Factor painting code out of RenderBox into a new class called BoxPainter.

Source/core/rendering/RenderBoxModelObject.cpp

Index: Source/core/rendering/RenderBoxModelObject.cpp
diff --git a/Source/core/rendering/RenderBoxModelObject.cpp b/Source/core/rendering/RenderBoxModelObject.cpp
index 73ecfa184ae293b19fa69210a4dd17232a5b2713..3e4c3e8c397f494a47ac5fad99423a7380fba2e7 100644
--- a/Source/core/rendering/RenderBoxModelObject.cpp
+++ b/Source/core/rendering/RenderBoxModelObject.cpp
@@ -42,6 +42,7 @@
 #include "core/rendering/RenderView.h"
 #include "core/rendering/compositing/CompositedLayerMapping.h"
 #include "core/rendering/compositing/RenderLayerCompositor.h"
+#include "core/rendering/style/BorderEdge.h"
 #include "core/rendering/style/ShadowList.h"
 #include "platform/LengthFunctions.h"
 #include "platform/geometry/TransformState.h"
@@ -1231,77 +1232,6 @@ bool RenderBoxModelObject::paintNinePieceImage(GraphicsContext* graphicsContext,
     return true;
 }
 
-class BorderEdge {
-public:
-    BorderEdge(int edgeWidth, const Color& edgeColor, EBorderStyle edgeStyle, bool edgeIsTransparent, bool edgeIsPresent = true)
-        : width(edgeWidth)
-        , color(edgeColor)
-        , style(edgeStyle)
-        , isTransparent(edgeIsTransparent)
-        , isPresent(edgeIsPresent)
-    {
-        if (style == DOUBLE && edgeWidth < 3)
-            style = SOLID;
-    }
-
-    BorderEdge()
-        : width(0)
-        , style(BHIDDEN)
-        , isTransparent(false)
-        , isPresent(false)
-    {
-    }
-
-    bool hasVisibleColorAndStyle() const { return style > BHIDDEN && !isTransparent; }
-    bool shouldRender() const { return isPresent && width && hasVisibleColorAndStyle(); }
-    bool presentButInvisible() const { return usedWidth() && !hasVisibleColorAndStyle(); }
-    bool obscuresBackgroundEdge(float scale) const
-    {
-        if (!isPresent || isTransparent || (width * scale) < 2 || color.hasAlpha() || style == BHIDDEN)
-            return false;
-
-        if (style == DOTTED || style == DASHED)
-            return false;
-
-        if (style == DOUBLE)
-            return width >= 5 * scale; // The outer band needs to be >= 2px wide at unit scale.
-
-        return true;
-    }
-    bool obscuresBackground() const
-    {
-        if (!isPresent || isTransparent || color.hasAlpha() || style == BHIDDEN)
-            return false;
-
-        if (style == DOTTED || style == DASHED || style == DOUBLE)
-            return false;
-
-        return true;
-    }
-
-    int usedWidth() const { return isPresent ? width : 0; }
-
-    void getDoubleBorderStripeWidths(int& outerWidth, int& innerWidth) const
-    {
-        int fullWidth = usedWidth();
-        outerWidth = fullWidth / 3;
-        innerWidth = fullWidth * 2 / 3;
-
-        // We need certain integer rounding results
-        if (fullWidth % 3 == 2)
-            outerWidth += 1;
-
-        if (fullWidth % 3 == 1)
-            innerWidth += 1;
-    }
-
-    int width;
-    Color color;
-    EBorderStyle style;
-    bool isTransparent;
-    bool isPresent;
-};
-
 static bool allCornersClippedOut(const RoundedRect& border, const LayoutRect& clipRect)
 {
     LayoutRect boundingRect = border.rect();
@@ -1364,11 +1294,6 @@ static inline bool includesAdjacentEdges(BorderEdgeFlags flags)
         || (flags & (LeftBorderEdge | TopBorderEdge)) == (LeftBorderEdge | TopBorderEdge);
 }
 
-inline bool edgesShareColor(const BorderEdge& firstEdge, const BorderEdge& secondEdge)
-{
-    return firstEdge.color == secondEdge.color;
-}
-
 inline bool styleRequiresClipPolygon(EBorderStyle style)
 {
     return style == DOTTED || style == DASHED; // These are drawn with a stroke, so we have to clip to get corner miters.
@@ -1409,7 +1334,7 @@ static inline bool colorsMatchAtCorner(BoxSide side, BoxSide adjacentSide, const
     if (edges[side].shouldRender() != edges[adjacentSide].shouldRender())
         return false;
 
-    if (!edgesShareColor(edges[side], edges[adjacentSide]))
+    if (!edges[side].sharesColorWith(edges[adjacentSide]))
         return false;
 
     return !borderStyleHasUnmatchedColorsAtCorner(edges[side].style, side, adjacentSide);
@@ -1424,7 +1349,7 @@ static inline bool colorNeedsAntiAliasAtCorner(BoxSide side, BoxSide adjacentSid
     if (edges[side].shouldRender() != edges[adjacentSide].shouldRender())
         return false;
 
-    if (!edgesShareColor(edges[side], edges[adjacentSide]))
+    if (!edges[side].sharesColorWith(edges[adjacentSide]))
         return true;
 
     return borderStyleHasUnmatchedColorsAtCorner(edges[side].style, side, adjacentSide);
@@ -1439,7 +1364,7 @@ static inline bool willBeOverdrawn(BoxSide side, BoxSide adjacentSide, const Bor
         if (edges[adjacentSide].presentButInvisible())
             return false;
 
-        if (!edgesShareColor(edges[side], edges[adjacentSide]) && edges[adjacentSide].color.hasAlpha())
+        if (!edges[side].sharesColorWith(edges[adjacentSide]) && edges[adjacentSide].color.hasAlpha())
             return false;
 
         if (!borderStyleFillsBorderArea(edges[adjacentSide].style))
@@ -1477,7 +1402,7 @@ static bool joinRequiresMitre(BoxSide side, BoxSide adjacentSide, const BorderEd
     if (allowOverdraw && willBeOverdrawn(side, adjacentSide, edges))
         return false;
 
-    if (!edgesShareColor(edges[side], edges[adjacentSide]))
+    if (!edges[side].sharesColorWith(edges[adjacentSide]))
         return true;
 
     if (borderStylesRequireMitre(side, adjacentSide, edges[side].style, edges[adjacentSide].style))
@@ -1650,7 +1575,7 @@ void RenderBoxModelObject::paintBorder(const PaintInfo& info, const LayoutRect&
         return;
 
     BorderEdge edges[4];
-    getBorderEdgeInfo(edges, style, includeLogicalLeftEdge, includeLogicalRightEdge);
+    style->getBorderEdgeInfo(edges, includeLogicalLeftEdge, includeLogicalRightEdge);
     RoundedRect outerBorder = style->getRoundedBorderFor(rect, includeLogicalLeftEdge, includeLogicalRightEdge);
     RoundedRect innerBorder = style->getRoundedInnerBorderFor(borderInnerRectAdjustedForBleedAvoidance(graphicsContext, rect, bleedAvoidance), includeLogicalLeftEdge, includeLogicalRightEdge);
 
@@ -2273,72 +2198,6 @@ void RenderBoxModelObject::clipBorderSideForComplexInnerPath(GraphicsContext* gr
         graphicsContext->clipOutRoundedRect(adjustedInnerRect);
 }
 
-void RenderBoxModelObject::getBorderEdgeInfo(BorderEdge edges[], const RenderStyle* style, bool includeLogicalLeftEdge, bool includeLogicalRightEdge) const
-{
-    bool horizontal = style->isHorizontalWritingMode();
-
-    edges[BSTop] = BorderEdge(style->borderTopWidth(),
-        resolveColor(style, CSSPropertyBorderTopColor),
-        style->borderTopStyle(),
-        style->borderTopIsTransparent(),
-        horizontal || includeLogicalLeftEdge);
-
-    edges[BSRight] = BorderEdge(style->borderRightWidth(),
-        resolveColor(style, CSSPropertyBorderRightColor),
-        style->borderRightStyle(),
-        style->borderRightIsTransparent(),
-        !horizontal || includeLogicalRightEdge);
-
-    edges[BSBottom] = BorderEdge(style->borderBottomWidth(),
-        resolveColor(style, CSSPropertyBorderBottomColor),
-        style->borderBottomStyle(),
-        style->borderBottomIsTransparent(),
-        horizontal || includeLogicalRightEdge);
-
-    edges[BSLeft] = BorderEdge(style->borderLeftWidth(),
-        resolveColor(style, CSSPropertyBorderLeftColor),
-        style->borderLeftStyle(),
-        style->borderLeftIsTransparent(),
-        !horizontal || includeLogicalLeftEdge);
-}
-
-bool RenderBoxModelObject::borderObscuresBackgroundEdge(const FloatSize& contextScale) const
-{
-    BorderEdge edges[4];
-    getBorderEdgeInfo(edges, style());
-
-    for (int i = BSTop; i <= BSLeft; ++i) {
-        const BorderEdge& currEdge = edges[i];
-        // FIXME: for vertical text
-        float axisScale = (i == BSTop || i == BSBottom) ? contextScale.height() : contextScale.width();
-        if (!currEdge.obscuresBackgroundEdge(axisScale))
-            return false;
-    }
-
-    return true;
-}
-
-bool RenderBoxModelObject::borderObscuresBackground() const
-{
-    if (!style()->hasBorder())
-        return false;
-
-    // Bail if we have any border-image for now. We could look at the image alpha to improve this.
-    if (style()->borderImage().image())
-        return false;
-
-    BorderEdge edges[4];
-    getBorderEdgeInfo(edges, style());
-
-    for (int i = BSTop; i <= BSLeft; ++i) {
-        const BorderEdge& currEdge = edges[i];
-        if (!currEdge.obscuresBackground())
-            return false;
-    }
-
-    return true;
-}
-
 bool RenderBoxModelObject::boxShadowShouldBeAppliedToBackground(BackgroundBleedAvoidance bleedAvoidance, InlineFlowBox* inlineFlowBox) const
 {
     if (bleedAvoidance != BackgroundBleedNone)