import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    boolean continuar = true;
    float velocidad = 1f;
    int dt = 10;
    int tiempo = 0;
    Thread hilo = null;
    GraficoView dinamica;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        dinamica = new GraficoView(this);
        setContentView(dinamica);
        hilo= new Thread(dinamica);
        hilo.start();
    }

    class GraficoView extends View implements Runnable{

        int x,y,ymax;
        Paint paintFondo,paintParticula,paint;

        public GraficoView(Context context) {
            super(context);
            paintFondo= new Paint();
            paintParticula= new Paint();
            paint= new Paint();
            paintFondo.setColor(Color.WHITE);
            paintParticula.setColor(Color.RED);
            paint.setColor(Color.BLACK);
            paint.setTextSize(30);
        }

        @Override
        public void run() {
            while (continuar){
                tiempo=tiempo+dt;
                y=y+(int)(velocidad*dt);
                if (y>ymax) velocidad=-velocidad;
                if (y<0) velocidad=-velocidad;
                postInvalidate();
                try {
                    Thread.sleep(dt);
                }catch (InterruptedException e){};
            }
        }

        @Override
        protected void onSizeChanged(int w, int h, int oldw, int oldh) {
            x=w/2;
            y=0;
            ymax=h;
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            canvas.drawPaint(paintFondo);
            canvas.drawCircle(x+150,y,30,paintParticula);
            canvas.drawText("Altura= "+y,50,50,paint);
            canvas.drawText("Tiempo= "+tiempo,50,90,paint);
        }
    }
}