Changeset 252915 in webkit

Timestamp:

Nov 27, 2019 6:34:02 PM (4 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Generate fewer InlineItems when new lines are not preserved
​https://bugs.webkit.org/show_bug.cgi?id=204653
<rdar://problem/57510133>

Reviewed by Antti Koivisto.

This patch reduces the number of InlineItems by merging (non-preserved)new lines with neighboring whitespace characters.
[text\n\n text] -> [text][ ][text]

• layout/inlineformatting/InlineTextItem.cpp:

(WebCore::Layout::isWhitespaceCharacter):
(WebCore::Layout::moveToNextNonWhitespacePosition):
(WebCore::Layout::InlineTextItem::createAndAppendTextItems):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/inlineformatting/InlineTextItem.cpp (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-11-27  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Generate fewer InlineItems when new lines are not preserved
+        https://bugs.webkit.org/show_bug.cgi?id=204653
+        <rdar://problem/57510133>
+
+        Reviewed by Antti Koivisto.
+
+        This patch reduces the number of InlineItems by merging (non-preserved)new lines with neighboring whitespace characters.
+        [text\n\n text] -> [text][   ][text]
+
+        * layout/inlineformatting/InlineTextItem.cpp:
+        (WebCore::Layout::isWhitespaceCharacter):
+        (WebCore::Layout::moveToNextNonWhitespacePosition):
+        (WebCore::Layout::InlineTextItem::createAndAppendTextItems):
+
 2019-11-27  Manuel Rego Casasnovas  <rego@igalia.com>
 

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

@@ -35 +35 @@
 namespace Layout {
 
-static inline bool isWhitespaceCharacter(char character)
+static inline bool isWhitespaceCharacter(char character, bool preserveNewline)
 {
-    return character == ' ' || character == '\t';
+    return character == ' ' || character == '\t' || (character == '\n' && !preserveNewline);
 }
 
-static unsigned moveToNextNonWhitespacePosition(const StringView& textContent, unsigned startPosition)
+static unsigned moveToNextNonWhitespacePosition(const StringView& textContent, unsigned startPosition, bool preserveNewline)
 {
     auto nextNonWhiteSpacePosition = startPosition;
-    while (nextNonWhiteSpacePosition < textContent.length() && isWhitespaceCharacter(textContent[nextNonWhiteSpacePosition]))
+    while (nextNonWhiteSpacePosition < textContent.length() && isWhitespaceCharacter(textContent[nextNonWhiteSpacePosition], preserveNewline))
         ++nextNonWhiteSpacePosition;
     return nextNonWhiteSpacePosition - startPosition;
@@ -105 +105 @@
         };
 
-        if (isSegmentBreakCandidate(text[currentPosition])) {
-            // Segment breaks with preserve new line style (white-space: pre, pre-wrap, break-spaces and pre-line) compute to forced line break.  
-            inlineContent.append(style.preserveNewline() ? makeUnique<InlineItem>(inlineBox, Type::ForcedLineBreak)
-                : InlineTextItem::createSegmentBreakItem(inlineBox, currentPosition));
+        // Segment breaks with preserve new line style (white-space: pre, pre-wrap, break-spaces and pre-line) compute to forced line break.
+        if (isSegmentBreakCandidate(text[currentPosition]) && style.preserveNewline()) {
+            inlineContent.append(makeUnique<InlineItem>(inlineBox, Type::ForcedLineBreak));
             ++currentPosition;
             continue;
         }
 
-        if (isWhitespaceCharacter(text[currentPosition])) {
-            auto length = moveToNextNonWhitespacePosition(text, currentPosition);
+        if (isWhitespaceCharacter(text[currentPosition], style.preserveNewline())) {
+            auto length = moveToNextNonWhitespacePosition(text, currentPosition, style.preserveNewline());
             auto simpleSingleWhitespaceContent = textContext.canUseSimplifiedContentMeasuring && (length == 1 || style.collapseWhiteSpace());
             auto width = simpleSingleWhitespaceContent ? makeOptional(LayoutUnit { font.spaceWidth() }) : inlineItemWidth(currentPosition, length);