I want to use an AutoCompleteTextView
in my activity and populate the data as the user types by querying a web API. How do I go about doing this?
Do I create a new class and override AutoCompleteTextView.performFiltering
, or do I use a custom list adapter and provide a custom android.widget.Filter
that overrides performFiltering?
Or is there a better way to obtain my end goal?
I've done something somewhat similar, but it was for the Quick Search box and it involved implementing a service, but I believe that's not what I want to do here.
I came up with a solution, I don't know if it is the best solution, but it appears to work very well. What I did was created a custom adapter that extends ArrayAdapter. In the custom adapter I overrode getFilter and created my own Filter class that overrides performFiltering. This starts a new thread so it doesn't interrupt the UI. Below is a barebones example.
MyActivity.java
public class MyActivity extends Activity {
private AutoCompleteTextView style;
@Override
public void onCreate(Bundle savedInstanceState) {
...
style = (AutoCompleteTextView) findViewById(R.id.style);
adapter = new AutoCompleteAdapter(this, android.R.layout.simple_dropdown_item_1line);
style.setAdapter(adapter);
}
}
AutoCompleteAdapter.java
public class AutoCompleteAdapter extends ArrayAdapter<Style> implements Filterable {
private ArrayList<Style> mData;
public AutoCompleteAdapter(Context context, int textViewResourceId) {
super(context, textViewResourceId);
mData = new ArrayList<Style>();
}
@Override
public int getCount() {
return mData.size();
}
@Override
public Style getItem(int index) {
return mData.get(index);
}
@Override
public Filter getFilter() {
Filter myFilter = new Filter() {
@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults filterResults = new FilterResults();
if(constraint != null) {
// A class that queries a web API, parses the data and returns an ArrayList<Style>
StyleFetcher fetcher = new StyleFetcher();
try {
mData = fetcher.retrieveResults(constraint.toString());
}
catch(Exception e) {
Log.e("myException", e.getMessage());
}
// Now assign the values and count to the FilterResults object
filterResults.values = mData;
filterResults.count = mData.size();
}
return filterResults;
}
@Override
protected void publishResults(CharSequence contraint, FilterResults results) {
if(results != null && results.count > 0) {
notifyDataSetChanged();
}
else {
notifyDataSetInvalidated();
}
}
};
return myFilter;
}
}