Expose layout diffing flag to java

Summary:
This diff exposes `shouldDiffLayoutWithoutLegacyStretchBehaviour` from YGConfig and `doesLegacyStretchFlagAffectsLayout` from YGLayout to YogaConfig and YogaNode respectively

Also added a positive test case. Didn't find the negative test case example. @[508947467:ianc] or @[759512522:emilsj], can you suggest a negative test case example.

Reviewed By: emilsjolander

Differential Revision: D7272067

fbshipit-source-id: e67e82eb057e4c7124904c715f9dca4dcfea21ea

java/com/facebook/yoga/YogaConfig.java

@@ -74,6 +74,19 @@ public class YogaConfig {
     jni_YGConfigSetUseLegacyStretchBehaviour(mNativePointer, useLegacyStretchBehaviour);
   }
 
+  private native void jni_YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour(
+      long nativePointer, boolean shouldDiffLayoutWithoutLegacyStretchBehaviour);
+  /**
+   * If this flag is set then yoga would diff the layout without legacy flag and would set a bool in
+   * YogaNode(mDoesLegacyStretchFlagAffectsLayout) with true if the layouts were different and false
+   * if not
+   */
+  public void setShouldDiffLayoutWithoutLegacyStretchBehaviour(
+      boolean shouldDiffLayoutWithoutLegacyStretchBehaviour) {
+    jni_YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour(
+        mNativePointer, shouldDiffLayoutWithoutLegacyStretchBehaviour);
+  }
+
   private native void jni_YGConfigSetLogger(long nativePointer, Object logger);
   public void setLogger(YogaLogger logger) {
     mLogger = logger;

java/com/facebook/yoga/YogaNode.java

@@ -82,6 +82,7 @@ public class YogaNode implements Cloneable {
   private int mLayoutDirection = 0;
   @DoNotStrip
   private boolean mHasNewLayout = true;
+  @DoNotStrip private boolean mDoesLegacyStretchFlagAffectsLayout = false;
 
   private native long jni_YGNodeNew();
   public YogaNode() {
@@ -136,6 +137,7 @@ public class YogaNode implements Cloneable {
     mMeasureFunction = null;
     mBaselineFunction = null;
     mData = null;
+    mDoesLegacyStretchFlagAffectsLayout = false;
 
     jni_YGNodeReset(mNativePointer);
   }
@@ -573,6 +575,10 @@ public class YogaNode implements Cloneable {
     return mHeight;
   }
 
+  public boolean getDoesLegacyStretchFlagAffectsLayout() {
+    return mDoesLegacyStretchFlagAffectsLayout;
+  }
+
   public float getLayoutMargin(YogaEdge edge) {
     switch (edge) {
       case LEFT:

java/jni/YGJNI.cpp

@@ -67,6 +67,9 @@ static void YGTransferLayoutOutputsRecursive(YGNodeRef root) {
 
       static auto edgeSetFlagField = obj->getClass()->getField<jint>("mEdgeSetFlag");
       static auto hasNewLayoutField = obj->getClass()->getField<jboolean>("mHasNewLayout");
+      static auto doesLegacyStretchBehaviour =
+          obj->getClass()->getField<jboolean>(
+              "mDoesLegacyStretchFlagAffectsLayout");
 
       /* Those flags needs be in sync with YogaNode.java */
       const int MARGIN = 1;
@@ -79,12 +82,19 @@ static void YGTransferLayoutOutputsRecursive(YGNodeRef root) {
       obj->setFieldValue(heightField, YGNodeLayoutGetHeight(root));
       obj->setFieldValue(leftField, YGNodeLayoutGetLeft(root));
       obj->setFieldValue(topField, YGNodeLayoutGetTop(root));
+      obj->setFieldValue<jboolean>(
+          doesLegacyStretchBehaviour,
+          YGNodeLayoutGetDidLegacyStretchFlagAffectLayout(root));
 
       if ((hasEdgeSetFlag & MARGIN) == MARGIN) {
-        obj->setFieldValue(marginLeftField, YGNodeLayoutGetMargin(root, YGEdgeLeft));
+        obj->setFieldValue(
-        obj->setFieldValue(marginTopField, YGNodeLayoutGetMargin(root, YGEdgeTop));
+            marginLeftField, YGNodeLayoutGetMargin(root, YGEdgeLeft));
-        obj->setFieldValue(marginRightField, YGNodeLayoutGetMargin(root, YGEdgeRight));
+        obj->setFieldValue(
-        obj->setFieldValue(marginBottomField, YGNodeLayoutGetMargin(root, YGEdgeBottom));
+            marginTopField, YGNodeLayoutGetMargin(root, YGEdgeTop));
+        obj->setFieldValue(
+            marginRightField, YGNodeLayoutGetMargin(root, YGEdgeRight));
+        obj->setFieldValue(
+            marginBottomField, YGNodeLayoutGetMargin(root, YGEdgeBottom));
       }
 
       if ((hasEdgeSetFlag & PADDING) == PADDING) {
@@ -467,6 +477,14 @@ void jni_YGConfigSetExperimentalFeatureEnabled(alias_ref<jobject>,
                                         enabled);
 }
 
+void jni_YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour(
+    alias_ref<jobject>,
+    jlong nativePointer,
+    jboolean enabled) {
+  const YGConfigRef config = _jlong2YGConfigRef(nativePointer);
+  YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour(config, enabled);
+}
+
 void jni_YGConfigSetUseWebDefaults(alias_ref<jobject>,
                                    jlong nativePointer,
                                    jboolean useWebDefaults) {
@@ -624,16 +642,19 @@ jint JNI_OnLoad(JavaVM *vm, void *) {
             YGMakeNativeMethod(jni_YGNodePrint),
             YGMakeNativeMethod(jni_YGNodeClone),
         });
-    registerNatives("com/facebook/yoga/YogaConfig",
+    registerNatives(
-                    {
+        "com/facebook/yoga/YogaConfig",
-                        YGMakeNativeMethod(jni_YGConfigNew),
+        {
-                        YGMakeNativeMethod(jni_YGConfigFree),
+            YGMakeNativeMethod(jni_YGConfigNew),
-                        YGMakeNativeMethod(jni_YGConfigSetExperimentalFeatureEnabled),
+            YGMakeNativeMethod(jni_YGConfigFree),
-                        YGMakeNativeMethod(jni_YGConfigSetUseWebDefaults),
+            YGMakeNativeMethod(jni_YGConfigSetExperimentalFeatureEnabled),
-                        YGMakeNativeMethod(jni_YGConfigSetPointScaleFactor),
+            YGMakeNativeMethod(jni_YGConfigSetUseWebDefaults),
-                        YGMakeNativeMethod(jni_YGConfigSetUseLegacyStretchBehaviour),
+            YGMakeNativeMethod(jni_YGConfigSetPointScaleFactor),
-                        YGMakeNativeMethod(jni_YGConfigSetLogger),
+            YGMakeNativeMethod(jni_YGConfigSetUseLegacyStretchBehaviour),
-                        YGMakeNativeMethod(jni_YGConfigSetHasNodeClonedFunc),
+            YGMakeNativeMethod(jni_YGConfigSetLogger),
-                    });
+            YGMakeNativeMethod(jni_YGConfigSetHasNodeClonedFunc),
+            YGMakeNativeMethod(
+                jni_YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour),
+        });
   });
 }

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

@@ -8,6 +8,7 @@
 package com.facebook.yoga;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
@@ -302,4 +303,27 @@ public class YogaNodeTest {
     }
     fail("YogaConfig leaked");
   }
+
+  @Test
+  public void testFlagShouldDiffLayoutWithoutLegacyStretchBehaviour() throws Exception {
+    YogaConfig config = new YogaConfig();
+    config.setShouldDiffLayoutWithoutLegacyStretchBehaviour(true);
+    config.setUseLegacyStretchBehaviour(true);
+    YogaNode root = new YogaNode(config);
+    root.setWidth(500);
+    root.setHeight(500);
+    YogaNode root_child0 = new YogaNode(config);
+    root_child0.setAlignItems(YogaAlign.FLEX_START);
+    root.addChildAt(root_child0, 0);
+    YogaNode root_child0_child0 = new YogaNode(config);
+    root_child0_child0.setFlexGrow(1);
+    root_child0_child0.setFlexShrink(1);
+    root_child0.addChildAt(root_child0_child0, 0);
+    YogaNode root_child0_child0_child0 = new YogaNode(config);
+    root_child0_child0_child0.setFlexGrow(1);
+    root_child0_child0_child0.setFlexShrink(1);
+    root_child0_child0.addChildAt(root_child0_child0_child0, 0);
+    root.calculateLayout(YogaConstants.UNDEFINED, YogaConstants.UNDEFINED);
+    assertFalse(root.getDoesLegacyStretchFlagAffectsLayout());
+  }
 }

yoga/Yoga.cpp

@@ -905,6 +905,10 @@ YG_NODE_LAYOUT_RESOLVED_PROPERTY_IMPL(float, Margin, margin);
 YG_NODE_LAYOUT_RESOLVED_PROPERTY_IMPL(float, Border, border);
 YG_NODE_LAYOUT_RESOLVED_PROPERTY_IMPL(float, Padding, padding);
 
+bool YGNodeLayoutGetDidLegacyStretchFlagAffectLayout(const YGNodeRef node) {
+  return node->getLayout().doesLegacyStretchFlagAffectsLayout;
+}
+
 uint32_t gCurrentGenerationCount = 0;
 
 bool YGLayoutNodeInternal(const YGNodeRef node,
@@ -3842,6 +3846,12 @@ void YGConfigSetLogger(const YGConfigRef config, YGLogger logger) {
   }
 }
 
+void YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour(
+    const YGConfigRef config,
+    const bool shouldDiffLayout) {
+  config->shouldDiffLayoutWithoutLegacyStretchBehaviour = shouldDiffLayout;
+}
+
 static void YGVLog(const YGConfigRef config,
                    const YGNodeRef node,
                    YGLogLevel level,

yoga/Yoga.h

@@ -236,6 +236,7 @@ YG_NODE_LAYOUT_PROPERTY(float, Width);
 YG_NODE_LAYOUT_PROPERTY(float, Height);
 YG_NODE_LAYOUT_PROPERTY(YGDirection, Direction);
 YG_NODE_LAYOUT_PROPERTY(bool, HadOverflow);
+bool YGNodeLayoutGetDidLegacyStretchFlagAffectLayout(const YGNodeRef node);
 
 // Get the computed values for these nodes after performing layout. If they were set using
 // point values then the returned value will be the same as YGNodeStyleGetXXX. However if
@@ -253,10 +254,12 @@ WIN_EXPORT void YGAssertWithNode(const YGNodeRef node, const bool condition, con
 WIN_EXPORT void YGAssertWithConfig(const YGConfigRef config,
                                    const bool condition,
                                    const char *message);
-
 // Set this to number of pixels in 1 point to round calculation results
 // If you want to avoid rounding - set PointScaleFactor to 0
 WIN_EXPORT void YGConfigSetPointScaleFactor(const YGConfigRef config, const float pixelsInPoint);
+void YGConfigSetShouldDiffLayoutWithoutLegacyStretchBehaviour(
+    const YGConfigRef config,
+    const bool shouldDiffLayout);
 
 // Yoga previously had an error where containers would take the maximum space possible instead of
 // the minimum