Changeset 251857 in webkit

Timestamp:

Oct 31, 2019 10:37:56 AM (4 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Add expansion context to Line::Run
​https://bugs.webkit.org/show_bug.cgi?id=203683
<rdar://problem/56785012>

Reviewed by Antti Koivisto.

This is in preparation for adding text-align: justify support.
The temporary Line::Run holds the number of expansion opportunities, while Display::Run holds both the expansion behavior and
the final expansion width.
The number of opportunities is used to compute the final expansion width for each run.

• layout/displaytree/DisplayPainter.cpp:

(WebCore::Display::paintInlineContent):

• layout/displaytree/DisplayRun.h:

(WebCore::Display::Run::TextContext::TextContext):
(WebCore::Display::Run::TextContext::setExpansion):
(WebCore::Display::Run::TextContext::expansion const):
(WebCore::Display::Run::TextContext::expansionBehavior const): Deleted.

• layout/inlineformatting/InlineLine.h:

(WebCore::Layout::Line::Run::hasExpansionOpportunity const):
(WebCore::Layout::Line::Run::expansionOpportunityCount const):
(WebCore::Layout::Line::Run::expansionBehavior const):
(WebCore::Layout::Line::Run::setHasExpansionOpportunity):
(WebCore::Layout::Line::Run::setComputedHorizontalExpansion):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/displaytree/DisplayPainter.cpp (modified) (1 diff)
• layout/displaytree/DisplayRun.h (modified) (4 diffs)
• layout/inlineformatting/InlineLine.h (modified) (3 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-10-31  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Add expansion context to Line::Run
+        https://bugs.webkit.org/show_bug.cgi?id=203683
+        <rdar://problem/56785012>
+
+        Reviewed by Antti Koivisto.
+
+        This is in preparation for adding text-align: justify support.
+        The temporary Line::Run holds the number of expansion opportunities, while Display::Run holds both the expansion behavior and
+        the final expansion width.
+        The number of opportunities is used to compute the final expansion width for each run.
+
+        * layout/displaytree/DisplayPainter.cpp:
+        (WebCore::Display::paintInlineContent):
+        * layout/displaytree/DisplayRun.h:
+        (WebCore::Display::Run::TextContext::TextContext):
+        (WebCore::Display::Run::TextContext::setExpansion):
+        (WebCore::Display::Run::TextContext::expansion const):
+        (WebCore::Display::Run::TextContext::expansionBehavior const): Deleted.
+        * layout/inlineformatting/InlineLine.h:
+        (WebCore::Layout::Line::Run::hasExpansionOpportunity const):
+        (WebCore::Layout::Line::Run::expansionOpportunityCount const):
+        (WebCore::Layout::Line::Run::expansionBehavior const):
+        (WebCore::Layout::Line::Run::setHasExpansionOpportunity):
+        (WebCore::Layout::Line::Run::setComputedHorizontalExpansion):
+
 2019-10-31  Zalan Bujtas  <zalan@apple.com>
 

trunk/Source/WebCore/layout/displaytree/DisplayPainter.cpp

@@ -127 +127 @@
             auto& lineBox = formattingState.lineBoxForRun(*run);
             auto baselineOffset = rootAbsoluteDisplayBox.top() + lineBox.logicalTop() + lineBox.baselineOffset();
-            context.drawText(style.fontCascade(),
-                TextRun { textContext->content(), logicalLeft, textContext->expansion().valueOr(0), textContext->expansionBehavior().valueOr(ForbidLeadingExpansion | ForbidTrailingExpansion)},
-                { logicalLeft, baselineOffset });
+            if (auto expansionContext = textContext->expansion())
+                context.drawText(style.fontCascade(), TextRun { textContext->content(), logicalLeft, expansionContext->horiztontalExpansion, expansionContext->behavior }, { logicalLeft, baselineOffset });
+            else
+                context.drawText(style.fontCascade(), TextRun { textContext->content(), logicalLeft }, { logicalLeft, baselineOffset });
         } else if (auto* cachedImage = run->image()) {
             auto runAbsoluteRect = FloatRect { rootAbsoluteDisplayBox.left() + run->logicalLeft(), rootAbsoluteDisplayBox.top() + run->logicalTop(), run->logicalWidth(), run->logicalHeight() };

trunk/Source/WebCore/layout/displaytree/DisplayRun.h

@@ -44 +44 @@
         WTF_MAKE_STRUCT_FAST_ALLOCATED;
     public:
-        TextContext(unsigned position, unsigned length, String content, Optional<ExpansionBehavior> = { }, Optional<LayoutUnit> expansion = { });
+        struct ExpansionContext;
+        TextContext(unsigned position, unsigned length, String content, Optional<ExpansionContext> = { });
 
         unsigned start() const { return m_start; }
@@ -51 +52 @@
         String content() const { return m_content; }
 
-        Optional<ExpansionBehavior> expansionBehavior() const { return m_expansionBehavior; }
-        Optional<LayoutUnit> expansion() const { return m_expansion; }
+        struct ExpansionContext {
+            ExpansionBehavior behavior;
+            LayoutUnit horiztontalExpansion;
+        };
+        void setExpansion(ExpansionContext expansionContext) { m_expansionContext = expansionContext; }
+        Optional<ExpansionContext> expansion() const { return m_expansionContext; }
 
         void expand(const TextContext& other);
@@ -59 +64 @@
         unsigned m_start { 0 };
         unsigned m_length { 0 };
-        Optional<ExpansionBehavior> m_expansionBehavior;
-        Optional<LayoutUnit> m_expansion;
+        Optional<ExpansionContext> m_expansionContext;
         // FIXME: This is temporary. We should have some mapping setup to identify associated text content instead.
         String m_content;
@@ -111 +115 @@
 }
 
-inline Run::TextContext::TextContext(unsigned start, unsigned length, String content, Optional<ExpansionBehavior> expansionBehavior, Optional<LayoutUnit> expansion)
+inline Run::TextContext::TextContext(unsigned start, unsigned length, String content, Optional<ExpansionContext> expansionContext)
     : m_start(start)
     , m_length(length)
-    , m_expansionBehavior(expansionBehavior)
-    , m_expansion(expansion)
+    , m_expansionContext(expansionContext)
     , m_content(content)
 {

trunk/Source/WebCore/layout/inlineformatting/InlineLine.h

@@ -94 +94 @@
         void setCollapsesToZeroAdvanceWidth();
 
+        void setHasExpansionOpportunity(ExpansionBehavior);
+        bool hasExpansionOpportunity() const { return m_expansionOpportunityCount.hasValue(); }
+        Optional<ExpansionBehavior> expansionBehavior() const;
+        Optional<unsigned> expansionOpportunityCount() const { return m_expansionOpportunityCount; }
+        void setComputedHorizontalExpansion(LayoutUnit logicalExpansion);
+
         bool isCollapsible() const { return m_isCollapsible; }
         bool hasTrailingCollapsedContent() const { return m_hasTrailingCollapsedContent; }
@@ -106 +112 @@
         bool m_collapsedToZeroAdvanceWidth { false };
         bool m_hasTrailingCollapsedContent { false };
+        Optional<unsigned> m_expansionOpportunityCount;
     };
     using RunList = Vector<std::unique_ptr<Run>>;
@@ -191 +198 @@
 }
 
+inline Optional<ExpansionBehavior> Line::Run::expansionBehavior() const
+{
+    ASSERT(isText());
+    if (auto expansionContext = m_displayRun.textContext()->expansion())
+        return expansionContext->behavior;
+    return { };
+}
+
+inline void Line::Run::setHasExpansionOpportunity(ExpansionBehavior expansionBehavior)
+{
+    ASSERT(isText());
+    ASSERT(!hasExpansionOpportunity());
+    m_expansionOpportunityCount = 1;
+    m_displayRun.textContext()->setExpansion({ expansionBehavior, { } });
+}
+
+inline void Line::Run::setComputedHorizontalExpansion(LayoutUnit logicalExpansion)
+{
+    ASSERT(isText());
+    ASSERT(hasExpansionOpportunity());
+    ASSERT(m_displayRun.textContext()->expansion());
+    m_displayRun.expandHorizontally(logicalExpansion);
+    m_displayRun.textContext()->setExpansion({ m_displayRun.textContext()->expansion()->behavior, logicalExpansion });
+}
+
 }
 }