Changeset 285948 in webkit

Timestamp:

Nov 17, 2021, 12:16:45 PM (5 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Do not apply the "do not trim whitespace followed by br" legacy line layout quirk when computing the intrinsic widths
​https://bugs.webkit.org/show_bug.cgi?id=233262

Reviewed by Antti Koivisto.

While legacy line layout applies this quirk at line layout, the preferred width computation (totally different) codepath omits this quirk.

• layout/formattingContexts/inline/InlineLine.cpp:

(WebCore::Layout::Line::removeTrailingTrimmableContent):

• layout/formattingContexts/inline/InlineLine.h:
• layout/formattingContexts/inline/InlineLineBuilder.cpp:

(WebCore::Layout::LineBuilder::close):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/formattingContexts/inline/InlineLine.cpp (modified) (3 diffs)
• layout/formattingContexts/inline/InlineLine.h (modified) (1 diff)
• layout/formattingContexts/inline/InlineLineBuilder.cpp (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-11-17  Alan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Do not apply the "do not trim whitespace followed by br" legacy line layout quirk when computing the intrinsic widths
+        https://bugs.webkit.org/show_bug.cgi?id=233262
+
+        Reviewed by Antti Koivisto.
+
+        While legacy line layout applies this quirk at line layout, the preferred width computation (totally different) codepath omits this quirk.
+
+        * layout/formattingContexts/inline/InlineLine.cpp:
+        (WebCore::Layout::Line::removeTrailingTrimmableContent):
+        * layout/formattingContexts/inline/InlineLine.h:
+        * layout/formattingContexts/inline/InlineLineBuilder.cpp:
+        (WebCore::Layout::LineBuilder::close):
+
 2021-11-17  Alan Bujtas  <zalan@apple.com>
 

trunk/Source/WebCore/layout/formattingContexts/inline/InlineLine.cpp

@@ -33 +33 @@
 #include "InlineSoftLineBreakItem.h"
 #include "LayoutBoxGeometry.h"
-#include "RuntimeEnabledFeatures.h"
 #include "TextFlags.h"
 #include "TextUtil.h"
@@ -174 +173 @@
 }
 
-void Line::removeTrailingTrimmableContent()
+void Line::removeTrailingTrimmableContent(ShouldApplyTrailingWhiteSpaceFollowedByBRQuirk shouldApplyTrailingWhiteSpaceFollowedByBRQuirk)
 {
     if (m_trimmableTrailingContent.isEmpty() || m_runs.isEmpty())
         return;
 
-    // Complex line layout quirk: keep the trailing whitespace around when it is followed by a line break, unless the content overflows the line.
-    if (RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled()) {
+    if (shouldApplyTrailingWhiteSpaceFollowedByBRQuirk == ShouldApplyTrailingWhiteSpaceFollowedByBRQuirk::Yes) {
         auto isTextAlignRight = [&] {
             auto textAlign = formattingContext().root().style().textAlign();
@@ -193 +191 @@
         }
     }
-
     m_contentLogicalWidth -= m_trimmableTrailingContent.remove();
 }

trunk/Source/WebCore/layout/formattingContexts/inline/InlineLine.h

@@ -64 +64 @@
     void addTrailingHyphen(InlineLayoutUnit hyphenLogicalWidth);
 
-    void removeTrailingTrimmableContent();
+    enum class ShouldApplyTrailingWhiteSpaceFollowedByBRQuirk { No, Yes };
+    void removeTrailingTrimmableContent(ShouldApplyTrailingWhiteSpaceFollowedByBRQuirk);
     void removeHangingGlyphs();
     void visuallyCollapseHangingOverflowingGlyphs(InlineLayoutUnit horizontalAvailableSpace);

trunk/Source/WebCore/layout/formattingContexts/inline/InlineLineBuilder.cpp

@@ -35 +35 @@
 #include "LayoutBoxGeometry.h"
 #include "LayoutState.h"
+#include "RuntimeEnabledFeatures.h"
 #include "TextUtil.h"
 #include <wtf/unicode/CharacterNames.h>
@@ -458 +459 @@
     }
     auto horizontalAvailableSpace = m_lineLogicalRect.width();
-    m_line.removeTrailingTrimmableContent();
-    if (isInIntrinsicWidthMode()) {
+    auto isInIntrinsicWidthMode = this->isInIntrinsicWidthMode();
+    // Legacy line layout quirk: keep the trailing whitespace around when it is followed by a line break, unless the content overflows the line.
+    // This quirk however should not be applied when running intrinsic width computation.
+    // FIXME: webkit.org/b/233261
+    auto shouldApplyTrailingWhiteSpaceFollowedByBRQuirk = isInIntrinsicWidthMode || !RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled()
+        ? Line::ShouldApplyTrailingWhiteSpaceFollowedByBRQuirk::No
+        : Line::ShouldApplyTrailingWhiteSpaceFollowedByBRQuirk::Yes;
+    m_line.removeTrailingTrimmableContent(shouldApplyTrailingWhiteSpaceFollowedByBRQuirk);
+
+    if (isInIntrinsicWidthMode) {
         // When a glyph at the start or end edge of a line hangs, it is not considered when measuring the line’s contents for fit.
         // https://drafts.csswg.org/css-text/#hanging