Reputation: 23

How can i make a moveable overlay?

I want to show a minimize moveable calling screen in top of the app

I tried with stack it does not meet my expectation

Upvotes: 1

Answers (3)

F.M.

Reputation: 760

Sadly the gif is not working... But by on taping and draging on the green window will make the green window move.

Try this:

import 'dart:math';

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return OverlayWindow(
      overlayChild: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: const [
          Text(
            "Overlay Window",
            style: TextStyle(fontSize: 20),
          ),
          Icon(
            Icons.android,
            size: 80,
          ),
        ],
      ),
      child: Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              const Text(
                'You have pushed the button this many times:',
              ),
              Text(
                '$_counter',
                style: Theme.of(context).textTheme.headlineMedium,
              ),
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: _incrementCounter,
          tooltip: 'Increment',
          child: const Icon(Icons.add),
        ),
      ),
    );
  }
}

class OverlayWindow extends StatefulWidget {
  const OverlayWindow(
      {Key? key, required this.overlayChild, required this.child})
      : super(key: key);

  final Widget overlayChild;
  final Widget child;

  @override
  State<OverlayWindow> createState() => _OverlayWindowState();
}

class _OverlayWindowState extends State<OverlayWindow> {
  double _top = 0;
  double _left = 0;

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        widget.child,
        Positioned(
          top: _top,
          left: _left,
          child: GestureDetector(
            onPanUpdate: (details) {
              setState(() {
                _top = max(0, _top + details.delta.dy);
                _left = max(0, _left + details.delta.dx);
              });
            },
            child: Container(
              height: 300,
              width: 200,
              color: Colors.green,
              child: widget.overlayChild,
            ),
          ),
        )
      ],
    );
  }
}

More about things like that, you can find here:

https://docs.flutter.dev/development/ui/advanced/gestures

Upvotes: 1