How to implement getFilter on a BaseAdapter?

Question

I am trying to implement a getFilter() on a base adapter to filter out search results on a List. Is there any example of how to implement a getFilter()?

MainActivity

Answer 1

this almost got me killed :)

1. implement your BaseAdapter like this:

2. define an ArrayList of List in your public adapter class which is gonna contain temporary items of your Original List.

   public class MyAdapter extends BaseAdapter implements Filterable{
   
       public static ArrayList temporarylist;
       public static ArrayList OriginalList;
       private Activity activity;
   
       public MyAdapter(Activity activity, ArrayList OriginalList) {
            super();
            this.activity=activity;
            this.OriginalList = OriginalList;
            temporarylist=OriginalList;
   
       }
       .
       .
       .
   

3. create getFilter() method with the following code[as an example]:

   public Filter getFilter() {
       Filter filter = new Filter() {
   
       @SuppressWarnings("unchecked")
       @Override
       protected void publishResults(CharSequence constraint, FilterResults results) {
           temporarylist=(ArrayList)results.values;
           notifyDataSetChanged();
       }
   
       @Override
       protected FilterResults performFiltering(CharSequence constraint) {
           FilterResults results = new FilterResults();
           ArrayList FilteredList= new ArrayList();
           if (constraint == null || constraint.length() == 0) {
               // No filter implemented we return all the list
               results.values = OriginalList;
               results.count = OriginalList.size();
           }
           else {
               for (int i = 0; i < OriginalList.size(); i++) {
                   String data = OriginalList.get(i);
                   if (data.toLowerCase().contains(constraint.toString()))  {
                       FilteredList.add(data);
                   }
               }
               results.values = FilteredList;
               results.count = FilteredList.size();
           }
           return results;
       }
   };
   return filter;
   }
   

And finally in your activity for your EditText:

MyAdapter adapter;
ArrayList items;


ListView list = (ListView) findViewById(R.id.list);
items = new ArrayList();
for (int i=0;i<30;i++){
     items.add("Hello world "+String.valueof(i));
}
adapter = new GameAdapter(this, items);
list.setAdapter(adapter);


EditText inputSearch = (EditText) findViewById(R.id.Search_txt);
     inputSearch.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
                // When user changed the Text
                MyActivity.this.adapter.getFilter().filter(cs);
            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                    int arg3) {
                // TODO Auto-generated method stub

            }

            @Override
            public void afterTextChanged(Editable arg0) {
                // TODO Auto-generated method stub                          
            }
        });