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

package de.hems.trafficsim;

import android.graphics.Canvas;

/**
 * Calculation thread, which runs the simulation itself and also updates the view with a set rate.
 */
public class Worker extends Thread {
    /**
     * the track to simulate
     */
    protected Track track;

    /**
     * Stop flag, indicating that the worker shall stop
     */
    protected boolean stop;

    /**
     * the MainActivity of the gui
     */
    protected MainActivity gui;

    /**
     * the Renderer drawing the Track
     */
    protected Renderer renderer;

    /**
     * Amount of simulation steps between two frames in the view. Zero means
     * that every simulation step is drawn.
     */
    protected int frameskip;

    /**
     * Construct a new worker.
     *
     * @param track     the track to simulate
     * @param gui       the MainActivity of the gui
     * @param renderer  the Renderer drawing the Track
     * @param frameskip Amount of simulation steps between two frames in the view. Zero means
     *                  that every simulation step is drawn
     */
    public Worker(Track track, MainActivity gui, Renderer renderer, int frameskip) {
        super();
        this.track = track;
        this.stop = false;
        this.gui = gui;
        this.renderer = renderer;
        this.frameskip = frameskip;
    }

    /**
     * Sets a flag that causes the worker to stop.
     *
     * @param stop flag whether the thread shall stop
     */
    public void setStop(boolean stop) {
        this.stop = stop;
    }

    /**
     * Updates the amount of simulation steps between to view frames.
     *
     * @param frames amount of steps
     */
    public void setFrameskip(int frames) {
        this.frameskip = frames;
    }

    /**
     * Method which is automatically executed when the thread is started. It alternates between
     * updating the simulation and drawing a new frame in the view.
     */
    @Override
    public void run() {
        Canvas canvas = null;
        int i = 0;
        while (!stop) {
            this.track.timeElapse();
            this.gui.updateStats();
            if (i >= this.frameskip) {
                this.renderer.draw();
                i = 0;
            }
            i++;
        }
    }

}