packages/flutter/test/painting/mocks_for_image_cache.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.

// @dart = 2.8

import 'dart:async';
import 'dart:ui' as ui show Image;

import 'package:flutter/foundation.dart';
import 'package:flutter/painting.dart';

class TestImageInfo implements ImageInfo {
  const TestImageInfo(this.value, { this.image, this.scale = 1.0, this.debugLabel });

  @override
  final ui.Image image;

  @override
  final double scale;

  @override
  final String debugLabel;

  final int value;

  @override
  String toString() => '$runtimeType($value)';
}

class TestImageProvider extends ImageProvider<int> {
  const TestImageProvider(this.key, this.imageValue, { @required this.image })
      : assert(image != null);

  final int key;
  final int imageValue;
  final ui.Image image;

  @override
  Future<int> obtainKey(ImageConfiguration configuration) {
    return Future<int>.value(key);
  }

  @override
  ImageStreamCompleter load(int key, DecoderCallback decode) {
    return OneFrameImageStreamCompleter(
      SynchronousFuture<ImageInfo>(TestImageInfo(imageValue, image: image))
    );
  }

  @override
  String toString() => '$runtimeType($key, $imageValue)';
}

class FailingTestImageProvider extends TestImageProvider {
  const FailingTestImageProvider(int key, int imageValue, { ui.Image image }) : super(key, imageValue, image: image);

  @override
  ImageStreamCompleter load(int key, DecoderCallback decode) {
    return OneFrameImageStreamCompleter(Future<ImageInfo>.sync(() => Future<ImageInfo>.error('loading failed!')));
  }
}

Future<ImageInfo> extractOneFrame(ImageStream stream) {
  final Completer<ImageInfo> completer = Completer<ImageInfo>();
  ImageStreamListener listener;
  listener = ImageStreamListener((ImageInfo image, bool synchronousCall) {
    completer.complete(image);
    stream.removeListener(listener);
  });
  stream.addListener(listener);
  return completer.future;
}

class ErrorImageProvider extends ImageProvider<ErrorImageProvider> {
  @override
  ImageStreamCompleter load(ErrorImageProvider key, DecoderCallback decode) {
    throw Error();
  }

  @override
  Future<ErrorImageProvider> obtainKey(ImageConfiguration configuration) {
    return SynchronousFuture<ErrorImageProvider>(this);
  }
}

class ObtainKeyErrorImageProvider extends ImageProvider<ObtainKeyErrorImageProvider> {
  @override
  ImageStreamCompleter load(ObtainKeyErrorImageProvider key, DecoderCallback decode) {
    throw Error();
  }

  @override
  Future<ObtainKeyErrorImageProvider> obtainKey(ImageConfiguration configuration) {
    throw Error();
  }
}

class LoadErrorImageProvider extends ImageProvider<LoadErrorImageProvider> {
  @override
  ImageStreamCompleter load(LoadErrorImageProvider key, DecoderCallback decode) {
    throw Error();
  }

  @override
  Future<LoadErrorImageProvider> obtainKey(ImageConfiguration configuration) {
    return SynchronousFuture<LoadErrorImageProvider>(this);
  }
}

class LoadErrorCompleterImageProvider extends ImageProvider<LoadErrorCompleterImageProvider> {
  @override
  ImageStreamCompleter load(LoadErrorCompleterImageProvider key, DecoderCallback decode) {
    final Completer<ImageInfo> completer = Completer<ImageInfo>.sync();
    completer.completeError(Error());
    return OneFrameImageStreamCompleter(completer.future);
  }

  @override
  Future<LoadErrorCompleterImageProvider> obtainKey(ImageConfiguration configuration) {
    return SynchronousFuture<LoadErrorCompleterImageProvider>(this);
  }
}

class TestImageStreamCompleter extends ImageStreamCompleter {
  void testSetImage(ui.Image image) {
    setImage(ImageInfo(image: image, scale: 1.0));
  }
}