plugins/IntentionPowerPak/src/com/siyeh/ipp/trivialif/MergeIfAndIntention.java

/*
 * Copyright 2003-2013 Dave Griffith, Bas Leijdekkers
 *
 * 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.siyeh.ipp.trivialif;

import com.intellij.psi.*;
import com.intellij.util.IncorrectOperationException;
import com.siyeh.ig.PsiReplacementUtil;
import com.siyeh.ig.psiutils.ControlFlowUtils;
import com.siyeh.ig.psiutils.ParenthesesUtils;
import com.siyeh.ipp.base.Intention;
import com.siyeh.ipp.base.PsiElementPredicate;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

public class MergeIfAndIntention extends Intention {

  @NotNull
  public PsiElementPredicate getElementPredicate() {
    return new MergeIfAndPredicate();
  }

  public void processIntention(PsiElement element)
    throws IncorrectOperationException {
    final PsiJavaToken token =
      (PsiJavaToken)element;
    final PsiIfStatement parentStatement =
      (PsiIfStatement)token.getParent();
    if (parentStatement == null) {
      return;
    }
    final PsiStatement parentThenBranch = parentStatement.getThenBranch();
    final PsiIfStatement childStatement =
      (PsiIfStatement)ControlFlowUtils.stripBraces(parentThenBranch);
    final PsiExpression childCondition = childStatement.getCondition();
    if (childCondition == null) {
      return;
    }
    final String childConditionText;
    if (ParenthesesUtils.getPrecedence(childCondition)
        > ParenthesesUtils.AND_PRECEDENCE) {
      childConditionText = '(' + childCondition.getText() + ')';
    }
    else {
      childConditionText = childCondition.getText();
    }

    final PsiExpression parentCondition = parentStatement.getCondition();
    if (parentCondition == null) {
      return;
    }
    final String parentConditionText;
    if (ParenthesesUtils.getPrecedence(parentCondition)
        > ParenthesesUtils.AND_PRECEDENCE) {
      parentConditionText = '(' + parentCondition.getText() + ')';
    }
    else {
      parentConditionText = parentCondition.getText();
    }
    final PsiStatement childThenBranch = childStatement.getThenBranch();
    if (childThenBranch == null) {
      return;
    }
    @NonNls final String statement = "if(" + parentConditionText + "&&" +
                                     childConditionText + ')' + childThenBranch.getText();
    PsiReplacementUtil.replaceStatement(parentStatement, statement);
  }
}