/*******************************************************************************
* Copyright (c) 2007, 2010 Association for Decentralized Information Management
* in Industry THTH ry.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* VTT Technical Research Centre of Finland - initial API and implementation
*******************************************************************************/
package org.simantics.browsing.ui.common;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* The default implementation of EvaluatorData
.
*
*
* Evaluator
s can be added by invoking
* {@link #addEvaluator(Class, org.simantics.browsing.ui.common.EvaluatorData.Evaluator)
* or {@link #addEvaluators(Class, Collection)}. The specified
* Evaluator
or collection of Evaluator
s are bound to
* the specified Java class. The reason for such a binding is that the
* implementation of {@link #get(Object)} is based on comparing the input object
* class to the classes specified to the addEvaluator
methods. The
* comparison works so that an Evaluator
will be added to the
* result of {@link #get(Object)} if:
*
*
* - the input object is assignable to the
Evaluator
's class
*
*
*
* This implementation keeps a Class
→Evaluator
* cache of previous results thus quickly producing results for a given input
* object class after the result has been cached. Note that there is no way to
* reset the cache, i.e. this class is intended to be initialized once, used
* after that and finally thrown away. Do not add evaluators once in use, they
* may or may not be reflected in the results.
*
*
* @author Tuukka Lehtonen
*/
public class EvaluatorDataImpl implements EvaluatorData {
private static final boolean DEBUG = false;
/**
* Contains only the original evaluator associations made directly by the
* client. This is used for initializing the evaluators
cache
* for different inputs.
*/
protected HashMap, Collection> originals = new HashMap, Collection>();
/**
* A cache that is only modified by
* {@link #findAndCacheEvaluatorsForClass(Class)}. This map is not filled in
* by client's initialization efforts.
*/
protected HashMap, Collection> evaluators = new HashMap, Collection>();
private Object browseContext;
public EvaluatorDataImpl() {
}
public void setBrowseContext(Object browseContext) {
this.browseContext = browseContext;
}
@Override
public Evaluator newEvaluator() {
return new EvaluatorImpl();
}
private synchronized void addEvaluator(HashMap, Collection> map, Class> clazz, Evaluator eval) {
Collection es = map.get(clazz);
if (es == null) {
es = new ArrayList();
map.put(clazz, es);
}
es.add(eval);
if (DEBUG) {
// new Exception().printStackTrace();
System.out.println("EvaluatorDataImpl: ADDED Evaluator: " + clazz + ": " + eval);
}
}
private synchronized void addEvaluators(HashMap, Collection> map, Class> clazz, Collection evals) {
Collection es = map.get(clazz);
if (es == null) {
es = new ArrayList();
map.put(clazz, es);
}
es.addAll(evals);
if (DEBUG)
System.out.println("EvaluatorDataImpl: ADDED Evaluators: " + clazz + ": " + evals);
}
public synchronized void addEvaluator(Class> clazz, Evaluator eval) {
addEvaluator(originals, clazz, eval);
}
public synchronized void addEvaluators(Class> clazz, Collection evals) {
addEvaluators(originals, clazz, evals);
}
@Override
public Collection get(Object object) {
Class> clazz = object.getClass();
Collection evaluator = evaluators.get(clazz);
if (evaluator != null) {
if (DEBUG)
System.out.println("EvaluatorDataImpl: get cached: " + clazz + ": " + evaluator);
return evaluator;
}
Collection evals = findAndCacheEvaluatorsForClass(clazz);
if (DEBUG) {
System.out.println("EvaluatorDataImpl: get: " + clazz + ": " + evals);
if (evals.isEmpty()) {
System.out.println("EvaluatorDataImpl: no match, evaluators available:");
for (Map.Entry, Collection> e : evaluators.entrySet()) {
if (!e.getValue().isEmpty())
System.out.println(" " + e.getKey() + " : " + e.getValue());
}
}
}
return evals;
}
private synchronized Collection findAndCacheEvaluatorsForClass(Class> clazz) {
if (DEBUG)
System.out.println("EvaluatorDataImpl: caching evaluators for " + clazz);
Set> usedClasses = new HashSet>();
Set used = new HashSet();
Collection result = new ArrayList();
Deque> fifo = new ArrayDeque>();
fifo.add(clazz);
while (!fifo.isEmpty()) {
Class> c = fifo.removeFirst();
if (!usedClasses.add(c))
continue;
Class> superClass = c.getSuperclass();
if (superClass != null)
fifo.addLast(superClass);
for (Class> i : c.getInterfaces())
fifo.addLast(i);
Collection evals = originals.get(c);
if (evals != null)
for (Evaluator eval : evals)
if (used.add(eval))
result.add(eval);
}
if (result.isEmpty()) {
result = Collections.emptyList();
}
evaluators.put(clazz, result);
return result;
}
@Override
public Collection enumEvaluators() {
Collection result = new ArrayList();
for (Map.Entry, Collection> entry : originals.entrySet()) {
result.add(new EvaluatorEntryImpl(entry.getKey(), entry.getValue()));
}
return result;
}
static class EvaluatorEntryImpl implements EvaluatorEntry {
private final Class> clazz;
private final Collection evaluators;
public EvaluatorEntryImpl(Class> clazz, Collection evaluators) {
this.clazz = clazz;
this.evaluators = evaluators;
}
@Override
public Class> getClazz() {
return clazz;
}
@Override
public Collection getEvaluators() {
return evaluators;
}
@Override
public String toString() {
return "class " + clazz.getSimpleName();
}
}
@SuppressWarnings("unchecked")
@Override
public T getBrowseContext() {
return (T)browseContext;
}
}