import 'package:flutter/material.dart';

/// Display an icon button with a badge
///
/// Based from Medium article called "Notification Badge in Flutter"
///
/// @author Pierre Hubert

class IconButtonWithBadge extends StatelessWidget {
  final Widget icon;
  final void Function() onPressed;
  final int number;

  const IconButtonWithBadge({
    Key key,
    @required this.icon,
    @required this.onPressed,
    this.number = 0,
  })  : assert(icon != null),
        assert(number != null),
        super(key: key);

  @override
  Widget build(BuildContext context) {
    return Stack(
      alignment: AlignmentDirectional.center,
      children: <Widget>[
        IconButton(icon: icon, onPressed: onPressed),
        number != 0
            ? Positioned(
                right: 6,
                top: 6,
                child: Container(
                  padding: EdgeInsets.all(2),
                  decoration: BoxDecoration(
                    color: Colors.red,
                    borderRadius: BorderRadius.circular(6),
                  ),
                  constraints: BoxConstraints(minWidth: 14, minHeight: 14),
                  child: Text(
                    "$number",
                    style: TextStyle(color: Colors.white, fontSize: 12),
                    textAlign: TextAlign.center,
                  ),
                ))
            : Container()
      ],
    );
  }
}