Bug 1468020 - Extract helper function to avoid duplicated code. r=mstange

MozReview-Commit-ID: JuirkAId7Km

--HG--
extra : rebase_source : c9d15e9fd4a823b321aff9c1048b659f87d03823

gfx/layers/wr/WebRenderCommandBuilder.cpp

@@ -248,6 +248,12 @@ struct Grouper
                                        wr::IpcResourceUpdateQueue& aResources,
                                        DIGroup* aGroup, nsDisplayList* aList,
                                        const StackingContextHelper& aSc);
+  // Helper method for processing a single inactive item
+  void ConstructItemInsideInactive(WebRenderCommandBuilder* aCommandBuilder,
+                                   wr::DisplayListBuilder& aBuilder,
+                                   wr::IpcResourceUpdateQueue& aResources,
+                                   DIGroup* aGroup, nsDisplayItem* aItem,
+                                   const StackingContextHelper& aSc);
   ~Grouper() {
   }
 };
@@ -972,7 +978,6 @@ Grouper::ConstructGroups(nsDisplayListBuilder* aDisplayListBuilder,
   nsDisplayItem* item = aList->GetBottom();
   nsDisplayItem* startOfCurrentGroup = item;
   while (item) {
-    nsDisplayList* children = item->GetChildren();
     if (IsItemProbablyActive(item, mDisplayListBuilder)) {
       currentGroup->EndGroup(aCommandBuilder->mManager, aDisplayListBuilder, aBuilder, aResources, this, startOfCurrentGroup, item);
       mClipManager.BeginItem(item, aSc);
@@ -1020,31 +1025,8 @@ Grouper::ConstructGroups(nsDisplayListBuilder* aDisplayListBuilder,
 
       startOfCurrentGroup = item->GetAbove();
     } else { // inactive item
-
-      if (item->GetType() == DisplayItemType::TYPE_TRANSFORM) {
-        nsDisplayTransform* transformItem = static_cast<nsDisplayTransform*>(item);
-        const Matrix4x4Flagged& t = transformItem->GetTransform();
-        Matrix t2d;
-        bool is2D = t.Is2D(&t2d);
-        MOZ_RELEASE_ASSERT(is2D, "Non-2D transforms should be treated as active");
-
-        // Save the current transform.
-        Matrix m = mTransform;
-
-        GP("t2d: %f %f\n", t2d._31, t2d._32);
-        mTransform.PreMultiply(t2d);
-        GP("mTransform: %f %f\n", mTransform._31, mTransform._32);
-        ConstructGroupInsideInactive(aCommandBuilder, aBuilder, aResources, currentGroup, children, aSc);
-
-        mTransform = m; // restore it
-      } else if (children) {
-        ConstructGroupInsideInactive(aCommandBuilder, aBuilder, aResources, currentGroup, children, aSc);
-      }
-
-      GP("Including %s of %d\n", item->Name(), currentGroup->mDisplayItems.Count());
-
-      BlobItemData* data = GetBlobItemDataForGroup(item, currentGroup);
-      currentGroup->ComputeGeometryChange(item, data, mTransform, mDisplayListBuilder); // we compute the geometry change here because we have the transform around still
+      ConstructItemInsideInactive(aCommandBuilder, aBuilder, aResources,
+                                  currentGroup, item, aSc);
     }
 
     item = item->GetAbove();
@@ -1062,40 +1044,48 @@ Grouper::ConstructGroupInsideInactive(WebRenderCommandBuilder* aCommandBuilder,
                                        DIGroup* aGroup, nsDisplayList* aList,
                                        const StackingContextHelper& aSc)
 {
-  DIGroup* currentGroup = aGroup;
-
   nsDisplayItem* item = aList->GetBottom();
   while (item) {
-    nsDisplayList* children = item->GetChildren();
-
-    if (item->GetType() == DisplayItemType::TYPE_TRANSFORM) {
-      nsDisplayTransform* transformItem = static_cast<nsDisplayTransform*>(item);
-      const Matrix4x4Flagged& t = transformItem->GetTransform();
-      Matrix t2d;
-      bool is2D = t.Is2D(&t2d);
-      MOZ_RELEASE_ASSERT(is2D, "Non-2D transforms should be treated as active");
-
-      Matrix m = mTransform;
-
-      GP("t2d: %f %f\n", t2d._31, t2d._32);
-      mTransform.PreMultiply(t2d);
-      GP("mTransform: %f %f\n", mTransform._31, mTransform._32);
-      ConstructGroupInsideInactive(aCommandBuilder, aBuilder, aResources, currentGroup, children, aSc);
-
-      mTransform = m;
-    } else if (children) {
-      ConstructGroupInsideInactive(aCommandBuilder, aBuilder, aResources, currentGroup, children, aSc);
-    }
-
-    GP("Including %s of %d\n", item->Name(), currentGroup->mDisplayItems.Count());
-
-    BlobItemData* data = GetBlobItemDataForGroup(item, currentGroup);
-    currentGroup->ComputeGeometryChange(item, data, mTransform, mDisplayListBuilder); // we compute the geometry change here because we have the transform around still
-
+    ConstructItemInsideInactive(aCommandBuilder, aBuilder, aResources,
+                                aGroup, item, aSc);
     item = item->GetAbove();
   }
 }
 
+void
+Grouper::ConstructItemInsideInactive(WebRenderCommandBuilder* aCommandBuilder,
+                                     wr::DisplayListBuilder& aBuilder,
+                                     wr::IpcResourceUpdateQueue& aResources,
+                                     DIGroup* aGroup, nsDisplayItem* aItem,
+                                     const StackingContextHelper& aSc)
+{
+  nsDisplayList* children = aItem->GetChildren();
+
+  if (aItem->GetType() == DisplayItemType::TYPE_TRANSFORM) {
+    nsDisplayTransform* transformItem = static_cast<nsDisplayTransform*>(aItem);
+    const Matrix4x4Flagged& t = transformItem->GetTransform();
+    Matrix t2d;
+    bool is2D = t.Is2D(&t2d);
+    MOZ_RELEASE_ASSERT(is2D, "Non-2D transforms should be treated as active");
+
+    Matrix m = mTransform;
+
+    GP("t2d: %f %f\n", t2d._31, t2d._32);
+    mTransform.PreMultiply(t2d);
+    GP("mTransform: %f %f\n", mTransform._31, mTransform._32);
+    ConstructGroupInsideInactive(aCommandBuilder, aBuilder, aResources, aGroup, children, aSc);
+
+    mTransform = m;
+  } else if (children) {
+    ConstructGroupInsideInactive(aCommandBuilder, aBuilder, aResources, aGroup, children, aSc);
+  }
+
+  GP("Including %s of %d\n", aItem->Name(), aGroup->mDisplayItems.Count());
+
+  BlobItemData* data = GetBlobItemDataForGroup(aItem, aGroup);
+  aGroup->ComputeGeometryChange(aItem, data, mTransform, mDisplayListBuilder); // we compute the geometry change here because we have the transform around still
+}
+
 /* This is just a copy of nsRect::ScaleToOutsidePixels with an offset added in.
  * The offset is applied just before the rounding. It's in the scaled space. */
 static mozilla::gfx::IntRect