| // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| library barback.asset_set; |
| |
| import 'dart:collection'; |
| |
| import 'asset.dart'; |
| import 'asset_id.dart'; |
| |
| /// A set of [Asset]s with distinct IDs. |
| /// |
| /// This uses the [AssetId] of each asset to determine uniqueness, so no two |
| /// assets with the same ID can be in the set. |
| class AssetSet extends IterableBase<Asset> { |
| final _assets = new Map<AssetId, Asset>(); |
| |
| AssetSet(); |
| |
| /// Creates a new AssetSet from the contents of [other]. |
| /// |
| /// If multiple assets in [other] have the same id, the last one takes |
| /// precedence. |
| AssetSet.from(Iterable<Asset> other) { |
| for (var asset in other) { |
| _assets[asset.id] = asset; |
| } |
| } |
| |
| Iterator<Asset> get iterator => _assets.values.iterator; |
| |
| int get length => _assets.length; |
| |
| /// Gets the [Asset] in the set with [id], or returns `null` if no asset with |
| /// that ID is present. |
| Asset operator[](AssetId id) => _assets[id]; |
| |
| /// Adds [asset] to the set. |
| /// |
| /// If there is already an asset with that ID in the set, it is replaced by |
| /// the new one. Returns [asset]. |
| Asset add(Asset asset) { |
| _assets[asset.id] = asset; |
| return asset; |
| } |
| |
| /// Adds [assets] to the set. |
| void addAll(Iterable<Asset> assets) { |
| assets.forEach(add); |
| } |
| |
| /// Returns `true` if the set contains [asset]. |
| bool contains(Asset asset) { |
| var other = _assets[asset.id]; |
| return other == asset; |
| } |
| |
| /// Returns `true` if the set contains an [Asset] with [id]. |
| bool containsId(AssetId id) { |
| return _assets.containsKey(id); |
| } |
| |
| /// If the set contains an [Asset] with [id], removes and returns it. |
| Asset removeId(AssetId id) => _assets.remove(id); |
| |
| /// Removes all assets from the set. |
| void clear() { |
| _assets.clear(); |
| } |
| } |