| /* |
| * Copyright 2000-2014 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. |
| */ |
| package com.intellij.psi.util; |
| |
| import com.intellij.psi.PsiElement; |
| |
| public class PsiMatcherImpl implements PsiMatcher { |
| private PsiElement myElement; |
| |
| public PsiMatcherImpl(PsiElement element) { |
| myElement = element; |
| } |
| |
| @Override |
| public PsiMatcher parent(PsiMatcherExpression e) { |
| myElement = myElement.getParent(); |
| if (myElement == null || e != null && e.match(myElement) != Boolean.TRUE) return NullPsiMatcherImpl.INSTANCE; |
| return this; |
| } |
| |
| @Override |
| public PsiMatcher firstChild(PsiMatcherExpression e) { |
| final PsiElement[] children = myElement.getChildren(); |
| for (PsiElement child : children) { |
| myElement = child; |
| if (e == null || e.match(myElement) == Boolean.TRUE) { |
| return this; |
| } |
| } |
| return NullPsiMatcherImpl.INSTANCE; |
| } |
| |
| @Override |
| public PsiMatcher ancestor(PsiMatcherExpression e) { |
| while (myElement != null) { |
| Boolean res = e == null ? Boolean.TRUE : e.match(myElement); |
| if (res == Boolean.TRUE) break; |
| if (res == null) return NullPsiMatcherImpl.INSTANCE; |
| myElement = myElement.getParent(); |
| } |
| if (myElement == null) return NullPsiMatcherImpl.INSTANCE; |
| return this; |
| } |
| |
| @Override |
| public PsiMatcher descendant(PsiMatcherExpression e) { |
| final PsiElement[] children = myElement.getChildren(); |
| for (PsiElement child : children) { |
| myElement = child; |
| final Boolean res = e == null ? Boolean.TRUE : e.match(myElement); |
| if (res == Boolean.TRUE) { |
| return this; |
| } |
| else if (res == Boolean.FALSE) { |
| final PsiMatcher grandChild = descendant(e); |
| if (grandChild != NullPsiMatcherImpl.INSTANCE) return grandChild; |
| } |
| } |
| return NullPsiMatcherImpl.INSTANCE; |
| } |
| |
| @Override |
| public PsiMatcher dot(PsiMatcherExpression e) { |
| return e == null || e.match(myElement) == Boolean.TRUE ? this : NullPsiMatcherImpl.INSTANCE; |
| } |
| |
| |
| @Override |
| public PsiElement getElement() { |
| return myElement; |
| } |
| |
| private static class NullPsiMatcherImpl implements PsiMatcher { |
| @Override |
| public PsiMatcher parent(PsiMatcherExpression e) { |
| return this; |
| } |
| |
| @Override |
| public PsiMatcher firstChild(PsiMatcherExpression e) { |
| return this; |
| } |
| |
| @Override |
| public PsiMatcher ancestor(PsiMatcherExpression e) { |
| return this; |
| } |
| |
| @Override |
| public PsiMatcher descendant(PsiMatcherExpression e) { |
| return this; |
| } |
| |
| @Override |
| public PsiMatcher dot(PsiMatcherExpression e) { |
| return this; |
| } |
| |
| @Override |
| public PsiElement getElement() { |
| return null; |
| } |
| |
| private static final NullPsiMatcherImpl INSTANCE = new NullPsiMatcherImpl(); |
| } |
| } |