Implement flex properties in java version as well

Summary: Implement flexShrink flexGrow and flexBasis in java as well because it will take a bit until the java code is removed

Reviewed By: lucasr

Differential Revision: D3753231

fbshipit-source-id: ea41d887cd99d1f03d2bc876a2fd7141dbe48320

java/com/facebook/csslayout/CSSNode.java

@@ -361,17 +361,72 @@ public class CSSNode implements CSSNodeAPI<CSSNode> {
    */
   @Override
   public float getFlex() {
-    return style.flex;
+    if (style.flexGrow > 0) {
+      return style.flexGrow;
+    } else if (style.flexShrink > 0) {
+      return -style.flexShrink;
+    }
+
+    return 0;
   }
 
   @Override
   public void setFlex(float flex) {
-    if (!valuesEqual(style.flex, flex)) {
-      style.flex = flex;
+    if (CSSConstants.isUndefined(flex) || flex == 0) {
+      setFlexGrow(0);
+      setFlexShrink(0);
+      setFlexBasis(CSSConstants.UNDEFINED);
+    } else if (flex > 0) {
+      setFlexGrow(flex);
+      setFlexShrink(0);
+      setFlexBasis(0);
+    } else {
+      setFlexGrow(0);
+      setFlexShrink(-flex);
+      setFlexBasis(CSSConstants.UNDEFINED);
+    }
+  }
+
+  @Override
+  public float getFlexGrow() {
+    return style.flexGrow;
+  }
+
+  @Override
+  public void setFlexGrow(float flexGrow) {
+    if (!valuesEqual(style.flexGrow, flexGrow)) {
+      style.flexGrow = flexGrow;
       dirty();
     }
   }
 
+  @Override
+  public float getFlexShrink() {
+    return style.flexShrink;
+  }
+
+  @Override
+  public void setFlexShrink(float flexShrink) {
+    if (!valuesEqual(style.flexShrink, flexShrink)) {
+      style.flexShrink = flexShrink;
+      dirty();
+    }
+  }
+
+  @Override
+  public float getFlexBasis() {
+    return style.flexBasis;
+  }
+
+  @Override
+  public void setFlexBasis(float flexBasis) {
+    if (!valuesEqual(style.flexBasis, flexBasis)) {
+      style.flexBasis = flexBasis;
+      dirty();
+    }
+  }
+
+
   /**
    * Get this node's margin, as defined by style + default margin.
    */