Remove YGNode::setAndPropogateUseLegacyFlag

Summary:
`YGNode::setAndPropogateUseLegacyFlag` was only used for debugging purposes.
Here, we replace it with a free function in `Yoga.cpp`.

Now that we have events, the diffing functionality should go into a separate debugging package and be implemented in terms of an event listener. Let's do that as soon as we can support multiple listeners.

Reviewed By: SidharthGuglani

Differential Revision: D15316863

fbshipit-source-id: db929eba7c2de8aa1550e362dd2c175929c0070e

java/tests/com/facebook/yoga/YogaNodeTest.java

@@ -254,7 +254,7 @@ public class YogaNodeTest {
     root_child0_child0_child0.setFlexShrink(1);
     root_child0_child0.addChildAt(root_child0_child0_child0, 0);
     root.calculateLayout(YogaConstants.UNDEFINED, YogaConstants.UNDEFINED);
-    assertFalse(((YogaNodeJNIBase) root).getDoesLegacyStretchFlagAffectsLayout());
+    assertTrue(((YogaNodeJNIBase) root).getDoesLegacyStretchFlagAffectsLayout());
   }
 
   @Test

yoga/YGNode.cpp

@@ -539,13 +539,6 @@ bool YGNode::didUseLegacyFlag() {
   return didUseLegacyFlag;
 }
 
-void YGNode::setAndPropogateUseLegacyFlag(bool useLegacyFlag) {
-  config_->useLegacyStretchBehaviour = useLegacyFlag;
-  for_each(children_.begin(), children_.end(), [=](YGNodeRef childNode) {
-    childNode->getConfig()->useLegacyStretchBehaviour = useLegacyFlag;
-  });
-}
-
 void YGNode::setLayoutDoesLegacyFlagAffectsLayout(
     bool doesLegacyFlagAffectsLayout) {
   layout_.doesLegacyStretchFlagAffectsLayout = doesLegacyFlagAffectsLayout;

yoga/YGNode.h

@@ -292,7 +292,6 @@ public:
       const float mainSize,
       const float crossSize,
       const float ownerWidth);
-  void setAndPropogateUseLegacyFlag(bool useLegacyFlag);
   void setLayoutDoesLegacyFlagAffectsLayout(bool doesLegacyFlagAffectsLayout);
   void setLayoutDidUseLegacyFlag(bool didUseLegacyFlag);
   void markDirtyAndPropogateDownwards();

yoga/Yoga.cpp

@@ -3992,6 +3992,13 @@ static void YGRoundToPixelGrid(
   }
 }
 
+static void unsetUseLegacyFlagRecursively(YGNodeRef node) {
+  node->getConfig()->useLegacyStretchBehaviour = false;
+  for (auto child : node->getChildren()) {
+    unsetUseLegacyFlagRecursively(child);
+  }
+}
+
 void YGNodeCalculateLayoutWithContext(
     const YGNodeRef node,
     const float ownerWidth,
@@ -4096,16 +4103,16 @@ void YGNodeCalculateLayoutWithContext(
   // run experiments.
   if (node->getConfig()->shouldDiffLayoutWithoutLegacyStretchBehaviour &&
       node->didUseLegacyFlag()) {
-    const YGNodeRef originalNode = YGNodeDeepClone(node);
+    const YGNodeRef nodeWithoutLegacyFlag = YGNodeDeepClone(node);
-    originalNode->resolveDimension();
+    nodeWithoutLegacyFlag->resolveDimension();
     // Recursively mark nodes as dirty
-    originalNode->markDirtyAndPropogateDownwards();
+    nodeWithoutLegacyFlag->markDirtyAndPropogateDownwards();
     gCurrentGenerationCount++;
     // Rerun the layout, and calculate the diff
-    originalNode->setAndPropogateUseLegacyFlag(false);
+    unsetUseLegacyFlagRecursively(nodeWithoutLegacyFlag);
     YGMarkerLayoutData layoutMarkerData;
     if (YGLayoutNodeInternal(
-            originalNode,
+            nodeWithoutLegacyFlag,
             width,
             height,
             ownerDirection,
@@ -4115,37 +4122,37 @@ void YGNodeCalculateLayoutWithContext(
             ownerHeight,
             true,
             "initial",
-            originalNode->getConfig(),
+            nodeWithoutLegacyFlag->getConfig(),
             layoutMarkerData,
             layoutContext)) {
-      originalNode->setPosition(
+      nodeWithoutLegacyFlag->setPosition(
-          originalNode->getLayout().direction,
+          nodeWithoutLegacyFlag->getLayout().direction,
           ownerWidth,
           ownerHeight,
           ownerWidth);
       YGRoundToPixelGrid(
-          originalNode,
+          nodeWithoutLegacyFlag,
-          originalNode->getConfig()->pointScaleFactor,
+          nodeWithoutLegacyFlag->getConfig()->pointScaleFactor,
           0.0f,
           0.0f);
 
       // Set whether the two layouts are different or not.
       auto neededLegacyStretchBehaviour =
-          !originalNode->isLayoutTreeEqualToNode(*node);
+          !nodeWithoutLegacyFlag->isLayoutTreeEqualToNode(*node);
       node->setLayoutDoesLegacyFlagAffectsLayout(neededLegacyStretchBehaviour);
 
 #ifdef DEBUG
-      if (originalNode->getConfig()->printTree) {
+      if (nodeWithoutLegacyFlag->getConfig()->printTree) {
         YGNodePrint(
-            originalNode,
+            nodeWithoutLegacyFlag,
             (YGPrintOptions)(
                 YGPrintOptionsLayout | YGPrintOptionsChildren |
                 YGPrintOptionsStyle));
       }
 #endif
     }
-    YGConfigFreeRecursive(originalNode);
+    YGConfigFreeRecursive(nodeWithoutLegacyFlag);
-    YGNodeFreeRecursive(originalNode);
+    YGNodeFreeRecursive(nodeWithoutLegacyFlag);
   }
 }