@Override
  public boolean addFoldRegion(@NotNull final FoldRegion region) {
    assertIsDispatchThreadForEditor();
    if (!isFoldingEnabled()) {
      return false;
    }
    if (!myIsBatchFoldingProcessing) {
      LOG.error("Fold regions must be added or removed inside batchFoldProcessing() only.");
      return false;
    }

    myFoldRegionsProcessed = true;
    if (myFoldTree.addRegion(region)) {
      final FoldingGroup group = region.getGroup();
      if (group != null) {
        myGroups.putValue(group, region);
      }
      for (FoldingListener listener : myListeners) {
        listener.onFoldRegionStateChange(region);
      }
      return true;
    }

    return false;
  }
 private void notifyListenersOnFoldRegionStateChange(@NotNull FoldRegion foldRegion) {
   for (FoldingListener listener : myListeners) {
     listener.onFoldRegionStateChange(foldRegion);
   }
 }
  private void notifyBatchFoldingProcessingDone(final boolean moveCaretFromCollapsedRegion) {
    rebuild();

    for (FoldingListener listener : myListeners) {
      listener.onFoldProcessingEnd();
    }

    myEditor.updateCaretCursor();
    myEditor.recalculateSizeAndRepaint();
    myEditor.getGutterComponentEx().updateSize();
    myEditor.getGutterComponentEx().repaint();

    for (Caret caret : myEditor.getCaretModel().getAllCarets()) {
      // There is a possible case that caret position is already visual position aware. But visual
      // position depends on number of folded
      // logical lines as well, hence, we can't be sure that target logical position defines correct
      // visual position because fold
      // regions have just changed. Hence, we use 'raw' logical position instead.
      LogicalPosition caretPosition = caret.getLogicalPosition().withoutVisualPositionInfo();
      int caretOffset = myEditor.logicalPositionToOffset(caretPosition);
      int selectionStart = caret.getSelectionStart();
      int selectionEnd = caret.getSelectionEnd();

      LogicalPosition positionToUse = null;
      int offsetToUse = -1;

      FoldRegion collapsed = myFoldTree.fetchOutermost(caretOffset);
      LogicalPosition savedPosition = caret.getUserData(SAVED_CARET_POSITION);
      if (savedPosition != null) {
        int savedOffset = myEditor.logicalPositionToOffset(savedPosition);
        FoldRegion collapsedAtSaved = myFoldTree.fetchOutermost(savedOffset);
        if (collapsedAtSaved == null) {
          positionToUse = savedPosition;
        } else {
          offsetToUse = collapsedAtSaved.getStartOffset();
        }
      }

      if (collapsed != null && positionToUse == null) {
        positionToUse = myEditor.offsetToLogicalPosition(collapsed.getStartOffset());
      }

      if (moveCaretFromCollapsedRegion && caret.isUpToDate()) {
        if (offsetToUse >= 0) {
          caret.moveToOffset(offsetToUse);
        } else if (positionToUse != null) {
          caret.moveToLogicalPosition(positionToUse);
        } else {
          caret.moveToLogicalPosition(caretPosition);
        }
      }

      caret.putUserData(SAVED_CARET_POSITION, savedPosition);

      if (isOffsetInsideCollapsedRegion(selectionStart)
          || isOffsetInsideCollapsedRegion(selectionEnd)) {
        caret.removeSelection();
      } else if (selectionStart < myEditor.getDocument().getTextLength()) {
        caret.setSelection(selectionStart, selectionEnd);
      }
    }

    if (mySavedCaretShift > 0) {
      final ScrollingModel scrollingModel = myEditor.getScrollingModel();
      scrollingModel.disableAnimation();
      scrollingModel.scrollVertically(
          myEditor.visibleLineToY(myEditor.getCaretModel().getVisualPosition().line)
              - mySavedCaretShift);
      scrollingModel.enableAnimation();
    }
  }
  private void doNotifyBatchFoldingProcessingDone() {
    myFoldTree.rebuild();

    for (FoldingListener listener : myListeners) {
      listener.onFoldProcessingEnd();
    }

    myEditor.updateCaretCursor();
    myEditor.recalculateSizeAndRepaint();
    if (myEditor.getGutterComponentEx().isFoldingOutlineShown()) {
      myEditor.getGutterComponentEx().repaint();
    }

    LogicalPosition caretPosition = myEditor.getCaretModel().getLogicalPosition();
    // There is a possible case that caret position is already visual position aware. But visual
    // position depends on number of folded
    // logical lines as well, hence, we can't be sure that target logical position defines correct
    // visual position because fold
    // regions have just changed. Hence, we use 'raw' logical position instead.
    if (caretPosition.visualPositionAware) {
      caretPosition = new LogicalPosition(caretPosition.line, caretPosition.column);
    }
    int caretOffset = myEditor.logicalPositionToOffset(caretPosition);
    boolean hasBlockSelection = myEditor.getSelectionModel().hasBlockSelection();
    int selectionStart = myEditor.getSelectionModel().getSelectionStart();
    int selectionEnd = myEditor.getSelectionModel().getSelectionEnd();

    int column = -1;
    int line = -1;
    int offsetToUse = -1;

    FoldRegion collapsed = myFoldTree.fetchOutermost(caretOffset);
    if (myCaretPositionSaved) {
      int savedOffset =
          myEditor.logicalPositionToOffset(new LogicalPosition(mySavedCaretY, mySavedCaretX));
      FoldRegion collapsedAtSaved = myFoldTree.fetchOutermost(savedOffset);
      if (collapsedAtSaved == null) {
        column = mySavedCaretX;
        line = mySavedCaretY;
      } else {
        offsetToUse = collapsedAtSaved.getStartOffset();
      }
    }

    if (collapsed != null && column == -1) {
      line = collapsed.getDocument().getLineNumber(collapsed.getStartOffset());
      column = myEditor.offsetToLogicalPosition(collapsed.getStartOffset()).column;
    }

    boolean oldCaretPositionSaved = myCaretPositionSaved;

    if (offsetToUse >= 0) {
      myEditor.getCaretModel().moveToOffset(offsetToUse);
    } else if (column != -1) {
      myEditor.getCaretModel().moveToLogicalPosition(new LogicalPosition(line, column));
    } else {
      myEditor.getCaretModel().moveToLogicalPosition(caretPosition);
    }

    myCaretPositionSaved = oldCaretPositionSaved;

    if (!hasBlockSelection && selectionStart < myEditor.getDocument().getTextLength()) {
      myEditor.getSelectionModel().setSelection(selectionStart, selectionEnd);
    }

    if (mySavedCaretShift > 0) {
      myEditor.getScrollingModel().disableAnimation();
      int scrollTo =
          myEditor.visibleLineToY(myEditor.getCaretModel().getVisualPosition().line)
              - mySavedCaretShift;
      myEditor.getScrollingModel().scrollVertically(scrollTo);
      myEditor.getScrollingModel().enableAnimation();
    }
  }