Bug 1055760 - Update some more bits of compositor layer code to deal with multiple FrameMetrics. r=BenWa,botond

gfx/layers/Layers.cpp

@@ -713,6 +713,15 @@ Layer::HasScrollableFrameMetrics() const
   return false;
 }
 
+bool
+Layer::IsScrollInfoLayer() const
+{
+  // A scrollable container layer with no children
+  return AsContainerLayer()
+      && HasScrollableFrameMetrics()
+      && !GetFirstChild();
+}
+
 const Matrix4x4
 Layer::GetTransform() const
 {

gfx/layers/Layers.h

@@ -1203,6 +1203,7 @@ public:
   uint32_t GetFrameMetricsCount() const { return mFrameMetrics.Length(); }
   const nsTArray<FrameMetrics>& GetAllFrameMetrics() { return mFrameMetrics; }
   bool HasScrollableFrameMetrics() const;
+  bool IsScrollInfoLayer() const;
   const EventRegions& GetEventRegions() const { return mEventRegions; }
   ContainerLayer* GetParent() { return mParent; }
   Layer* GetNextSibling() { return mNextSibling; }

gfx/layers/composite/ContainerLayerComposite.cpp

@@ -23,6 +23,7 @@
 #include "mozilla/layers/TextureHost.h"  // for CompositingRenderTarget
 #include "mozilla/layers/AsyncPanZoomController.h"  // for AsyncPanZoomController
 #include "mozilla/layers/AsyncCompositionManager.h" // for ViewTransform
+#include "mozilla/layers/LayerMetricsWrapper.h" // for LayerMetricsWrapper
 #include "mozilla/mozalloc.h"           // for operator delete, etc
 #include "nsAutoPtr.h"                  // for nsRefPtr
 #include "nsDebug.h"                    // for NS_ASSERTION
@@ -254,10 +255,18 @@ RenderLayers(ContainerT* aContainer,
   // composited area. If the layer has a background color, fill these areas
   // with the background color by drawing a rectangle of the background color
   // over the entire composited area before drawing the container contents.
-  if (AsyncPanZoomController* apzc = aContainer->GetAsyncPanZoomController()) {
-    // Make sure not to do this on a "scrollinfo" layer (one with an empty visible
-    // region) because it's just a placeholder for APZ purposes.
-    if (apzc->IsOverscrolled() && !aContainer->GetVisibleRegion().IsEmpty()) {
+  // Make sure not to do this on a "scrollinfo" layer because it's just a
+  // placeholder for APZ purposes.
+  if (aContainer->HasScrollableFrameMetrics() && !aContainer->IsScrollInfoLayer()) {
+    bool overscrolled = false;
+    for (uint32_t i = 0; i < aContainer->GetFrameMetricsCount(); i++) {
+      AsyncPanZoomController* apzc = aContainer->GetAsyncPanZoomController(i);
+      if (apzc && apzc->IsOverscrolled()) {
+        overscrolled = true;
+        break;
+      }
+    }
+    if (overscrolled) {
       gfxRGBA color = aContainer->GetBackgroundColor();
       // If the background is completely transparent, there's no point in
       // drawing anything for it. Hopefully the layers behind, if any, will
@@ -421,8 +430,11 @@ ContainerRender(ContainerT* aContainer,
   }
   aContainer->mPrepared = nullptr;
 
-  if (aContainer->GetFrameMetrics().IsScrollable()) {
-    const FrameMetrics& frame = aContainer->GetFrameMetrics();
+  for (uint32_t i = 0; i < aContainer->GetFrameMetricsCount(); i++) {
+    if (!aContainer->GetFrameMetrics(i).IsScrollable()) {
+      continue;
+    }
+    const FrameMetrics& frame = aContainer->GetFrameMetrics(i);
     LayerRect layerBounds = frame.mCompositionBounds * ParentLayerToLayerScale(1.0);
     gfx::Rect rect(layerBounds.x, layerBounds.y, layerBounds.width, layerBounds.height);
     gfx::Rect clipRect(aClipRect.x, aClipRect.y, aClipRect.width, aClipRect.height);

gfx/layers/composite/LayerManagerComposite.cpp

@@ -797,7 +797,13 @@ LayerManagerComposite::ComputeRenderIntegrity()
     return 1.f;
   }
 
-  const FrameMetrics& rootMetrics = root->GetFrameMetrics();
+  FrameMetrics rootMetrics = LayerMetricsWrapper::TopmostScrollableMetrics(root);
+  if (!rootMetrics.IsScrollable()) {
+    // The root may not have any scrollable metrics, in which case rootMetrics
+    // will just be an empty FrameMetrics. Instead use the actual metrics from
+    // the root layer.
+    rootMetrics = LayerMetricsWrapper(root).Metrics();
+  }
   ParentLayerIntRect bounds = RoundedToInt(rootMetrics.mCompositionBounds);
   nsIntRect screenRect(bounds.x,
                        bounds.y,

gfx/layers/composite/ThebesLayerComposite.cpp

@@ -172,19 +172,6 @@ ThebesLayerComposite::GenEffectChain(EffectChain& aEffect)
   aEffect.mPrimaryEffect = mBuffer->GenEffect(GetEffectFilter());
 }
 
-CSSToScreenScale
-ThebesLayerComposite::GetEffectiveResolution()
-{
-  for (ContainerLayer* parent = GetParent(); parent; parent = parent->GetParent()) {
-    const FrameMetrics& metrics = parent->GetFrameMetrics();
-    if (metrics.GetScrollId() != FrameMetrics::NULL_SCROLL_ID) {
-      return metrics.GetZoom();
-    }
-  }
-
-  return CSSToScreenScale(1.0);
-}
-
 void
 ThebesLayerComposite::PrintInfo(std::stringstream& aStream, const char* aPrefix)
 {

gfx/layers/composite/ThebesLayerComposite.h

@@ -86,8 +86,6 @@ protected:
 private:
   gfx::Filter GetEffectFilter() { return gfx::Filter::LINEAR; }
 
-  CSSToScreenScale GetEffectiveResolution();
-
 private:
   RefPtr<ContentHost> mBuffer;
 };

gfx/layers/composite/TiledContentHost.cpp

@@ -9,6 +9,7 @@
 #include "mozilla/gfx/Matrix.h"         // for Matrix4x4
 #include "mozilla/layers/Compositor.h"  // for Compositor
 #include "mozilla/layers/Effects.h"     // for TexturedEffect, Effect, etc
+#include "mozilla/layers/LayerMetricsWrapper.h" // for LayerMetricsWrapper
 #include "mozilla/layers/TextureHostOGL.h"  // for TextureHostOGL
 #include "nsAString.h"
 #include "nsDebug.h"                    // for NS_WARNING
@@ -367,7 +368,7 @@ TiledContentHost::Composite(EffectChain& aEffectChain,
     // Background colors are only stored on scrollable layers. Grab
     // the one from the nearest scrollable ancestor layer.
     for (Layer* ancestor = GetLayer(); ancestor; ancestor = ancestor->GetParent()) {
-      if (ancestor->GetFrameMetrics().IsScrollable()) {
+      if (ancestor->HasScrollableFrameMetrics()) {
         backgroundColor = ancestor->GetBackgroundColor();
         break;
       }