replace getRawX and getRawY with shims

Author: Kaushik Iska

shell/platform/android/io/flutter/embedding/android/AndroidTouchProcessor.java

@@ -1,5 +1,6 @@
 package io.flutter.embedding.android;
 
+import android.graphics.Matrix;
 import android.os.Build;
 import android.view.InputDevice;
 import android.view.MotionEvent;
@@ -69,6 +70,8 @@ public class AndroidTouchProcessor {
 
   private static final int _POINTER_BUTTON_PRIMARY = 1;
 
+  private static final Matrix IDENTITY_TRANSFORM = new Matrix();
+
   private final boolean trackMotionEvents;
 
   /**
@@ -83,8 +86,12 @@ public AndroidTouchProcessor(@NonNull FlutterRenderer renderer, boolean trackMot
     this.trackMotionEvents = trackMotionEvents;
   }
 
-  /** Sends the given {@link MotionEvent} data to Flutter in a format that Flutter understands. */
   public boolean onTouchEvent(@NonNull MotionEvent event) {
+    return onTouchEvent(event, IDENTITY_TRANSFORM);
+  }
+
+  /** Sends the given {@link MotionEvent} data to Flutter in a format that Flutter understands. */
+  public boolean onTouchEvent(@NonNull MotionEvent event, Matrix transformMatrix) {
     int pointerCount = event.getPointerCount();
 
     // Prepare a data packet of the appropriate size and order.
@@ -102,26 +109,27 @@ public boolean onTouchEvent(@NonNull MotionEvent event) {
                 || maskedAction == MotionEvent.ACTION_POINTER_UP);
     if (updateForSinglePointer) {
       // ACTION_DOWN and ACTION_POINTER_DOWN always apply to a single pointer only.
-      addPointerForIndex(event, event.getActionIndex(), pointerChange, 0, packet);
+      addPointerForIndex(event, event.getActionIndex(), pointerChange, 0, transformMatrix, packet);
     } else if (updateForMultiplePointers) {
       // ACTION_UP and ACTION_POINTER_UP may contain position updates for other pointers.
       // We are converting these updates to move events here in order to preserve this data.
       // We also mark these events with a flag in order to help the framework reassemble
       // the original Android event later, should it need to forward it to a PlatformView.
       for (int p = 0; p < pointerCount; p++) {
         if (p != event.getActionIndex() && event.getToolType(p) == MotionEvent.TOOL_TYPE_FINGER) {
-          addPointerForIndex(event, p, PointerChange.MOVE, POINTER_DATA_FLAG_BATCHED, packet);
+          addPointerForIndex(
+              event, p, PointerChange.MOVE, POINTER_DATA_FLAG_BATCHED, transformMatrix, packet);
         }
       }
       // It's important that we're sending the UP event last. This allows PlatformView
       // to correctly batch everything back into the original Android event if needed.
-      addPointerForIndex(event, event.getActionIndex(), pointerChange, 0, packet);
+      addPointerForIndex(event, event.getActionIndex(), pointerChange, 0, transformMatrix, packet);
     } else {
       // ACTION_MOVE may not actually mean all pointers have moved
       // but it's the responsibility of a later part of the system to
       // ignore 0-deltas if desired.
       for (int p = 0; p < pointerCount; p++) {
-        addPointerForIndex(event, p, pointerChange, 0, packet);
+        addPointerForIndex(event, p, pointerChange, 0, transformMatrix, packet);
       }
     }
 
@@ -163,7 +171,7 @@ public boolean onGenericMotionEvent(@NonNull MotionEvent event) {
     packet.order(ByteOrder.LITTLE_ENDIAN);
 
     // ACTION_HOVER_MOVE always applies to a single pointer only.
-    addPointerForIndex(event, event.getActionIndex(), pointerChange, 0, packet);
+    addPointerForIndex(event, event.getActionIndex(), pointerChange, 0, IDENTITY_TRANSFORM, packet);
     if (packet.position() % (POINTER_DATA_FIELD_COUNT * BYTES_PER_FIELD) != 0) {
       throw new AssertionError("Packet position is not on field boundary.");
     }
@@ -174,7 +182,12 @@ public boolean onGenericMotionEvent(@NonNull MotionEvent event) {
   // TODO(mattcarroll): consider creating a PointerPacket class instead of using a procedure that
   // mutates inputs.
   private void addPointerForIndex(
-      MotionEvent event, int pointerIndex, int pointerChange, int pointerData, ByteBuffer packet) {
+      MotionEvent event,
+      int pointerIndex,
+      int pointerChange,
+      int pointerData,
+      Matrix transformMatrix,
+      ByteBuffer packet) {
     if (pointerChange == -1) {
       return;
     }
@@ -201,8 +214,14 @@ private void addPointerForIndex(
     packet.putLong(signalKind); // signal_kind
     packet.putLong(event.getPointerId(pointerIndex)); // device
     packet.putLong(0); // pointer_identifier, will be generated in pointer_data_packet_converter.cc.
-    packet.putDouble(event.getRawX(pointerIndex)); // physical_x
-    packet.putDouble(event.getRawY(pointerIndex)); // physical_y
+
+    // We use this in lieu of using event.getRawX and event.getRawY as we wish to support
+    // earlier versions than API level 29.
+    float viewToScreenCoords[] = {event.getX(pointerIndex), event.getY(pointerIndex)};
+    transformMatrix.mapPoints(viewToScreenCoords);
+    packet.putDouble(viewToScreenCoords[0]); // physical_x
+    packet.putDouble(viewToScreenCoords[1]); // physical_y
+
     packet.putDouble(
         0.0); // physical_delta_x, will be generated in pointer_data_packet_converter.cc.
     packet.putDouble(

shell/platform/android/io/flutter/embedding/engine/mutatorsstack/FlutterMutatorView.java

@@ -33,10 +33,10 @@ public FlutterMutatorView(
   }
 
   /** Initialize the FlutterMutatorView. */
-  public FlutterMutatorView(@NonNull Context context, AndroidTouchProcessor androidTouchProcessor) {
+  public FlutterMutatorView(@NonNull Context context) {
     super(context, null);
     this.screenDensity = 1;
-    this.androidTouchProcessor = androidTouchProcessor;
+    this.androidTouchProcessor = null;
   }
 
   /**
@@ -78,7 +78,14 @@ public void dispatchDraw(Canvas canvas) {
     // Apply all the transforms on the child canvas.
     canvas.save();
 
+    canvas.concat(getPlatformViewMatrix());
+    super.dispatchDraw(canvas);
+    canvas.restore();
+  }
+
+  private Matrix getPlatformViewMatrix() {
     Matrix finalMatrix = new Matrix(mutatorsStack.getFinalMatrix());
+
     // Reverse scale based on screen scale.
     //
     // The Android frame is set based on the logical resolution instead of physical.
@@ -87,6 +94,7 @@ public void dispatchDraw(Canvas canvas) {
     // 500 points in Android. And until this point, we did all the calculation based on the flow
     // resolution. So we need to scale down to match Android's logical resolution.
     finalMatrix.preScale(1 / screenDensity, 1 / screenDensity);
+
     // Reverse the current offset.
     //
     // The frame of this view includes the final offset of the bounding rect.
@@ -95,9 +103,7 @@ public void dispatchDraw(Canvas canvas) {
     // all the clipping paths
     finalMatrix.postTranslate(-left, -top);
 
-    canvas.concat(finalMatrix);
-    super.dispatchDraw(canvas);
-    canvas.restore();
+    return finalMatrix;
   }
 
   @Override
@@ -108,6 +114,15 @@ public boolean onInterceptTouchEvent(MotionEvent event) {
 
   @Override
   public boolean onTouchEvent(MotionEvent event) {
-    return androidTouchProcessor.onTouchEvent(event);
+    if (androidTouchProcessor == null) {
+      return super.onTouchEvent(event);
+    }
+
+    // Mutator view itself doesn't rotate, scale, skew, etc.
+    // we only need to account for translation.
+    Matrix screenMatrix = new Matrix();
+    screenMatrix.postTranslate(getLeft(), getTop());
+
+    return androidTouchProcessor.onTouchEvent(event, screenMatrix);
   }
 }