed by Antti Koivisto.
+
+        This patch enables the simplified vertical alignment for cases when the line has non-stretching empty inline boxes.
+        e.g.
+        <div>text<span></span>content</div>
+        but not
+        <div>text<span style="font-size: 100px"></span>content</div> (in standards mode the empty inline box starts with a strut, so this would be stretching the root inline box to ~100px).
+
+        * layout/inlineformatting/InlineFormattingContextGeometry.cpp:
+        (WebCore::Layout::LineBoxBuilder::constructAndAlignInlineLevelBoxes):
+        (WebCore::Layout::LineBoxBuilder::SimplifiedVerticalAlignment::canUseSimplifiedAlignment):
+        (WebCore::Layout::LineBoxBuilder::SimplifiedVerticalAlignment::align):
+        * layout/inlineformatting/InlineLineBox.h:
+        (WebCore::Layout::LineBox::InlineLevelBox::LayoutBounds::operator== const):
+
 2021-03-02  Manuel Rego Casasnovas  <rego@igalia.com>
 

trunk/Source/WebCore/layout/inlineformatting/InlineFormattingContextGeometry.cpp

@@ -342 +342 @@
             setVerticalGeometryForInlineBox(*inlineBox);
             lineBox.addInlineLevelBox(WTFMove(inlineBox));
-            simplifiedVerticalAlignment.setEnabled(!lineHasContent);
             continue;
         }
@@ -350 +349 @@
             ASSERT(inlineBox.isInlineBox());
             // Inline box run is based on margin box. Let's convert it to border box.
-            auto marginEnd = std::max(0_lu, formattingContext().geometryForBox(layoutBox).marginEnd());
+            auto& inlineBoxGeometry = formattingContext().geometryForBox(layoutBox);
+            auto marginEnd = std::max(0_lu, inlineBoxGeometry.marginEnd());
             auto inlineBoxLogicalRight = logicalLeft + run.logicalWidth() - marginEnd;
             inlineBox.setLogicalWidth(inlineBoxLogicalRight - inlineBox.logicalLeft());
-            simplifiedVerticalAlignment.setEnabled(!lineHasContent);
+            simplifiedAlignVerticallyIfApplicable(inlineBox, inlineBoxGeometry);
             continue;
         }
@@ -639 +639 @@
     if (inlineLevelBox.isLineBreakBox()) {
         // Baseline aligned, non-stretchy line breaks e.g. <div><span><br></span></div> but not <div><span style="font-size: 100px;"><br></span></div>.
-        auto& layoutBox = inlineLevelBox.layoutBox();
-        return layoutBox.style().verticalAlign() == VerticalAlign::Baseline
-            && inlineLevelBox.baseline() <= rootInlineBox.baseline();
+        return inlineLevelBox.layoutBox().style().verticalAlign() == VerticalAlign::Baseline && inlineLevelBox.baseline() <= rootInlineBox.baseline();
+    }
+    if (inlineLevelBox.isInlineBox()) {
+        // Baseline aligned, non-stretchy inline boxes e.g. <div><span></span></div> but not <div><span style="font-size: 100px;"></span></div>.
+        return inlineLevelBox.layoutBox().style().verticalAlign() == VerticalAlign::Baseline && inlineLevelBox.layoutBounds() == rootInlineBox.layoutBounds();
     }
     return false;
@@ -648 +650 @@
 void LineBoxBuilder::SimplifiedVerticalAlignment::align(LineBox::InlineLevelBox& inlineLevelBox)
 {
-    if (inlineLevelBox.isAtomicInlineLevelBox() || inlineLevelBox.isLineBreakBox()) {
+    if (inlineLevelBox.isAtomicInlineLevelBox() || inlineLevelBox.isLineBreakBox() || inlineLevelBox.isInlineBox()) {
         // Only baseline alignment for now.
         inlineLevelBox.setLogicalTop(m_rootInlineBox.baseline() - inlineLevelBox.baseline());

trunk/Source/WebCore/layout/inlineformatting/InlineLineBox.h

@@ -73 +73 @@
         struct LayoutBounds {
             InlineLayoutUnit height() const { return ascent + descent; }
+            bool operator==(const LayoutBounds& other) const { return ascent == other.ascent && descent == other.descent; }
 
             InlineLayoutUnit ascent { 0 };