/** Constructor for the class. Calls initComponents to set up all the buttons on the window */
  private MainWindow() {
    initComponents();

    // edit object and all simulation buttons are disabled until we add an object
    editObject.setEnabled(false);
    runSimulation.setEnabled(false);
    stopSimulation.setEnabled(false);
    pauseSimulation.setEnabled(false);
    this.threadExec.start();
  }