flutter/examples/api/lib/widgets/routes/popup_route.0.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';

/// Flutter code sample for [PopupRoute].

void main() => runApp(const PopupRouteApp());

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: PopupRouteExample(),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: OutlinedButton(
          onPressed: () {
            // This shows a dismissible dialog.
            Navigator.of(context).push(DismissibleDialog<void>());
          },
          child: const Text('Open DismissibleDialog'),
        ),
      ),
    );
  }
}

class DismissibleDialog<T> extends PopupRoute<T> {
  @override
  Color? get barrierColor => Colors.black.withAlpha(0x50);

  // This allows the popup to be dismissed by tapping the scrim or by pressing
  // the escape key on the keyboard.
  @override
  bool get barrierDismissible => true;

  @override
  String? get barrierLabel => 'Dismissible Dialog';

  @override
  Duration get transitionDuration => const Duration(milliseconds: 300);

  @override
  Widget buildPage(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
    return Center(
      // Provide DefaultTextStyle to ensure that the dialog's text style
      // matches the rest of the text in the app.
      child: DefaultTextStyle(
        style: Theme.of(context).textTheme.bodyMedium!,
        // UnconstrainedBox is used to make the dialog size itself
        // to fit to the size of the content.
        child: UnconstrainedBox(
          child: Container(
            padding: const EdgeInsets.all(20.0),
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(10),
              color: Colors.white,
            ),
            child: Column(
              children: <Widget>[
                Text('Dismissible Dialog', style: Theme.of(context).textTheme.headlineSmall),
                const SizedBox(height: 20),
                const Text('Tap in the scrim or press escape key to dismiss.'),
              ],
            ),
          ),
        ),
      ),
    );
  }
}