From 9e68599daf844b06bd010c43cbabf3dc593bb114 Mon Sep 17 00:00:00 2001
From: Nishan <nishanbende@gmail.com>
Date: Fri, 1 Sep 2023 13:03:50 -0700
Subject: [PATCH] feat: android transform origin (#38558)

Summary:
This PR adds transform-origin support for android to make it easier to review. https://github.com/facebook/react-native/pull/37606#pullrequestreview-1513082850 by javache. I'll answer feedback from javache below.

## Changelog:
[Android] [ADDED] - Transform origin
<!-- Help reviewers and the release process by writing your own changelog entry.

Pick one each for the category and type tags:

[ANDROID|GENERAL|IOS|INTERNAL] [BREAKING|ADDED|CHANGED|DEPRECATED|REMOVED|FIXED|SECURITY] - Message

For more details, see:
https://reactnative.dev/contributing/changelogs-in-pull-requests

Pull Request resolved: https://github.com/facebook/react-native/pull/38558

Test Plan: Run iOS RNTester app in old architecture and test transform-origin example in `TransformExample.js`.

Reviewed By: NickGerleman

Differential Revision: D48528339

Pulled By: javache

fbshipit-source-id: e255a7f364e57396dada60b2c69c724cec406f51
---
 .../NativeComponent/BaseViewConfig.android.js |   1 +
 .../react/uimanager/BaseViewManager.java      |  71 ++++++++-
 .../uimanager/BaseViewManagerDelegate.java    |   3 +
 .../uimanager/BaseViewManagerInterface.java   |   2 +
 .../react/uimanager/TransformHelper.java      | 144 ++++++++++++------
 .../facebook/react/uimanager/ViewProps.java   |   2 +
 .../main/res/views/uimanager/values/ids.xml   |   9 ++
 7 files changed, 182 insertions(+), 50 deletions(-)

diff --git a/packages/react-native/Libraries/NativeComponent/BaseViewConfig.android.js b/packages/react-native/Libraries/NativeComponent/BaseViewConfig.android.js
index 249e81199a5399..0326ec9afd621d 100644
--- a/packages/react-native/Libraries/NativeComponent/BaseViewConfig.android.js
+++ b/packages/react-native/Libraries/NativeComponent/BaseViewConfig.android.js
@@ -165,6 +165,7 @@ const validAttributesForNonEventProps = {
   // @ReactProps from BaseViewManager
   backgroundColor: {process: require('../StyleSheet/processColor').default},
   transform: true,
+  transformOrigin: true,
   opacity: true,
   elevation: true,
   shadowColor: {process: require('../StyleSheet/processColor').default},
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManager.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManager.java
index a7970346275fd7..20c3fd2d7fcefa 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManager.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManager.java
@@ -40,7 +40,7 @@
  * provides support for base view properties such as backgroundColor, opacity, etc.
  */
 public abstract class BaseViewManager<T extends View, C extends LayoutShadowNode>
-    extends ViewManager<T, C> implements BaseViewManagerInterface<T> {
+    extends ViewManager<T, C> implements BaseViewManagerInterface<T>, View.OnLayoutChangeListener {
 
   private static final int PERSPECTIVE_ARRAY_INVERTED_CAMERA_DISTANCE_INDEX = 2;
   private static final float CAMERA_DISTANCE_NORMALIZATION_MULTIPLIER = (float) Math.sqrt(5);
@@ -90,6 +90,10 @@ protected T prepareToRecycleView(@NonNull ThemedReactContext reactContext, T vie
     view.setElevation(0);
     view.setAnimationMatrix(null);
 
+    view.setTag(R.id.transform, null);
+    view.setTag(R.id.transform_origin, null);
+    view.setTag(R.id.invalidate_transform, null);
+    view.removeOnLayoutChangeListener(this);
     // setShadowColor
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
       view.setOutlineAmbientShadowColor(Color.BLACK);
@@ -129,6 +133,35 @@ protected T prepareToRecycleView(@NonNull ThemedReactContext reactContext, T vie
     return view;
   }
 
+  // Currently. onLayout listener is only attached when transform origin prop is being used.
+  @Override
+  public void onLayoutChange(
+      View v,
+      int left,
+      int top,
+      int right,
+      int bottom,
+      int oldLeft,
+      int oldTop,
+      int oldRight,
+      int oldBottom) {
+    // Old width and height
+    int oldWidth = oldRight - oldLeft;
+    int oldHeight = oldBottom - oldTop;
+
+    // Current width and height
+    int currentWidth = right - left;
+    int currentHeight = bottom - top;
+
+    if ((currentHeight != oldHeight || currentWidth != oldWidth)) {
+      ReadableArray transformOrigin = (ReadableArray) v.getTag(R.id.transform_origin);
+      ReadableArray transformMatrix = (ReadableArray) v.getTag(R.id.transform);
+      if (transformMatrix != null && transformOrigin != null) {
+        setTransformProperty((T) v, transformMatrix, transformOrigin);
+      }
+    }
+  }
+
   @Override
   @ReactProp(
       name = ViewProps.BACKGROUND_COLOR,
@@ -141,10 +174,19 @@ public void setBackgroundColor(@NonNull T view, int backgroundColor) {
   @Override
   @ReactProp(name = ViewProps.TRANSFORM)
   public void setTransform(@NonNull T view, @Nullable ReadableArray matrix) {
-    if (matrix == null) {
-      resetTransformProperty(view);
+    view.setTag(R.id.transform, matrix);
+    view.setTag(R.id.invalidate_transform, true);
+  }
+
+  @Override
+  @ReactProp(name = ViewProps.TRANSFORM_ORIGIN)
+  public void setTransformOrigin(@NonNull T view, @Nullable ReadableArray transformOrigin) {
+    view.setTag(R.id.transform_origin, transformOrigin);
+    view.setTag(R.id.invalidate_transform, true);
+    if (transformOrigin != null) {
+      view.addOnLayoutChangeListener(this);
     } else {
-      setTransformProperty(view, matrix);
+      view.removeOnLayoutChangeListener(this);
     }
   }
 
@@ -439,9 +481,15 @@ public void setAccessibilityLiveRegion(@NonNull T view, @Nullable String liveReg
     }
   }
 
-  private static void setTransformProperty(@NonNull View view, ReadableArray transforms) {
+  private static void setTransformProperty(
+      @NonNull View view, ReadableArray transforms, @Nullable ReadableArray transformOrigin) {
     sMatrixDecompositionContext.reset();
-    TransformHelper.processTransform(transforms, sTransformDecompositionArray);
+    TransformHelper.processTransform(
+        transforms,
+        sTransformDecompositionArray,
+        PixelUtil.toDIPFromPixel(view.getWidth()),
+        PixelUtil.toDIPFromPixel(view.getHeight()),
+        transformOrigin);
     MatrixMathHelper.decomposeMatrix(sTransformDecompositionArray, sMatrixDecompositionContext);
     view.setTranslationX(
         PixelUtil.toPixelFromDIP(
@@ -526,6 +574,17 @@ private void updateViewAccessibility(@NonNull T view) {
   protected void onAfterUpdateTransaction(@NonNull T view) {
     super.onAfterUpdateTransaction(view);
     updateViewAccessibility(view);
+    Boolean invalidateTransform = (Boolean) view.getTag(R.id.invalidate_transform);
+    if (invalidateTransform != null && invalidateTransform) {
+      ReadableArray transformOrigin = (ReadableArray) view.getTag(R.id.transform_origin);
+      ReadableArray transformMatrix = (ReadableArray) view.getTag(R.id.transform);
+      if (transformMatrix != null) {
+        setTransformProperty(view, transformMatrix, transformOrigin);
+      } else {
+        resetTransformProperty(view);
+      }
+      view.setTag(R.id.invalidate_transform, false);
+    }
   }
 
   @Override
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerDelegate.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerDelegate.java
index e59a1c4da3b80f..2a845e1903c59d 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerDelegate.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerDelegate.java
@@ -121,6 +121,9 @@ public void setProperty(T view, String propName, @Nullable Object value) {
       case ViewProps.TRANSFORM:
         mViewManager.setTransform(view, (ReadableArray) value);
         break;
+      case ViewProps.TRANSFORM_ORIGIN:
+        mViewManager.setTransformOrigin(view, (ReadableArray) value);
+        break;
       case ViewProps.TRANSLATE_X:
         mViewManager.setTranslateX(view, value == null ? 0.0f : ((Double) value).floatValue());
         break;
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerInterface.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerInterface.java
index 5887ff5ba31535..6ef232813dbc3f 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerInterface.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManagerInterface.java
@@ -72,6 +72,8 @@ public interface BaseViewManagerInterface<T extends View> {
 
   void setTransform(T view, @Nullable ReadableArray matrix);
 
+  void setTransformOrigin(T view, @Nullable ReadableArray transformOrigin);
+
   void setTranslateX(T view, float translateX);
 
   void setTranslateY(T view, float translateY);
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/TransformHelper.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/TransformHelper.java
index 49d6af12396a01..5a5a9ddaa92750 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/TransformHelper.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/TransformHelper.java
@@ -46,65 +46,121 @@ private static double convertToRadians(ReadableMap transformMap, String key) {
   }
 
   public static void processTransform(ReadableArray transforms, double[] result) {
+    processTransform(transforms, result, 0, 0, null);
+  }
+
+  public static void processTransform(
+      ReadableArray transforms,
+      double[] result,
+      float viewWidth,
+      float viewHeight,
+      ReadableArray transformOrigin) {
     double[] helperMatrix = sHelperMatrix.get();
     MatrixMathHelper.resetIdentityMatrix(result);
+    float[] offsets = getTranslateForTransformOrigin(viewWidth, viewHeight, transformOrigin);
 
+    if (offsets != null) {
+      MatrixMathHelper.resetIdentityMatrix(helperMatrix);
+      MatrixMathHelper.applyTranslate3D(helperMatrix, offsets[0], offsets[1], offsets[2]);
+      MatrixMathHelper.multiplyInto(result, result, helperMatrix);
+    }
     // If the transforms array is actually just the matrix itself,
     // copy that directly. This is for Fabric LayoutAnimations support.
     // All of the stuff this Java helper does is already done in C++ in Fabric, so we
     // can just use that matrix directly.
     if (transforms.size() == 16 && transforms.getType(0) == ReadableType.Number) {
+      MatrixMathHelper.resetIdentityMatrix(helperMatrix);
       for (int i = 0; i < transforms.size(); i++) {
-        result[i] = transforms.getDouble(i);
+        helperMatrix[i] = transforms.getDouble(i);
       }
-      return;
-    }
-
-    for (int transformIdx = 0, size = transforms.size(); transformIdx < size; transformIdx++) {
-      ReadableMap transform = transforms.getMap(transformIdx);
-      String transformType = transform.keySetIterator().nextKey();
+      MatrixMathHelper.multiplyInto(result, result, helperMatrix);
+    } else {
+      for (int transformIdx = 0, size = transforms.size(); transformIdx < size; transformIdx++) {
+        ReadableMap transform = transforms.getMap(transformIdx);
+        String transformType = transform.keySetIterator().nextKey();
 
-      MatrixMathHelper.resetIdentityMatrix(helperMatrix);
-      if ("matrix".equals(transformType)) {
-        ReadableArray matrix = transform.getArray(transformType);
-        for (int i = 0; i < 16; i++) {
-          helperMatrix[i] = matrix.getDouble(i);
+        MatrixMathHelper.resetIdentityMatrix(helperMatrix);
+        if ("matrix".equals(transformType)) {
+          ReadableArray matrix = transform.getArray(transformType);
+          for (int i = 0; i < 16; i++) {
+            helperMatrix[i] = matrix.getDouble(i);
+          }
+        } else if ("perspective".equals(transformType)) {
+          MatrixMathHelper.applyPerspective(helperMatrix, transform.getDouble(transformType));
+        } else if ("rotateX".equals(transformType)) {
+          MatrixMathHelper.applyRotateX(helperMatrix, convertToRadians(transform, transformType));
+        } else if ("rotateY".equals(transformType)) {
+          MatrixMathHelper.applyRotateY(helperMatrix, convertToRadians(transform, transformType));
+        } else if ("rotate".equals(transformType) || "rotateZ".equals(transformType)) {
+          MatrixMathHelper.applyRotateZ(helperMatrix, convertToRadians(transform, transformType));
+        } else if ("scale".equals(transformType)) {
+          double scale = transform.getDouble(transformType);
+          MatrixMathHelper.applyScaleX(helperMatrix, scale);
+          MatrixMathHelper.applyScaleY(helperMatrix, scale);
+        } else if ("scaleX".equals(transformType)) {
+          MatrixMathHelper.applyScaleX(helperMatrix, transform.getDouble(transformType));
+        } else if ("scaleY".equals(transformType)) {
+          MatrixMathHelper.applyScaleY(helperMatrix, transform.getDouble(transformType));
+        } else if ("translate".equals(transformType)) {
+          ReadableArray value = transform.getArray(transformType);
+          double x = value.getDouble(0);
+          double y = value.getDouble(1);
+          double z = value.size() > 2 ? value.getDouble(2) : 0d;
+          MatrixMathHelper.applyTranslate3D(helperMatrix, x, y, z);
+        } else if ("translateX".equals(transformType)) {
+          MatrixMathHelper.applyTranslate2D(helperMatrix, transform.getDouble(transformType), 0d);
+        } else if ("translateY".equals(transformType)) {
+          MatrixMathHelper.applyTranslate2D(helperMatrix, 0d, transform.getDouble(transformType));
+        } else if ("skewX".equals(transformType)) {
+          MatrixMathHelper.applySkewX(helperMatrix, convertToRadians(transform, transformType));
+        } else if ("skewY".equals(transformType)) {
+          MatrixMathHelper.applySkewY(helperMatrix, convertToRadians(transform, transformType));
+        } else {
+          FLog.w(ReactConstants.TAG, "Unsupported transform type: " + transformType);
         }
-      } else if ("perspective".equals(transformType)) {
-        MatrixMathHelper.applyPerspective(helperMatrix, transform.getDouble(transformType));
-      } else if ("rotateX".equals(transformType)) {
-        MatrixMathHelper.applyRotateX(helperMatrix, convertToRadians(transform, transformType));
-      } else if ("rotateY".equals(transformType)) {
-        MatrixMathHelper.applyRotateY(helperMatrix, convertToRadians(transform, transformType));
-      } else if ("rotate".equals(transformType) || "rotateZ".equals(transformType)) {
-        MatrixMathHelper.applyRotateZ(helperMatrix, convertToRadians(transform, transformType));
-      } else if ("scale".equals(transformType)) {
-        double scale = transform.getDouble(transformType);
-        MatrixMathHelper.applyScaleX(helperMatrix, scale);
-        MatrixMathHelper.applyScaleY(helperMatrix, scale);
-      } else if ("scaleX".equals(transformType)) {
-        MatrixMathHelper.applyScaleX(helperMatrix, transform.getDouble(transformType));
-      } else if ("scaleY".equals(transformType)) {
-        MatrixMathHelper.applyScaleY(helperMatrix, transform.getDouble(transformType));
-      } else if ("translate".equals(transformType)) {
-        ReadableArray value = transform.getArray(transformType);
-        double x = value.getDouble(0);
-        double y = value.getDouble(1);
-        double z = value.size() > 2 ? value.getDouble(2) : 0d;
-        MatrixMathHelper.applyTranslate3D(helperMatrix, x, y, z);
-      } else if ("translateX".equals(transformType)) {
-        MatrixMathHelper.applyTranslate2D(helperMatrix, transform.getDouble(transformType), 0d);
-      } else if ("translateY".equals(transformType)) {
-        MatrixMathHelper.applyTranslate2D(helperMatrix, 0d, transform.getDouble(transformType));
-      } else if ("skewX".equals(transformType)) {
-        MatrixMathHelper.applySkewX(helperMatrix, convertToRadians(transform, transformType));
-      } else if ("skewY".equals(transformType)) {
-        MatrixMathHelper.applySkewY(helperMatrix, convertToRadians(transform, transformType));
-      } else {
-        FLog.w(ReactConstants.TAG, "Unsupported transform type: " + transformType);
+
+        MatrixMathHelper.multiplyInto(result, result, helperMatrix);
       }
+    }
 
+    if (offsets != null) {
+      MatrixMathHelper.resetIdentityMatrix(helperMatrix);
+      MatrixMathHelper.applyTranslate3D(helperMatrix, -offsets[0], -offsets[1], -offsets[2]);
       MatrixMathHelper.multiplyInto(result, result, helperMatrix);
     }
   }
+
+  private static float[] getTranslateForTransformOrigin(
+      float viewWidth, float viewHeight, ReadableArray transformOrigin) {
+    if (transformOrigin == null || (viewHeight == 0 && viewWidth == 0)) {
+      return null;
+    }
+    float viewCenterX = viewWidth / 2;
+    float viewCenterY = viewHeight / 2;
+
+    float[] origin = {viewCenterX, viewCenterY, 0.0f};
+
+    for (int i = 0; i < transformOrigin.size() && i < 3; i++) {
+      switch (transformOrigin.getType(i)) {
+        case Number:
+          origin[i] = (float) transformOrigin.getDouble(i);
+          break;
+        case String:
+          {
+            String part = transformOrigin.getString(i);
+            if (part.endsWith("%")) {
+              float val = Float.parseFloat(part.substring(0, part.length() - 1));
+              origin[i] = (i == 0 ? viewWidth : viewHeight) * val / 100.0f;
+            }
+            break;
+          }
+      }
+    }
+
+    float newTranslateX = -viewCenterX + origin[0];
+    float newTranslateY = -viewCenterY + origin[1];
+    float newTranslateZ = origin[2];
+
+    return new float[] {newTranslateX, newTranslateY, newTranslateZ};
+  }
 }
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewProps.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewProps.java
index cc9f7178e65919..fa6eae38a49771 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewProps.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewProps.java
@@ -151,6 +151,8 @@ public class ViewProps {
   public static final String ON_LAYOUT = "onLayout";
 
   public static final String TRANSFORM = "transform";
+
+  public static final String TRANSFORM_ORIGIN = "transformOrigin";
   public static final String ELEVATION = "elevation";
   public static final String SHADOW_COLOR = "shadowColor";
   public static final String Z_INDEX = "zIndex";
diff --git a/packages/react-native/ReactAndroid/src/main/res/views/uimanager/values/ids.xml b/packages/react-native/ReactAndroid/src/main/res/views/uimanager/values/ids.xml
index d2928f810dfb90..84ebee0466979e 100644
--- a/packages/react-native/ReactAndroid/src/main/res/views/uimanager/values/ids.xml
+++ b/packages/react-native/ReactAndroid/src/main/res/views/uimanager/values/ids.xml
@@ -45,6 +45,15 @@
   <!-- tag is used store bitset of pointer events observed -->
   <item type="id" name="pointer_events"/>
 
+  <!-- tag is used store raw transform style on the view -->
+  <item type="id" name="transform"/>
+
+  <!-- tag is used store raw transform origin style on the view -->
+  <item type="id" name="transform_origin"/>
+
   <!-- tag is used to store role tag-->
   <item type="id" name="role"/>
+
+  <!-- tag is used to invalidate transform style in view manager -->
+  <item type="id" name="invalidate_transform"/>
 </resources>