Recompute maximum outline size only when outline changes.

https://bugs.webkit.org/show_bug.cgi?id=148576

Reviewed by Andreas Kling.

We should only recompute the cached maximum outline size when
either the outline size (offset/width) or the style (from or to
auto) changes.
Setting 'outline-style: auto' can change the final outline width as 'auto' triggers
the focus ring mode. In this mode, we ignore outline-width and use the platform default value instead.

Covered by existing test cases.

* rendering/RenderElement.cpp:
(WebCore::RenderElement::computeMaxOutlineSize):
(WebCore::RenderElement::styleWillChange):
(WebCore::RenderElement::initializeStyle): Deleted.
(WebCore::RenderElement::setStyle): Deleted.
* rendering/RenderElement.h:


Canonical link: https://commits.webkit.org/166820@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@189242 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

@@ -1,3 +1,25 @@
+2015-09-01  Zalan Bujtas  <zalan@apple.com>
+
+        Recompute maximum outline size only when outline changes.
+        https://bugs.webkit.org/show_bug.cgi?id=148576
+
+        Reviewed by Andreas Kling.
+
+        We should only recompute the cached maximum outline size when
+        either the outline size (offset/width) or the style (from or to
+        auto) changes.
+        Setting 'outline-style: auto' can change the final outline width as 'auto' triggers
+        the focus ring mode. In this mode, we ignore outline-width and use the platform default value instead.  
+
+        Covered by existing test cases.
+
+        * rendering/RenderElement.cpp:
+        (WebCore::RenderElement::computeMaxOutlineSize):
+        (WebCore::RenderElement::styleWillChange):
+        (WebCore::RenderElement::initializeStyle): Deleted.
+        (WebCore::RenderElement::setStyle): Deleted.
+        * rendering/RenderElement.h:
+
 2015-09-01  Chris Dumez  <cdumez@apple.com>
 
         Range API should throw a TypeError for null Node parameters

Source/WebCore/rendering/RenderElement.cpp

@@ -364,15 +364,15 @@ void RenderElement::updateShapeImage(const ShapeValue* oldShapeValue, const Shap
 }
 #endif
 
-void RenderElement::computeMaxOutlineSize() const
+void RenderElement::computeMaxOutlineSize(const RenderStyle& style) const
 {
     // We need to ensure that view->maximalOutlineSize() is valid for any repaints that happen
     // during styleDidChange (it's used by clippedOverflowRectForRepaint()).
-    if (!m_style->outlineWidth())
+    if (!style.outlineWidth())
         return;
-    int maxOutlineSize = m_style->outlineSize();
-    if (m_style->outlineStyleIsAuto())
-        maxOutlineSize = std::max(theme().platformFocusRingWidth() + m_style->outlineOffset(), maxOutlineSize);
+    int maxOutlineSize = style.outlineSize();
+    if (style.outlineStyleIsAuto())
+        maxOutlineSize = std::max(theme().platformFocusRingWidth() + style.outlineOffset(), maxOutlineSize);
 
     if (maxOutlineSize < view().maximalOutlineSize())
         return;
@@ -396,8 +396,6 @@ void RenderElement::initializeStyle()
     updateShapeImage(nullptr, m_style->shapeOutside());
 #endif
 
-    computeMaxOutlineSize();
-
     styleDidChange(StyleDifferenceNewStyle, nullptr);
 
     // We shouldn't have any text children that would need styleDidChange at this point.
@@ -447,8 +445,6 @@ void RenderElement::setStyle(Ref<RenderStyle>&& style, StyleDifference minimalSt
     updateShapeImage(oldStyle.get().shapeOutside(), m_style->shapeOutside());
 #endif
 
-    computeMaxOutlineSize();
-
     bool doesNotNeedLayout = !parent();
 
     styleDidChange(diff, oldStyle.ptr());
@@ -916,6 +912,11 @@ void RenderElement::styleWillChange(StyleDifference diff, const RenderStyle& new
 
     if (isRoot() || isBody())
         view().frameView().updateExtendBackgroundIfNecessary();
+
+    if (!oldStyle || (oldStyle->outlineSize() != newStyle.outlineSize()
+        || (oldStyle->outlineStyleIsAuto() && !newStyle.outlineStyleIsAuto())
+        || (!oldStyle->outlineStyleIsAuto() && newStyle.outlineStyleIsAuto())))
+        computeMaxOutlineSize(newStyle);
 }
 
 void RenderElement::handleDynamicFloatPositionChange()

Source/WebCore/rendering/RenderElement.h

@@ -307,7 +307,7 @@ class RenderElement : public RenderObject {
 
     bool shouldWillChangeCreateStackingContext() const;
 
-    void computeMaxOutlineSize() const;
+    void computeMaxOutlineSize(const RenderStyle&) const;
 
     unsigned m_baseTypeFlags : 6;
     unsigned m_ancestorLineBoxDirty : 1;