I am building an Android app (my first app actually) and it's about getting similar tracks to the one you searched for. I am using retrofit2 with rxJava and gson for my calls.
For each track i found i add the corresponding image provided by the response in an imageview, but this image is not the actual album image, it's just an image of the band. I want to have the album image which i can get from the API if i do an album search.
So is there a way to make a API call that returns the album info for each track without losing to much time loading? I want these calls to happen in parallel with each other so as to be less visible to the "user" (me).
This is the code that i use to search for the similar tracks:
private void loadSimilarTracks() {
String mbid = selectedTrack.getMbid();
String artist = selectedTrack.getmArtist();
String track = selectedTrack.getName();
searchService = new LastFMSearchService();
Flowable<List<TrackSimilar>> fetchDataObservable = null;
if(!mbid.equals("")) {
fetchDataObservable = searchService.getSimilarTracks(mbid);
}
else{
fetchDataObservable = searchService.getSimilarTracks(artist, track);
}
mCompositeSubscription.add(fetchDataObservable
.timeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS)
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribeWith(new DisposableSubscriber<List<TrackSimilar>>() {
#Override
public void onNext(List<TrackSimilar> tracks) {
mTracks = tracks;
similarTrackAdapter.setTrackList(tracks);
}
#Override
public void onError(Throwable e) {
Toast.makeText(getActivity(), "API CALL ERROR", Toast.LENGTH_SHORT).show();
}
#Override
public void onComplete() {
resultsView.setVisibility(View.VISIBLE);
}
})
);
}
P.S i am using the lastFM api for my info.
Thanks in advance for any response.
Your code is good, one thing that you can do is that you can segment your code into multiple functions instead of a single one and run them as separate threads.
One function that makes api calls to search for similar tracks and other to get the image and trust me that significantly improves the response. Hope it helps..
Related
I am developing an application that uses the Spotify API. It has to start a specific track. I can achieve this.
But after the track is finished the playback stops. I want Spotify to play the following tracks of the album then. Is there a way to do so?
I have not messed with the player state yet too much (only grabbing cover art uri), but here is how I would go about it off the top of my head.
I would first subscribe to the player state to see what is going on with the player. If it is paused, I would then play the album you were talking about or want to talk about. Here is a small example that might be helpful.
SpotifyAppRemote mSpotifyAppRemote; // The app remote
/* For mAppRemoteSet the connection parameters */
connectionParams = new ConnectionParams.Builder(CLIENT_ID)
.setRedirectUri(REDIRECT_URI)
.showAuthView(true)
.build();
/* Connect to SpotifyAppRemote */
SpotifyAppRemote.connect(this, connectionParams, new Connector.ConnectionListener() {
#Override
public void onConnected(SpotifyAppRemote spotifyAppRemote) {
mSpotifyAppRemote = spotifyAppRemote;
Log.d(TAG, "App remote Connected!");
connected();
#Override
public void onFailure(Throwable throwable) {
Log.e(TAG, throwable.getMessage(), throwable);
// Hanfle errors here
}
});
}
public connected() {
/* Subscribe to the PlayerState */
mSpotifyAppRemote.getPlayerApi()
.subscribeToPlayerState()
.setEventCallback(playerState -> {
if (playerState.isPaused) {
mSpotifyAppRemote.getPlayerApi().play("ALBUM URI");
}
});
}
Where "CLIENT_ID" and "REDIRECT_URI" are specific to what you defined in your code already from the dashboard.
Where "ALBUM URI" is the id specific to that album you want to play after you play the first song you mentioned.
You can also play the specific track then set the offset of the album to the beginning and start the whole album over if the specific track is in the middle, end, etc of the album.
I am still learning the sdk and the many options it offers so I apologize ahead of time if this is completely irrelevant or unhelpful.
I want to create an activity in which you can insert/remove/move/connect nodes between each others and based on them to generate a string value that would be later sent through Bluetooth to an other device.
Something like this
And the resulting string should look like:
`"do[i<0-2>]:
{case[i]:
{0:"Hello ",1:"World",2:"!"}
}"
My problem is that I have no idea how to start creating the view where the nodes will be placed and the nodes themselves
I think that the "workspace" should be just a simple empty view where you can pan and zoom in/out
But for the nodes I have no idea where to start because they need to be able to have multiple inputs/outputs... maybe I need to create a custom veiw/component but like i said :( i don't know how to start
Thanks for the help in advance!
EDIT:
I have decided to use Google's Blockly to generate the string, I have customized the block the way I need to generate the string, but I can't figure it out how to get the "code" generated as a string so I can use it later... does anyone has an idea?
Blockly for Android uses a CodeGenerationRequest.CodeGeneratorCallback to pass the code string back to the application.
See this example from the TurtleActivity:
private final CodeGenerationRequest.CodeGeneratorCallback mCodeGeneratorCallback =
new CodeGenerationRequest.CodeGeneratorCallback() {
#Override
public void onFinishCodeGeneration(final String generatedCode) {
// Sample callback.
Log.i(TAG, "generatedCode:\n" + generatedCode);
Toast.makeText(getApplicationContext(), generatedCode,
Toast.LENGTH_LONG).show();
mHandler.post(new Runnable() {
#Override
public void run() {
String encoded = "Turtle.execute("
+ JavascriptUtil.makeJsString(generatedCode) + ")";
mTurtleWebview.loadUrl("javascript:" + encoded);
}
});
}
};
#Override
public void getLeaderboardGPGS() {
if (gameHelper.isSignedIn()) {
startActivityForResult(Games.Leaderboards.getLeaderboardIntent(gameHelper.getApiClient(), getString(R.string.event_score)), 100);
}
else if (!gameHelper.isConnecting()) {
loginGPGS();
}
}
#Override
public void getAchievementsGPGS() {
if (gameHelper.isSignedIn()) {
startActivityForResult(Games.Achievements.getAchievementsIntent(gameHelper.getApiClient()), 101);
}
else if (!gameHelper.isConnecting()) {
loginGPGS();
}
}
Can anyone explain to me what these methods do? I have them as part of implementing a GoogleApi interface I made in the context of a tutorial. I especially don't understand the 100 / 101 parts, but the whole thing, in general, is quite confusing for me.
PS. I am making a game in LibGDX and this is my first time touching the Google Play API (or I think any API for that matter)
First Method getLeaderboardGPGS show you Leaderboard above your Activity
if you are already Signed in otherwise it start signing process.
Above method definition is from Libgdx wiki but it should be
private final static int REQUEST_CODE_UNUSED = 9002;
startActivityForResult(Games.Leaderboards.getLeaderboardIntent(gameHelper.getApiClient(), getString(R.string.leaderboardId)), REQUEST_CODE_UNUSED);
REQUEST_CODE_UNUSED is an arbitrary integer for the request code
getString(R.string.leaderboardId) is LEADERBOARD_ID
taken from Google wiki
Second Method getAchievementsGPGS is used to show a player's achievements, call getAchievementsIntent() to get an Intent to create the default achievements UI.
startActivityForResult(Games.Achievements.getAchievementsIntent(gameHelper.getApiClient()), REQUEST_ACHIEVEMENTS);
where REQUEST_ACHIEVEMENTS is an arbitrary integer used as the request code.
I'm trying to implement a Google Fit Listener when data is updated into Google Fit services.
In this link of Google Fit documentation there is a simple example, however, it is not 100% clear. For that reason, I have two problems:
I don't know how to implement mResultCallback variable (there aren't any examples in this documentation).
When I define a simple ResultCallback (it seems to work but I'm not sure) and I launch the application, it gives me a result error code: java.lang.SecurityException: Signature check failed
The code within the HistortyApi lists one of android.permission.ACCESS_FINE_LOCATION or android.permission.BODY_SENSORS as being required.
Adding those permissions to my code hasn't resolved the same problem though.
Confirmed bug in Google Fit services. See discussion in https://plus.google.com/110141422948118561903/posts/Lqri4LVR7cD
mResultCallback is a ResultCallback<Status> so you need to implement a class of that type. Documentation is here, but there's only one method you need to implement:
public abstract void onResult (Status result)
The standard way is to do this using an anonymous class either when you declare mResultCallback or when you're using it as a parameter. Below is an example from Google's BasicRecordingAPI example:
Fitness.RecordingApi.subscribe(mClient, DataType.TYPE_ACTIVITY_SAMPLE)
.setResultCallback(new ResultCallback<Status>() {
#Override
public void onResult(Status status) {
if (status.isSuccess()) {
if (status.getStatusCode()
== FitnessStatusCodes.SUCCESS_ALREADY_SUBSCRIBED) {
Log.i(TAG, "Existing subscription for activity detected.");
} else {
Log.i(TAG, "Successfully subscribed!");
}
} else {
Log.i(TAG, "There was a problem subscribing.");
}
}
});
If you want to use a member variable you can simply make an assignment instead:
ResultCallback<Status> mResultCallback = new ResultCallback<Status>() {
#Override
public void onResult(Status status) {
...
}
});
Of course you can define a non-anonymous class, but if you did that for every callback you had you would end up creating a LOT of classes.
Intro to me and my application school project
Hi,
iam pretty new with android and for some school project iam building an application where users can configure regions to recieve alerts from. The app need also make it posible to recieve alerts around the current location of the app user.
The app gets its info from a xml feed and sorts the data by the configured regions. The workflow is 1. to get the alerts which are in the configured regions. 2. When gps alerts are enabled the app need to get the location and when it is known it needs to do the first step again but this time the gps region is included. (i need to optimize this proces LATER)
(questions bellow)
intro to my app and problem
I'm using a asynctask in my application to download some xml feed. When the asynctask is ready i need to call 3 places for do something with the result.
1 class saves the result in the local database (alertmanager)
2 fragments (in a tabview) needs to show the results (1 in a map an one in a listview)
Now i use weakreferences for giving the call back "references" to the asynctask. in the onPostExecute() i use theWeakReference.get().updateMethod(result); for updating the class/fragments.
The alertmanager (the class who needs to recieve the updates) also calls a gps manager in the same method where it calls the asynctask to get the gps location. When i comment out (in my case with a if) the line what calls the gps manager the weak reference of the alertmanager will go to null in the asynctask between the constructor (all references are filled) and the doInBackground (the alertmanager reference is null, the other 2 still filled) which results in a crashing app.
When i dont comment out the if the app works fine.....
Alertmanager information
This is the method in the alertmanager who calls the async task. The references are filled on this place.
public void GetAlerts(List<WeakReference<e_Alerts>> callbackReferences, Context context) {
//Update the alerts in the listview and mapview with the local alerts.
List<Alert> localAlerts = internalDc.GetAllAlerts();
try {
for (WeakReference<e_Alerts> callback : callbackReferences) {
callback.get().UpdateAlerts(localAlerts);
}
} catch (Exception e) {
Log.e("AlertManager", e.getMessage());
}
//If connected to the internet then update the local db and the views
if (isConnectingToInternet(context)) {
WeakReference<e_Alerts> wr = new WeakReference<e_Alerts>(this);
callbackReferences.add(wr);
// Update the alerts where no location is needed for so the user has a quick result
externalDc.getAlerts(callbackReferences, areaManager.GetActiveAreas(false));
// If gps region is enabled then find the phones location and update the alerts
if (areaManager.GetGpsArea().IsActive()) {
new GpsManager(this.context, this, callbackReferences);
}
}
}
The GpsManager extends the LocationListener:
public class GpsManager extends Service implements LocationListener {
The listener is implemented by the Alertmanager
// This method is caled by the GPS Manager when the GPS location is changed
#Override
public void OnLocationChanged(Location location, List<WeakReference<e_Alerts>> references) {Area gpsArea = areaManager.GetGpsArea();
gpsArea.SetLocation(location);
areaManager.SaveArea(gpsArea);
externalDc.getAlerts(references, areaManager.GetActiveAreas(true));
}
Asynctask information
This are the asynctask methods:
Asynctask constructor:
Here the list callbackReferences contains 3 weakrefrences and all of them are filled (2x fragment reference 1x alertmanager reference)
public At_allAlerts(List<WeakReference<e_Alerts>> callbackReferences, List<Area> areas) {
this.mCallbackReferences = callbackReferences;
this.mAreas = areas;
}
doInBackground code:
The XmlDownloader: Downloads an xml feed an parses the xml to objects with a library
The AlertConverter: converts the xml object to the object i use in my app
Both classes can work without the asynctask class and don't use the references.
#Override
protected String doInBackground(String... inputUrl) {
Log.i("At_allAlerts", "Asynctask for downloading and parsing mAlerts is started");
try {
//Downloads the alert XMLs from the internet and parses it to xmlAlerts
this.mAlerts = new XmlDownloader().DownloadAlerts(inputUrl);
// Filters the mXml mAlerts so only the mAlerts where the enduser is interessed in will remain
this.mAlerts = filterAlerts(this.mAlerts);
// Converts the remaining xmlAlerts to Alerts;
this.mResult = new AlertConverter().Convert(this.mAlerts);
}catch (Exception e) {
Log.e("At_allAlerts",e.getMessage());
}
return null;
}
The onPostExecute method:
When the programm comes in this method the this.references.get(2) reference (alertmanager reference) = null, the other 2 references are still filed
#Override
protected void onPostExecute(String xml){
for (WeakReference<e_Alerts> reference : activityWeakReferences)
{
reference.get().UpdateAlerts(this.result);
}
}
filterAlerts Method:
private List<Item> filterAlerts(List<Item> alerts) {
List<Item> filteredXmlAlerts = new ArrayList<>();
for (Item alert : alerts)
{
Location alertLocation = new Location("");
alertLocation.setLatitude(alert.getGeometries().get(0).getLocations().get(0).getLat());
alertLocation.setLongitude(alert.getGeometries().get(0).getLocations().get(0).getLng());
for(Area area : this.mAreas)
{
if (area.IsOrganization() && alert.getCountryCode().toLowerCase().equals(area.getOrganizationcode().toLowerCase())){
filteredXmlAlerts.add(alert);
break;
}
else if(!area.IsOrganization() && isAlertInRegion(alertLocation, area)) {
filteredXmlAlerts.add(alert);
break;
}
}
}
return filteredXmlAlerts;
}
My Question(s)
I think Weakreference are the right way for giving references to asynctask is this correct or do i need to give it as an other object? (class or object or whatever?).
Why goes my reference to null? and only one of the 3? and only when i dont use the gps location class? and how to solve this?
I read something about the garbage collector what can be the cause of this problem, is this true and when yes how can i solve this?
It would be fine when the answere are simple to understand since android is pretty new for me.