How can I filter ListView data when typing on EditText in android-ThrowExceptions

Exception or error:

I have a ListView and a EditText. How can I filter ListView data when typing on EditText?

How to solve:
  1. Add TextWatcher to EditText#addTextChangedListener
  2. In onTextChanged add or remove items from your ListView‘s adapter. If you are subclassing ArrayAdapter it would have add and remove methods

###

Yes you can, just implement this code. Use the following code to implement search and filter list in android:

SearchAndFilterList.java

public class SearchAndFilterList extends Activity {

    private ListView mSearchNFilterLv;

    private EditText mSearchEdt;

    private ArrayList<String> mStringList;

    private ValueAdapter valueAdapter;

    private TextWatcher mSearchTw;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_search_and_filter_list);

        initUI();

        initData();

        valueAdapter=new ValueAdapter(mStringList,this);

        mSearchNFilterLv.setAdapter(valueAdapter);

        mSearchEdt.addTextChangedListener(mSearchTw);


    }
    private void initData() {

        mStringList=new ArrayList<String>();

        mStringList.add("one");

        mStringList.add("two");

        mStringList.add("three");

        mStringList.add("four");

        mStringList.add("five");

        mStringList.add("six");

        mStringList.add("seven");

        mStringList.add("eight");

        mStringList.add("nine");

        mStringList.add("ten");

        mStringList.add("eleven");

        mStringList.add("twelve");

        mStringList.add("thirteen");

        mStringList.add("fourteen");

        mSearchTw=new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

                valueAdapter.getFilter().filter(s);
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {

            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        };

    }

    private void initUI() {

        mSearchNFilterLv=(ListView) findViewById(R.id.list_view);

        mSearchEdt=(EditText) findViewById(R.id.txt_search);
    }

}

Custom Value adapter:
ValueAdapter.java

public class ValueAdapter extends BaseAdapter implements Filterable{

private ArrayList<String> mStringList;

private ArrayList<String> mStringFilterList;

private LayoutInflater mInflater;

private ValueFilter valueFilter;

public ValueAdapter(ArrayList<String> mStringList,Context context) {

    this.mStringList=mStringList;

    this.mStringFilterList=mStringList;

    mInflater=LayoutInflater.from(context);

    getFilter();
}

//How many items are in the data set represented by this Adapter.
@Override
public int getCount() {

    return mStringList.size();
}

//Get the data item associated with the specified position in the data set.
@Override
public Object getItem(int position) {

    return mStringList.get(position);
}

//Get the row id associated with the specified position in the list.
@Override
public long getItemId(int position) {

    return position;
}

//Get a View that displays the data at the specified position in the data set.
@Override
public View getView(int position, View convertView, ViewGroup parent) {

    Holder viewHolder;

    if(convertView==null) {

        viewHolder=new Holder();

        convertView=mInflater.inflate(R.layout.list_item,null);

        viewHolder.nameTv=(TextView)convertView.findViewById(R.id.txt_listitem);

        convertView.setTag(viewHolder);

    }else{

        viewHolder=(Holder)convertView.getTag();
    }

        viewHolder.nameTv.setText(mStringList.get(position).toString());

        return convertView;
}

private class  Holder{

    TextView nameTv;
}

//Returns a filter that can be used to constrain data with a filtering pattern.
@Override
public Filter getFilter() {

    if(valueFilter==null) {

        valueFilter=new ValueFilter();
    }

    return valueFilter;
}


private class ValueFilter extends Filter {


    //Invoked in a worker thread to filter the data according to the constraint.
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {

        FilterResults results=new FilterResults();

        if(constraint!=null && constraint.length()>0){

            ArrayList<String> filterList=new ArrayList<String>();

            for(int i=0;i<mStringFilterList.size();i++){

                if(mStringFilterList.get(i).contains(constraint)) {

                    filterList.add(mStringFilterList.get(i));

                }
            }


            results.count=filterList.size();

            results.values=filterList;

        }else{

            results.count=mStringFilterList.size();

            results.values=mStringFilterList;

        }

        return results;
    }


    //Invoked in the UI thread to publish the filtering results in the user interface.
    @SuppressWarnings("unchecked")
    @Override
    protected void publishResults(CharSequence constraint,
            FilterResults results) {

        mStringList=(ArrayList<String>) results.values;

        notifyDataSetChanged();


    }

}

activity_search_and_filter_list.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/txt_search"
        tools:context=".SearchAndFilterList"
        android:hint="Enter text to search" />
    <ListView 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/list_view"
        android:layout_below="@+id/txt_search"></ListView>

</RelativeLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    <TextView 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txt_listitem"/>

</RelativeLayout>

AndroidManifext.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.searchandfilterlistview"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".SearchAndFilterList"
            android:label="@string/title_activity_search_and_filter_list" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

I hope this code will will helpful to implement custom search and filter listview.

###

You can use:

http://developer.android.com/reference/android/widget/TextView.html

addTextChangedListener( TextWatcher watcher )

to figure out when the textview was changed. I believe it should be called everytime a letter is added or removed.

Then update your list adapter to dislplay the new items by either:

  1. creating a new list adapter and populating it with the items that satisfy the filter or
  2. having a subclass of the BaseAdapter to accept your filter and call notifyDataSetChanged() after it has finished removing the items you no longer want

http://developer.android.com/reference/android/widget/BaseAdapter.html

###

Search a listview based on input in EditText

     public class MainActivity extends Activity {
private ListView lv,lv2;
private EditText et;
String listview_array[]={"01634 ABOHAR","080 Bangalore","011 Delhi","Dell Inspiron", "HTC One X", "HTC Wildfire S", "HTC Sense", "1234", "iPhone 4S", "Samsung Galaxy Note 800", "Samsung Galaxy S3", "MacBook Air", "Mac Mini", "MacBook Pro"};
private ArrayList<String> array_sort = new ArrayList<String>();
int textlength = 0;

public void onCreate(Bundle savedInstanceState)

{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    lv = (ListView) findViewById(R.id.ListView01);
    lv2 = (ListView) findViewById(R.id.ListView02);
    et = (EditText) findViewById(R.id.EditText01);
    lv.setAdapter(new ArrayAdapter<String>(this,
    android.R.layout.simple_list_item_1, listview_array));
    int x= lv.getHeaderViewsCount ();
    System.out.println("x========"+x);
    lv.setAdapter(new ArrayAdapter<String>
    (MainActivity.this,
    android.R.layout.simple_list_item_1, listview_array));

    et.addTextChangedListener(new TextWatcher()
    {
        public void afterTextChanged(Editable s)
        {
            // Abstract Method of TextWatcher Interface.

        }
        public void beforeTextChanged(CharSequence s,
        int start, int count, int after)
        {

            // Abstract Method of TextWatcher Interface.

        }
        public void onTextChanged(CharSequence s,
        int start, int before, int count)
        {
            textlength = et.getText().length();
            array_sort.clear();
            for (int i = 0; i < listview_array.length; i++)
            {
                if (textlength <= listview_array[i].length())
                {

                    String s2= et.getText().toString();
                    if(listview_array[i].toString().contains(et.getText().toString()))
                    {
                        array_sort.add(listview_array[i]);
                    }


                }
            }

            lv.setAdapter(new ArrayAdapter<String>
            (MainActivity.this,
            android.R.layout.simple_list_item_1, array_sort));
        }
    });

}
 }

For search in custom listview based on class item refer the link implement search on a custom listview. Modify it according to your needs.

###

when you use custom listView

Adapter :

public class Adapter extends ArrayAdapter {
ArrayList<String> list = new ArrayList<>();
ArrayList<String> filteredData = new ArrayList<>();

public Adapter(@NonNull Context context, int resource) {
    super(context, resource);
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {

    LayoutInflater inflate = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
    @SuppressLint("ViewHolder") View vi = inflate.inflate(R.layout.ly_items, null);
    try {
        JSONObject js = new JSONObject(list.get(position));
        TextView txtItem = vi.findViewById(R.id.txtItem);
        ImageView imgItem = vi.findViewById(R.id.imgItem);
        txtItem.setText(js.getString("name") + " - " + js.getInt("number"));
        Picasso.get().load(js.getString("logo_url")).into(imgItem);

    } catch (JSONException e) {
        e.printStackTrace();
    }

    return vi;
}

@Override
public void add(@Nullable Object object) {
    super.add(object);
    list.add(object.toString());
    filteredData.add(object.toString());
}

@Override
public int getCount() {
    return list.size();
}

@Nullable
@Override
public Object getItem(int position) {
    return list.get(position);
}


public void filter(String charText) {
    charText = charText.toLowerCase(Locale.getDefault());
    list.clear();
    if (charText.length() == 0) {
        list.addAll(filteredData);
    } else {
        for (String wp : filteredData) {

            try {
                JSONObject json = new JSONObject(wp);
                if (json.getString("name").toLowerCase().contains(charText) || json.getString("number").contains(charText)) {
                    list.add(wp);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }
    notifyDataSetChanged();
    }
}

And your class:

 Adapter adapter;
ListView list;
EditText edtSearch;

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

list = findViewById(R.id.list);

edtSearch = findViewById(R.id.edtSearch);

 adapter = new Adapter(this, android.R.layout.simple_list_item_1);


list.setAdapter(adapter);

edtSearch.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                adapter.filter(s.toString());
            }

            @Override
            public void afterTextChanged(Editable s) {
            }
        });

    }

###

1) create a custom adapter for your list view and create a removeIfMatch(String s) method:

public void removeIfMatch(String s) {
  for item in adapter:
    if item.matches(s) {
       data.removeItem(item);
       notifyDataSetChanged();
       break
    }
}

2) create a callback for when the EditText contents change

3) invoke adapter.removeIfMatch(editText.getText())

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