plugins/IntentionPowerPak/src/com/siyeh/ipp/psiutils/BoolUtils.java

/*
 * Copyright 2003-2014 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.psiutils;

import com.intellij.psi.*;
import com.intellij.psi.tree.IElementType;
import com.siyeh.ig.psiutils.ComparisonUtils;
import com.siyeh.ig.psiutils.ParenthesesUtils;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.Nullable;

public class BoolUtils {

  private BoolUtils() {}

  public static boolean isNegated(PsiExpression exp) {
    PsiExpression ancestor = exp;
    PsiElement parent = ancestor.getParent();
    while (parent instanceof PsiParenthesizedExpression) {
      ancestor = (PsiExpression)parent;
      parent = ancestor.getParent();
    }
    if (parent instanceof PsiPrefixExpression) {
      final PsiPrefixExpression prefixAncestor = (PsiPrefixExpression)parent;
      final IElementType tokenType = prefixAncestor.getOperationTokenType();
      if (tokenType.equals(JavaTokenType.EXCL)) {
        return true;
      }
    }
    return false;
  }

  @Nullable
  public static PsiExpression findNegation(PsiExpression expression) {
    PsiExpression ancestor = expression;
    PsiElement parent = ancestor.getParent();
    while (parent instanceof PsiParenthesizedExpression) {
      ancestor = (PsiExpression)parent;
      parent = ancestor.getParent();
    }
    if (parent instanceof PsiPrefixExpression) {
      final PsiPrefixExpression prefixAncestor = (PsiPrefixExpression)parent;
      if (JavaTokenType.EXCL.equals(prefixAncestor.getOperationTokenType())) {
        return prefixAncestor;
      }
    }
    return null;
  }

  public static boolean isNegation(PsiExpression exp) {
    if (!(exp instanceof PsiPrefixExpression)) {
      return false;
    }
    final PsiPrefixExpression prefixExp = (PsiPrefixExpression)exp;
    final IElementType tokenType = prefixExp.getOperationTokenType();
    return tokenType.equals(JavaTokenType.EXCL);
  }

  @Nullable
  public static PsiExpression getNegated(PsiExpression expression) {
    if (!(expression instanceof PsiPrefixExpression)) {
      return null;
    }
    final PsiPrefixExpression prefixExpression = (PsiPrefixExpression)expression;
    final IElementType tokenType = prefixExpression.getOperationTokenType();
    if (!JavaTokenType.EXCL.equals(tokenType)) {
      return null;
    }
    final PsiExpression operand = prefixExpression.getOperand();
    return ParenthesesUtils.stripParentheses(operand);
  }

  public static boolean isBooleanLiteral(PsiExpression expression) {
    if (!(expression instanceof PsiLiteralExpression)) {
      return false;
    }
    final PsiLiteralExpression literalExpression = (PsiLiteralExpression)expression;
    @NonNls final String text = literalExpression.getText();
    return PsiKeyword.TRUE.equals(text) || PsiKeyword.FALSE.equals(text);
  }

  public static String getNegatedExpressionText(@Nullable PsiExpression condition) {
    if (condition == null) {
      return "";
    }
    if (condition instanceof PsiParenthesizedExpression) {
      final PsiParenthesizedExpression parenthesizedExpression = (PsiParenthesizedExpression)condition;
      final PsiExpression expression = parenthesizedExpression.getExpression();
      return '(' + getNegatedExpressionText(expression) + ')';
    }
    else if (isNegation(condition)) {
      final PsiExpression negated = getNegated(condition);
      if (negated == null) {
        return "";
      }
      return negated.getText();
    }
    else if (ComparisonUtils.isComparison(condition)) {
      final PsiBinaryExpression binaryExpression = (PsiBinaryExpression)condition;
      final String negatedComparison = ComparisonUtils.getNegatedComparison(binaryExpression.getOperationTokenType());
      final PsiExpression lhs = binaryExpression.getLOperand();
      final PsiExpression rhs = binaryExpression.getROperand();
      if (rhs == null) {
        return lhs.getText() + negatedComparison;
      }
      return lhs.getText() + negatedComparison + rhs.getText();
    }
    else if (ParenthesesUtils.getPrecedence(condition) > ParenthesesUtils.PREFIX_PRECEDENCE) {
      return "!(" + condition.getText() + ')';
    }
    else {
      return '!' + condition.getText();
    }
  }
}