/**
* Copyright 2009 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 org.waveprotocol.wave.model.document.util;
/**
* Property object for use by external handlers to add extra
* transient data to elements and guarantee their fields
* won't conflict
*
* @param <T>
*
* @author danilatos@google.com (Daniel Danilatos)
*/
public abstract class Property<T> {
private static int uniqueId;
private static class ImmutableProperty<T> extends Property<T> {
private ImmutableProperty(String debugName) {
super(debugName);
}
/** {@inheritDoc} */
@Override
public String toString() {
return "ImmutableProperty[" + getName() + "]";
}
}
private static class MutableProperty<T> extends Property<T> {
private MutableProperty(String debugName) {
super(debugName);
}
/** {@inheritDoc} */
@Override
public String toString() {
return "MutableProperty[" + getName() + "]";
}
}
/**
* Create a property that may be set more than once
*
* @param debugName Name that is useful for debugging
* @return A new property identifier
*/
public static <T> MutableProperty<T> mutable(String debugName) {
return new MutableProperty<T>(debugName == null ? "[unnamed]" : debugName);
}
/**
* Create a property that may only be set once
*
* @param debugName Name that is useful for debugging
* @return A new property identifier
*/
public static <T> ImmutableProperty<T> immutable(String debugName) {
return new ImmutableProperty<T>(debugName == null ? "[unnamed]" : debugName);
}
private final int id;
private final String name;
private Property(String debugName) {
id = ++uniqueId;
name = debugName;
}
/**
* @return The unique id of this property. The id is not guaranteed to be the
* same between application runs
*/
public int getId() {
return id;
}
String getName() {
return name;
}
}