Add support for aspectRatio style prop

Summary:
Expose aspectRatio style prop from css-layout to React Native.

This means the following will now work:

    <View style={{backgroundColor: 'blue', aspectRatio: 1}}/>

Reviewed By: javache

Differential Revision: D4226472

fbshipit-source-id: c8709a7c0abbf77089a4e867879b42dcd9116f65

Libraries/StyleSheet/LayoutPropTypes.js

@@ -365,6 +365,21 @@ var LayoutPropTypes = {
   flexShrink: ReactPropTypes.number,
   flexBasis: ReactPropTypes.number,
 
+  /**
+   * Aspect ratio control the size of the undefined dimension of a node. Aspect ratio is a
+   * non-standard property only available in react native and not CSS.
+   *
+   * - On a node with a set width/height aspect ratio control the size of the unset dimension
+   * - On a node with a set flex basis aspect ratio controls the size of the node in the cross axis
+   *   if unset
+   * - On a node with a measure function aspect ratio works as though the measure function measures
+   *   the flex basis
+   * - On a node with flex grow/shrink aspect ratio controls the size of the node in the cross axis
+   *   if unset
+   * - Aspect ratio takes min/max dimensions into account
+   */
+  aspectRatio: ReactPropTypes.number,
+
   /** `zIndex` controls which components display on top of others.
    *  Normally, you don't use `zIndex`. Components render according to
    *  their order in the document tree, so later components draw over

React/Views/RCTShadowView.h

@@ -138,6 +138,8 @@ typedef void (^RCTApplierBlock)(NSDictionary<NSNumber *, UIView *> *viewRegistry
 @property (nonatomic, assign) float flexShrink;
 @property (nonatomic, assign) float flexBasis;
 
+@property (nonatomic, assign) float aspectRatio;
+
 - (void)setFlex:(float)flex;
 
 /**

React/Views/RCTShadowView.m

@@ -652,6 +652,7 @@ RCT_STYLE_PROPERTY(AlignItems, alignItems, AlignItems, CSSAlign)
 RCT_STYLE_PROPERTY(Position, position, PositionType, CSSPositionType)
 RCT_STYLE_PROPERTY(FlexWrap, flexWrap, FlexWrap, CSSWrap)
 RCT_STYLE_PROPERTY(Overflow, overflow, Overflow, CSSOverflow)
+RCT_STYLE_PROPERTY(AspectRatio, aspectRatio, AspectRatio, float)
 
 - (void)setBackgroundColor:(UIColor *)color
 {

React/Views/RCTViewManager.m

@@ -294,6 +294,7 @@ RCT_EXPORT_SHADOW_PROPERTY(justifyContent, CSSJustify)
 RCT_EXPORT_SHADOW_PROPERTY(alignItems, CSSAlign)
 RCT_EXPORT_SHADOW_PROPERTY(alignSelf, CSSAlign)
 RCT_EXPORT_SHADOW_PROPERTY(position, CSSPositionType)
+RCT_EXPORT_SHADOW_PROPERTY(aspectRatio, float)
 
 RCT_EXPORT_SHADOW_PROPERTY(overflow, CSSOverflow)
 

ReactAndroid/src/main/java/com/facebook/react/uimanager/LayoutShadowNode.java

@@ -112,6 +112,11 @@ public class LayoutShadowNode extends ReactShadowNode {
     super.setFlexBasis(flexBasis);
   }
 
+  @ReactProp(name = ViewProps.ASPECT_RATIO, defaultFloat = CSSConstants.UNDEFINED)
+  public void setAspectRatio(float aspectRatio) {
+    setStyleAspectRatio(aspectRatio);
+  }
+
   @ReactProp(name = ViewProps.FLEX_DIRECTION)
   public void setFlexDirection(@Nullable String flexDirection) {
     if (isVirtual()) {

ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactShadowNode.java

@@ -576,6 +576,10 @@ public class ReactShadowNode {
     mCSSNode.setFlexBasis(flexBasis);
   }
 
+  public void setStyleAspectRatio(float aspectRatio) {
+    mCSSNode.setStyleAspectRatio(aspectRatio);
+  }
+
   public void setFlexDirection(CSSFlexDirection flexDirection) {
     mCSSNode.setFlexDirection(flexDirection);
   }

ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewProps.java

@@ -64,6 +64,8 @@ public class ViewProps {
   public static final String MIN_HEIGHT = "minHeight";
   public static final String MAX_HEIGHT = "maxHeight";
 
+  public static final String ASPECT_RATIO = "aspectRatio";
+
   // Props that affect more than just layout
   public static final String ENABLED = "enabled";
   public static final String BACKGROUND_COLOR = "backgroundColor";