private void loadData() {
// Check if GPS is enabled and fetch posts
if (Utils.isGPSEnabled(this)) {
if (lastLocation == null || isLoctionStale(lastLocation)) {
connectToGoogleAPI();
} else {
getPosts();
}
} else {
refreshLayout.setRefreshing(false);
Toast.makeText(getApplicationContext(), "GPS is disabled", Toast.LENGTH_SHORT).show();
}
}
private void getPosts() {
// Check if internet is enabled first
if (!Utils.isInternetEnabled(getApplicationContext())) {
Toast.makeText(getApplicationContext(), "No internet connection", Toast.LENGTH_SHORT).show();
refreshLayout.setRefreshing(false);
} else {
// Retreive posts by first fetching post locations near current locations
// and then fetching the post details for those posts
locationKeys = new ArrayList<>();
posts = new ArrayList<>();
// Get post locations in range
final GeoQuery query =
geofireRef.queryAtLocation(
new GeoLocation(lastLocation.getLatitude(), lastLocation.getLongitude()),
postRangeInKm);
query.addGeoQueryEventListener(
new GeoQueryEventListener() {
@Override
public void onKeyEntered(String key, GeoLocation location) {
// Once a post location is received add it to the list
locationKeys.add(key);
}
@Override
public void onKeyExited(String key) {}
@Override
public void onKeyMoved(String key, GeoLocation location) {}
@Override
public void onGeoQueryReady() {
// Once all posts locations are retrieved, remove listener
query.removeGeoQueryEventListener(this);
// If no posts stop refreshing
if (locationKeys.size() == 0) {
refreshLayout.setRefreshing(false);
}
// TODO: Should this br done off the UI thread? Where
// would the listeners run?
for (final String key : locationKeys) {
// For each location post, retreive its post details
firebaseRef
.child(key)
.addListenerForSingleValueEvent(
new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// Create a post object out of the details
QueryPosts post = dataSnapshot.getValue(QueryPosts.class);
// If post is stale, delete it. This should be done server side,
// but we don't have one
if (isPostStale(post)) {
firebaseRef.child(key).removeValue();
geofireRef.removeLocation(key);
} else {
// Otherwise, add it to the list of post details
posts.add(new Post(key, post.getMessage(), post.getTimestamp()));
}
// Remove post location, if details have been fetched and
// once all posts are fetched, call onSucces
locationKeys.remove(key);
if (locationKeys.size() == 0) {
onSuccess();
}
}
@Override
public void onCancelled(FirebaseError firebaseError) {
onError(firebaseError);
}
});
}
}
@Override
public void onGeoQueryError(FirebaseError error) {
onError(error);
}
});
}
}