/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.devtools.depan.eclipse.editors;
import com.google.devtools.depan.eclipse.trees.GraphData;
import com.google.devtools.depan.eclipse.trees.NodeTreeProvider;
import com.google.devtools.depan.graph.api.DirectedRelationFinder;
import com.google.devtools.depan.model.GraphModel;
import com.google.devtools.depan.model.GraphNode;
import com.google.devtools.depan.view.TreeModel;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import java.util.Collection;
import java.util.Map;
/**
* Maintain a set of known hierarchies over a set of nodes.
* This also create new hiearchies on demand,
* if the relation finder hasn't been seen before.
*
* @author <a href='mailto:leeca@google.com'>Lee Carver </a>
*/
public class HierarchyCache<T> {
private final NodeTreeProvider<T> provider;
private final GraphModel graph;
/**
* We store all the trees for now, which allows quick switch when changing
* from one view to another. If it's too memory consuming, we could change
* that easily.
*/
private Map<DirectedRelationFinder, GraphData<T>> hierarchies =
Maps.newHashMap();
/**
* Construct the cache, saving the values needed to create new hierarchies.
*
* @param provider source if information about nodes
* @param graph set of nodes for hierarchies.
*/
public HierarchyCache(NodeTreeProvider<T> provider, GraphModel graph) {
this.provider = provider;
this.graph = graph;
}
/**
* Provide a description of a hierarchy ({@code GraphData}) based on the
* internal set of nodes and the provided set of relations. A new
* {@code GraphData} is created if the {@code relFinder} has not been
* used before.
*
* @param relFinder relations to use for hierarchy construction
* @return description of hierarchy
*/
public GraphData<T> getHierarchy(DirectedRelationFinder relFinder) {
if (!hierarchies.containsKey(relFinder)) {
GraphData<T> result =
GraphData.createGraphData(provider, graph, relFinder);
hierarchies.put(relFinder, result);
}
return hierarchies.get(relFinder);
}
public GraphData<T> allNodes() {
Collection<GraphNode> nodes = graph.getNodes();
TreeModel hierarchy = new TreeModel.Flat(nodes);
return new GraphData<T>(provider, hierarchy );
}
public GraphData<T> excludedNodes(Collection<GraphNode> included) {
Collection<GraphNode> nodes = Lists.newArrayList(graph.getNodes());
nodes.removeAll(included);
TreeModel hierarchy = new TreeModel.Flat(nodes);
return new GraphData<T>(provider, hierarchy );
}
}