Separate repaint and layout requirements of StyleDifference (Step 1)

Source/core/rendering/RenderObject.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 1848 matching lines @@
     // not to layout for 3d transforms, but we should be invoking a simplified relayout. Is it possible we are avoiding
     // doing this for some performance reason at this time?
     if (contextSensitiveProperties & ContextSensitivePropertyTransform) {
         // Text nodes share style with their parents but transforms don't apply to them,
         // hence the !isText() check.
         // FIXME: when transforms are taken into account for overflow, we will need to do a layout.
         if (!isText() && (!hasLayer() || !toRenderLayerModelObject(this)->layer()->hasDirectReasonsForCompositing())) {
             // We need to set at least SimplifiedLayout, but if PositionedMovementOnly is already set
             // then we actually need SimplifiedLayoutAndPositionedMovement.
             if (!hasLayer())
-                diff = StyleDifferenceLayout; // FIXME: Do this for now since SimplifiedLayout cannot handle updating floating objects lists.
-            else if (diff < StyleDifferenceLayoutPositionedMovementOnly)
-                diff = StyleDifferenceSimplifiedLayout;
-            else if (diff < StyleDifferenceSimplifiedLayout)
-                diff = StyleDifferenceSimplifiedLayoutAndPositionedMovement;
-        } else if (diff < StyleDifferenceRecompositeLayer)
-            diff = StyleDifferenceRecompositeLayer;
+                diff.setNeedsFullLayout(); // FIXME: Do this for now since SimplifiedLayout cannot handle updating floating objects lists.
+            else
+                diff.setNeedsSimplifiedLayout();
+        } else {
+            diff.setNeedsRecompositeLayer();
+        }
     }
 
     // If opacity or filters changed, and the layer does not paint into its own separate backing, then we need to repaint (also
     // ignoring text nodes)
-    if (contextSensitiveProperties & ContextSensitivePropertyOpacity && diff <= StyleDifferenceRepaintLayer) {
+    if (contextSensitiveProperties & ContextSensitivePropertyOpacity && !diff.needsLayout()) {
         if (!isText() && (!hasLayer() || !toRenderLayerModelObject(this)->layer()->hasDirectReasonsForCompositing()))
-            diff = StyleDifferenceRepaintLayer;
-        else if (diff < StyleDifferenceRecompositeLayer)
-            diff = StyleDifferenceRecompositeLayer;
+            diff.setNeedsRepaintLayer();
+        else
+            diff.setNeedsRecompositeLayer();
     }
 
-    if ((contextSensitiveProperties & ContextSensitivePropertyFilter) && hasLayer() && diff <= StyleDifferenceRepaintLayer) {
+    if ((contextSensitiveProperties & ContextSensitivePropertyFilter) && hasLayer() && !diff.needsLayout()) {
         RenderLayer* layer = toRenderLayerModelObject(this)->layer();
         if (!layer->hasDirectReasonsForCompositing() || layer->paintsWithFilters())
-            diff = StyleDifferenceRepaintLayer;
-        else if (diff < StyleDifferenceRecompositeLayer)
-            diff = StyleDifferenceRecompositeLayer;
+            diff.setNeedsRepaintLayer();
+        else
+            diff.setNeedsRecompositeLayer();
     }
 
-    if ((contextSensitiveProperties & ContextSensitivePropertyTextOrColor) && diff < StyleDifferenceRepaint
+    if ((contextSensitiveProperties & ContextSensitivePropertyTextOrColor) && !diff.needsRepaint() && !diff.needsLayout()
         && hasImmediateNonWhitespaceTextChildOrPropertiesDependentOnColor())
-        diff = StyleDifferenceRepaint;
+        diff.setNeedsRepaintObject();
 
     // The answer to layerTypeRequired() for plugins, iframes, and canvas can change without the actual
     // style changing, since it depends on whether we decide to composite these elements. When the
     // layer status of one of these elements changes, we need to force a layout.
-    if (diff == StyleDifferenceEqual && style() && isLayerModelObject()) {
+    if (diff.hasNoChange() && style() && isLayerModelObject()) {
         bool requiresLayer = toRenderLayerModelObject(this)->layerTypeRequired() != NoLayer;
         if (hasLayer() != requiresLayer)
-            diff = StyleDifferenceLayout;
+            diff.setNeedsFullLayout();
     }
 
     // If we have no layer(), just treat a RepaintLayer hint as a normal Repaint.
-    if (diff == StyleDifferenceRepaintLayer && !hasLayer())
-        diff = StyleDifferenceRepaint;
+    if (diff.needsRepaintLayer() && !hasLayer()) {
+        diff.clearNeedsRepaint();
+        diff.setNeedsRepaintObject();
+    }
 
     return diff;
 }
 
 void RenderObject::setPseudoStyle(PassRefPtr<RenderStyle> pseudoStyle)
 {
     ASSERT(pseudoStyle->styleType() == BEFORE || pseudoStyle->styleType() == AFTER);
 
     // FIXME: We should consider just making all pseudo items use an inherited style.
 
@@ skipping 31 matching lines @@
 {
     ASSERT(style);
 
     if (m_style == style) {
         // We need to run through adjustStyleDifference() for iframes, plugins, and canvas so
         // style sharing is disabled for them. That should ensure that we never hit this code path.
         ASSERT(!isRenderIFrame() && !isEmbeddedObject() && !isCanvas());
         return;
     }
 
-    StyleDifference diff = StyleDifferenceEqual;
+    StyleDifference diff;
     unsigned contextSensitiveProperties = ContextSensitivePropertyNone;
     if (m_style)
         diff = m_style->visualInvalidationDiff(*style, contextSensitiveProperties);
 
     diff = adjustStyleDifference(diff, contextSensitiveProperties);
 
     styleWillChange(diff, *style);
 
     RefPtr<RenderStyle> oldStyle = m_style.release();
     setStyleInternal(style);
@@ skipping 14 matching lines @@
     // its first-letter block gets an update in RenderTextFragment::styleDidChange. For RenderTextFragment(s),
     // we will safely bail out with the doesNotNeedLayout flag. We might want to broaden this condition
     // in the future as we move renderer changes out of layout and into style changes.
     if (doesNotNeedLayout)
         return;
 
     // Now that the layer (if any) has been updated, we need to adjust the diff again,
     // check whether we should layout now, and decide if we need to repaint.
     StyleDifference updatedDiff = adjustStyleDifference(diff, contextSensitiveProperties);
 
-    if (diff <= StyleDifferenceLayoutPositionedMovementOnly) {
-        if (updatedDiff == StyleDifferenceLayout)
+    if (!diff.needsFullLayout()) {
+        if (updatedDiff.needsFullLayout()) {
             setNeedsLayoutAndPrefWidthsRecalc();
-        else if (updatedDiff == StyleDifferenceLayoutPositionedMovementOnly)
-            setNeedsPositionedMovementLayout();
-        else if (updatedDiff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
-            setNeedsPositionedMovementLayout();
-            setNeedsSimplifiedNormalFlowLayout();
-        } else if (updatedDiff == StyleDifferenceSimplifiedLayout)
-            setNeedsSimplifiedNormalFlowLayout();
+        } else {
+            if (updatedDiff.needsPositionedMovementLayout())
+                setNeedsPositionedMovementLayout();
+            if (updatedDiff.needsSimplifiedLayout())
+                setNeedsSimplifiedNormalFlowLayout();
+        }
     }
 
-    if (updatedDiff == StyleDifferenceRepaint || updatedDiff == StyleDifferenceRepaintLayer) {
+    if (updatedDiff.needsRepaint()) {
         // Do a repaint with the new style now, e.g., for example if we go from
         // not having an outline to having an outline.
         repaint();
     }
 }
 
 static inline bool rendererHasBackground(const RenderObject* renderer)
 {
     return renderer && renderer->hasBackground();
 }
@@ skipping 13 matching lines @@
         }
 
         // Keep layer hierarchy visibility bits up to date if visibility changes.
         if (m_style->visibility() != newStyle.visibility()) {
             // We might not have an enclosing layer yet because we might not be in the tree.
             if (RenderLayer* layer = enclosingLayer()) {
                 if (newStyle.visibility() == VISIBLE) {
                     layer->setHasVisibleContent();
                 } else if (layer->hasVisibleContent() && (this == layer->renderer() || layer->renderer()->style()->visibility() != VISIBLE)) {
                     layer->dirtyVisibleContentStatus();
-                    if (diff > StyleDifferenceRepaintLayer)
+                    if (diff.needsLayout())
                         repaint();
                 }
             }
         }
 
-        if (m_parent && diff == StyleDifferenceRepaint)
+        if (m_parent && diff.needsRepaintObjectOnly())
             repaint();
         if (isFloating() && (m_style->floating() != newStyle.floating()))
             // For changes in float styles, we need to conceivably remove ourselves
             // from the floating objects list.
             toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
         else if (isOutOfFlowPositioned() && (m_style->position() != newStyle.position()))
             // For changes in positioning styles, we need to conceivably remove ourselves
             // from the positioned objects list.
             toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
 
         s_affectsParentBlock = isFloatingOrOutOfFlowPositioned()
             && (!newStyle.isFloating() && !newStyle.hasOutOfFlowPosition())
             && parent() && (parent()->isRenderBlockFlow() || parent()->isRenderInline());
 
         // Clearing these bits is required to avoid leaving stale renderers.
         // FIXME: We shouldn't need that hack if our logic was totally correct.
-        if (diff == StyleDifferenceLayout || diff == StyleDifferenceLayoutPositionedMovementOnly) {
+        if (diff.needsFullLayout() || diff.needsPositionedMovementLayout()) {
             setFloating(false);
             clearPositionedState();
         }
-    } else
+    } else {
         s_affectsParentBlock = false;
+    }
 
     if (view()->frameView()) {
         bool shouldBlitOnFixedBackgroundImage = false;
 #if ENABLE(FAST_MOBILE_SCROLLING)
         // On low-powered/mobile devices, preventing blitting on a scroll can cause noticeable delays
         // when scrolling a page with a fixed background image. As an optimization, assuming there are
         // no fixed positoned elements on the page, we can acclerate scrolling (via blitting) if we
         // ignore the CSS property "background-attachment: fixed".
         shouldBlitOnFixedBackgroundImage = true;
 #endif
@@ skipping 47 matching lines @@
 }
 
 void RenderObject::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     if (s_affectsParentBlock)
         handleDynamicFloatPositionChange();
 
     if (!m_parent)
         return;
 
-    if (diff == StyleDifferenceLayout || diff == StyleDifferenceSimplifiedLayout) {
+    if (diff.needsFullLayout() || diff.needsSimplifiedLayout()) {
         RenderCounter::rendererStyleChanged(*this, oldStyle, m_style.get());
 
         // If the object already needs layout, then setNeedsLayout won't do
         // any work. But if the containing block has changed, then we may need
         // to mark the new containing blocks for layout. The change that can
         // directly affect the containing block of this object is a change to
         // the position style.
         if (needsLayout() && oldStyle->position() != m_style->position())
             markContainingBlocksForLayout();
 
-        if (diff == StyleDifferenceLayout)
+        if (diff.needsFullLayout())
             setNeedsLayoutAndPrefWidthsRecalc();
         else
             setNeedsSimplifiedNormalFlowLayout();
-    } else if (diff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
-        setNeedsPositionedMovementLayout();
-        setNeedsSimplifiedNormalFlowLayout();
-    } else if (diff == StyleDifferenceLayoutPositionedMovementOnly)
+    }
+    if (diff.needsPositionedMovementLayout())
         setNeedsPositionedMovementLayout();
 
     // Don't check for repaint here; we need to wait until the layer has been
     // updated by subclasses before we know if we have to repaint (in setStyle()).
 
     if (oldStyle && !areCursorsEqual(oldStyle, style())) {
         if (LocalFrame* frame = this->frame())
             frame->eventHandler().scheduleCursorUpdate();
     }
 }
@@ skipping 1222 matching lines @@
 {
     if (object1) {
         const WebCore::RenderObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif