TrafficSim/app/src/main/java/de/hems/trafficsim/MainActivity.java

package de.hems.trafficsim;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.TextView;

import java.util.Observable;
import java.util.Observer;

public class MainActivity extends AppCompatActivity implements Observer, SeekBar.OnSeekBarChangeListener {
    public static final int defaultNoOfVehicles = 25;
    public static final int defaultTrackLength = 100;
    public static final float defaultBrakeProb = 0.3f;
    public static final float defaultMaxVelocity = 5.0f;
    protected Track track;
    protected TimeRecordView trackView;
    protected Worker worker;
    protected LinearLayout viewStack;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.track = new Track(defaultNoOfVehicles, defaultTrackLength, defaultBrakeProb, defaultMaxVelocity);
        this.track.addObserver(this);
        this.viewStack = (LinearLayout) findViewById(R.id.trackViewStack);

        SeekBar trackLengthSeekBar = (SeekBar) findViewById(R.id.trackLengthSeekBar);
        trackLengthSeekBar.setOnSeekBarChangeListener(this);
        trackLengthSeekBar.setProgress(defaultTrackLength);
        ((TextView)(findViewById(R.id.trackLengthTextView))).setText(String.valueOf(defaultTrackLength));

        SeekBar maxVelocitySeekBar = (SeekBar) findViewById(R.id.maxVelocitySeekBar);
        maxVelocitySeekBar.setOnSeekBarChangeListener(this);
        maxVelocitySeekBar.setProgress((int)defaultMaxVelocity);
        ((TextView)(findViewById(R.id.maxVeloTextView))).setText(String.valueOf((int)defaultMaxVelocity));

        SeekBar noOfVehiclesSeekBar = (SeekBar) findViewById(R.id.noOfVehiclesSeekBar);
        noOfVehiclesSeekBar.setOnSeekBarChangeListener(this);
        noOfVehiclesSeekBar.setProgress(defaultNoOfVehicles);
        ((TextView)(findViewById(R.id.noOfVehiclesTextView))).setText(String.valueOf(defaultNoOfVehicles));

        SeekBar brakeProbabilitySeekBar = (SeekBar) findViewById(R.id.brakeProbabilitySeekBar);
        brakeProbabilitySeekBar.setOnSeekBarChangeListener(this);
        brakeProbabilitySeekBar.setProgress((int)(defaultBrakeProb*20));
        ((TextView)(findViewById(R.id.brakeProbTextView))).setText(String.valueOf(defaultBrakeProb));
    }

    @Override
    public void update(Observable observable, Object o) {
        final Track trackRef = this.track;
        final LinearLayout viewStackRef = this.viewStack;
        final MainActivity mainActivity = this;
        final TextView lastAvgView = (TextView) findViewById(R.id.avgVeloLastView);
        final TextView overallAvgView = (TextView) findViewById(R.id.avgVeloOverallView);
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                TimeRecordView newTrView = new TimeRecordView(mainActivity, trackRef);
                if (viewStackRef.getChildCount() > 0)
                    viewStackRef.removeViewAt(0);
                viewStackRef.addView(newTrView);
                lastAvgView.setText(String.valueOf(trackRef.getLastAvg()));
                overallAvgView.setText(String.valueOf(trackRef.getOverallAvg()));
            }
        });
    }

    public void onStepButtonClick(View view) {
        this.track.timeElapse();
    }

    public void onPlayButtonClick(View view) {
        Button playButton = (Button) findViewById(R.id.playButton);
        playButton.setEnabled(false);
        Button stepButton = (Button) findViewById(R.id.stepButton);
        stepButton.setEnabled(false);
        Button stopButton = (Button) findViewById(R.id.stopButton);
        stopButton.setEnabled(true);

        this.worker = new Worker(track);
        this.worker.start();
    }

    public void onStopButtonClick(View view) {
        Button playButton = (Button) findViewById(R.id.playButton);
        playButton.setEnabled(true);
        Button stepButton = (Button) findViewById(R.id.stepButton);
        stepButton.setEnabled(true);
        Button stopButton = (Button) findViewById(R.id.stopButton);
        stopButton.setEnabled(false);

        this.worker.setStop(true);
        try {
            this.worker.join();
        } catch (InterruptedException ex) {

        }
        this.worker = null;
    }

    protected void updateTrack() {
        int newTrackLength = ((SeekBar)(findViewById(R.id.trackLengthSeekBar))).getProgress();
        SeekBar noOfVehiclesSeekBar = (SeekBar)(findViewById(R.id.noOfVehiclesSeekBar));
        int newNoOfVehicles = noOfVehiclesSeekBar.getProgress();
        if (newTrackLength < newNoOfVehicles) { // Dont allow values greater than track length!
            newNoOfVehicles = (int) newTrackLength;
            noOfVehiclesSeekBar.setProgress(newNoOfVehicles);

        }
        TextView noOfVehiclesTextView = (TextView)(findViewById(R.id.noOfVehiclesTextView));
        noOfVehiclesTextView.setText(String.valueOf(newNoOfVehicles));

        TextView trackLengthTextView = (TextView)(findViewById(R.id.trackLengthTextView));
        trackLengthTextView.setText(String.valueOf(newTrackLength));

        float newMaxVelocity = ((SeekBar) findViewById(R.id.maxVelocitySeekBar)).getProgress();
        SeekBar brakeProbabilitySeekBar = (SeekBar) findViewById(R.id.brakeProbabilitySeekBar);
        float newBrakeProb = (float)brakeProbabilitySeekBar.getProgress() / (float)brakeProbabilitySeekBar.getMax();

        this.track = new Track(newNoOfVehicles, newTrackLength, newBrakeProb, newMaxVelocity);
        this.track.addObserver(this);
        if (this.worker != null) { // There was a simulation running already
            this.worker.setStop(true);
            try {
                this.worker.join();
            } catch (InterruptedException ex) {
            }
            this.worker = new Worker(track);
            this.worker.start();
        }
    }

    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        if (seekBar == (SeekBar)(findViewById(R.id.noOfVehiclesSeekBar))) {
            this.updateTrack();
        } else if (seekBar == (SeekBar)(findViewById(R.id.brakeProbabilitySeekBar))) {
            float newBrakeProb = (float)seekBar.getProgress() / (float)seekBar.getMax();
            this.track.setBrakeProb(newBrakeProb);
            TextView newBrakeProbTextView = (TextView)(findViewById(R.id.brakeProbTextView));
            newBrakeProbTextView.setText(String.valueOf((newBrakeProb)));
        } else if (seekBar == (SeekBar)(findViewById(R.id.maxVelocitySeekBar))) {
            this.track.setMaxVelocity(seekBar.getProgress());
            TextView tv = (TextView)(findViewById(R.id.maxVeloTextView));
            tv.setText(String.valueOf(progress));
        } else if (seekBar == (SeekBar)(findViewById(R.id.trackLengthSeekBar))) {
            this.updateTrack();
        }
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {

    }
}