// Copyright 2015 The Chromium 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/services.dart'; import 'package:flutter/widgets.dart'; import 'constants.dart'; import 'theme.dart'; /// A circle that represents a user. /// /// Typically used with a user's profile image, or, in the absence of /// such an image, the user's initials. A given user's initials should /// always be paired with the same background color, for consistency. /// /// If the avatar is to have an image, the image should be specified in the /// [backgroundImage] property: /// /// ```dart /// new CircleAvatar( /// backgroundImage: new NetworkImage(userAvatarUrl), /// ) /// ``` /// /// The image will be cropped to have a circle shape. /// /// If the avatar is to just have the user's initials, they are typically /// provided using a [Text] widget as the [child] and a [backgroundColor]: /// /// ```dart /// new CircleAvatar( /// backgroundColor: Colors.brown[800], /// child: new Text('AH'), /// ); /// ``` /// /// See also: /// /// * [Chip], for representing users or concepts in long form. /// * [ListItem], which combines an icon (such as a [CircleAvatar]) with some /// text in a horizontal row. /// * <https://material.google.com/components/chips.html#chips-contact-chips> class CircleAvatar extends StatelessWidget { /// Creates a circle that represents a user. CircleAvatar({ Key key, this.child, this.backgroundColor, this.backgroundImage, this.radius: 20.0 }) : super(key: key); /// The widget below this widget in the tree. /// /// Typically a [Text] widget. If the [CircleAvatar] is to have an image, use /// [backgroundImage] instead. final Widget child; /// The color with which to fill the circle. Changing the background /// color will cause the avatar to animate to the new color. final Color backgroundColor; /// The background image of the circle. Changing the background /// image will cause the avatar to animate to the new image. /// /// If the [CircleAvatar] is to have the user's initials, use [child] instead. final ImageProvider backgroundImage; /// The size of the avatar. Changing the radius will cause the /// avatar to animate to the new size. /// /// Defaults to 20 logical pixels. final double radius; @override Widget build(BuildContext context) { final ThemeData theme = Theme.of(context); final Color color = backgroundColor ?? theme.primaryColor; return new AnimatedContainer( width: radius * 2.0, height: radius * 2.0, duration: kThemeChangeDuration, decoration: new BoxDecoration( backgroundColor: color, backgroundImage: backgroundImage != null ? new BackgroundImage( image: backgroundImage ) : null, shape: BoxShape.circle, ), child: child != null ? new Center( child: new DefaultTextStyle( style: theme.primaryTextTheme.title, child: child, ) ) : null, ); } }