Fixed PositionedTapDetector2's transformation of global to local coor…

…ds (#1676)

lib/src/misc/private/positioned_tap_detector_2.dart

@@ -164,23 +164,10 @@ class _TapPositionDetectorState extends State<PositionedTapDetector2> {
   ) async {
     _firstTap = null;
     if (callback != null) {
-      callback(_getTapPositions(details));
+      callback(TapPosition(details.globalPosition, details.localPosition));
     }
   }
 
-  TapPosition _getTapPositions(TapDownDetails details) {
-    final topLeft = _getWidgetTopLeft();
-    final global = details.globalPosition;
-    final relative = topLeft != null ? global - topLeft : null;
-    return TapPosition(global, relative);
-  }
-
-  Offset? _getWidgetTopLeft() {
-    final translation =
-        context.findRenderObject()?.getTransformTo(null).getTranslation();
-    return translation != null ? Offset(translation.x, translation.y) : null;
-  }
-
   @override
   void dispose() {
     _controller.close();

test/misc/private/positioned_tap_detector_2_test.dart

@@ -0,0 +1,80 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_map/src/misc/private/positioned_tap_detector_2.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Test tap is detected where expected.', (tester) async {
+    const screenSize = Size(400, 400);
+    await tester.binding.setSurfaceSize(screenSize);
+
+    // PositionedTapDetector2 fills the full screen.
+    Offset? lastTap;
+    final widget = PositionedTapDetector2(
+      onTap: (position) => lastTap = position.relative,
+      child: SizedBox(
+        width: screenSize.width,
+        height: screenSize.height,
+        child: Container(
+          color: Colors.red,
+        ),
+      ),
+    );
+
+    await tester.pumpWidget(widget);
+
+    Future<void> tap(Offset pos) async {
+      lastTap = null;
+      await tester.tapAt(pos);
+      expect(lastTap, pos);
+    }
+
+    // Tap top left
+    await tap(Offset.zero);
+    // Tap middle
+    await tap(Offset(screenSize.width / 2, screenSize.height / 2));
+    // Tap bottom right
+    await tap(Offset(screenSize.width - 1, screenSize.height - 1));
+  });
+
+  testWidgets('Test tap is detected where expected with scale and offset.',
+      (tester) async {
+    const screenSize = Size(400, 400);
+    await tester.binding.setSurfaceSize(screenSize);
+
+    Offset? lastTap;
+    // The Transform.scale fills the screen, but the PositionedTapDetector2
+    // occupies the center, with height of 200 (0.5 * 400) and width 400.
+    final widget = Transform.scale(
+      scaleY: 0.5,
+      child: PositionedTapDetector2(
+        onTap: (position) => lastTap = position.relative,
+        child: SizedBox(
+          width: screenSize.width,
+          height: screenSize.height,
+          child: Container(
+            color: Colors.red,
+          ),
+        ),
+      ),
+    );
+
+    await tester.pumpWidget(widget);
+
+    // On the screen the PositionedTapDetector2 is actually 400x200, but the
+    // widget thinks its 400x400.
+    expect(screenSize, tester.getSize(find.byType(SizedBox)));
+
+    Future<void> tap(Offset pos, Offset expected) async {
+      lastTap = null;
+      await tester.tapAt(pos);
+      expect(lastTap, expected);
+    }
+
+    // Tap top left of PositionedTapDetector2 which should be 0,0.
+    await tap(const Offset(0, 100), Offset.zero);
+
+    // Tap bottom right of PositionedTapDetector2
+    await tap(const Offset(400 - 1, 300 - 0.5),
+        Offset(screenSize.width - 1, screenSize.height - 1));
+  });
+}