Fixed element in iframe support

We first identify the iframe for each LayerAndroid.
Then when traverse to update the fixed elements, we use the parent iframe
info to update the fixed position.

Change-Id: I13e0333fc6453414cea2343a787c41d525f6e3d2

1 files changed, 32 insertions, 4 deletions

diff --git a/WebCore/platform/graphics/android/LayerAndroid.cpp b/WebCore/platform/graphics/android/LayerAndroid.cpp
index f969999..3706d20 100644
--- a/WebCore/platform/graphics/android/LayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/LayerAndroid.cpp
@@ -65,6 +65,7 @@ LayerAndroid::LayerAndroid(RenderLayer* owner, bool isRootLayer) : SkLayer(),
     m_isRootLayer(isRootLayer),
     m_haveClip(false),
     m_isFixed(false),
+    m_isIframe(false),
     m_preserves3D(false),
     m_anchorPointZ(0),
     m_recordingPicture(0),
@@ -83,7 +84,7 @@ LayerAndroid::LayerAndroid(RenderLayer* owner, bool isRootLayer) : SkLayer(),
 
     m_preserves3D = false;
     m_dirty = false;
-
+    m_iframeOffset.set(0,0);
 #ifdef DEBUG_COUNT
     ClassTracker::instance()->increment("LayerAndroid");
 #endif
@@ -92,6 +93,7 @@ LayerAndroid::LayerAndroid(RenderLayer* owner, bool isRootLayer) : SkLayer(),
 LayerAndroid::LayerAndroid(const LayerAndroid& layer) : SkLayer(layer),
     m_isRootLayer(layer.m_isRootLayer),
     m_haveClip(layer.m_haveClip),
+    m_isIframe(layer.m_isIframe),
     m_extra(0), // deliberately not copied
     m_uniqueId(layer.m_uniqueId),
     m_drawingTexture(0),
@@ -115,7 +117,7 @@ LayerAndroid::LayerAndroid(const LayerAndroid& layer) : SkLayer(layer),
     m_fixedMarginRight = layer.m_fixedMarginRight;
     m_fixedMarginBottom = layer.m_fixedMarginBottom;
     m_fixedRect = layer.m_fixedRect;
-
+    m_iframeOffset = layer.m_iframeOffset;
     m_recordingPicture = layer.m_recordingPicture;
     SkSafeRef(m_recordingPicture);
 
@@ -144,6 +146,7 @@ LayerAndroid::LayerAndroid(SkPicture* picture) : SkLayer(),
     m_isRootLayer(true),
     m_haveClip(false),
     m_isFixed(false),
+    m_isIframe(false),
     m_recordingPicture(picture),
     m_contentsImage(0),
     m_extra(0),
@@ -158,6 +161,7 @@ LayerAndroid::LayerAndroid(SkPicture* picture) : SkLayer(),
     m_backgroundColor = 0;
     m_dirty = false;
     SkSafeRef(m_recordingPicture);
+    m_iframeOffset.set(0,0);
 #ifdef DEBUG_COUNT
     ClassTracker::instance()->increment("LayerAndroid");
 #endif
@@ -466,9 +470,31 @@ const LayerAndroid* LayerAndroid::find(int* xPtr, int* yPtr, SkPicture* root) co
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void LayerAndroid::updateFixedLayersPositions(const SkRect& viewport)
+void LayerAndroid::updateFixedLayersPositions(SkRect viewport, LayerAndroid* parentIframeLayer)
 {
+    // If this is an iframe, accumulate the offset from the parent with
+    // current position, and change the parent pointer.
+    if (m_isIframe) {
+        // If this is the top level, take the current position
+        SkPoint parentOffset;
+        parentOffset.set(0,0);
+        if (parentIframeLayer)
+            parentOffset = parentIframeLayer->getPosition();
+
+        m_iframeOffset = parentOffset + getPosition();
+
+        parentIframeLayer = this;
+    }
+
     if (m_isFixed) {
+        // So if this is a fixed layer inside a iframe, use the iframe offset
+        // and the iframe's size as the viewport and pass to the children
+        if (parentIframeLayer) {
+            viewport = SkRect::MakeXYWH(parentIframeLayer->m_iframeOffset.fX,
+                                 parentIframeLayer->m_iframeOffset.fY,
+                                 parentIframeLayer->getSize().width(),
+                                 parentIframeLayer->getSize().height());
+        }
         float w = viewport.width();
         float h = viewport.height();
         float dx = viewport.fLeft;
@@ -500,7 +526,7 @@ void LayerAndroid::updateFixedLayersPositions(const SkRect& viewport)
 
     int count = this->countChildren();
     for (int i = 0; i < count; i++)
-        this->getChild(i)->updateFixedLayersPositions(viewport);
+        this->getChild(i)->updateFixedLayersPositions(viewport, parentIframeLayer);
 }
 
 void LayerAndroid::updatePositions()
@@ -1207,6 +1233,8 @@ void LayerAndroid::dumpLayers(FILE* file, int indentLevel) const
     writeIntVal(file, indentLevel + 1, "haveClip", m_haveClip);
     writeIntVal(file, indentLevel + 1, "isRootLayer", m_isRootLayer);
     writeIntVal(file, indentLevel + 1, "isFixed", m_isFixed);
+    writeIntVal(file, indentLevel + 1, "m_isIframe", m_isIframe);
+    writePoint(file, indentLevel + 1, "m_iframeOffset", m_iframeOffset);
 
     writeFloatVal(file, indentLevel + 1, "opacity", getOpacity());
     writeSize(file, indentLevel + 1, "size", getSize());