Invalidate first line display item clients when first line style changes

third_party/WebKit/Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 707 matching lines @@
     if (hasNonCompositedScrollbars())
         return false;
 
     // We can't detect whether a plugin has box effects, so disable this optimization for that case.
     if (isEmbeddedObject())
         return false;
 
     return !hasBoxEffect();
 }
 
-LayoutBlock* LayoutObject::firstLineBlock() const
-{
-    return nullptr;
-}
-
 static inline bool objectIsRelayoutBoundary(const LayoutObject* object)
 {
     // FIXME: In future it may be possible to broaden these conditions in order to improve performance.
     if (object->isTextControl())
         return true;
 
     if (object->isSVGRoot())
         return true;
 
     if (!object->hasOverflowClip())
@@ skipping 1087 matching lines @@
         setStyle(style.release());
         return;
     }
 
     setStyle(pseudoStyle);
 }
 
 void LayoutObject::firstLineStyleDidChange(const ComputedStyle& oldStyle, const ComputedStyle& newStyle)
 {
     StyleDifference diff = oldStyle.visualInvalidationDiff(newStyle);
-    if (diff.hasDifference()) {
-        // TODO(rune@opera.com): We should use the diff to determine whether a repaint vs. layout
-        // is needed, but for now just assume a layout will be required. The diff code
-        // in LayoutObject::setStyle would need to be factored out so that it could be reused.
-        setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReason::StyleChange);
+
+    if (diff.needsPaintInvalidation() || diff.textDecorationOrColorChanged()) {
+        LayoutBlockFlow* firstLineContainer = nullptr;
+        if (canHaveFirstLineOrFirstLetterStyle()) {

[chrishtr, 2015/12/03 18:41:56]

It seems it would be cleaner to make firstLineStyleDidChange() virtual and
implement this stuff in LayoutBlockFlow, LayoutButton and LayoutInline.

[Xianzhu, 2015/12/03 19:10:40]

That would need to duplicate more than half of this method into three copies.
How about making 'LayoutBlockFlow* firstLineContainerBlock()' virtual, so that
line 1838-1846 can be one line:
   if (LayoutBlockFlow* firstLineContainerBlock =
this->firstLineContainerBlock())
?

[Xianzhu, 2015/12/03 19:45:13]

I think it might be be better to separate FIRST_LINE (for LayoutBlock) and
FIRST_LINE_INHERITED (for LayoutInline) for firstLineStyleDidChange() from
Element::pseudoStyleCacheIsValid(). Trying this.

[mstensho (USE GERRIT), 2015/12/03 19:58:02]

FWIW, I think what we already have here is good.

+            firstLineContainer = toLayoutBlock(this)->nearestInnerBlockWithFirstLine();
+        } else if (isLayoutInline()) {
+            if (InlineBox* firstLineBox = toLayoutInline(this)->firstLineBoxIncludingCulling()) {
+                if (firstLineBox->isFirstLineStyle())
+                    firstLineContainer = toLayoutBlockFlow(containingBlock());
+            }
+        }
+        if (firstLineContainer) {
+            firstLineContainer->invalidateDisplayItemClientsOfFirstLine();
+            if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+                firstLineContainer->setShouldDoFullPaintInvalidation();
+        }
     }
+    if (diff.needsLayout())
+        setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);
 }
 
 void LayoutObject::markContainingBlocksForOverflowRecalc()
 {
     for (LayoutBlock* container = containingBlock(); container && !container->childNeedsOverflowRecalcAfterStyleChange(); container = container->containingBlock())
         container->setChildNeedsOverflowRecalcAfterStyleChange();
 }
 
 void LayoutObject::setNeedsOverflowRecalcAfterStyleChange()
 {
@@ skipping 939 matching lines @@
     Cached,
     Uncached
 };
 
 static PassRefPtr<ComputedStyle> firstLineStyleForCachedUncachedType(StyleCacheState type, const LayoutObject* layoutObject, ComputedStyle* style)
 {
     const LayoutObject* layoutObjectForFirstLineStyle = layoutObject;
     if (layoutObject->isBeforeOrAfterContent())
         layoutObjectForFirstLineStyle = layoutObject->parent();
 
-    if (layoutObjectForFirstLineStyle->isLayoutBlockFlow() || layoutObjectForFirstLineStyle->isLayoutButton()) {
-        if (LayoutBlock* firstLineBlock = layoutObjectForFirstLineStyle->firstLineBlock()) {
+    if (layoutObjectForFirstLineStyle->canHaveFirstLineOrFirstLetterStyle()) {
+        if (LayoutBlock* firstLineBlock = toLayoutBlock(layoutObjectForFirstLineStyle)->enclosingFirstLineStyleBlock()) {
             if (type == Cached)
                 return firstLineBlock->getCachedPseudoStyle(FIRST_LINE, style);
             return firstLineBlock->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE), style, firstLineBlock == layoutObject ? style : 0);
         }
     } else if (!layoutObjectForFirstLineStyle->isAnonymous() && layoutObjectForFirstLineStyle->isLayoutInline()
         && !layoutObjectForFirstLineStyle->node()->isFirstLetterPseudoElement()) {
         const ComputedStyle* parentStyle = layoutObjectForFirstLineStyle->parent()->firstLineStyle();
         if (parentStyle != layoutObjectForFirstLineStyle->parent()->style()) {
             if (type == Cached) {
                 // A first-line style is in effect. Cache a first-line style for ourselves.
@@ skipping 682 matching lines @@
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     } else {
         fprintf(stderr, "Cannot showLayoutTree. Root is (nil)\n");
     }
 }
 
 #endif