Question

I have a program where I want to draw a line between two points. I then want another line to draw between another two points. When I draw one line it removes the previous line. I have tried making both lines different Overlays but it still removes the old line and puts in the new line. Do I prevent this from happing and how do I make all the Overlays stay? Any help would be greatly appreciated.

The Overlay class in inside the Activity class.

This is in onKeyDown()

case KeyEvent.KEYCODE_8:
            twoPoints.add(a);
            twoPoints.add(b);

            MapOverlay newOverlay = new MapOverlay();
            listOfOverlays = mapView.getOverlays();
            listOfOverlays.add(newOverlay);

            mapView.postInvalidate();
            System.out.println("Test overlays 1 Point");

            break;

        case KeyEvent.KEYCODE_9:
            twoPoints.remove(1);
            twoPoints.add(c);

            MapOverlay newOverlay1 = new MapOverlay();
            listOfOverlays.add(newOverlay1);
            mapView.postInvalidate();

            System.out.println("Test Overlays 2 Point");
            break;

And this is the Overlay class:

   public class MapOverlay extends com.google.android.maps.Overlay
   {        
    @Override
    public void draw(Canvas canvas, MapView mapView, boolean shadow)
    {       
        super.draw(canvas,mapView,shadow);

        //-- Create new paint object --
        Paint mPaint = new Paint();
        mPaint.setDither(true);
        mPaint.setColor(Color.RED);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStrokeWidth(2);

        //System.out.println("Point 1");


            //System.out.println("Point 2");

            for(int i =0; i < twoPoints.size()-1;i++)
            {
                Point screenPt1 = new Point();
                mapView.getProjection().toPixels(twoPoints.get(i), screenPt1);

                Point screenPt2 = new Point();
                mapView.getProjection().toPixels(twoPoints.get(i+1), screenPt2);

                canvas.drawLine(screenPt1.x, screenPt1.y, screenPt2.x, screenPt2.y, mPaint);

                System.out.println("Point 3");
            }   

        //mapView.invalidate();
    }
}

It has been really confusing me for a while now.

Answer 1

Eyespyus was on the right track the problem was that I had the Overlay class in the activity and was changing the array that both used. Moving the class outside the activity fixed the problem.

This was a really silly mistake and I thank everyone for taking the time to look at this, I am very new to Android.