Zoom on a set of graphics

Question

I'm using Java with ArcGIS 100.1.0—ArcGIS Runtime SDK for Android. I have a number of locations(Point s) on the map, after I added all the markers as graphics (on a graphic overlay), I want to zoom the map to be able to see all of them with the zoom adjusting to fit them on the map. I tried drawing a polygon and getting its envelope. And used

Envelope envelope = graphicsOverlay.getExtent();
mapView.setViewInsets(  envelope.getXMin() - DEFAULT_PADDING,
                        envelope.getYMax() + DEFAULT_PADDING,
                        envelope.getXMax() + DEFAULT_PADDING,
                        envelope.getYMin() - DEFAULT_PADDING);

and I get a very bad zoom (too close) and not displaying the whole graphics.

Then I tried :

//1-we create a polygon out of these locations
PointCollection corners = new PointCollection(spatialReference);
for(Point point : points){
    corners.add(point.getX(),point.getY());
}
Polygon polygon = new Polygon(corners);

//2- we get the extent
Envelope envelope = polygon.getExtent();
mapView.setViewInsets(  envelope.getXMin() - DEFAULT_PADDING,
                        envelope.getYMax() + DEFAULT_PADDING,
                        envelope.getXMax() + DEFAULT_PADDING,
                        envelope.getYMin() - DEFAULT_PADDING);

I still have the same unwanted result. Does anyone has and answer? Coming from Google Maps API v2 Android, I used to use the latlongBound to achieve this behavior.

Another solution would be to be able to evaluate the scale that I should apply to the mapview once I am able to get the extent of the overlay on which my markers/graphics (coming from Google Maps) are displayed. Does anyone know how to get that scale?

Answer 1

The problem was that i called mapview.setViewInsets(). This is the solution:

            //1- we compile the locations in a collection
            PointCollection corners = new PointCollection(points);

            //2- we get the extent
            Envelope envelope = new Polygon(corners).getExtent();

            //3- we move the camera
            moveWithAnimation(envelope,mapView);

The code to move the camera with animation :

    /**
     *  Move the camera with an animation
     * @param envelope to fix the borders of the desired view
     * @param mapView the mapview
     */
    private static void moveWithAnimation(final Envelope envelope, final MapView mapView){
        if(envelope != null && mapView != null){
            final ListenableFuture<Boolean> listenableFuture = mapView.setViewpointGeometryAsync(envelope,DEFAULT_PADDING);
            listenableFuture.addDoneListener(new Runnable() {
               @Override
               public void run() {
                   listenableFuture.removeDoneListener(this);
               }
           });
        }
    }