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Android applications that use the MyLocationOverlay class crash on the new Droid X


Update: August 29, 2010
Tested this myself on a friend’s phone and this bug is definitively not fixed yet despite the recent Motorola updates! The burden is on you (the developer) to fix this if you want your applications to run on a Droid X.
Update: August 23, 2010
Still getting reports that the update issued by Motorola last month did not fix this issue!

As soon as the new Motorola Droid X came out I started getting reports that my applications would crash on it.

The description I was getting from people was that the application would start, then it would show the Google map and start moving the map and zooming in on to their current location and then all of a sudden the app would crash. By crash I mean they get taken back to the phone’s home screen. No “Force Close” dialog pops up… nothing… just gets back to the home screen.

If both the GPS and the Wireless Networks are turned off from the Locations settings then the applications would work fine, but of course that means that the current location of the device would be impossible to find.

At this point I knew that the problem had to do with either the LocationManagers or the LocationOverlays but I had no way of finding out exactly what the problem was until I could get my hands on a Droid X phone and connect it to my computer to look at the execution stack.

Well it turns out the problem is with the default MyLocationOverlay class. The Droid X phones throw an exception when they try to draw the dot showing the location of the device:

E/AndroidRuntime(10458): Uncaught handler: thread main exiting due to  uncaught exception
E/AndroidRuntime(10458): java.lang.ClassCastException:  android.graphics.drawable.BitmapDrawable
E/AndroidRuntime(10458): 	at com.google.android.maps.MyLocationOverlay.getLocationDot(MyLocationOverlay.java:180)
E/AndroidRuntime(10458): 	at com.google.android.maps.MyLocationOverlay.drawMyLocation(MyLocationOverlay.java:561)

Another developer (rgfindl) who had the same problem like I did and who had already made the trip to the Verizon store gave me the above stack trace.

Several possible solutions popped into my head:

1. Stop using the MyLocationOverlay class and start relying only on the LocationManager classes and draw/redraw my current location onLocationChanged.
2. Extend from MyLocationOverlay class and override the draw method.
3. Stop supporting the Droid X.

None of these solutions are ideal with the last one being almost unacceptable.

Luckily the same developer also gave me a link to a solution implementing the 2nd option above, so I did not even have to code it myself. Apparently that is not the first time Motorola phones (Motorola Cliq and Motorola Dext) have a problem with this class. Most likely their builds are missing the drawable resource.

Anyway, the solution consists of the .java file that implements the FixedMyLocationOverlay class, which inherits from the default MyLocationOverlay class and overrides the drawMyLocation method. And a .png file with a dot that will be representing the current location on the map.

Just use this derived class FixedMyLocationOverlay instead of the default MyLocationOverlay. If you look at the implementation of the drawMyLocation method, you will see that if the phone has no problem it will use the default implementation of the parent class, but if it throws an exception it will use the custom code to draw the location.

I would think that there are a lot of applications in the Android Market right now that use the default MyLocationOverlay class and all of them will be crashing on the new Droid X until either Motorola gets their act together or the developers realize the issue and work around it.


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