On zoom event for google maps on android

Question

We\'re building an application which is using the google maps api for android.

I have my MapController and MapView, and I enable the built-in zoom controls using:

Answer 1

You can implement your own basic "polling" of the zoom value to detect when the zoom has been changed using the android Handler.

Using the following code for your runnable event. This is where your processing should be done.

private Handler handler = new Handler();

public static final int zoomCheckingDelay = 500; // in ms

private Runnable zoomChecker = new Runnable()
{
    public void run()
    {
        checkMapIcons();

        handler.removeCallbacks(zoomChecker); // remove the old callback
        handler.postDelayed(zoomChecker, zoomCheckingDelay); // register a new one
    }
};

Start a callback event using

protected void onResume()
{
    super.onResume();
    handler.postDelayed(zoomChecker, zoomCheckingDelay);
}

and stop it when you're leaving the activity using

protected void onPause()
{
    super.onPause();
    handler.removeCallbacks(zoomChecker); // stop the map from updating
}

Article this is based on can be found here if you want a longer write up.