Develop Reference

AutoCompleteTextView does not populate from Firebase [duplicate]

I want to periodically change the suggestions given by an AutoCompleteTextview by getting the list from a RESTful web service, and can't get it working smoothly. I set up a hard-coded list of suggestions to make sure it's working:
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_item, new String[] {"Hi", "Ho"});
speciesName.setAdapter(adapter);//my autocomplete tv
I have got a TextWatcher on the textview and when the text changes that launches a non-blocking call to get a new list of suggestions -- this part which gets a new list is working fine. Then I want to reset the adapter, like so:
public void setOptionsAndUpdate(String[] options) {
Log.d(TAG, "setting options");
//speciesName.setAdapter((ArrayAdapter<String>)null);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_item, options);
speciesName.setAdapter(adapter);
}
This method is called, but doesn't work -- the list of suggestions either disappears or the displayed suggestions remain unchanged despite the call to setAdapter.
Is this even the right approach? I looked at SimpleCursorAdapter but couldn't see how to register my web service as a content provider. (It's of the form http://www.blah.com/query?term=XX, where the XX is the input from my app, and the response is a JSON Array of strings.)

I didn't have any luck using adapter.notifyDataSetChanged() when dynamically adding and changing the data in the adapter. In my situation, I was hitting an external api asynchronously and getting a list of completion data periodically.
This code clears the adapter, and adds the new data as you'd expect. However, I had to call the getFilter().Filter method to force the data to show. Also, I had to explicitly filter based on the current text in the AutocompleteTextView because my api call was asynchronous.
adapter.clear();
for (Map<String, String> map : completions) {
adapter.add(map.get("name"));
}
//Force the adapter to filter itself, necessary to show new data.
//Filter based on the current text because api call is asynchronous.
adapter.getFilter().filter(autocompleteTextView.getText(), null);

This is how I update my AutoCompleteTextView:
String[] data = terms.toArray(new String[terms.size()]); // terms is a List<String>
ArrayAdapter<?> adapter = new ArrayAdapter<Object>(activity, android.R.layout.simple_dropdown_item_1line, data);
keywordField.setAdapter(adapter); // keywordField is a AutoCompleteTextView
if(terms.size() < 40) keywordField.setThreshold(1);
else keywordField.setThreshold(2);
Now of course, this is static and doesn't deal with an over-the-air suggestions but, I can also suggest you to notify adapter for the changes after you assign it to the AutoCompleteTextView:
adapter.notifyDataSetChanged();
Hope this helps.
-serkan

There was a pretty good tutorial on this topic using remote data in the Google Map API to populate a AutoCompleteTextView here.
If you need a cached version, I retrieved it from here.
The original tutorial has been deleted, but essentially you need to write an ArrayAdapter with a custom filter in a similar way to that shown below and assign it to your AutoCompleteTextView.
Note: You need to implement a method autocomplete() that does whatever operation is required to synchronously fetch and return the autocompletion items. As the filter is invoked in a background thread, this will not block the main UI thread.
private class PlacesAutoCompleteAdapter extends ArrayAdapter<String> implements Filterable {
private ArrayList<String> resultList;
public PlacesAutoCompleteAdapter(Context context, int textViewResourceId) {
super(context, textViewResourceId);
}
#Override
public int getCount() {
return resultList.size();
}
#Override
public String getItem(int index) {
return resultList.get(index);
}
#Override
public Filter getFilter() {
Filter filter = new Filter() {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults filterResults = new FilterResults();
if (constraint != null) {
// Retrieve the autocomplete results.
resultList = autocomplete(constraint.toString());
// Assign the data to the FilterResults
filterResults.values = resultList;
filterResults.count = resultList.size();
}
return filterResults;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
if (results != null && results.count > 0) {
notifyDataSetChanged();
}
else {
notifyDataSetInvalidated();
}
}};
return filter;
}
}

Since i am not able to add a comment, i am giving a new answer
There is no need for clearing the adapter or calling adapter.getFilter().filter(...)...
To dynamically update an AutoCompleteTextView adapter, simply add the new item to the adapter and setAdapter again. For the example given in the original question, i tried the following and it works (the code below does not show the initial setting of the adapter, since multiple answers here cover that. This just shows updating the adapter dynamically). The adapter update can be alongside the code that updates the List associated with the ArrayAdapter.
adapter.add(String newSuggestion); // this goes inside a loop for adding multiple suggestions
speciesName.setAdapter(adapter) ; // speciesName is an AutoCompleteTextView as given in the original question.

The best solution I found for updating the adapter:
Editable text = autocomplete.getText();
autocomplete.setText(text);
autocomplete.setSelection(text.length());
How it works:
We set the text of autoCompleteTextView with its current text, so the adapter notifies that data is changed and updates the listViews's content.
But by this trick the cursor moves to the beginning of edittext. so we use autocomplete.setSelection(text.length()) for moving the cursor to the end.
Works like a charm!
Edit:
Also you must use clear(), add() and remove() methods directly on your ArrayAdapter instead of your ArrayList.

Custom ListView ArrayAdapter not displaying filtered data

I am displaying some data in ListView using my custom ArrayAdapter class. I have a spinner in Action Bar and based on it's item selection I want to filter the data and repopulate it in the list view.
Currently when my activity loads the data shows up correctly, but when I select any item from the spinner, the ListView gets empty and does not show any data, although the Actionbar still appears.
Could you please tell me what I am doing wrong?
This is my custom ArrayAdapter Class :
public class MyAdapter extends ArrayAdapter implements Filterable {
private ArrayList < ArrayList < String >> arrayList;
private LayoutInflater theInflater;
public MyAdapter(Context context, ArrayList arrayList) {
super(context, R.layout.row_layout, arrayList);
this.arrayList = arrayList;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
theInflater = LayoutInflater.from(getContext());
View theView = theInflater.inflate(R.layout.row_layout, parent, false);
ArrayList < String > values = (ArrayList < String > ) getItem(position);
TextView a= (TextView) theView.findViewById(R.id.a);
TextView b= (TextView) theView.findViewById(R.id.b);
TextView c= (TextView) theView.findViewById(R.id.c);
a.setText(values.get(0));
b.setText(values.get(1));
c.setText(values.get(2));
return theView;
}
public Filter geFilter() {
Filter filter = new Filter() {#Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
ArrayList al = new ArrayList();
al.add("ValueA1");
al.add("ValueA2");
al.add("ValueA3");
ArrayList bl = new ArrayList();
bl.add("ValueB1");
bl.add("ValueB2");
bl.add("ValueB3");
ArrayList < ArrayList < String >> array = new ArrayList < > ();
array.add(al);
array.add(bl);
results.count = array.size();
results.values = array;
return results;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
arrayList = (ArrayList) results.values;
notifyDataSetChanged();
}
};
return filter;
}
}
In Spinner's item selected listener, I have :
theAdapter.getFilter().filter("Incoming");

Unfortunately, there's a lot you are doing wrong with the adapter. Such as not implementing the ViewHolder paradigm. Note, this is not why you are seeing issues. However it does solve performance issues your solution will create.
The filtering itself is not working because ArrayAdapter tracks it's own internal list of data. The ArrayAdapter makes no guarantees that the list you are tracking externally is the same one. This is especially true during a filter operation. You can read more about the dangers of tracking an external list like you are here.
Your Filter is very problematic.
It re-assigns your external list of data to a new list, which means your arrayList is no longer the same one the internal ArrayAdapter is tracking. This will cause issues later on when you mutate the adapter.
As it stands, your implementation doesn't seem to actually filter anything. Usually you'll also have a second ArrayList in order to track the original data before the filtering starts. Otherwise there's no way to restore the data that was filtered out.
performFiltering() takes place on a background thread. While you don't seem to access arrayList during this method (which would be the only way to actually filter the data), you need to ensure all list modifications are synchronized. ArrayAdapter itself already handles synchronization but there's no way to sync your external arrayList with it. Meaning you can't actually write a filter without risking concurrent modification errors.
In publishResults() when results.count == 0, you must notifyDataSetInvalidated(). If results.count > 0, you must notifyDataSetChanged().
ArrayAdapter already implements Filterable. It's redundant to add that to your custom adapter.
There are a few bugs with the ArrayAdapter own filterable implementation. Here's a piece which talks about the problem and how to work around it. The relevance is that it discusses how to create your own filterable logic to fix the problem. The short, you can't create your own custom filter with the ArrayAdapter. You need to create your own adapter from scratch using BaseAdapter instead.
Alternatively, you can use a third party library which provides a very easy means to implement your own custom filtering logic. I highly suggest taking a look at that guy instead. Additionaly, I highly recommend you Google around more on how to properly create a custom adapter. There's a lot to them and a lot you'll need to learn to properly implement one from scratch.

Do the following in publishResults() method:
Clear the list, add the resultant data again and call notifyDataSetInvalidated() again.
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
arrayList = (ArrayList) results.values;
notifyDataSetChanged();
clear();
for(int i = 0, l = arrayList.size(); i < l; i++) {
add(arrayList.get(i));
}
notifyDataSetInvalidated();
}

AutoCompleteTextView custom ArrayAdapter & Filter performance

I have an AutoCompleteTextView with a custom ArrayAdapter that uses ArrayList<Product>.
I've came to the conclusion that a custom ArrayAdapter of an AutoCompleteTextView must implements Filterable and you have to make your own Filtering.
From this SO-question & accepted answer and this example, I have made the following ArrayAdapter:
public class AutoCompleteAdapter extends ArrayAdapter<Product> implements Filterable
{
// Logcat tag
private static final String TAG = "AutoCompleteAdapter";
// The OrderedProductItem we need to get the Filtered ProductNames
OrderedProductItem orderedProductItem;
private Context context;
private ArrayList<Product> productsShown, productsAll;
// Default Constructor for an ArrayAdapter
public AutoCompleteAdapter(Context c, int layoutId, ArrayList<Product> objects, OrderedProductItem opi){
// Though we don't use the Layout-ResourceID , we still need it for the super
super(c, layoutId, objects);
L.Log(TAG, "AutoCompleteAdapter Constructor", LogType.VERBOSE);
// ArrayAdapter's setNotifyOnChange is true by default,
// but I set it nonetheless, just in case
setNotifyOnChange(true);
context = c;
replaceList(objects, true);
orderedProductItem = opi;
}
// Setup the ListItem's UI-elements
#Override
public View getView(int position, View convertView, ViewGroup parent){
return createTextViewAsItem(position);
}
#Override
public View getDropDownView(int position, View convertView, ViewGroup parent){
return createTextViewAsItem(position);
}
// To prevent repetition, we have this private method
private TextView createTextViewAsItem(int position){
TextView label = new TextView(context);
String name = "";
if(productsShown != null && productsShown.size() > 0 && position >= 0 && position < productsShown.size() - 1)
name = productsShown.get(position).getName();
label.setText(name);
return label;
}
// Replace the List
// When the boolean is set, we replace this ArrayAdapter's List entirely,
// instead of just the filtering
#SuppressWarnings("unchecked")
public void replaceList(ArrayList<Product> p, boolean replaceInitialList){
if(p != null && p.size() > 0){
productsShown = p;
if(replaceInitialList)
productsAll = (ArrayList<Product>)productsShown.clone();
notifyDataSetChanged();
}
}
// Since we are using an AutoCompleteTextView, the Filtering has been reset and we need to apply this ourselves..
Filter filter = new Filter(){
#Override
public String convertResultToString(Object resultValue){
return ((Product)resultValue).getName();
}
#Override
protected FilterResults performFiltering(CharSequence constraint){
FilterResults filterResults = new FilterResults();
if(productsAll != null){
// If no constraint is given, return the whole list
if(constraint == null){
filterResults.values = productsAll;
filterResults.count = productsAll.size();
}
else if(V.notNull(constraint.toString(), true)){
L.Log(TAG, "performFiltering: " + constraint.toString(), LogType.VERBOSE);
ArrayList<Product> suggestions = new ArrayList<Product>();
if(p.size() > 0)
for(Product p : productsAll)
if(p.getName().toLowerCase(Locale.ENGLISH).contains(constraint.toString().toLowerCase(Locale.ENGLISH)))
suggestions.add(p);
filterResults.values = suggestions;
filterResults.count = suggestions.size();
}
}
return filterResults;
}
#SuppressWarnings("unchecked")
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
if(results != null && results.count > 0)
replaceList((ArrayList<Product>)results.values, false);
}
};
#Override
public Filter getFilter(){
return filter;
}
}
Everything works perfectly. However, since I have a list of around 1250 Products and these are all looped every time the User changes his input in the AutoCompleteTextView, including the creation of two new instantiations (FilterResults and ArrayList), I was wondering if there is a better solution for this without having to loop though everything on every user input change.
If there isn't I just keep this. I was just wondering since with an AutoCompleteTextView containing around 1250 objects, with a custom ArrayAdapter (including custom Filtering) and a custom TextWatcher, it isn't that good for the performance. Especially since this AutoCompleteTextView is used inside the item of a ListView. Which means I have an AutoCompleteTextView for every item (potentially ranging from ~ 5 to 50, with an average of around 15).

This is coming fairly late, however I thought I'd weigh in on your problem...mostly because the rather scaring things occurring with your implementation. To answer your immediate question, there's not much you can easily do to avoid the full ArrayList iteration when filtering. If you need something faster, you'll need to look into pre-processing your data into something with faster search times. AutoComplete Algorithm?.
I have a general rule of thumb for customizing the ArrayAdapter filtering logic. Don't do it. Whenever you run into this situation, the correct solution is to roll your own adapter solution (Using BaseAdapter)...or find a 3rd party solution that allows you too. Part of the issue is that internally the ArrayAdapter has it's own two lists for filtering and it's own internal synchronized lock. Your AutoCompleteAdapter is exposing a ton of mutators, all of which synchronize on an object you can't sync on. That means you risk concurrency issues if the adapter is mutated while filtering is occurring.
As it stands with your code, the ArrayAdapter is linked up with your productsAll list. Any mutations, accessors, methods etc will always reference that list. At first I was surprised your solution worked! Then I realized you aren't using getItem as is the norm. I imagine you are completely neglecting all the other ArrayAdapter methods, else you'd have seen rather strange behavior. If that's the case, ArrayAdapter isn't really doing anything for you and you're loading up this huge class for nothing. Would be trivial to switch it out with BaseAdapter.
In fact I'm surprised you aren't seeing other strange problems. For instance, no matter what your filtered list shows, your adapter is always registering the productsAll list count instead of the productsShown count. Which may be why you have all these index out of bounds checks? Typically not needed.
I'm also surprised your filtering operation updates the list since you fail to invoke notifyDataSetChanged when finished.
Next big problem, you should never nest adapters. I'm usually advocating this because people embed ListViews...which is another no no of itself. This is the first I've heard about nesting with AutoCompleteTextView though. Slightly different situation, yet I'd still say this is a bad idea. Why? There's no guarantee how many times getView will be invoked for a given position. It could call it once...it could call it 4 times...or more. So imagine recreating your adapter 4 times per item. Even if only 10 items display at a time, you're looking at 40 instantiations of your custom adapter! I sure hope you figured out a way to recycle those adapters to lower that number.
However considering you aren't using the ViewHolder I'm assuming you don't even know about the recycling behavior? ViewHolder is a must do for any adapter. It single handily will provide an enormous performance boast. Right now, you are creating a new view with every getView invocation and ignoring any of the recycled views provided. There a million examples online that show and explain the ViewHolder. Here's one such link.
Side note, ArrayAdapter already implements Filterable. Re-adding the implements in your custom adapter is not needed.
To sum up:
Implement BaseAdapter instead
Don't embed adapters. Find a different way to display your UI without requiring multiple AutoCompleteTextViews inside of a ListView.
Can't really improve your filtering logic without some heavy data pre-processing.
Use ViewHolder paradigm.
Must watch video from Google I/O about ListViews and adapters.
Here's some further readings about the ArrayAdapter.

Android AutoCompleteTextView with List<String>

I have an AutoCompleteTextView where the user types an address. I want to be able to show suggestions below as he types. To do that I get a list of possible addresses via the Reverse Geocoding API. i want then to show this list of strings (possible addresses) to the user. Just like the google maps app does.
I have added a TextChangedListener to the AutoCompleteTextView. On the onTextChanged() event an AsyncTask is executed where the list of possible address gets updated on the onPostExecute().
autoText.addTextChangedListener(new TextWatcher() {
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
new GeoTask().execute();
}
});
Attempt 1
This is the list:
static List<String> suggestionList = new ArrayList<String>();
And this is the code for the adapter for the AutoCompleteTextView :
autoText.setThreshold(3);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, suggestionList);
autoText.setAdapter(adapter);
adapter.setNotifyOnChange(true);
With the above code nothing shows up.
Attempt 2
I also tried using an array as an argument for the adapter and every time the list of address gets updated I convert it to the array.
static String[] suggestions;
static List<String> suggestionList = new ArrayList<String>();
Adapter:
autoText.setThreshold(3);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, suggestionList);
autoText.setAdapter(adapter);
adapter.setNotifyOnChange(true);
AsyncTask:
protected void onPostExecute(Void aVoid) {
...
suggestions = suggestionList.toArray(new String[suggestionList.size()]);
super.onPostExecute(aVoid);
}
How can i make it work? Is there a way to use the adapter with the list?

The reason why nothing shows up is because the list is empty and in onPostExecute of your AsyncTask your only assigning new array to your suggestions reference, what you should really do is use adapters methods to add and remove elements. You can try this code:
adapter.clear();
adapter.addAll(/*new collection of suggestions*/);
in your onPostExecute method.
NOTE: adapter.addAll() method appeared only from 11th API, so if you use lower, then you would have to add each item manually.

Prevent an AutocompleteTextView from reducing the results

I have an AutoCompleteTextView in my application, but there is a lot more behind every item in the DropDownMenu than what is displayed.
I have my own ArrayAdapter for the AutoCompleteTextView, and when the user starts typing anything the autocompleteTextView starts to reduce the drop down list. This is what I want to change. Every time the user types a new letter, I´m making a new search from the database and would like to show all of those in the drop down menu that pops up, i.e I dont want the autocompleteTextView to reduce the list due to what the user is typing.
So, my question is, is there a way to block an autocompleteTextView from reducing the results, or is it easier to just do an edit text view with my own drop down menu?
Thanks.

Finally, I found a solution that worked perfectly. Just want to share it since I spend a lot of time to get it work.
The AutoCompleteTextView does not have any methods to set no filter, or any way to use a custom filer.
As I wrote I have a custom ArrayAdapter to the AutoCompleteTextView. So what I did was in the ArrayAdapter class, override the function getFilter.
And give the cred to the people posting the answer here.
#Override
public Filter getFilter() {
return new KNoFilter();
}
private class KNoFilter extends Filter {
#Override
protected FilterResults performFiltering(CharSequence arg0) {
FilterResults result = new FilterResults();
result.values = searchResults;
result.count = searchResults.size();
return result;
}
#Override
protected void publishResults(CharSequence arg0, FilterResults arg1) {
notifyDataSetChanged();
}
}