No accessibility support (Talkback), if backdropEnabled is true

[nilsreichardt]

Description

If backdropEnabled is true, all widgets behind the SlidingUpPanel can't be detected by a screen reader anymore. This is very cricitle, because the whole app (except the SlidingUpPanel widget) can't be used with a screen reader. With this bug it's nearly impossible to get featured by Apple...

Demo

backdropEnabled is true (no accessibility support ❌ )

backdropEnabled is false (accessibility support ✅ )

Steps to reproduce

Code to reproduce

import 'package:flutter/material.dart';
import 'package:sliding_up_panel/sliding_up_panel.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Demo',
      home: Scaffold(
        appBar: AppBar(
          title: Text("SlidingUpPanelExample"),
        ),
        body: SlidingUpPanel(
          backdropEnabled: true, // <-- This is the problem
          panel: Center(
            child: Text("This is the sliding Widget"),
          ),
          body: Center(
            child: Text("This Text can't be read by screen readers :("),
          ),
        ),
      ),
    );
  }
}

1. Copy code to reproduce
2. Run app
3. Enable a screen reader (like Talkback on Android)
4. Try to focus Text("This is the sliding Widget") with a screen reader --> impossible