Merge r220795 - Move first-letter renderer mutation code out of Rende…

…rBlock and into RenderTreeUpdater

https://bugs.webkit.org/show_bug.cgi?id=175627

Reviewed by Andreas Kling.

Render tree should not mutate itself. We already fixed this for first-letter, supporting code
can now move to RenderTreeUpdater too.

* CMakeLists.txt:
* WebCore.xcodeproj/project.pbxproj:
* rendering/RenderBlock.cpp:
(WebCore::styleForFirstLetter): Deleted.
(WebCore::isPunctuationForFirstLetter): Deleted.
(WebCore::shouldSkipForFirstLetter): Deleted.
(WebCore::RenderBlock::updateFirstLetterStyle): Deleted.
(WebCore::RenderBlock::createFirstLetterRenderer): Deleted.
(WebCore::RenderBlock::updateFirstLetter): Deleted.
* rendering/RenderBlock.h:
* rendering/RenderRubyRun.cpp:
(WebCore::RenderRubyRun::updateFirstLetter): Deleted.
* rendering/RenderRubyRun.h:
* rendering/RenderTable.cpp:
(WebCore::RenderTable::updateFirstLetter): Deleted.
* rendering/RenderTable.h:

    Virtual overrides just disabled first letter for some RenderBlock subclasses. This is now achieved via
    supportsFirstLetter test in the first letter updater.

* rendering/TextAutoSizing.cpp:
(WebCore::TextAutoSizingValue::adjustTextNodeSizes):
* rendering/svg/RenderSVGText.cpp:
(WebCore::RenderSVGText::updateFirstLetter): Deleted.
* rendering/svg/RenderSVGText.h:
* style/RenderTreeUpdater.cpp:
(WebCore::RenderTreeUpdater::popParent):
* style/RenderTreeUpdater.h:
* style/RenderTreeUpdaterFirstLetter.cpp: Added.
(WebCore::styleForFirstLetter):
(WebCore::isPunctuationForFirstLetter):
(WebCore::shouldSkipForFirstLetter):
(WebCore::updateFirstLetterStyle):
(WebCore::createFirstLetterRenderer):
(WebCore::supportsFirstLetter):
(WebCore::RenderTreeUpdater::FirstLetter::update):
* style/RenderTreeUpdaterFirstLetter.h: Added.

Source/WebCore/CMakeLists.txt

@@ -2795,6 +2795,7 @@ set(WebCore_SOURCES
     style/InlineTextBoxStyle.cpp
     style/RenderTreePosition.cpp
     style/RenderTreeUpdater.cpp
+    style/RenderTreeUpdaterFirstLetter.cpp
     style/StyleChange.cpp
     style/StyleFontSizeFunctions.cpp
     style/StyleInvalidator.cpp

Source/WebCore/ChangeLog

@@ -1,3 +1,51 @@
+2017-08-16  Antti Koivisto  <antti@apple.com>
+
+        Move first-letter renderer mutation code out of RenderBlock and into RenderTreeUpdater
+        https://bugs.webkit.org/show_bug.cgi?id=175627
+
+        Reviewed by Andreas Kling.
+
+        Render tree should not mutate itself. We already fixed this for first-letter, supporting code
+        can now move to RenderTreeUpdater too.
+
+        * CMakeLists.txt:
+        * WebCore.xcodeproj/project.pbxproj:
+        * rendering/RenderBlock.cpp:
+        (WebCore::styleForFirstLetter): Deleted.
+        (WebCore::isPunctuationForFirstLetter): Deleted.
+        (WebCore::shouldSkipForFirstLetter): Deleted.
+        (WebCore::RenderBlock::updateFirstLetterStyle): Deleted.
+        (WebCore::RenderBlock::createFirstLetterRenderer): Deleted.
+        (WebCore::RenderBlock::updateFirstLetter): Deleted.
+        * rendering/RenderBlock.h:
+        * rendering/RenderRubyRun.cpp:
+        (WebCore::RenderRubyRun::updateFirstLetter): Deleted.
+        * rendering/RenderRubyRun.h:
+        * rendering/RenderTable.cpp:
+        (WebCore::RenderTable::updateFirstLetter): Deleted.
+        * rendering/RenderTable.h:
+
+            Virtual overrides just disabled first letter for some RenderBlock subclasses. This is now achieved via
+            supportsFirstLetter test in the first letter updater.
+
+        * rendering/TextAutoSizing.cpp:
+        (WebCore::TextAutoSizingValue::adjustTextNodeSizes):
+        * rendering/svg/RenderSVGText.cpp:
+        (WebCore::RenderSVGText::updateFirstLetter): Deleted.
+        * rendering/svg/RenderSVGText.h:
+        * style/RenderTreeUpdater.cpp:
+        (WebCore::RenderTreeUpdater::popParent):
+        * style/RenderTreeUpdater.h:
+        * style/RenderTreeUpdaterFirstLetter.cpp: Added.
+        (WebCore::styleForFirstLetter):
+        (WebCore::isPunctuationForFirstLetter):
+        (WebCore::shouldSkipForFirstLetter):
+        (WebCore::updateFirstLetterStyle):
+        (WebCore::createFirstLetterRenderer):
+        (WebCore::supportsFirstLetter):
+        (WebCore::RenderTreeUpdater::FirstLetter::update):
+        * style/RenderTreeUpdaterFirstLetter.h: Added.
+
 2017-08-15  Darin Adler  <darin@apple.com>
 
         REGRESSION(r220052): http/tests/appcache/deferred-events-delete-while-raising-timer.html is crashing.

Source/WebCore/rendering/RenderBlock.cpp

@@ -3085,70 +3085,6 @@ RenderBlock* RenderBlock::firstLineBlock() const
     return firstLineBlock;
 }
 
-static RenderStyle styleForFirstLetter(const RenderElement& firstLetterBlock, const RenderObject& firstLetterContainer)
-{
-    auto* containerFirstLetterStyle = firstLetterBlock.getCachedPseudoStyle(FIRST_LETTER, &firstLetterContainer.firstLineStyle());
-    // FIXME: There appears to be some path where we have a first letter renderer without first letter style.
-    ASSERT(containerFirstLetterStyle);
-    auto firstLetterStyle = RenderStyle::clone(containerFirstLetterStyle ? *containerFirstLetterStyle : firstLetterContainer.firstLineStyle());
-
-    // If we have an initial letter drop that is >= 1, then we need to force floating to be on.
-    if (firstLetterStyle.initialLetterDrop() >= 1 && !firstLetterStyle.isFloating())
-        firstLetterStyle.setFloating(firstLetterStyle.isLeftToRightDirection() ? LeftFloat : RightFloat);
-
-    // We have to compute the correct font-size for the first-letter if it has an initial letter height set.
-    auto* paragraph = firstLetterContainer.isRenderBlockFlow() ? &firstLetterContainer : firstLetterContainer.containingBlock();
-    if (firstLetterStyle.initialLetterHeight() >= 1 && firstLetterStyle.fontMetrics().hasCapHeight() && paragraph->style().fontMetrics().hasCapHeight()) {
-        // FIXME: For ideographic baselines, we want to go from line edge to line edge. This is equivalent to (N-1)*line-height + the font height.
-        // We don't yet support ideographic baselines.
-        // For an N-line first-letter and for alphabetic baselines, the cap-height of the first letter needs to equal (N-1)*line-height of paragraph lines + cap-height of the paragraph
-        // Mathematically we can't rely on font-size, since font().height() doesn't necessarily match. For reliability, the best approach is simply to
-        // compare the final measured cap-heights of the two fonts in order to get to the closest possible value.
-        firstLetterStyle.setLineBoxContain(LineBoxContainInitialLetter);
-        int lineHeight = paragraph->style().computedLineHeight();
-
-        // Set the font to be one line too big and then ratchet back to get to a precise fit. We can't just set the desired font size based off font height metrics
-        // because many fonts bake ascent into the font metrics. Therefore we have to look at actual measured cap height values in order to know when we have a good fit.
-        auto newFontDescription = firstLetterStyle.fontDescription();
-        float capRatio = firstLetterStyle.fontMetrics().floatCapHeight() / firstLetterStyle.computedFontPixelSize();
-        float startingFontSize = ((firstLetterStyle.initialLetterHeight() - 1) * lineHeight + paragraph->style().fontMetrics().capHeight()) / capRatio;
-        newFontDescription.setSpecifiedSize(startingFontSize);
-        newFontDescription.setComputedSize(startingFontSize);
-        firstLetterStyle.setFontDescription(newFontDescription);
-        firstLetterStyle.fontCascade().update(firstLetterStyle.fontCascade().fontSelector());
-
-        int desiredCapHeight = (firstLetterStyle.initialLetterHeight() - 1) * lineHeight + paragraph->style().fontMetrics().capHeight();
-        int actualCapHeight = firstLetterStyle.fontMetrics().capHeight();
-        while (actualCapHeight > desiredCapHeight) {
-            auto newFontDescription = firstLetterStyle.fontDescription();
-            newFontDescription.setSpecifiedSize(newFontDescription.specifiedSize() - 1);
-            newFontDescription.setComputedSize(newFontDescription.computedSize() -1);
-            firstLetterStyle.setFontDescription(newFontDescription);
-            firstLetterStyle.fontCascade().update(firstLetterStyle.fontCascade().fontSelector());
-            actualCapHeight = firstLetterStyle.fontMetrics().capHeight();
-        }
-    }
-
-    // Force inline display (except for floating first-letters).
-    firstLetterStyle.setDisplay(firstLetterStyle.isFloating() ? BLOCK : INLINE);
-    // CSS2 says first-letter can't be positioned.
-    firstLetterStyle.setPosition(StaticPosition);
-    return firstLetterStyle;
-}
-
-// CSS 2.1 http://www.w3.org/TR/CSS21/selector.html#first-letter
-// "Punctuation (i.e, characters defined in Unicode [UNICODE] in the "open" (Ps), "close" (Pe),
-// "initial" (Pi). "final" (Pf) and "other" (Po) punctuation classes), that precedes or follows the first letter should be included"
-static inline bool isPunctuationForFirstLetter(UChar c)
-{
-    return U_GET_GC_MASK(c) & (U_GC_PS_MASK | U_GC_PE_MASK | U_GC_PI_MASK | U_GC_PF_MASK | U_GC_PO_MASK);
-}
-
-static inline bool shouldSkipForFirstLetter(UChar c)
-{
-    return isSpaceOrNewline(c) || c == noBreakSpace || isPunctuationForFirstLetter(c);
-}
-
 static inline RenderBlock* findFirstLetterBlock(RenderBlock* start)
 {
     RenderBlock* firstLetterBlock = start;
@@ -3169,117 +3105,6 @@ static inline RenderBlock* findFirstLetterBlock(RenderBlock* start)
     return nullptr;
 }
 
-void RenderBlock::updateFirstLetterStyle(RenderElement* firstLetterBlock, RenderObject* currentChild)
-{
-    RenderElement* firstLetter = currentChild->parent();
-    RenderElement* firstLetterContainer = firstLetter->parent();
-    auto pseudoStyle = styleForFirstLetter(*firstLetterBlock, *firstLetterContainer);
-    ASSERT(firstLetter->isFloating() || firstLetter->isInline());
-
-    if (Style::determineChange(firstLetter->style(), pseudoStyle) == Style::Detach) {
-        // The first-letter renderer needs to be replaced. Create a new renderer of the right type.
-        RenderBoxModelObject* newFirstLetter;
-        if (pseudoStyle.display() == INLINE)
-            newFirstLetter = new RenderInline(document(), WTFMove(pseudoStyle));
-        else
-            newFirstLetter = new RenderBlockFlow(document(), WTFMove(pseudoStyle));
-        newFirstLetter->initializeStyle();
-
-        // Move the first letter into the new renderer.
-        LayoutStateDisabler layoutStateDisabler(view());
-        while (RenderObject* child = firstLetter->firstChild()) {
-            if (is<RenderText>(*child))
-                downcast<RenderText>(*child).removeAndDestroyTextBoxes();
-            firstLetter->removeChild(*child);
-            newFirstLetter->addChild(child, nullptr);
-        }
-
-        RenderObject* nextSibling = firstLetter->nextSibling();
-        if (RenderTextFragment* remainingText = downcast<RenderBoxModelObject>(*firstLetter).firstLetterRemainingText()) {
-            ASSERT(remainingText->isAnonymous() || remainingText->textNode()->renderer() == remainingText);
-            // Replace the old renderer with the new one.
-            remainingText->setFirstLetter(*newFirstLetter);
-            newFirstLetter->setFirstLetterRemainingText(remainingText);
-        }
-        // To prevent removal of single anonymous block in RenderBlock::removeChild and causing
-        // |nextSibling| to go stale, we remove the old first letter using removeChildNode first.
-        firstLetterContainer->removeChildInternal(*firstLetter, NotifyChildren);
-        firstLetter->destroy();
-        firstLetter = newFirstLetter;
-        firstLetterContainer->addChild(firstLetter, nextSibling);
-    } else
-        firstLetter->setStyle(WTFMove(pseudoStyle));
-}
-
-void RenderBlock::createFirstLetterRenderer(RenderElement* firstLetterBlock, RenderText* currentTextChild)
-{
-    RenderElement* firstLetterContainer = currentTextChild->parent();
-    auto pseudoStyle = styleForFirstLetter(*firstLetterBlock, *firstLetterContainer);
-    RenderBoxModelObject* firstLetter = nullptr;
-    if (pseudoStyle.display() == INLINE)
-        firstLetter = new RenderInline(document(), WTFMove(pseudoStyle));
-    else
-        firstLetter = new RenderBlockFlow(document(), WTFMove(pseudoStyle));
-    firstLetter->initializeStyle();
-    firstLetterContainer->addChild(firstLetter, currentTextChild);
-
-    // The original string is going to be either a generated content string or a DOM node's
-    // string.  We want the original string before it got transformed in case first-letter has
-    // no text-transform or a different text-transform applied to it.
-    String oldText = currentTextChild->originalText();
-    ASSERT(!oldText.isNull());
-
-    if (!oldText.isEmpty()) {
-        unsigned length = 0;
-
-        // Account for leading spaces and punctuation.
-        while (length < oldText.length() && shouldSkipForFirstLetter(oldText[length]))
-            length++;
-
-        // Account for first grapheme cluster.
-        length += numCharactersInGraphemeClusters(StringView(oldText).substring(length), 1);
-
-        // Keep looking for whitespace and allowed punctuation, but avoid
-        // accumulating just whitespace into the :first-letter.
-        for (unsigned scanLength = length; scanLength < oldText.length(); ++scanLength) {
-            UChar c = oldText[scanLength];
-
-            if (!shouldSkipForFirstLetter(c))
-                break;
-
-            if (isPunctuationForFirstLetter(c))
-                length = scanLength + 1;
-         }
-
-        // Construct a text fragment for the text after the first letter.
-        // This text fragment might be empty.
-        RenderTextFragment* remainingText;
-        if (currentTextChild->textNode())
-            remainingText = new RenderTextFragment(*currentTextChild->textNode(), oldText, length, oldText.length() - length);
-        else
-            remainingText = new RenderTextFragment(document(), oldText, length, oldText.length() - length);
-
-        if (remainingText->textNode())
-            remainingText->textNode()->setRenderer(remainingText);
-
-        firstLetterContainer->addChild(remainingText, currentTextChild);
-        firstLetterContainer->removeChild(*currentTextChild);
-        remainingText->setFirstLetter(*firstLetter);
-        firstLetter->setFirstLetterRemainingText(remainingText);
-
-        // construct text fragment for the first letter
-        RenderTextFragment* letter;
-        if (remainingText->textNode())
-            letter = new RenderTextFragment(*remainingText->textNode(), oldText, 0, length);
-        else
-            letter = new RenderTextFragment(document(), oldText, 0, length);
-
-        firstLetter->addChild(letter);
-
-        currentTextChild->destroy();
-    }
-}
-
 void RenderBlock::getFirstLetter(RenderObject*& firstLetter, RenderElement*& firstLetterContainer, RenderObject* skipObject)
 {
     firstLetter = nullptr;
@@ -3335,32 +3160,6 @@ void RenderBlock::getFirstLetter(RenderObject*& firstLetter, RenderElement*& fir
         firstLetterContainer = nullptr;
 }
 
-void RenderBlock::updateFirstLetter()
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!view().layoutState());
-
-    RenderObject* firstLetterObj;
-    RenderElement* firstLetterContainer;
-    // FIXME: The first letter might be composed of a variety of code units, and therefore might
-    // be contained within multiple RenderElements.
-    getFirstLetter(firstLetterObj, firstLetterContainer);
-
-    if (!firstLetterObj || !firstLetterContainer)
-        return;
-
-    // If the child already has style, then it has already been created, so we just want
-    // to update it.
-    if (firstLetterObj->parent()->style().styleType() == FIRST_LETTER) {
-        updateFirstLetterStyle(firstLetterContainer, firstLetterObj);
-        return;
-    }
-
-    if (!is<RenderText>(*firstLetterObj))
-        return;
-
-    createFirstLetterRenderer(firstLetterContainer, downcast<RenderText>(firstLetterObj));
-}
-
 RenderFlowThread* RenderBlock::cachedFlowThreadContainingBlock() const
 {
     RenderBlockRareData* rareData = getBlockRareData(*this);

Source/WebCore/rendering/RenderBlock.h

@@ -263,7 +263,6 @@ class RenderBlock : public RenderBox {
     LayoutUnit collapsedMarginBeforeForChild(const RenderBox& child) const;
     LayoutUnit collapsedMarginAfterForChild(const RenderBox& child) const;
 
-    virtual void updateFirstLetter();
     void getFirstLetter(RenderObject*& firstLetter, RenderElement*& firstLetterContainer, RenderObject* skipObject = nullptr);
 
     virtual void scrollbarsChanged(bool /*horizontalScrollbarChanged*/, bool /*verticalScrollbarChanged*/) { }
@@ -454,9 +453,6 @@ class RenderBlock : public RenderBox {
     bool isSelfCollapsingBlock() const override;
     virtual bool childrenPreventSelfCollapsing() const;
 
-    void createFirstLetterRenderer(RenderElement* firstLetterBlock, RenderText* currentTextChild);
-    void updateFirstLetterStyle(RenderElement* firstLetterBlock, RenderObject* firstLetterContainer);
-
     Node* nodeForHitTest() const;
 
     // FIXME-BLOCKFLOW: Remove virtualizaion when all callers have moved to RenderBlockFlow

Source/WebCore/rendering/RenderRubyRun.cpp

@@ -101,10 +101,6 @@ RenderBlock* RenderRubyRun::firstLineBlock() const
     return 0;
 }
 
-void RenderRubyRun::updateFirstLetter()
-{
-}
-
 bool RenderRubyRun::isChildAllowed(const RenderObject& child, const RenderStyle&) const
 {
     return child.isInline() || child.isRubyText();

Source/WebCore/rendering/RenderRubyRun.h

@@ -60,7 +60,6 @@ class RenderRubyRun final : public RenderBlockFlow {
     void removeChild(RenderObject&) override;
 
     RenderBlock* firstLineBlock() const override;
-    void updateFirstLetter() override;
 
     void getOverhang(bool firstLine, RenderObject* startRenderer, RenderObject* endRenderer, float& startOverhang, float& endOverhang) const;
 

Source/WebCore/rendering/RenderTable.cpp

@@ -1485,10 +1485,6 @@ RenderBlock* RenderTable::firstLineBlock() const
     return nullptr;
 }
 
-void RenderTable::updateFirstLetter()
-{
-}
-
 int RenderTable::baselinePosition(FontBaseline baselineType, bool firstLine, LineDirectionMode direction, LinePositionMode linePositionMode) const
 {
     return valueOrCompute(firstLineBaseline(), [&] {

Source/WebCore/rendering/RenderTable.h

@@ -302,7 +302,6 @@ class RenderTable : public RenderBlock {
     void invalidateCachedColumnOffsets();
 
     RenderBlock* firstLineBlock() const final;
-    void updateFirstLetter() final;
 
     void updateLogicalWidth() final;
 

Source/WebCore/rendering/TextAutoSizing.cpp

@@ -36,6 +36,7 @@
 #include "RenderListMarker.h"
 #include "RenderText.h"
 #include "RenderTextFragment.h"
+#include "RenderTreeUpdaterFirstLetter.h"
 #include "StyleResolver.h"
 
 namespace WebCore {
@@ -157,15 +158,15 @@ auto TextAutoSizingValue::adjustTextNodeSizes() -> StillHasNodes
         parentRenderer->setStyle(WTFMove(newParentStyle));
     }
 
-    // FIXME: All render tree mutations should be done via RenderTreeUpdater.
     for (auto& node : m_autoSizedNodes) {
         auto& textRenderer = *node->renderer();
         if (!is<RenderTextFragment>(textRenderer))
             continue;
         auto* block = downcast<RenderTextFragment>(textRenderer).blockForAccompanyingFirstLetter();
         if (!block)
             continue;
-        block->updateFirstLetter();
+        // FIXME: All render tree mutations should be done by RenderTreeUpdater commit.
+        RenderTreeUpdater::FirstLetter::update(*block);
     }
 
     return stillHasNodes;

Source/WebCore/rendering/svg/RenderSVGText.cpp

@@ -542,10 +542,4 @@ RenderBlock* RenderSVGText::firstLineBlock() const
     return 0;
 }
 
-// Fix for <rdar://problem/8048875>. We should not render :first-letter CSS Style
-// in a SVG text element context.
-void RenderSVGText::updateFirstLetter()
-{
-}
-
 }

Source/WebCore/rendering/svg/RenderSVGText.h

@@ -91,7 +91,6 @@ class RenderSVGText final : public RenderSVGBlock {
     std::unique_ptr<RootInlineBox> createRootInlineBox() override;
 
     RenderBlock* firstLineBlock() const override;
-    void updateFirstLetter() override;
 
     bool shouldHandleSubtreeMutations() const;
 

Source/WebCore/style/RenderTreeUpdater.cpp

@@ -41,6 +41,7 @@
 #include "RenderFullScreen.h"
 #include "RenderNamedFlowThread.h"
 #include "RenderQuote.h"
+#include "RenderTreeUpdaterFirstLetter.h"
 #include "StyleResolver.h"
 #include "StyleTreeResolver.h"
 #include <wtf/SystemTracing.h>
@@ -234,7 +235,7 @@ void RenderTreeUpdater::popParent()
 
         auto* renderer = parent.element->renderer();
         if (is<RenderBlock>(renderer))
-            downcast<RenderBlock>(*renderer).updateFirstLetter();
+            FirstLetter::update(downcast<RenderBlock>(*renderer));
 
         if (parent.element->hasCustomStyleResolveCallbacks() && parent.styleChange == Style::Detach && renderer)
             parent.element->didAttachRenderers();