fluffychat/lib/widgets/content_banner.dart

import 'dart:ui';

import 'package:flutter/material.dart';

import 'package:cached_network_image/cached_network_image.dart';
import 'package:matrix/matrix.dart';

import 'matrix.dart';

class ContentBanner extends StatelessWidget {
  final Uri? mxContent;
  final double height;
  final IconData defaultIcon;
  final bool loading;
  final void Function()? onEdit;
  final Client? client;
  final double opacity;

  const ContentBanner(
      {this.mxContent,
      this.height = 400,
      this.defaultIcon = Icons.people_outlined,
      this.loading = false,
      this.onEdit,
      this.client,
      this.opacity = 0.75,
      Key? key})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    final onEdit = this.onEdit;
    return Container(
      height: height,
      alignment: Alignment.center,
      decoration: BoxDecoration(
        color: Theme.of(context).secondaryHeaderColor,
      ),
      child: Stack(
        children: <Widget>[
          Positioned(
            left: 0,
            right: 0,
            top: 0,
            bottom: 0,
            child: Opacity(
              opacity: opacity,
              child: (!loading)
                  ? LayoutBuilder(builder:
                      (BuildContext context, BoxConstraints constraints) {
                      // #775 don't request new image resolution on every resize
                      // by rounding up to the next multiple of stepSize
                      const stepSize = 300;
                      final bannerSize =
                          constraints.maxWidth * window.devicePixelRatio;
                      final steppedBannerSize =
                          (bannerSize / stepSize).ceil() * stepSize;
                      final src = mxContent?.getThumbnail(
                        client ?? Matrix.of(context).client,
                        width: steppedBannerSize,
                        height: steppedBannerSize,
                        method: ThumbnailMethod.scale,
                        animated: true,
                      );
                      return CachedNetworkImage(
                        imageUrl: src.toString(),
                        height: 300,
                        fit: BoxFit.cover,
                        errorWidget: (c, m, e) => Icon(defaultIcon, size: 200),
                      );
                    })
                  : Icon(defaultIcon, size: 200),
            ),
          ),
          if (onEdit != null)
            Container(
              margin: const EdgeInsets.all(8),
              alignment: Alignment.bottomRight,
              child: FloatingActionButton(
                mini: true,
                onPressed: onEdit,
                backgroundColor: Theme.of(context).backgroundColor,
                foregroundColor: Theme.of(context).textTheme.bodyText1?.color,
                child: const Icon(Icons.camera_alt_outlined),
              ),
            ),
        ],
      ),
    );
  }
}