@Override
    public void actionPerformed(ActionContext context) {
    	FieldHeaderLocation loc = (FieldHeaderLocation) context.getContextObject();
        FieldFormatModel modelAtLocation = loc.getModel();
    	panel.setTabLock( true );
    	modelAtLocation.addFactory(new SpacerFieldFactory(), loc.getRow(), loc.getColumn());
    }
Method called when the action is invoked.
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/format/actions/AddSpacerFieldAction.java