platform/core-impl/src/com/intellij/codeInsight/CodeInsightUtilCore.java

/*
 * 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.codeInsight;

import com.intellij.lang.Language;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.RangeMarker;
import com.intellij.psi.PsiDocumentManager;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiFile;
import com.intellij.psi.PsiWhiteSpace;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.psi.util.PsiUtilCore;
import com.intellij.util.ReflectionUtil;
import org.jetbrains.annotations.NotNull;

public abstract class CodeInsightUtilCore extends FileModificationService {
  public static <T extends PsiElement> T findElementInRange(@NotNull PsiFile file,
                                                             int startOffset,
                                                             int endOffset,
                                                             @NotNull Class<T> klass,
                                                             @NotNull Language language) {
    PsiElement element1 = file.getViewProvider().findElementAt(startOffset, language);
    PsiElement element2 = file.getViewProvider().findElementAt(endOffset - 1, language);
    if (element1 instanceof PsiWhiteSpace) {
      startOffset = element1.getTextRange().getEndOffset();
      element1 = file.getViewProvider().findElementAt(startOffset, language);
    }
    if (element2 instanceof PsiWhiteSpace) {
      endOffset = element2.getTextRange().getStartOffset();
      element2 = file.getViewProvider().findElementAt(endOffset - 1, language);
    }
    if (element2 == null || element1 == null) return null;
    final PsiElement commonParent = PsiTreeUtil.findCommonParent(element1, element2);
    final T element =
      ReflectionUtil.isAssignable(klass, commonParent.getClass())
      ? (T)commonParent : PsiTreeUtil.getParentOfType(commonParent, klass);
    if (element == null || element.getTextRange().getStartOffset() != startOffset || element.getTextRange().getEndOffset() != endOffset) {
      return null;
    }
    return element;
  }

  public static <T extends PsiElement> T forcePsiPostprocessAndRestoreElement(@NotNull T element) {
    return forcePsiPostprocessAndRestoreElement(element, false);
  }

  public static <T extends PsiElement> T forcePsiPostprocessAndRestoreElement(@NotNull T element,
                                                                              boolean useFileLanguage) {
    final PsiFile psiFile = element.getContainingFile();
    final Document document = psiFile.getViewProvider().getDocument();
    //if (document == null) return element;
    final Language language = useFileLanguage ? psiFile.getLanguage() : PsiUtilCore.getDialect(element);
    final PsiDocumentManager documentManager = PsiDocumentManager.getInstance(psiFile.getProject());
    final RangeMarker rangeMarker = document.createRangeMarker(element.getTextRange());
    documentManager.doPostponedOperationsAndUnblockDocument(document);
    documentManager.commitDocument(document);

    T elementInRange = findElementInRange(psiFile, rangeMarker.getStartOffset(), rangeMarker.getEndOffset(),
                                          (Class<? extends T>)element.getClass(),
                                          language);
    rangeMarker.dispose();
    return elementInRange;
  }
}