/*
 * 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 com.google.gwt.gen2.table.client.property;

/**
 * A simple property of a column.
 */
public abstract class ColumnProperty {
    /**
     * Type class used to register properties.
     */
    public abstract static class Type<P extends ColumnProperty> {
        private static int nextHashCode;
        private final int index;

        /**
         * Construct a new type.
         */
        public Type() {
            index = ++nextHashCode;
        }

        /**
         * Get the default property value of this type. This method should never
         * return null.
         *
         * @return the default (non null) property value
         */
        public abstract P getDefault();

        @Override
        public final int hashCode() {
            return index;
        }
    }
}