Using ArcGIS Android API,
After my MobileMapPackage loads, I want to store the inital map extents (i.e., getVisibleArea()) so that I can later allow the user the option of viewing the initial map extents.
APPROACH:
After my MobileMapPackage's getLoadStatus() returns "LOADED", I get a reference to the ArcGISMap contained therein. Next, I listen for the ArcGISMap's getLoadStatus() to return "LOADED". Finally, I ask the MapView containing the ArcGISMap for it's visible area but sometimes the following Exception is thrown:
Attempt to invoke virtual method 'com.esri.arcgisruntime.geometry.Envelope com.esri.arcgisruntime.geometry.Geometry.getExtent()' on a null object reference
Is there some other async process that I should be waiting for before inquiring about the visible area of the mMapView? Relevant snippet code below:
this.mapPackage = new MobileMapPackage(mmpkFile);
// load the mobile map package asynchronously
this.mapPackage.loadAsync();
// add done listener which will invoke when mobile map package has loaded
this.mapPackage.addDoneLoadingListener(new Runnable() {
@Override
public void run() {
// check load status and that the mobile map package has maps
switch (MainActivity.this.mapPackage.getLoadStatus()) {
case LOADING, FAILED_TO_LOAD, NOT_LOADED: // do nothing for now...
break;
case LOADED:
if (MainActivity.this.mapPackage.getMaps().size() > 0) {
// add the map from the mobile map package to the MapView
ArcGISMap map = MainActivity.this.mapPackage.getMaps().get(0);
MainActivity.this.arcGISMap = map;
MainActivity.this.mMapView.setMap(map);
MainActivity.this.arcGISMap.addDoneLoadingListener(new Runnable() {
@Override
public void run() {
try {
switch (MainActivity.this.arcGISMap.getLoadStatus()) {
case LOADING, FAILED_TO_LOAD, NOT_LOADED: // do nothing for now...
break;
case LOADED:
MainActivity.this.initialEnvelope = MainActivity.this.mMapView.getVisibleArea().getExtent();
if (initialEnvelope != null) {
Log.d("LoadMobileMapPackage", "initialEnvelope: " + initialEnvelope);
}
break;
}
} catch (Exception e) {
Log.e(TAG, e.getMessage());
}
}
});
}
}
}
});
