Changeset 285863 in webkit

Timestamp:

Nov 16, 2021, 8:38:52 AM (5 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Fix fast/text/basic/005.html
​https://bugs.webkit.org/show_bug.cgi?id=233150

Reviewed by Antti Koivisto.

Negative word-spacing acts as negative margin, pulling the content to the left. In this patch we account for such negative values when
computing the overall content width.

Note that this patch is in preparation for enabling IFC preferred width computation.

• layout/formattingContexts/inline/InlineLine.cpp:

(WebCore::Layout::Line::appendTextContent):

Location:

trunk/Source/WebCore

Files:

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

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-11-16  Alan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Fix fast/text/basic/005.html
+        https://bugs.webkit.org/show_bug.cgi?id=233150
+
+        Reviewed by Antti Koivisto.
+
+        Negative word-spacing acts as negative margin, pulling the content to the left. In this patch we account for such negative values when
+        computing the overall content width.
+
+        Note that this patch is in preparation for enabling IFC preferred width computation.
+
+        * layout/formattingContexts/inline/InlineLine.cpp:
+        (WebCore::Layout::Line::appendTextContent):
+
 2021-11-16  Wenson Hsieh  <wenson_hsieh@apple.com>
 

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

@@ -344 +344 @@
         m_contentLogicalWidth = std::max(oldContentLogicalWidth, contentLogicalRight);
     } else if (style.letterSpacing() >= 0) {
-        m_runs.last().expand(inlineTextItem, logicalWidth);
-        m_contentLogicalWidth += logicalWidth;
+        auto& lastRun = m_runs.last();
+        lastRun.expand(inlineTextItem, logicalWidth);
+        // Ensure that property values that act like negative margin are not making the line wider.
+        m_contentLogicalWidth = std::max(oldContentLogicalWidth, lastRun.logicalRight());
     } else {
         auto& lastRun = m_runs.last();
@@ -351 +353 @@
         // Negative letter spacing should only shorten the content to the boundary of the previous run.
         // FIXME: We may need to traverse all the way to the previous non-text run (or even across inline boxes).
-        auto lastRunLogicalWidth = lastRun.logicalWidth();
-        auto contentWidthWithoutLastTextRun = m_contentLogicalWidth - std::max(0.f, lastRunLogicalWidth);
+        auto contentWidthWithoutLastTextRun = [&] {
+            if (style.fontCascade().wordSpacing() >= 0)
+                return m_contentLogicalWidth - std::max(0.f, lastRun.logicalWidth());
+            // FIXME: Let's see if we need to optimize for this is the rare case of both letter and word spacing being negative.
+            auto rightMostPosition = InlineLayoutUnit { };
+            for (auto& run : makeReversedRange(m_runs))
+                rightMostPosition = std::max(rightMostPosition, run.logicalRight());
+            return std::max(0.f, rightMostPosition);
+        }();
+        auto lastRunLogicalRight = lastRun.logicalRight();
         lastRun.expand(inlineTextItem, logicalWidth);
-        m_contentLogicalWidth = std::max(contentWidthWithoutLastTextRun, lastRunLogicalWidth + logicalWidth);
+        m_contentLogicalWidth = std::max(contentWidthWithoutLastTextRun, lastRunLogicalRight + logicalWidth);
     }