Expose layout paddding in java api

Summary: Expose layout padding api from D4376572

Reviewed By: passy

Differential Revision: D4377069

fbshipit-source-id: 2e0c04104560e1be586562b27b3457576590dc18

java/com/facebook/yoga/YogaNode.java

@@ -69,6 +69,14 @@ public class YogaNode implements YogaNodeAPI<YogaNode> {
   @DoNotStrip
   private float mLeft = YogaConstants.UNDEFINED;
   @DoNotStrip
+  private float mPaddingLeft = 0;
+  @DoNotStrip
+  private float mPaddingTop = 0;
+  @DoNotStrip
+  private float mPaddingRight = 0;
+  @DoNotStrip
+  private float mPaddingBottom = 0;
+  @DoNotStrip
   private int mLayoutDirection = 0;
 
   private native long jni_YGNodeNew();
@@ -564,6 +572,26 @@ public class YogaNode implements YogaNodeAPI<YogaNode> {
     return mHeight;
   }
 
+  @Override
+  public float getLayoutPadding(YogaEdge edge) {
+    switch (edge) {
+      case LEFT:
+        return mPaddingLeft;
+      case TOP:
+        return mPaddingTop;
+      case RIGHT:
+        return mPaddingRight;
+      case BOTTOM:
+        return mPaddingBottom;
+      case START:
+        return getLayoutDirection() == YogaDirection.RTL ? mPaddingRight : mPaddingLeft;
+      case END:
+        return getLayoutDirection() == YogaDirection.RTL ? mPaddingLeft : mPaddingRight;
+      default:
+        throw new IllegalArgumentException("Cannot get layout paddings of multi-edge shorthands");
+    }
+  }
+
   @Override
   public YogaDirection getLayoutDirection() {
     return YogaDirection.values()[mLayoutDirection];

java/com/facebook/yoga/YogaNodeAPI.java

@@ -81,6 +81,7 @@ public interface YogaNodeAPI<YogaNodeType extends YogaNodeAPI> {
   float getLayoutY();
   float getLayoutWidth();
   float getLayoutHeight();
+  float getLayoutPadding(YogaEdge edge);
   YogaDirection getLayoutDirection();
   YogaOverflow getOverflow();
   void setOverflow(YogaOverflow overflow);

java/jni/YGJNI.cpp

@@ -30,10 +30,21 @@ static void YGTransferLayoutOutputsRecursive(YGNodeRef root) {
     static auto leftField = obj->getClass()->getField<jfloat>("mLeft");
     static auto topField = obj->getClass()->getField<jfloat>("mTop");
 
+    static auto paddingLeftField = obj->getClass()->getField<jfloat>("mPaddingLeft");
+    static auto paddingTopField = obj->getClass()->getField<jfloat>("mPaddingTop");
+    static auto paddingRightField = obj->getClass()->getField<jfloat>("mPaddingRight");
+    static auto paddingBottomField = obj->getClass()->getField<jfloat>("mPaddingBottom");
+
     obj->setFieldValue(widthField, YGNodeLayoutGetWidth(root));
     obj->setFieldValue(heightField, YGNodeLayoutGetHeight(root));
     obj->setFieldValue(leftField, YGNodeLayoutGetLeft(root));
     obj->setFieldValue(topField, YGNodeLayoutGetTop(root));
+
+    obj->setFieldValue(paddingLeftField, YGNodeLayoutGetPadding(root, YGEdgeLeft));
+    obj->setFieldValue(paddingTopField, YGNodeLayoutGetPadding(root, YGEdgeTop));
+    obj->setFieldValue(paddingRightField, YGNodeLayoutGetPadding(root, YGEdgeRight));
+    obj->setFieldValue(paddingBottomField, YGNodeLayoutGetPadding(root, YGEdgeBottom));
+
     YGTransferLayoutDirection(root, obj);
 
     for (uint32_t i = 0; i < YGNodeGetChildCount(root); i++) {

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

@@ -138,4 +138,21 @@ public class YogaNodeTest {
     node0.copyStyle(node1);
     assertEquals(100, (int) node0.getMaxHeight().value);
   }
+
+  @Test
+  public void testLayoutPadding() {
+    final YogaNode node = new YogaNode();
+    node.setWidth(100);
+    node.setHeight(100);
+    node.setPadding(YogaEdge.START, 1);
+    node.setPadding(YogaEdge.END, 2);
+    node.setPadding(YogaEdge.TOP, 3);
+    node.setPadding(YogaEdge.BOTTOM, 4);
+    node.calculateLayout();
+
+    assertEquals(1, (int) node.getLayoutPadding(YogaEdge.LEFT));
+    assertEquals(2, (int) node.getLayoutPadding(YogaEdge.RIGHT));
+    assertEquals(3, (int) node.getLayoutPadding(YogaEdge.TOP));
+    assertEquals(4, (int) node.getLayoutPadding(YogaEdge.BOTTOM));
+  }
 }