Propagate positions of secondary pointers in UP events on Android (#23797)

bin/internal/engine.version

-88cb78cdf62ceb206e740853d3afd060bb8d781c
+b5758d0d3848d8ed77308d97734b9a7933c3844f

dev/integration_tests/android_views/lib/motion_event_diff.dart

@@ -95,23 +95,6 @@ void diffPointerCoordsList(StringBuffer diffBuffer,
     return;
   }
 
-  if (isSinglePointerAction(originalEvent['action'])) {
-    final int idx = getPointerIdx(originalEvent['action']);
-    final Map<String, dynamic> expected =
-        expectedList[idx].cast<String, dynamic>();
-    final Map<String, dynamic> actual = actualList[idx].cast<String, dynamic>();
-    diffPointerCoords(expected, actual, idx, diffBuffer);
-    // For POINTER_UP and POINTER_DOWN events the engine drops the data for all pointers
-    // but for the pointer that was taken up/down.
-    // See: https://github.com/flutter/flutter/issues/19882
-    //
-    // Until that issue is resolved, we only compare the pointer for which the action
-    // applies to here.
-    //
-    // TODO(amirh): Compare all pointers once the issue mentioned above is resolved.
-    return;
-  }
-
   for (int i = 0; i < expectedList.length; i++) {
     final Map<String, dynamic> expected =
         expectedList[i].cast<String, dynamic>();
@@ -151,12 +134,6 @@ void diffMaps(
   }
 }
 
-bool isSinglePointerAction(int action) {
-  final int actionMasked = getActionMasked(action);
-  return actionMasked == 5 || // POINTER_DOWN
-      actionMasked == 6; // POINTER_UP
-}
-
 int getActionMasked(int action) => action & 0xff;
 
 int getPointerIdx(int action) => (action >> 8) & 0xff;

packages/flutter/lib/src/gestures/converter.dart

@@ -239,7 +239,8 @@ class PointerEventConverter {
             radiusMin: radiusMin,
             radiusMax: radiusMax,
             orientation: datum.orientation,
-            tilt: datum.tilt
+            tilt: datum.tilt,
+            platformData: datum.platformData,
           );
           break;
         case ui.PointerChange.up:

packages/flutter/lib/src/gestures/events.dart

@@ -115,6 +115,7 @@ abstract class PointerEvent {
     this.radiusMax = 0.0,
     this.orientation = 0.0,
     this.tilt = 0.0,
+    this.platformData = 0,
     this.synthesized = false,
   });
 
@@ -245,6 +246,9 @@ abstract class PointerEvent {
   /// the stylus is flat on that surface).
   final double tilt;
 
+  /// Opaque platform-specific data associated with the event.
+  final int platformData;
+
   /// We occasionally synthesize PointerEvents that aren't exact translations
   /// of [ui.PointerData] from the engine to cover small cross-OS discrepancies
   /// in pointer behaviors.
@@ -285,6 +289,7 @@ abstract class PointerEvent {
              'radiusMax: $radiusMax, '
              'orientation: $orientation, '
              'tilt: $tilt, '
+             'platformData: $platformData, '
              'synthesized: $synthesized'
            ')';
   }
@@ -495,6 +500,7 @@ class PointerMoveEvent extends PointerEvent {
     double radiusMax = 0.0,
     double orientation = 0.0,
     double tilt = 0.0,
+    int platformData = 0,
     bool synthesized = false,
   }) : super(
     timeStamp: timeStamp,
@@ -518,6 +524,7 @@ class PointerMoveEvent extends PointerEvent {
     radiusMax: radiusMax,
     orientation: orientation,
     tilt: tilt,
+    platformData: platformData,
     synthesized: synthesized,
   );
 }

packages/flutter/lib/src/rendering/platform_view.dart

@@ -447,16 +447,21 @@ class _MotionEventsDispatcher {
     final int pointerIdx = pointers.indexOf(event.pointer);
     final int numPointers = pointers.length;
 
+    // This value must match the value in engine's FlutterView.java.
+    // This flag indicates whether the original Android pointer events were batched together.
+    const int kPointerDataFlagBatched = 1;
+
     // Android MotionEvent objects can batch information on multiple pointers.
     // Flutter breaks these such batched events into multiple PointerEvent objects.
     // When there are multiple active pointers we accumulate the information for all pointers
     // as we get PointerEvents, and only send it to the embedded Android view when
     // we see the last pointer. This way we achieve the same batching as Android.
-    if(isSinglePointerAction(event) && pointerIdx < numPointers - 1)
+    if (event.platformData == kPointerDataFlagBatched ||
+        (isSinglePointerAction(event) && pointerIdx < numPointers - 1))
       return;
 
     int action;
-    switch(event.runtimeType){
+    switch (event.runtimeType) {
       case PointerDownEvent:
         action = numPointers == 1 ? AndroidViewController.kActionDown
             : AndroidViewController.pointerAction(pointerIdx, AndroidViewController.kActionPointerDown);

packages/flutter/test/widgets/widget_inspector_test.dart

@@ -1806,6 +1806,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
       await expectLater(
         layer.toImage(renderObject.semanticBounds.inflate(50.0)),
         matchesGoldenFile('inspector.repaint_boundary_margin.png'),
+        skip: !Platform.isLinux,
       );
 
       // Regression test for how rendering with a pixel scale other than 1.0
@@ -1816,6 +1817,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           pixelRatio: 0.5,
         ),
         matchesGoldenFile('inspector.repaint_boundary_margin_small.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -1824,6 +1826,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           pixelRatio: 2.0,
         ),
         matchesGoldenFile('inspector.repaint_boundary_margin_large.png'),
+        skip: !Platform.isLinux,
       );
 
       final Layer layerParent = layer.parent;
@@ -1839,6 +1842,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 300.0,
         ),
         matchesGoldenFile('inspector.repaint_boundary.png'),
+        skip: !Platform.isLinux,
       );
 
       // Verify that taking a screenshot didn't change the layers associated with
@@ -1856,6 +1860,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           margin: 50.0,
         ),
         matchesGoldenFile('inspector.repaint_boundary_margin.png'),
+        skip: !Platform.isLinux,
       );
 
       // Verify that taking a screenshot didn't change the layers associated with
@@ -1876,6 +1881,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           debugPaint: true,
         ),
         matchesGoldenFile('inspector.repaint_boundary_debugPaint.png'),
+        skip: !Platform.isLinux,
       );
       // Verify that taking a screenshot with debug paint on did not change
       // the number of children the layer has.
@@ -1886,6 +1892,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
       await expectLater(
         find.byType(RepaintBoundaryWithDebugPaint),
         matchesGoldenFile('inspector.repaint_boundary.png'),
+        skip: !Platform.isLinux,
       );
 
       expect(renderObject.debugLayer, equals(layer));
@@ -1899,6 +1906,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 100.0,
         ),
         matchesGoldenFile('inspector.container.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -1909,6 +1917,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           debugPaint: true,
         ),
         matchesGoldenFile('inspector.container_debugPaint.png'),
+        skip: !Platform.isLinux,
       );
 
       {
@@ -1929,6 +1938,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
             debugPaint: true,
           ),
           matchesGoldenFile('inspector.container_debugPaint.png'),
+          skip: !Platform.isLinux,
         );
         expect(container.debugNeedsLayout, isFalse);
       }
@@ -1941,6 +1951,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 100.0,
         ),
         matchesGoldenFile('inspector.container_small.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -1951,6 +1962,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           maxPixelRatio: 3.0,
         ),
         matchesGoldenFile('inspector.container_large.png'),
+        skip: !Platform.isLinux,
       );
 
       // This screenshot will show the clip rect debug paint but no other
@@ -1963,6 +1975,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           debugPaint: true,
         ),
         matchesGoldenFile('inspector.clipRect_debugPaint.png'),
+        skip: !Platform.isLinux,
       );
 
       final Element clipRect = find.byType(ClipRRect).evaluate().single;
@@ -2007,6 +2020,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
       await expectLater(
         screenshotImage,
         matchesReferenceImage(await clipRectScreenshot),
+        skip: !Platform.isLinux,
       );
 
       // Test with a very visible debug paint
@@ -2018,6 +2032,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           debugPaint: true,
         ),
         matchesGoldenFile('inspector.padding_debugPaint.png'),
+        skip: !Platform.isLinux,
       );
 
       // The bounds for this box crop its rendered content.
@@ -2029,6 +2044,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           debugPaint: true,
         ),
         matchesGoldenFile('inspector.sizedBox_debugPaint.png'),
+        skip: !Platform.isLinux,
       );
 
       // Verify that setting a margin includes the previously cropped content.
@@ -2041,6 +2057,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           debugPaint: true,
         ),
         matchesGoldenFile('inspector.sizedBox_debugPaint_margin.png'),
+        skip: !Platform.isLinux,
       );
     });
 
@@ -2112,6 +2129,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
       await expectLater(
         find.byKey(mainStackKey),
         matchesGoldenFile('inspector.composited_transform.only_offsets.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -2121,11 +2139,13 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 500.0,
         ),
         matchesGoldenFile('inspector.composited_transform.only_offsets_follower.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
         WidgetInspectorService.instance.screenshot(find.byType(Stack).evaluate().first, width: 300.0, height: 300.0),
         matchesGoldenFile('inspector.composited_transform.only_offsets_small.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -2135,6 +2155,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 500.0,
         ),
         matchesGoldenFile('inspector.composited_transform.only_offsets_target.png'),
+        skip: !Platform.isLinux,
       );
     });
 
@@ -2207,6 +2228,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
       await expectLater(
         find.byKey(mainStackKey),
         matchesGoldenFile('inspector.composited_transform.with_rotations.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -2216,6 +2238,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 500.0,
         ),
         matchesGoldenFile('inspector.composited_transform.with_rotations_small.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -2225,6 +2248,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 500.0,
         ),
         matchesGoldenFile('inspector.composited_transform.with_rotations_target.png'),
+        skip: !Platform.isLinux,
       );
 
       await expectLater(
@@ -2234,6 +2258,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
           height: 500.0,
         ),
         matchesGoldenFile('inspector.composited_transform.with_rotations_follower.png'),
+        skip: !Platform.isLinux,
       );
 
       // Make sure taking screenshots hasn't modified the positions of the