Question

I wonder if there is a chance to set a final Overlay in Google Maps. I wanna set my cross hairs this way, so that it isn’t moving while zooming.

Code:

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.map_view);
            initData();

            mapView = (MapView) findViewById(R.id.mapView);

            mapView.setSatellite(true);
            mapView.setTraffic(true); 
            mapView.setBuiltInZoomControls(true);

            controller = mapView.getController();
            controller.animateTo(coordinate);
            controller.setZoom(18);

    // TODO:
            CrossHairsOverlay chOverlay = new CrossHairsOverlay();

    // Pin
            MapOverlay mapOverlay = new MapOverlay();
            mapOverlay.setPointToDraw(coordinate);

            List<Overlay> listOfOverlays = mapView.getOverlays();
            listOfOverlays.clear();
            listOfOverlays.add(mapOverlay);
            listOfOverlays.add(chOverlay);
        }

Cross hairs:

    public class CrossHairsOverlay extends Overlay {

        public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) {
            super.draw(canvas, mapView, shadow);
            Projection projection = mapView.getProjection();
            Point centerPoint = projection.toPixels(mapView.getMapCenter(), null);

            Bitmap crossHairs = BitmapFactory.decodeResource(getResources(), R.drawable.cross_hair);
            canvas.drawBitmap(crossHairs, centerPoint.x - (int)(27 * dpi + 0.5f), centerPoint.y - (int)(27 * dpi + 0.5f), new Paint());
            return true;
        }
    }

If I use it this way, it recenters after zooming is finished. Left/right draging works correct. I don’t really wanna set a “ZoomListener” and redraw all the time. I hope there is a bether solution to do this.

Thanks

Answer 1

Forgive me for not fully understanding your question…

But, to draw to a simple point no need to use the projection, just draw your bitmap strictly to the center of the mapview.

ie…

// make the coordinated constant also.

canvas.drawBitam(bitmap, center.x-(imageWidth/2), center.y-(imageHeight/2),new Paint());

where center.x and center.y are just equal to

Point center = new Point(canvas.getWidth()/2,canvas.getHeight()/2);

Also dont reload your bitmap on every onDraw!, memory leak ftl ;).