Changeset 273805 in webkit

Timestamp:

Mar 2, 2021, 8:29:26 PM (6 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Enable simplified vertical alignment for hard line breaks
​https://bugs.webkit.org/show_bug.cgi?id=222606

Reviewed by Antti Koivisto.

This patch enables the simplified vertical alignment for cases when the line ends with a non-stretching hard line break.
e.g.
<div>text<br>content</div>
<div>text<span><br></span>content</div>
but not when
<div>text<span style="font-size: 100px;"><br></span>content</div>

• layout/inlineformatting/InlineFormattingContextGeometry.cpp:

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

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/inlineformatting/InlineFormattingContextGeometry.cpp (modified) (3 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-03-02  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Enable simplified vertical alignment for hard line breaks
+        https://bugs.webkit.org/show_bug.cgi?id=222606
+
+        Reviewed by Antti Koivisto.
+
+        This patch enables the simplified vertical alignment for cases when the line ends with a non-stretching hard line break.
+        e.g.
+        <div>text<br>content</div>
+        <div>text<span><br></span>content</div>
+        but not when
+        <div>text<span style="font-size: 100px;"><br></span>content</div>
+
+        * layout/inlineformatting/InlineFormattingContextGeometry.cpp:
+        (WebCore::Layout::LineBoxBuilder::constructAndAlignInlineLevelBoxes):
+        (WebCore::Layout::LineBoxBuilder::SimplifiedVerticalAlignment::canUseSimplifiedAlignment):
+        (WebCore::Layout::LineBoxBuilder::SimplifiedVerticalAlignment::align):
+
 2021-03-02  Yusuke Suzuki  <ysuzuki@apple.com>
 

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

@@ -365 +365 @@
             auto lineBreakBox = LineBox::InlineLevelBox::createLineBreakBox(layoutBox, logicalLeft);
             setVerticalGeometryForInlineBox(*lineBreakBox);
+            simplifiedAlignVerticallyIfApplicable(*lineBreakBox, formattingContext().geometryForBox(layoutBox));
             lineBox.addInlineLevelBox(WTFMove(lineBreakBox));
-            simplifiedVerticalAlignment.setEnabled(false);
             continue;
         }
@@ -637 +637 @@
             && inlineLevelBoxGeometry.marginBoxHeight() <= rootInlineBox.baseline();
     }
+    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 false;
 }
@@ -642 +648 @@
 void LineBoxBuilder::SimplifiedVerticalAlignment::align(LineBox::InlineLevelBox& inlineLevelBox)
 {
-    if (inlineLevelBox.isAtomicInlineLevelBox()) {
+    if (inlineLevelBox.isAtomicInlineLevelBox() || inlineLevelBox.isLineBreakBox()) {
         // Only baseline alignment for now.
         inlineLevelBox.setLogicalTop(m_rootInlineBox.baseline() - inlineLevelBox.baseline());