# ConditionalOperators.java

    /*
     * Licensed to the Apache Software Foundation (ASF) under one or more
     * contributor license agreements.  See the NOTICE file distributed with
     * this work for additional information regarding copyright ownership.
     * The ASF licenses this file to You 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.apache.pdfbox.pdmodel.common.function.type4;

    import java.util.Stack;

    /**
     * Provides the conditional operators such as "if" and "ifelse".
     *
     */
    class ConditionalOperators
    {

        private ConditionalOperators()
        {
            // Private constructor.
        }

        /** Implements the "if" operator. */
        static class If implements Operator
        {
            @Override
            public void execute(ExecutionContext context)
            {
                Stack<Object> stack = context.getStack();
                InstructionSequence proc = (InstructionSequence)stack.pop();
                Boolean condition = (Boolean)stack.pop();
                if (condition)
                {
                    proc.execute(context);
                }
            }

        }

        /** Implements the "ifelse" operator. */
        static class IfElse implements Operator
        {
            @Override
            public void execute(ExecutionContext context)
            {
                Stack<Object> stack = context.getStack();
                InstructionSequence proc2 = (InstructionSequence)stack.pop();
                InstructionSequence proc1 = (InstructionSequence)stack.pop();
                Boolean condition = (Boolean)stack.pop();
                if (condition)
                {
                    proc1.execute(context);
                }
                else
                {
                    proc2.execute(context);
                }
            }

        }

    }