private void updateButtonState() {

        if (Simulation.isPaused() && !Simulation.isStarted()) { //if paused and simulation stopped
            pauseSim.setText("Pause Simulation");
            startSim.setText("Start Simulation");
            pauseSim.setEnabled(false);

        } else if (Simulation.isPaused() && Simulation.isStarted()) { // if paused and simulated is running
            pauseSim.setText("Resume Simulation");
            startSim.setText("Stop Simulation");
            pauseSim.setEnabled(true);

        } else if (!Simulation.isPaused() && Simulation.isStarted()) { // if not paused and simulation is running
            pauseSim.setText("Pause Simulation");
            startSim.setText("Stop Simulation");
            pauseSim.setEnabled(true);

        } else if (!Simulation.isPaused() && !Simulation.isStarted()) { //if not paused and not started
            pauseSim.setText("Pause Simulation");
            startSim.setText("Start Simulation");
            pauseSim.setEnabled(false);
            outputStatistics.setEnabled(true);
        }
    }