How can I simulate a tap event on a Flutter widget? - dart

Question

How can I simulate tap event on a Flutter widget?
For example, how do I simulate tapping on a Tabbar title? And more importantly, how can I find the widget in the first place? Please note that I don't want to call the relevant callbacks, nor testing widgets using Flutter test classes, but I'd like to simulate the tapping on widgets at runtime instead.
EDIT 1: (Please Note)
I DO NOT want to test a widget or call a method that is assigned to a GestureDetector.onTap or RaisedButton.onPressed etc...

Answer 1

First, obtain a RenderBox. Then just call hitTest method. Any will do, as long as it's mounted in the tree.
To do so you'll have to use BuildContext through context.findRenderObject().
BuildContext context;
final renderObj = context.findRenderObject();
if (renderObj is RenderBox) {
final hitTestResult = HitTestResult();
if (renderObj.hitTest(hitTestResult, position: /* The offset where you want to "tap" */)) {
// a descendant of `renderObj` got tapped
print(hitTestResult.path);
}
}

Answer 2

Use GestureBinding to simulate a click event anywhere on the screen:
Full example:
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Column(
children: [
ElevatedButton(
onPressed: () {},
style: ElevatedButton.styleFrom(
primary: Colors.red[900],
),
child: SizedBox(
width: 400,
height: 400,
child: Center(child: Text("I'm a big button.")),
),
),
ElevatedButton(
onPressed: () async {
GestureBinding.instance!.handlePointerEvent(PointerDownEvent(
position: Offset(200, 300),
));
await Future.delayed(Duration(milliseconds: 500));
GestureBinding.instance!.handlePointerEvent(PointerUpEvent(
position: Offset(200, 300),
));
},
child: Text('Simulate Click'),
),
],
),
),
);
}
}