@Nullable
 public TextRange performReplace(
     final FindResult occurrence, final String replacement, final Editor editor) {
   if (myReplaceDenied
       || !ReadonlyStatusHandler.ensureDocumentWritable(editor.getProject(), editor.getDocument()))
     return null;
   FindModel findModel = mySearchResults.getFindModel();
   TextRange result =
       FindUtil.doReplace(
           editor.getProject(),
           editor.getDocument(),
           findModel,
           new FindResultImpl(occurrence.getStartOffset(), occurrence.getEndOffset()),
           replacement,
           true,
           new ArrayList<Pair<TextRange, String>>());
   myLivePreview.inSmartUpdate();
   mySearchResults.updateThreadSafe(findModel, true, result, mySearchResults.getStamp());
   return result;
 }
  @Override
  public String getStringToReplace(Editor editor, FindResult findResult) {
    if (findResult == null) {
      return null;
    }
    String foundString = editor.getDocument().getText(findResult);
    String documentText = editor.getDocument().getText();
    FindModel currentModel = mySearchResults.getFindModel();
    String stringToReplace = null;

    if (currentModel != null) {
      if (currentModel.isReplaceState()) {
        FindManager findManager = FindManager.getInstance(editor.getProject());
        try {
          stringToReplace =
              findManager.getStringToReplace(
                  foundString, currentModel, findResult.getStartOffset(), documentText);
        } catch (FindManager.MalformedReplacementStringException e) {
          return null;
        }
      }
    }
    return stringToReplace;
  }
  public void performReplaceAll(Editor e) {
    if (!ReadonlyStatusHandler.ensureDocumentWritable(e.getProject(), e.getDocument())) return;
    if (mySearchResults.getFindModel() != null) {
      final FindModel copy = new FindModel();
      copy.copyFrom(mySearchResults.getFindModel());

      final SelectionModel selectionModel = mySearchResults.getEditor().getSelectionModel();

      final int offset;
      if ((!selectionModel.hasSelection() && !selectionModel.hasBlockSelection())
          || copy.isGlobal()) {
        copy.setGlobal(true);
        offset = 0;
      } else {
        offset = selectionModel.getBlockSelectionStarts()[0];
      }
      FindUtil.replace(e.getProject(), e, offset, copy, this);
    }
  }