Android™ Application Development - Bahar Ali Khan

Chapter 7: Maps, Geocoding, and Location-Based Services
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}
}
}
RectF oval = new RectF(myPoint.x-rad, myPoint.y-rad,
myPoint.x+rad, myPoint.y+rad);
canvas.drawOval(oval, paint);
6. Return to the EarthquakeMap class. Within the onCreate method, create a Cursor that
returns the earthquakes you want to display on the map. Use this Cursor to create a new
EarthquakeOverlay before adding the new instance to the Map View’s list of overlays.
Cursor earthquakeCursor;
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.earthquake_map);
String earthquakeURI = EarthquakeProvider.CONTENT_URI;
earthquakeCursor = getContentResolver().query(earthquakeURI,
null, null, null, null);
}
MapView earthquakeMap = (MapView)findViewById(R.id.map_view);
EarthquakeOverlay eo = new EarthquakeOverlay(earthquakeCursor);
earthquakeMap.getOverlays().add(eo);
7. Finally, override onResume to call requery on the Earthquake result set whenever this Activity
becomes visible. Also, override onPause and onDestroy to optimize use of the Cursor resources.
@Override
public void onResume() {
earthquakeCursor.requery();
super.onResume();
}
@Override
public void onPause() {
earthquakeCursor.deactivate();
super.onPause();
}
@Override
public void onDestroy() {
earthquakeCursor.close();
super.onDestroy();
}
8. If you run the application and select Earthquake Map from the main menu, your application
should appear as shown in Figure 7-8.