floating_overlay 1.2.1

A widget wrapper that allows a floating widget be dragged and rescaled.

example/lib/main.dart

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

import 'package:provider/provider.dart';

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

class App extends StatelessWidget {
  const App({Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    // Create one of this and pass it to the FloatingOverlay, to be able to pop
    // and push new pages and the floating overlay don't continue showing in
    // all new pages on top and show again when you come back
    final routeObserver = RouteObserver();
    return MaterialApp(
      title: 'Floating Overlay Example',
      navigatorObservers: [routeObserver], // Give it to the main materialApp
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Provider<RouteObserver>(
        // One way to make it avaliable through all your files and pages, but
        // global variables and other means will work just fine as well.
        create: (_) => routeObserver,
        child: const HomePage(),
      ),
    );
  }
}

class HomePage extends StatelessWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final controller = FloatingOverlayController.absoluteSize(
      maxSize: const Size(200, 200),
      minSize: const Size(100, 100),
      padding: const EdgeInsets.all(20.0),
      constrained: true,
    );
    final routeObserver = Provider.of<RouteObserver>(context, listen: false);
    return Scaffold(
      appBar: AppBar(
        title: const Text('Floating Overlay Example'),
        centerTitle: true,
      ),
      body: FloatingOverlay(
        // Passing the RouteObserver created at line 17 as a parameter, will
        // make so that when you push pages on top of this one, the floating
        // child will vanish and reappear when you return.
        routeObserver: routeObserver,
        controller: controller,
        floatingChild: SizedBox.square(
          dimension: 100.0,
          child: Container(
            decoration: BoxDecoration(
              color: Theme.of(context).primaryColor,
              border: Border.all(
                color: Colors.black,
                width: 5.0,
              ),
            ),
          ),
        ),
        child: Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              CustomButton(
                title: 'Toggle Overlay',
                onPressed: () {
                  controller.toggle();
                },
              ),
              CustomButton(
                title: 'Set Screen Center Offset',
                onPressed: () {
                  final size = MediaQuery.of(context).size;
                  final rect = Rect.fromPoints(
                    Offset.zero,
                    Offset(size.width, size.height),
                  );
                  controller.offset = rect.center;
                },
              ),
              CustomButton(
                title: 'Set Scale to 2.0',
                onPressed: () {
                  controller.scale = 2.0;
                },
              ),
              CustomButton(
                title: 'New Page',
                onPressed: () {
                  Navigator.of(context).push(
                    MaterialPageRoute(builder: (context) => const NewPage()),
                  );
                },
              ),
              CustomButton(
                title: 'New Page with AnimationController',
                onPressed: () {
                  Navigator.of(context).push(
                    MaterialPageRoute(
                      builder: (context) => Provider<RouteObserver>(
                        // There is a difference to initializing the
                        // controller inside a Stateful Widget that has an
                        // [AnimationController].
                        create: (_) => routeObserver,
                        child: const AnimationPage(),
                      ),
                    ),
                  );
                },
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class CustomButton extends StatelessWidget {
  const CustomButton({
    Key? key,
    required this.onPressed,
    required this.title,
  }) : super(key: key);

  final VoidCallback onPressed;
  final String title;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: ElevatedButton(
        child: Text(title),
        onPressed: onPressed,
      ),
    );
  }
}

class NewPage extends StatelessWidget {
  const NewPage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('New Page'), centerTitle: true),
    );
  }
}

class AnimationPage extends StatefulWidget {
  const AnimationPage({Key? key}) : super(key: key);

  @override
  _AnimationPageState createState() => _AnimationPageState();
}

class _AnimationPageState extends State<AnimationPage>
    with SingleTickerProviderStateMixin {
  late final AnimationController animationController;
  late final FloatingOverlayController controller;

  @override
  void initState() {
    animationController = AnimationController(
      vsync: this,
      duration: const Duration(seconds: 1),
    );

    /// The [FloatingOverlayController] needs to be initialized only once when
    /// there is an [AnimationController] inside the same State.
    controller = FloatingOverlayController.absoluteSize(
      maxSize: const Size(200, 200),
      minSize: const Size(100, 100),
      padding: const EdgeInsets.all(20.0),
      constrained: true,
    );
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Floating Overlay Example'),
        centerTitle: true,
      ),
      body: FloatingOverlay(
        // Passing the RouteObserver created at line 17 as a parameter, will
        // make so that when you push pages on top of this one, the floating
        // child will vanish and reappear when you return.
        routeObserver: Provider.of<RouteObserver>(context, listen: false),
        controller: controller,
        floatingChild: SizedBox.square(
          dimension: 100.0,
          child: Container(
            decoration: BoxDecoration(
              color: Theme.of(context).primaryColor,
              border: Border.all(
                color: Colors.black,
                width: 5.0,
              ),
            ),
          ),
        ),
        child: Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: ElevatedButton(
                  child: const Text('Toggle Overlay'),
                  onPressed: () {
                    controller.toggle();
                  },
                ),
              ),
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: ElevatedButton(
                  child: const Text('New Page'),
                  onPressed: () {
                    Navigator.of(context).push(
                      MaterialPageRoute(builder: (context) => const NewPage()),
                    );
                  },
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}