guru_sdk/guru_ui/lib/widget/image/adaptive_image.dart

import 'dart:io';

import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:guru_utils/http/http_ex.dart';
import 'package:guru_utils/uri/uri_utils.dart';

/// Created by Haoyi on 2022/9/7

class AdaptiveImage extends StatelessWidget {
  final String uri;

  /// If non-null, require the image to have this width.
  ///
  /// If null, the image will pick a size that best preserves its intrinsic
  /// aspect ratio.
  ///
  /// It is strongly recommended that either both the [width] and the [height]
  /// be specified, or that the widget be placed in a context that sets tight
  /// layout constraints, so that the image does not change size as it loads.
  /// Consider using [fit] to adapt the image's rendering to fit the given width
  /// and height if the exact image dimensions are not known in advance.
  final double? width;

  /// If non-null, require the image to have this height.
  ///
  /// If null, the image will pick a size that best preserves its intrinsic
  /// aspect ratio.
  ///
  /// It is strongly recommended that either both the [width] and the [height]
  /// be specified, or that the widget be placed in a context that sets tight
  /// layout constraints, so that the image does not change size as it loads.
  /// Consider using [fit] to adapt the image's rendering to fit the given width
  /// and height if the exact image dimensions are not known in advance.
  final double? height;

  /// If non-null, this color is blended with each image pixel using [colorBlendMode].
  final Color? color;

  /// If non-null, the value from the [Animation] is multiplied with the opacity
  /// of each image pixel before painting onto the canvas.
  ///
  /// This is more efficient than using [FadeTransition] to change the opacity
  /// of an image, since this avoids creating a new composited layer. Composited
  /// layers may double memory usage as the image is painted onto an offscreen
  /// render target.
  ///
  /// See also:
  ///
  ///  * [AlwaysStoppedAnimation], which allows you to create an [Animation]
  ///    from a single opacity value.
  final Animation<double>? opacity;

  /// The rendering quality of the image.
  ///
  /// If the image is of a high quality and its pixels are perfectly aligned
  /// with the physical screen pixels, extra quality enhancement may not be
  /// necessary. If so, then [FilterQuality.none] would be the most efficient.
  ///
  /// If the pixels are not perfectly aligned with the screen pixels, or if the
  /// image itself is of a low quality, [FilterQuality.none] may produce
  /// undesirable artifacts. Consider using other [FilterQuality] values to
  /// improve the rendered image quality in this case. Pixels may be misaligned
  /// with the screen pixels as a result of transforms or scaling.
  ///
  /// See also:
  ///
  ///  * [FilterQuality], the enum containing all possible filter quality
  ///    options.
  final FilterQuality filterQuality;

  /// Used to combine [color] with this image.
  ///
  /// The default is [BlendMode.srcIn]. In terms of the blend mode, [color] is
  /// the source and this image is the destination.
  ///
  /// See also:
  ///
  ///  * [BlendMode], which includes an illustration of the effect of each blend mode.
  final BlendMode? colorBlendMode;

  /// How to inscribe the image into the space allocated during layout.
  ///
  /// The default varies based on the other fields. See the discussion at
  /// [paintImage].
  final BoxFit? fit;

  /// How to align the image within its bounds.
  ///
  /// The alignment aligns the given position in the image to the given position
  /// in the layout bounds. For example, an [Alignment] alignment of (-1.0,
  /// -1.0) aligns the image to the top-left corner of its layout bounds, while an
  /// [Alignment] alignment of (1.0, 1.0) aligns the bottom right of the
  /// image with the bottom right corner of its layout bounds. Similarly, an
  /// alignment of (0.0, 1.0) aligns the bottom middle of the image with the
  /// middle of the bottom edge of its layout bounds.
  ///
  /// To display a subpart of an image, consider using a [CustomPainter] and
  /// [Canvas.drawImageRect].
  ///
  /// If the [alignment] is [TextDirection]-dependent (i.e. if it is a
  /// [AlignmentDirectional]), then an ambient [Directionality] widget
  /// must be in scope.
  ///
  /// Defaults to [Alignment.center].
  ///
  /// See also:
  ///
  ///  * [Alignment], a class with convenient constants typically used to
  ///    specify an [AlignmentGeometry].
  ///  * [AlignmentDirectional], like [Alignment] for specifying alignments
  ///    relative to text direction.
  final AlignmentGeometry alignment;

  /// A builder that specifies the widget to display to the user while an image
  /// is still loading.
  ///
  /// If this is null, and the image is loaded incrementally (e.g. over a
  /// network), the user will receive no indication of the progress as the
  /// bytes of the image are loaded.
  ///
  /// For more information on how to interpret the arguments that are passed to
  /// this builder, see the documentation on [ImageLoadingBuilder].
  ///
  /// ## Performance implications
  ///
  /// If a [loadingBuilder] is specified for an image, the [Image] widget is
  /// likely to be rebuilt on every
  /// [rendering pipeline frame](rendering/RendererBinding/drawFrame.html) until
  /// the image has loaded. This is useful for cases such as displaying a loading
  /// progress indicator, but for simpler cases such as displaying a placeholder
  /// widget that doesn't depend on the loading progress (e.g. static "loading"
  /// text), [frameBuilder] will likely work and not incur as much cost.
  ///
  /// ## Chaining with [frameBuilder]
  ///
  /// If a [frameBuilder] has _also_ been specified for an image, the two
  /// builders will be chained together: the `child` argument to this
  /// builder will contain the _result_ of the [frameBuilder]. For example,
  /// consider the following builders used in conjunction:
  ///
  /// {@macro flutter.widgets.Image.frameBuilder.chainedBuildersExample}
  ///
  /// {@tool dartpad}
  /// The following sample uses [loadingBuilder] to show a
  /// [CircularProgressIndicator] while an image loads over the network.
  ///
  /// ** See code in examples/api/lib/widgets/image/image.loading_builder.0.dart **
  /// {@end-tool}
  ///
  /// Run against a real-world image on a slow network, the previous example
  /// renders the following loading progress indicator while the image loads
  /// before rendering the completed image.
  ///
  /// {@animation 400 400 https://flutter.github.io/assets-for-api-docs/assets/widgets/loading_progress_image.mp4}
  final ImageLoadingBuilder? loadingBuilder;

  /// A builder function that is called if an error occurs during image loading.
  ///
  /// If this builder is not provided, any exceptions will be reported to
  /// [FlutterError.onError]. If it is provided, the caller should either handle
  /// the exception by providing a replacement widget, or rethrow the exception.
  ///
  /// {@tool dartpad}
  /// The following sample uses [errorBuilder] to show a '😢' in place of the
  /// image that fails to load, and prints the error to the console.
  ///
  /// ** See code in examples/api/lib/widgets/image/image.error_builder.0.dart **
  /// {@end-tool}
  final ImageErrorWidgetBuilder? errorBuilder;

  final UriType uriType;

  AdaptiveImage(this.uri,
      {Key? key,
        this.width,
        this.height,
        this.loadingBuilder,
        this.errorBuilder,
        this.color,
        this.opacity,
        this.colorBlendMode,
        this.fit,
        this.alignment = Alignment.center,
        this.filterQuality = FilterQuality.low})
      : uriType = UriUtils.parseUriType(uri),
        super(key: key);

  @override
  Widget build(BuildContext context) {
    late ImageProvider _provider;
    switch (uriType) {
      case UriType.assets:
        _provider = AssetImage(uri);
        break;
      case UriType.file:
        _provider = FileImage(File(uri));
        break;
      default:
        _provider = CachedNetworkImageProvider(HttpEx.selectCdn(Uri.parse(uri)).uri.toString());
        break;
    }
    return Image(
      image: _provider,
      width: width,
      height: height,
      color: color,
      opacity: opacity,
      colorBlendMode: colorBlendMode,
      fit: fit,
      alignment: alignment,
      filterQuality: filterQuality,
      loadingBuilder: loadingBuilder,
      errorBuilder: errorBuilder,
    );
  }
}