java/debugger/impl/src/com/intellij/debugger/engine/evaluation/expression/ConditionalExpressionEvaluator.java

/*
 * Copyright 2000-2009 JetBrains s.r.o.
 *
 * 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.
 */

/*
 * Class ConditionalExpressionEvaluator
 * @author Jeka
 */
package com.intellij.debugger.engine.evaluation.expression;

import com.intellij.debugger.DebuggerBundle;
import com.intellij.debugger.engine.evaluation.EvaluateException;
import com.intellij.debugger.engine.evaluation.EvaluateExceptionUtil;
import com.intellij.debugger.engine.evaluation.EvaluationContextImpl;
import com.sun.jdi.BooleanValue;
import com.sun.jdi.Value;

class ConditionalExpressionEvaluator implements Evaluator {
  private final Evaluator myConditionEvaluator;
  private final Evaluator myThenEvaluator;
  private final Evaluator myElseEvaluator;

  public ConditionalExpressionEvaluator(Evaluator conditionEvaluator, Evaluator thenEvaluator, Evaluator elseEvaluator) {
    myConditionEvaluator = conditionEvaluator;
    myThenEvaluator = thenEvaluator;
    myElseEvaluator = elseEvaluator;
  }

  @Override
  public Modifier getModifier() {
    return null;
  }

  @Override
  public Object evaluate(EvaluationContextImpl context) throws EvaluateException {
    Value condition = (Value)myConditionEvaluator.evaluate(context);
    if (condition == null || !(condition instanceof BooleanValue)) {
      throw EvaluateExceptionUtil.createEvaluateException(DebuggerBundle.message("evaluation.error.boolean.condition.expected"));
    }
    return ((BooleanValue)condition).booleanValue()? myThenEvaluator.evaluate(context) : myElseEvaluator.evaluate(context);
  }
}