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); } }