Changeset 283486 in webkit

Timestamp:

Oct 3, 2021, 9:34:43 PM (5 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Do not take hanging whitespace sequence into account while finding expansion opportunities
​https://bugs.webkit.org/show_bug.cgi?id=231132

Reviewed by Antti Koivisto.

Source/WebCore:

Ignore hanging whitespace for expansion opportunities.
This patch fixes imported/w3c/web-platform-tests/css/css-text/white-space/textarea-pre-wrap-014.html

• layout/formattingContexts/inline/InlineLine.cpp:

(WebCore::Layout::Line::applyRunExpansion):

LayoutTests:

• TestExpectations:

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/TestExpectations (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/layout/formattingContexts/inline/InlineLine.cpp (modified) (3 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-10-03  Alan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Do not take hanging whitespace sequence into account while finding expansion opportunities
+        https://bugs.webkit.org/show_bug.cgi?id=231132
+
+        Reviewed by Antti Koivisto.
+
+        * TestExpectations:
+
 2021-10-03  Alan Bujtas  <zalan@apple.com>
 

trunk/LayoutTests/TestExpectations

@@ -4448 +4448 @@
 webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/seg-break-transformation-019.html [ ImageOnlyFailure ]
 webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/textarea-pre-wrap-012.html [ ImageOnlyFailure ]
-webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/textarea-pre-wrap-014.html [ ImageOnlyFailure ]
 webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/trailing-other-space-separators-001.html [ ImageOnlyFailure ]
 webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/trailing-other-space-separators-002.html [ ImageOnlyFailure ]

trunk/Source/WebCore/ChangeLog

@@ -1 +1 @@
 2021-10-03  Alan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Do not take hanging whitespace sequence into account while finding expansion opportunities
+        https://bugs.webkit.org/show_bug.cgi?id=231132
+
+        Reviewed by Antti Koivisto.
+
+        Ignore hanging whitespace for expansion opportunities.
+        This patch fixes imported/w3c/web-platform-tests/css/css-text/white-space/textarea-pre-wrap-014.html
+
+        * layout/formattingContexts/inline/InlineLine.cpp:
+        (WebCore::Layout::Line::applyRunExpansion):
+
+2021-10-03  Zalan Bujtas  <zalan@apple.com>
 
         [LFC][IFC] HangingTrailingContent should cache width/length

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

@@ -80 +80 @@
     if (m_runs.isEmpty() || m_runs.last().isLineBreak())
         return;
-    // Anything to distribute?
-    auto spaceToDistribute = horizontalAvailableSpace - contentLogicalWidth();
+    // A hanging glyph is still enclosed inside its parent inline box and still participates in text justification:
+    // its character advance is just not measured when determining how much content fits on the line, how much the line’s contents
+    // need to be expanded or compressed for justification, or how to position the content within the line box for text alignment.
+    auto spaceToDistribute = horizontalAvailableSpace - contentLogicalWidth() + m_hangingTrailingContent.width();
     if (spaceToDistribute <= 0)
         return;
-
     // Collect and distribute the expansion opportunities.
     size_t lineExpansionOpportunities = 0;
@@ -93 +94 @@
     // Line start behaves as if we had an expansion here (i.e. fist runs should not start with allowing left expansion).
     auto runIsAfterExpansion = true;
+    auto hangingTrailingContentLength = m_hangingTrailingContent.length();
     for (size_t runIndex = 0; runIndex < m_runs.size(); ++runIndex) {
         auto& run = m_runs[runIndex];
@@ -98 +100 @@
         size_t expansionOpportunitiesInRun = 0;
 
-        if (run.isText() && !TextUtil::shouldPreserveSpacesAndTabs(run.layoutBox())) {
+        // FIXME: Check why we don't apply expansion when whitespace is preserved.
+        if (run.isText() && (!TextUtil::shouldPreserveSpacesAndTabs(run.layoutBox()) || hangingTrailingContentLength)) {
             if (run.hasTextCombine())
                 expansionBehavior = ForbidLeftExpansion | ForbidRightExpansion;
             else {
                 expansionBehavior = (runIsAfterExpansion ? ForbidLeftExpansion : AllowLeftExpansion) | AllowRightExpansion;
-                std::tie(expansionOpportunitiesInRun, runIsAfterExpansion) = FontCascade::expansionOpportunityCount(StringView(downcast<InlineTextBox>(run.layoutBox()).content()).substring(run.textContent()->start, run.textContent()->length), run.inlineDirection(), expansionBehavior);
+                auto& textContent = *run.textContent();
+                // Trailing hanging whitespace sequence is ignored when computing the expansion opportunities.
+                auto hangingTrailingContentInCurrentRun = std::min(textContent.length, hangingTrailingContentLength);
+                auto length = textContent.length - hangingTrailingContentInCurrentRun;
+                hangingTrailingContentLength -= hangingTrailingContentInCurrentRun;
+                std::tie(expansionOpportunitiesInRun, runIsAfterExpansion) = FontCascade::expansionOpportunityCount(StringView(downcast<InlineTextBox>(run.layoutBox()).content()).substring(textContent.start, length), run.inlineDirection(), expansionBehavior);
             }
         } else if (run.isBox())