Question

I have a MapView, with various markers on it. On entering the MapActivity the first time, I set the bounds of drawables set on the markers, and everything appears fine. The markers and shadows all appear correctly. But when I click over to another activity, and return, the shadows, or the markers are no longer bound correctly. Sometimes its only some of the markers that are affected. Can anyone tell me what is going on here? Here is some code. Below is where I set the bounds on the marker drawable:

InputStream is = assetManager.open(imageName);
drawable = Drawable.createFromStream(is, null);
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
drawable.setBounds(-width / 2, -height, width - (width / 2), 0);

And here is how I create/add the overlay item to the map:

GeoPoint point = createGeoPoint(lat, lon);
OverlayItem overlayItem = new OverlayItem(point, character.get_id(), "");
Drawable image = drawable;
overlayItem.setMarker(image);
itemizedOverlay.addOverlay(overlayItem);

From what I can tell, the overlays are not being re-added to the map, this is simply a redraw after an onResume() event. Any ideas?

Update: I’ve actually figured out, only images of the type tapped move, and its not the shadow, but the image that moves. So, of there are x images of type A, and y images of type B, and I tap on any image of type A, all images of type A are misaligned with their shadows when I return to the MapActivity, while all images of type B are still properly aligned.

Another update: I am outputting the bounds to the log, and see that the bounds are changing after returning to the map screen. When the marker is initially added, its bounds are:

[Rect(-25, -48 – 25, 1)]

But when returning to the map screen, the bounds have changed to:

[Rect(0, 0 – 50, 49)]

…why would this be?

Yet another update: I have a workaround… but I would still like an answer as to why this is happening. The workaround is to override the draw method, and set the bounds (to center bottom) whenever the draw method is called. Here is the code:

@Override
public void draw(Canvas canvas) {
  int dWidth = getIntrinsicWidth();
  int dHeight = getIntrinsicHeight();
  setBounds(-dWidth / 2, -dHeight, dWidth / 2, 0);
  super.draw(canvas);
}

Answer 1

I found out what the problem was. You can see from the code in the question, I am reading in BitmapDrawables from an InputStream. To reduce waste, I put all images created in a flyweight and reuse them when I can. That means, when I put 3 ‘sunshines’ on the map, all three are based on the same image. In addition, when I place them on the map via an ItemizedOverlay, I am calling boundCenterBottom() so the shadow will display in the correct place.

When I open a different Activity, that Activity has an ImageView that I was populating with the same image. Turns out, that ImageView must have been resetting the bounds. I know this because, after overriding the draw() method, and setting the bounds on every draw, I was no longer able to see the images in the ImageViews. When I comment out the overridden draw() method, I am able to see the images in the ImageViews, but the images are shifted when I return to the map. This tells me that adding the image to the ImageView must be updating the bounds.

My solution is to create two distinct images for each image type; one for the map, and one for the ImageViews on the other Activities. I can still put them in the flyweight, but they have separate keys so multiple image instances can exist for the same image.

Hope this helps someone. I know there was another question of StackOverflow about this, but I can’t find it to link to or to answer.