Changeset 286104 in webkit

Timestamp:

Nov 21, 2021, 12:43:00 PM (5 years ago)

Author:

Alan Bujtas

Message:

[LFC][IFC] Add support for caching bidi InlineTextItem widths
​https://bugs.webkit.org/show_bug.cgi?id=233402

Reviewed by Antti Koivisto.

Let's do a "text content measure" pass when the inline item boundaries are finalized (including bidi split).

• layout/formattingContexts/inline/InlineItem.h:

(WebCore::Layout::InlineItem::setWidth):

• layout/formattingContexts/inline/InlineItemsBuilder.cpp:

(WebCore::Layout::InlineItemsBuilder::build):
(WebCore::Layout::InlineItemsBuilder::computeInlineTextItemWidths):
(WebCore::Layout::InlineItemsBuilder::handleTextContent):

• layout/formattingContexts/inline/InlineItemsBuilder.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/formattingContexts/inline/InlineItem.h (modified) (2 diffs)
• layout/formattingContexts/inline/InlineItemsBuilder.cpp (modified) (7 diffs)
• layout/formattingContexts/inline/InlineItemsBuilder.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-11-21  Alan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Add support for caching bidi InlineTextItem widths
+        https://bugs.webkit.org/show_bug.cgi?id=233402
+
+        Reviewed by Antti Koivisto.
+
+        Let's do a "text content measure" pass when the inline item boundaries are finalized (including bidi split).
+
+        * layout/formattingContexts/inline/InlineItem.h:
+        (WebCore::Layout::InlineItem::setWidth):
+        * layout/formattingContexts/inline/InlineItemsBuilder.cpp:
+        (WebCore::Layout::InlineItemsBuilder::build):
+        (WebCore::Layout::InlineItemsBuilder::computeInlineTextItemWidths):
+        (WebCore::Layout::InlineItemsBuilder::handleTextContent):
+        * layout/formattingContexts/inline/InlineItemsBuilder.h:
+
 2021-11-21  Alan Bujtas  <zalan@apple.com>
 

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

@@ -71 +71 @@
 
     void setBidiLevel(UBiDiLevel bidiLevel) { m_bidiLevel = bidiLevel; }
+    void setWidth(InlineLayoutUnit);
 
     const Box* m_layoutBox { nullptr };
@@ -97 +98 @@
 }
 
+inline void InlineItem::setWidth(InlineLayoutUnit width)
+{
+    m_width = width;
+    m_hasWidth = true;
+}
+
 #define SPECIALIZE_TYPE_TRAITS_INLINE_ITEM(ToValueTypeName, predicate) \
 SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::Layout::ToValueTypeName) \

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

@@ -89 +89 @@
     if (hasSeenBidiContent())
         breakAndComputeBidiLevels(inlineItems);
+    computeInlineTextItemWidths(inlineItems);
     return inlineItems;
 }
@@ -368 +369 @@
 }
 
+void InlineItemsBuilder::computeInlineTextItemWidths(InlineItems& inlineItems)
+{
+    for (auto& inlineItem : inlineItems) {
+        if (!inlineItem.isText())
+            continue;
+
+        auto& inlineTextItem = downcast<InlineTextItem>(inlineItem);
+        auto& inlineTextBox = inlineTextItem.inlineTextBox();
+        auto start = inlineTextItem.start();
+        auto length = inlineTextItem.length();
+        if (!canCacheMeasuredWidthOnInlineTextItem(inlineTextBox, start, length, inlineTextItem.isWhitespace()))
+            continue;
+
+        auto width = [&]() -> std::optional<InlineLayoutUnit> {
+            auto singleWhiteSpace = inlineTextItem.isWhitespace() && (!TextUtil::shouldPreserveSpacesAndTabs(inlineTextBox) || (length == 1 && inlineTextBox.canUseSimplifiedContentMeasuring()));
+            if (singleWhiteSpace)
+                return inlineTextItem.style().fontCascade().spaceWidth();
+            if (length && !inlineTextItem.isZeroWidthSpaceSeparator())
+                return TextUtil::width(inlineTextBox, inlineTextItem.style().fontCascade(), start, start + length, { });
+            return { };
+        }();
+        if (width)
+            inlineTextItem.setWidth(*width);
+    }
+}
+
 void InlineItemsBuilder::handleTextContent(const InlineTextBox& inlineTextBox, InlineItems& inlineItems)
 {
@@ -379 +406 @@
 
     auto& style = inlineTextBox.style();
-    auto& fontCascade = style.fontCascade();
-    auto whiteSpaceWidth = std::optional<InlineLayoutUnit> { fontCascade.spaceWidth() };
     auto shouldPreserveSpacesAndTabs = TextUtil::shouldPreserveSpacesAndTabs(inlineTextBox);
-    auto whitespaceContentIsTreatedAsSingleSpace = !shouldPreserveSpacesAndTabs;
     auto shouldPreserveNewline = TextUtil::shouldPreserveNewline(inlineTextBox);
     auto shouldTreatNonBreakingSpaceAsRegularSpace = style.nbspMode() == NBSPMode::Space;
@@ -401 +425 @@
 
         auto handleWhitespace = [&] {
-            auto stopAtWordSeparatorBoundary = shouldPreserveSpacesAndTabs && fontCascade.wordSpacing();
+            auto stopAtWordSeparatorBoundary = shouldPreserveSpacesAndTabs && style.fontCascade().wordSpacing();
             auto whitespaceContent = moveToNextNonWhitespacePosition(text, currentPosition, shouldPreserveNewline, shouldPreserveSpacesAndTabs, shouldTreatNonBreakingSpaceAsRegularSpace, stopAtWordSeparatorBoundary);
             if (!whitespaceContent)
@@ -407 +431 @@
 
             ASSERT(whitespaceContent->length);
-            auto appendWhitespaceItem = [&] (auto startPosition, auto itemLength) {
-                auto width = [&]() -> std::optional<InlineLayoutUnit> {
-                    if (!canCacheMeasuredWidthOnInlineTextItem(inlineTextBox, startPosition, itemLength, true))
-                        return { };
-                    if (whitespaceContentIsTreatedAsSingleSpace || (itemLength == 1 && inlineTextBox.canUseSimplifiedContentMeasuring()))
-                        return whiteSpaceWidth;
-                    return TextUtil::width(inlineTextBox, fontCascade, startPosition, startPosition + itemLength, { });
-                }();
-                inlineItems.append(InlineTextItem::createWhitespaceItem(inlineTextBox, startPosition, itemLength, UBIDI_DEFAULT_LTR, whitespaceContent->isWordSeparator, width));
-            };
             if (style.whiteSpace() == WhiteSpace::BreakSpaces) {
                 // https://www.w3.org/TR/css-text-3/#white-space-phase-1
@@ -422 +436 @@
                 // FIXME: if this turns out to be a perf hit with too many individual whitespace inline items, we should transition this logic to line breaking.
                 for (size_t i = 0; i < whitespaceContent->length; ++i)
-                    appendWhitespaceItem(currentPosition + i, 1);
+                    inlineItems.append(InlineTextItem::createWhitespaceItem(inlineTextBox, currentPosition + i, 1, UBIDI_DEFAULT_LTR, whitespaceContent->isWordSeparator, { }));
             } else
-                appendWhitespaceItem(currentPosition, whitespaceContent->length);
+                inlineItems.append(InlineTextItem::createWhitespaceItem(inlineTextBox, currentPosition, whitespaceContent->length, UBIDI_DEFAULT_LTR, whitespaceContent->isWordSeparator, { }));
             currentPosition += whitespaceContent->length;
             return true;
@@ -447 +461 @@
             }
             ASSERT_IMPLIES(style.hyphens() == Hyphens::None, !hasTrailingSoftHyphen);
-            auto length = endPosition - startPosition;
-            auto textWidth = [&]() -> std::optional<InlineLayoutUnit> {
-                // Delay non-whitespace content measuring until after bidi split.
-                if (hasSeenBidiContent() || !canCacheMeasuredWidthOnInlineTextItem(inlineTextBox, startPosition, length, false))
-                    return { };
-                return TextUtil::width(inlineTextBox, fontCascade, startPosition, endPosition, { });
-            }();
-            inlineItems.append(InlineTextItem::createNonWhitespaceItem(inlineTextBox, startPosition, length, UBIDI_DEFAULT_LTR, hasTrailingSoftHyphen, textWidth));
+            inlineItems.append(InlineTextItem::createNonWhitespaceItem(inlineTextBox, startPosition, endPosition - startPosition, UBIDI_DEFAULT_LTR, hasTrailingSoftHyphen, { }));
             currentPosition = endPosition;
             return true;

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

@@ -44 +44 @@
     void collectInlineItems(InlineItems&);
     void breakAndComputeBidiLevels(InlineItems&);
+    void computeInlineTextItemWidths(InlineItems&);
 
     void handleTextContent(const InlineTextBox&, InlineItems&);