@Override
 public void execute(final jetbrains.mps.openapi.editor.EditorContext context) {
   EditorComponent editorComponent = ((EditorComponent) context.getEditorComponent());
   SelectionManager selectionManager = editorComponent.getSelectionManager();
   Selection selection = selectionManager.getSelection();
   if (selection instanceof SingularSelection) {
     EditorCell selectedCell = ((SingularSelection) selection).getEditorCell();
     SNode selectedNode = selectedCell.getSNode();
     SNode topMostNodeInSingularContainment =
         findTopMostNodeWithSingularContainment(selectedNode);
     if (topMostNodeInSingularContainment != selectedNode) {
       EditorCell nodeCell = editorComponent.findNodeCell(topMostNodeInSingularContainment);
       if (nodeCell != null) {
         editorComponent.pushSelection(nodeCell);
         editorComponent.scrollToCell(nodeCell);
       }
     } else {
       Selection newSelection =
           selectionManager.createRangeSelection(selectedNode, selectedNode);
       if (newSelection instanceof NodeRangeSelection && selectedCell.isBigCell()) {
         newSelection = ((NodeRangeSelection) newSelection).enlargeSelection(myUp);
       }
       if (newSelection != null) {
         selectionManager.pushSelection(newSelection);
         newSelection.ensureVisible();
       }
     }
   } else if (selection instanceof NodeRangeSelection) {
     Selection newSelection = ((NodeRangeSelection) selection).enlargeSelection(myUp);
     if (newSelection != null) {
       selectionManager.pushSelection(newSelection);
       newSelection.ensureVisible();
     }
   }
 }
 public void execute(jetbrains.mps.openapi.editor.EditorContext context) {
   EditorComponent editorComponent = ((EditorComponent) context.getEditorComponent());
   EditorCell target = findTarget(editorComponent);
   if (target instanceof EditorCell_Label) {
     EditorCell_Label label = (EditorCell_Label) target;
     label.end();
     editorComponent.resetLastCaretX();
   }
   editorComponent.changeSelection(target);
 }
 public void execute(jetbrains.mps.openapi.editor.EditorContext context) {
   EditorCell selectedCell = getDeepestSelectedCell(context);
   int caretX = selectedCell.getCaretX();
   EditorComponent editorComponent = (EditorComponent) context.getEditorComponent();
   if (editorComponent.hasLastCaretX()) {
     caretX = editorComponent.getLastCaretX();
   }
   editorComponent.saveLastCaretX(caretX);
   EditorCell target = findTarget(selectedCell, caretX);
   target.setCaretX(caretX);
   editorComponent.changeSelection(target, false);
 }
 private EditorCell findTarget(EditorComponent editorComponent) {
   Selection selection = editorComponent.getSelectionManager().getSelection();
   if (selection == null) {
     return null;
   }
   List<EditorCell> selectedCells = selection.getSelectedCells();
   EditorCell cell = selectedCells.get(selectedCells.size() - 1);
   return cell.getEndCell(CellConditions.SELECTABLE);
 }
 private static void navigatePage(
     jetbrains.mps.openapi.editor.EditorContext context, boolean isDown) {
   EditorComponent editor = (EditorComponent) context.getEditorComponent();
   jetbrains.mps.openapi.editor.cells.EditorCell selection = editor.getSelectedCell();
   Rectangle rect = editor.getVisibleRect();
   int height = (int) rect.getHeight();
   height = isDown ? height : -height;
   int caretX = selection.getCaretX();
   int y = selection.getY() + (selection.getHeight() / 2);
   int newY = y + height;
   jetbrains.mps.openapi.editor.cells.EditorCell target = editor.findCellWeak(caretX, newY);
   if (target == null) {
     target =
         isDown
             ? editor.myRootCell.findChild(CellFinders.LAST_SELECTABLE_LEAF)
             : editor.myRootCell.findChild(CellFinders.FIRST_SELECTABLE_LEAF);
     editor.changeSelection(target);
   } else {
     target.setCaretX(caretX);
     editor.changeSelection(target);
   }
 }
 public void execute(jetbrains.mps.openapi.editor.EditorContext context) {
   EditorComponent editorComponent = (EditorComponent) context.getEditorComponent();
   EditorCell selection = editorComponent.getSelectedCell();
   editorComponent.changeSelection(selection.getPrevLeaf(CellConditions.EDITABLE));
 }