Implement margin for fixed elements.

Last missing piece to fix Bug:2252505

Billmonk.com uses a centered fixed element with negative margins,
and we were not accounting for those...
Accounting for the margins move the fixed layer at the same place
than webkit think it is, and therefore clicks do work.

Change-Id: I6a736d06273df7d2bbc597c17ce042aa8b75b4e2

1 files changed, 12 insertions, 4 deletions

diff --git a/WebCore/platform/graphics/android/LayerAndroid.cpp b/WebCore/platform/graphics/android/LayerAndroid.cpp
index 3b1743d..bfb086c 100644
--- a/WebCore/platform/graphics/android/LayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/LayerAndroid.cpp
@@ -79,6 +79,10 @@ LayerAndroid::LayerAndroid(const LayerAndroid& layer) : SkLayer(layer),
     m_fixedTop = layer.m_fixedTop;
     m_fixedRight = layer.m_fixedRight;
     m_fixedBottom = layer.m_fixedBottom;
+    m_fixedMarginLeft = layer.m_fixedMarginLeft;
+    m_fixedMarginTop = layer.m_fixedMarginTop;
+    m_fixedMarginRight = layer.m_fixedMarginRight;
+    m_fixedMarginBottom = layer.m_fixedMarginBottom;
     m_fixedWidth = layer.m_fixedWidth;
     m_fixedHeight = layer.m_fixedHeight;
 
@@ -256,14 +260,14 @@ void LayerAndroid::updateFixedLayersPositions(const SkRect& viewport)
         float y = dy;
 
         if (m_fixedLeft.defined())
-            x += m_fixedLeft.calcFloatValue(w);
+            x += m_fixedMarginLeft.calcFloatValue(w) + m_fixedLeft.calcFloatValue(w);
         else if (m_fixedRight.defined())
-            x += w - m_fixedRight.calcFloatValue(w) - m_fixedWidth;
+            x += w - m_fixedMarginRight.calcFloatValue(w) - m_fixedRight.calcFloatValue(w) - m_fixedWidth;
 
         if (m_fixedTop.defined())
-            y += m_fixedTop.calcFloatValue(h);
+            y += m_fixedMarginTop.calcFloatValue(h) + m_fixedTop.calcFloatValue(h);
         else if (m_fixedBottom.defined())
-            y += h - m_fixedBottom.calcFloatValue(h) - m_fixedHeight;
+            y += h - m_fixedMarginBottom.calcFloatValue(h) - m_fixedBottom.calcFloatValue(h) - m_fixedHeight;
 
         this->setPosition(x, y);
     }
@@ -492,6 +496,10 @@ void LayerAndroid::dumpLayers(FILE* file, int indentLevel) const
     writeLength(file, indentLevel + 1, "fixedTop", m_fixedTop);
     writeLength(file, indentLevel + 1, "fixedRight", m_fixedRight);
     writeLength(file, indentLevel + 1, "fixedBottom", m_fixedBottom);
+    writeLength(file, indentLevel + 1, "fixedMarginLeft", m_fixedMarginLeft);
+    writeLength(file, indentLevel + 1, "fixedMarginTop", m_fixedMarginTop);
+    writeLength(file, indentLevel + 1, "fixedMarginRight", m_fixedMarginRight);
+    writeLength(file, indentLevel + 1, "fixedMarginBottom", m_fixedMarginBottom);
     writeIntVal(file, indentLevel + 1, "fixedWidth", m_fixedWidth);
     writeIntVal(file, indentLevel + 1, "fixedHeight", m_fixedHeight);