import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.os.CountDownTimer; import android.view.View;

@SuppressLint("DrawAllocation") public class MyDraw extends View { int N = 5; int[] x = new int[N]; int[] y = new int[N]; int[] vx = new int[N]; int[] vy = new int[N]; int[] L = new int[N]; int[] Red = new int[N]; int[] Green = new int[N]; int[] Blue = new int[N]; int[] R = new int[N]; int z = -1; double a = 0, ha = Math.PI / 180;

void fillArrayRandom(int[] a, int min, int max) {
    for (int i = 0; i < a.length; i++) {
        a[i] = (int) (Math.random() * (max - min + 1)) + min;
    }
}

void makeBalls() {
    fillArrayRandom(x, 50, 250);
    fillArrayRandom(y, 50, 250);
    fillArrayRandom(vx, -50, 100);
    fillArrayRandom(vy, -50, 100);
    fillArrayRandom(L, 3, 10);
    fillArrayRandom(Red, 50, 255);
    fillArrayRandom(Green, 50, 255);
    fillArrayRandom(Blue, 50, 255);
    fillArrayRandom(R, 20, 40);
}

void moveBalls() {
    for (int i = 0; i < N; i++) {
        if (i % 2 == 0) {
            x[i] = this.getWidth() / 2 + (int) (L[i] * vx[i] * Math.cos(a));
            y[i] = this.getHeight() / 2 + (int) (z * L[i] * vy[i] * Math.sin(a));
        } else {
            x[i] = this.getWidth() / 2 + (int) (L[i] * vx[i] * Math.cos(a));
            y[i] = this.getHeight() / 2 + (int) (L[i] * vy[i] * Math.sin(a));
        }
    }
    a = a + ha;
}

MyDraw(Context context) {
    super(context);
    makeBalls();
    MyTimer timer = new MyTimer();
    timer.start();
}

@Override
protected void onDraw(Canvas canvas) {
    Paint paint = new Paint();
    paint.setColor(Color.RED);
    canvas.drawCircle(this.getWidth() / 2, this.getHeight() / 2, 70, paint);
    paint.setStyle(Paint.Style.FILL);
    for (int i = 0; i < N; i++) {
        paint.setColor(Color.argb(200, Red[i], Green[i], Blue[i]));
        canvas.drawCircle(x[i], y[i], R[i], paint);
        paint.setTextSize(30.0f);
        paint.setColor(Color.BLACK);
        canvas.drawText("P " + i + " (" + x[i] + ", " + y[i] + ")", x[i] + 10, y[i] - 15, paint);
    }
}
void nextFrame() {
    moveBalls();
    invalidate();
}
class MyTimer extends CountDownTimer {
    MyTimer() {
        super(1000000, 1);
    }
    @Override
    public void onTick(long millisUntilFinished) {
        // TODO Auto-generated method stub
        nextFrame();
    }
    @Override
    public void onFinish() {
        // TODO Auto-generated method stub
    }
}

}