[iOS] Fix Use element spec conformance (x and y interpretation)

elements/Use.js

@@ -14,7 +14,7 @@ export default class Use extends Shape {
 
     render() {
         const { props } = this;
-        const { children, width, height, href } = props;
+        const { children, x, y, width, height, href } = props;
 
         // match "url(#pattern)"
         const matched = href.match(idPattern);
@@ -31,8 +31,13 @@ export default class Use extends Shape {
         return (
             <RNSVGUse
                 ref={this.refMethod}
-                {...extractProps(props, this)}
+                {...extractProps(
+                    { ...props, x: undefined, y: undefined },
+                    this,
+                )}
                 href={match}
+                x={x}
+                y={y}
                 width={width}
                 height={height}
             >

ios/Elements/RNSVGUse.h

@@ -16,6 +16,8 @@
 @interface RNSVGUse : RNSVGRenderable
 
 @property (nonatomic, strong) NSString *href;
+@property (nonatomic, strong) RNSVGLength *x;
+@property (nonatomic, strong) RNSVGLength *y;
 @property (nonatomic, strong) RNSVGLength *usewidth;
 @property (nonatomic, strong) RNSVGLength *useheight;
 @end

ios/Elements/RNSVGUse.m

@@ -21,6 +21,27 @@
     _href = href;
 }
 
+- (void)setX:(RNSVGLength *)x
+{
+    if ([x isEqualTo:_x]) {
+        return;
+    }
+
+    [self invalidate];
+    _x = x;
+}
+
+- (void)setY:(RNSVGLength *)y
+{
+    if ([y isEqualTo:_y]) {
+        return;
+    }
+
+    [self invalidate];
+    _y = y;
+}
+
+
 - (void)setUsewidth:(RNSVGLength *)usewidth
 {
     if ([usewidth isEqualTo:_usewidth]) {
@@ -43,6 +64,7 @@
 
 - (void)renderLayerTo:(CGContextRef)context rect:(CGRect)rect
 {
+    CGContextTranslateCTM(context, [self relativeOnWidth:self.x], [self relativeOnWidth:self.y]);
     RNSVGNode* template = [self.svgView getDefinedTemplate:self.href];
     if (template) {
         [self beginTransparencyLayer:context];

ios/ViewManagers/RNSVGUseManager.m

@@ -19,6 +19,14 @@ RCT_EXPORT_MODULE()
 }
 
 RCT_EXPORT_VIEW_PROPERTY(href, NSString)
+RCT_CUSTOM_VIEW_PROPERTY(x, id, RNSVGUse)
+{
+    view.x = [RCTConvert RNSVGLength:json];
+}
+RCT_CUSTOM_VIEW_PROPERTY(y, id, RNSVGUse)
+{
+    view.y = [RCTConvert RNSVGLength:json];
+}
 RCT_EXPORT_VIEW_PROPERTY(useheight, RNSVGLength*)
 RCT_EXPORT_VIEW_PROPERTY(usewidth, RNSVGLength*)
 RCT_CUSTOM_VIEW_PROPERTY(height, id, RNSVGUse)