I'm fairly new to android programming and I'm currently stuck on how I'm going to display data to my spinner dynamically. Basically I am using websocket to receive data and run it on my UI thread my problem is that there is no list of data showing in my spinner.
You Should Create an ArrayList like the following.
ArrayList<String> spinnerArray = new ArrayList<String>();
Spinner is associated with Adapter view so to fill the data in spinner you need to use one of the adapter. An adapter is a bridge between UI component and data source that helps us to fill data in UI component.
simply you can use ArrayAdapter like below (to use a custom adapter see this)
ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>
(this, android.R.layout.simple_spinner_item,
spinnerArray);
After that, you have to set your adapter to your spinner like the following.
spin.setAdapter(spinnerArrayAdapter);
EXAMPLE: Your code should be like following.
ArrayList<String> spinnerArray;
ArrayAdapter<String> spinnerArrayAdapter
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.popup);
WayPointData = new SubscribedData<>();
final Type WayPointType = new TypeToken<SubscribedData<WayPoint>>() {
}.getType();
// spinner element
spin = (Spinner) findViewById(R.id.spinner);
spinnerArray = new ArrayList<String>();
spinnerArrayAdapter = new ArrayAdapter<String>
(this, android.R.layout.simple_spinner_item,
spinnerArray);
spin.setAdapter(spinnerArrayAdapter);
rosbridge = new RosbridgeListener("ws://10.24.204.231:9090");
rosbridge.setOnDataReceivedListener(new RosbridgeMessageListener() {
/**
* a running thread that when the connection is made the data of the topic will serialize and deserialized java objects
* to (and from) JSON.
* @param msg
*/
@Override
public void onDataReceived(final String msg) {
try {
runOnUiThread( new Runnable() {
@Override
public void run() {
try {
WayPointData = new Gson().fromJson(msg,WayPointType);
// modify below lines like
JSONObject mainObject = new JSONObject(msg); // add msg in JSONObject parameter
JSONObject msgObject = mainObject.getJSONObject("msg"); // get msgObject from main object
JSONArray wayPointJsonArray = msgObject.getJSONArray("waypoints"); // get wayPointJsonAarry from msg object
for (int i = 0; i < wayPointJsonArray.length(); i++) {
JSONObject wayPointJsonObject = wayPointJsonArray.getJSONObject(i);
// Parse name
String name = wayPointJsonObject.getString("name");
WayPoint wayPoint = new WayPoint();
wayPoint.name = name;
// here you have to add name to your spinner array
spinnerArray.add(name)
}
// After all your data added to arraylist you should notify adapter that data set changed
spinnerArrayAdapter.notifyDataSetChanged();
} catch (Exception e) {
e.printStackTrace();
}
}
});
/** a msg that will display once the data is received **/
Log.d("B9T", String.format("Received data: %s", msg));
} catch (Exception e) {
e.printStackTrace();
}
}
});
spin.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int p, long id) {
WayPoint wayPoint = (WayPoint) parent.getItemAtPosition(p);
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
/** a set of the waypoints popup window **/
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
int width = dm.widthPixels;
int height = dm.heightPixels;
getWindow().setLayout((int) (width * .6), (int) (height * .6));
}
}
Hope it helps you. Happy Coding