    001    // Copyright 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.plastic;
    016
    017    /**
    018     * Condition used with {@link InstructionBuilder#when(Condition, WhenCallback)}. Most conditions
    019     * pop the top element off the stack; some pop two elements.
    020     */
    021    public enum Condition
    022    {
    023        /** Is the top element of the stack null? */
    024        NULL,
    025
    026        /** Is the top element of the stack non-null? */
    027        NON_NULL,
    028
    029        /** Is the top element of the stack the integer zero? */
    030        ZERO,
    031
    032        /** Is the top element of the stack not the integer zero? */
    033        NON_ZERO,
    034
    035        /**
    036         * Compare two integer elements on the stack; branch if the deeper
    037         * element is less than the top element.
    038         */
    039        LESS_THAN,
    040
    041        /**
    042         * Compare two integer elements on the stack; branch if the deeper
    043         * element equal to the top element.
    044         */
    045        EQUAL,
    046
    047        /**
    048         * Compare two integer elements on the stack; branch if the deeper
    049         * element is not equal to the top element.
    050         */
    051        NOT_EQUAL,
    052
    053        /**
    054         * Compare two integer elements on the stack; branch if the deeper
    055         * element is greater than the top element.
    056         */
    057        GREATER;
    058    }