Implement transform-origin for old arch iOS (facebook#38626)

Summary:
Adds transform-origin for old arch iOS

See also intergalacticspacehighway's work for iOS Fabric and Android:-

- facebook#38559
- facebook#38558

## Changelog:

[IOS] [ADDED] - Added support for transform-origin on old arch

Pull Request resolved: facebook#38626

Test Plan: See RN tester

Reviewed By: NickGerleman

Differential Revision: D48528353

Pulled By: javache

fbshipit-source-id: 09592411e26484d81a999a7e601eff751ca7ae0b

packages/react-native/React/Views/RCTTransformOrigin.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import <Foundation/Foundation.h>
+#import <yoga/Yoga.h>
+
+typedef struct {
+  YGValue x;
+  YGValue y;
+  CGFloat z;
+} RCTTransformOrigin;

packages/react-native/React/Views/RCTViewManager.m

@@ -15,6 +15,7 @@
 #import "RCTConvert.h"
 #import "RCTLog.h"
 #import "RCTShadowView.h"
+#import "RCTTransformOrigin.h"
 #import "RCTUIManager.h"
 #import "RCTUIManagerUtils.h"
 #import "RCTUtils.h"
@@ -121,6 +122,13 @@ @implementation RCTConvert (UIAccessibilityTraits)
     UIAccessibilityTraitNone,
     unsignedLongLongValue)
 
++ (RCTTransformOrigin)RCTTransformOrigin:(id)json
+{
+  RCTTransformOrigin transformOrigin = {
+      [RCTConvert YGValue:json[0]], [RCTConvert YGValue:json[1]], [RCTConvert CGFloat:json[2]]};
+  return transformOrigin;
+}
+
 @end
 
 @implementation RCTViewManager
@@ -216,13 +224,8 @@ - (RCTShadowView *)shadowView
       view.layer.shouldRasterize ? [UIScreen mainScreen].scale : defaultView.layer.rasterizationScale;
 }
 
-RCT_CUSTOM_VIEW_PROPERTY(transform, CATransform3D, RCTView)
-{
-  view.layer.transform = json ? [RCTConvert CATransform3D:json] : defaultView.layer.transform;
-  // Enable edge antialiasing in rotation, skew, or perspective transforms
-  view.layer.allowsEdgeAntialiasing =
-      view.layer.transform.m12 != 0.0f || view.layer.transform.m21 != 0.0f || view.layer.transform.m34 != 0.0f;
-}
+RCT_REMAP_VIEW_PROPERTY(transform, reactTransform, CATransform3D)
+RCT_REMAP_VIEW_PROPERTY(transformOrigin, reactTransformOrigin, RCTTransformOrigin)
 
 RCT_CUSTOM_VIEW_PROPERTY(accessibilityRole, UIAccessibilityTraits, RCTView)
 {

packages/react-native/React/Views/UIView+React.h

@@ -8,6 +8,7 @@
 #import <UIKit/UIKit.h>
 
 #import <React/RCTComponent.h>
+#import <React/RCTTransformOrigin.h>
 #import <yoga/YGEnums.h>
 
 @class RCTShadowView;
@@ -104,6 +105,13 @@
 @property (nonatomic, readonly) UIEdgeInsets reactCompoundInsets;
 @property (nonatomic, readonly) CGRect reactContentFrame;
 
+/**
+ * The anchorPoint property doesn't work in the same way as on web - updating it updates the frame.
+ * To work around this, we take both the transform and the transform-origin, and compute it ourselves
+ */
+@property (nonatomic, assign) CATransform3D reactTransform;
+@property (nonatomic, assign) RCTTransformOrigin reactTransformOrigin;
+
 /**
  * The (sub)view which represents this view in terms of accessibility.
  * ViewManager will apply all accessibility properties directly to this view.

packages/react-native/React/Views/UIView+React.m

@@ -203,6 +203,73 @@ - (void)reactSetFrame:(CGRect)frame
 
   self.center = position;
   self.bounds = bounds;
+
+  updateTransform(self);
+}
+
+#pragma mark - Transforms
+
+- (CATransform3D)reactTransform
+{
+  id obj = objc_getAssociatedObject(self, _cmd);
+  return obj != nil ? [obj CATransform3DValue] : CATransform3DIdentity;
+}
+
+- (void)setReactTransform:(CATransform3D)reactTransform
+{
+  objc_setAssociatedObject(self, @selector(reactTransform), @(reactTransform), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+  updateTransform(self);
+}
+
+- (RCTTransformOrigin)reactTransformOrigin
+{
+  id obj = objc_getAssociatedObject(self, _cmd);
+  if (obj != nil) {
+    RCTTransformOrigin transformOrigin;
+    [obj getValue:&transformOrigin];
+    return transformOrigin;
+  } else {
+    return (RCTTransformOrigin){(YGValue){50, YGUnitPercent}, (YGValue){50, YGUnitPercent}, 0};
+  }
+}
+
+- (void)setReactTransformOrigin:(RCTTransformOrigin)reactTransformOrigin
+{
+  id obj = [NSValue value:&reactTransformOrigin withObjCType:@encode(RCTTransformOrigin)];
+  objc_setAssociatedObject(self, @selector(reactTransformOrigin), obj, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+  updateTransform(self);
+}
+
+static void updateTransform(UIView *view)
+{
+  CGSize size = view.bounds.size;
+  RCTTransformOrigin transformOrigin = view.reactTransformOrigin;
+
+  CGFloat anchorPointX = 0;
+  CGFloat anchorPointY = 0;
+  CGFloat anchorPointZ = 0;
+
+  if (transformOrigin.x.unit == YGUnitPoint) {
+    anchorPointX = transformOrigin.x.value - size.width * 0.5;
+  } else if (transformOrigin.x.unit == YGUnitPercent) {
+    anchorPointX = (transformOrigin.x.value * 0.01 - 0.5) * size.width;
+  }
+
+  if (transformOrigin.y.unit == YGUnitPoint) {
+    anchorPointY = transformOrigin.y.value - size.height * 0.5;
+  } else if (transformOrigin.y.unit == YGUnitPercent) {
+    anchorPointY = (transformOrigin.y.value * 0.01 - 0.5) * size.height;
+  }
+
+  anchorPointZ = transformOrigin.z;
+
+  CATransform3D transform = CATransform3DMakeTranslation(anchorPointX, anchorPointY, anchorPointZ);
+  transform = CATransform3DConcat(view.reactTransform, transform);
+  transform = CATransform3DTranslate(transform, -anchorPointX, -anchorPointY, -anchorPointZ);
+
+  view.layer.transform = transform;
+  // Enable edge antialiasing in rotation, skew, or perspective transforms
+  view.layer.allowsEdgeAntialiasing = transform.m12 != 0.0f || transform.m21 != 0.0f || transform.m34 != 0.0f;
 }
 
 - (UIViewController *)reactViewController