gistfile1.java

private void addRoskildeGroundOverlay() {
        int[] mapResourceIds = {
            R.drawable.map_mdpi,
            R.drawable.map_hdpi,
            R.drawable.map_xhdpi,
            R.drawable.map_xxhdpi,
        };

        int startIndex = (getResources().getDisplayMetrics().densityDpi / 160) - 1;
        startIndex = Math.min(mapResourceIds.length - 1, startIndex);
        startIndex = Math.max(0, startIndex);

        for (int index = startIndex; index >= 0; index--) {
            int mapResourceId = mapResourceIds[index];
            Bitmap bitmap = null;

            try {
                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inJustDecodeBounds = true; // we are only interrested in the meta data.

                BitmapFactory.decodeResource(getResources(), mapResourceId, options);

                int estimatedBitmapMemoryUsage = options.outWidth * options.outHeight * 8;

                Log.e("FASTTRACK", "INDEX: " + Integer.toString(index));
                Log.e("FASTTRACK", "Image size: " + Integer.toString(options.outWidth) + 'x' + Integer.toString(options.outHeight));
                Log.e("FASTTRACK", "Estimated memory usage: " + Integer.toString(estimatedBitmapMemoryUsage));
                Log.e("FASTTRACK", "System memory max: " + Long.toString(Runtime.getRuntime().maxMemory()));
                Log.e("FASTTRACK", "System memory free: " + Long.toString(Runtime.getRuntime().freeMemory()));

                // add a overhead buffer. and check if we have enought memory
                if ((estimatedBitmapMemoryUsage * 1.2) >= Runtime.getRuntime().maxMemory()) {
                    Log.e("FASTTRACK", "Estimated memory usage is too large, skipping this resolution");
                    continue;
                }

                // "decode" bitmap, this sometimes causes a out-of-memory error to be thrown, given our catch phase a chance to cleanup / try a lower res bitmap.
                bitmap = BitmapFactory.decodeResource(getResources(), mapResourceId);

                // add roskilde map overlay.
                GroundOverlayOptions mapOverlay = new GroundOverlayOptions()
                        .image(BitmapDescriptorFactory.fromBitmap(bitmap))
                        .positionFromBounds(new LatLngBounds(new LatLng(55.60902308597556, 12.057436019946294), new LatLng(55.62452291455987, 12.098813659716825)));

                this.map.addGroundOverlay(mapOverlay);


                Log.e("FASTTRACK", "Image loaded: " + Integer.toString(index));
                break;

            } catch (OutOfMemoryError error) {
                Log.e("FASTTRACK", "OUT OF MEMORY");

                if (bitmap != null) {
                    bitmap.recycle();
                    bitmap = null;
                }

                System.gc();
            }
        }
    }