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

3 files changed, 40 insertions, 5 deletions

diff --git a/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp b/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
index f2163cc..8ea274e 100644
--- a/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
@@ -227,6 +227,9 @@ void GraphicsLayerAndroid::updateFixedPosition()
     RenderLayer* renderLayer = renderLayerFromClient(m_client);
     RenderView* view = static_cast<RenderView*>(renderLayer->renderer());
 
+    // We will need the Iframe flag in the LayerAndroid tree for fixed position
+    if (view && view->isRenderIFrame())
+        m_contentLayer->setIsIframe(true);
     // If we are a fixed position layer, just set it
     if (view->isPositioned() && view->style()->position() == FixedPosition) {
         // We need to get the passed CSS properties for the element
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());
diff --git a/WebCore/platform/graphics/android/LayerAndroid.h b/WebCore/platform/graphics/android/LayerAndroid.h
index 7d4eac9..c315488 100644
--- a/WebCore/platform/graphics/android/LayerAndroid.h
+++ b/WebCore/platform/graphics/android/LayerAndroid.h
@@ -202,7 +202,7 @@ public:
         This call is recursive, so it should be called on the root of the
         hierarchy.
     */
-    void updateFixedLayersPositions(const SkRect& viewPort);
+    void updateFixedLayersPositions(SkRect viewPort, LayerAndroid* parentIframeLayer = 0);
 
     /** Call this to update the position attribute, so that later calls
         like bounds() will report the corrected position.
@@ -248,6 +248,8 @@ public:
 
     RenderLayer* owningLayer() const { return m_owningLayer; }
 
+    void setIsIframe(bool isIframe) { m_isIframe = isIframe; }
+
 protected:
     virtual void onDraw(SkCanvas*, SkScalar opacity);
 
@@ -266,6 +268,7 @@ private:
     bool m_haveClip;
     bool m_isFixed;
     bool m_backgroundColorSet;
+    bool m_isIframe;
 
     SkLength m_fixedLeft;
     SkLength m_fixedTop;
@@ -277,6 +280,7 @@ private:
     SkLength m_fixedMarginBottom;
     SkRect m_fixedRect;
 
+    SkPoint m_iframeOffset;
     // When fixed element is undefined or auto, the render layer's position
     // is needed for offset computation
     IntPoint m_renderLayerPos;