| // 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.asset_node_set; |
| |
| import 'package:collection/collection.dart'; |
| |
| import 'asset_id.dart'; |
| import 'asset_node.dart'; |
| |
| /// A set of [AssetNode]s that automatically ensures that nodes are removed from |
| /// the set as soon as they're marked as [AssetState.REMOVED]. |
| /// |
| /// Asset nodes may be accessed by their ids. This means that only one node with |
| /// a given id may be stored in the set at a time. |
| class AssetNodeSet extends DelegatingSet<AssetNode> { |
| // TODO(nweiz): Use DelegatingMapSet when issue 18705 is fixed. |
| /// A map from asset ids to assets in the set. |
| final _assetsById = new Map<AssetId, AssetNode>(); |
| |
| AssetNodeSet() : super(new Set()); |
| |
| /// Returns the asset node in the set with [id], or `null` if none exists. |
| AssetNode operator [](AssetId id) => _assetsById[id]; |
| |
| bool add(AssetNode node) { |
| if (node.state.isRemoved) return false; |
| node.whenRemoved(() { |
| super.remove(node); |
| _assetsById.remove(node.id); |
| }); |
| _assetsById[node.id] = node; |
| return super.add(node); |
| } |
| |
| /// Returns whether an asset node with the given [id] is in the set. |
| bool containsId(AssetId id) => _assetsById.containsKey(id); |
| |
| void addAll(Iterable<AssetNode> nodes) => nodes.forEach(add); |
| } |