Android SearchView Example Tutorial using DataBinding

Today we will look into Android SearchView widget and develop an application that filters a ListView by the queried text. We’ll be using DataBinding to hook up the layouts in the Activities and Adapters. If you haven’t read about DataBinding refer this tutorial first for a better understanding.

Android SearchView

Android allows us to use the search functionality in our app by displaying the SearchView widget either in the ToolBar/ActionBar or inserting it into a layout. Android SearchView widget is available from Android 3.0 onwards. The SearchView is defined in the XML layout as shown below.

<android.support.v7.widget.SearchView
        android:id="@+id/search"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

There are many forms for searching in Android such as voice search, suggestions etc. In this tutorial we’ll use SearchView.OnQueryTextListener and Filterable interfaces. The Filterable interface filters the queried text over a ListView and displays the resulted ListView rows. OnQueryTextListener interface can detect two events.

1. onQueryTextChange is called when the user types each character in the text field
2. onQueryTextSubmit is triggered when the search is pressed

Android SearchView Example

Below image shows the final android SearchView example project. The project consists of an Activity and an Adapter for the ListView.

Android SearchView Example Code

The activity_main.xml is given below. It consists of a ListView with a SearchView on top. activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="https://schemas.android.com/apk/res/android">

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <android.support.v7.widget.SearchView
            android:id="@+id/search"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:clickable="true" />

        <ListView
            android:id="@+id/list_view"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_below="@+id/search" />

    </RelativeLayout>

</layout>

The MainActivity.java is given below.

package com.journaldev.searchview;

import android.databinding.DataBindingUtil;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.SearchView;

import com.journaldev.searchview.databinding.ActivityMainBinding;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    ActivityMainBinding activityMainBinding;
    ListAdapter adapter;

    List<String> arrayList= new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        activityMainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);

        arrayList.add("January");
        arrayList.add("February");
        arrayList.add("March");
        arrayList.add("April");
        arrayList.add("May");
        arrayList.add("June");
        arrayList.add("July");
        arrayList.add("August");
        arrayList.add("September");
        arrayList.add("October");
        arrayList.add("November");
        arrayList.add("December");

        adapter= new ListAdapter(arrayList);
        activityMainBinding.listView.setAdapter(adapter);

        activityMainBinding.search.setActivated(true);
        activityMainBinding.search.setQueryHint("Type your keyword here");
        activityMainBinding.search.onActionViewExpanded();
        activityMainBinding.search.setIconified(false);
        activityMainBinding.search.clearFocus();

        activityMainBinding.search.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {

                adapter.getFilter().filter(newText);

                return false;
            }
        });
    }
}

In the above code, we are passing an ArrayList of Months to the List Adapter. We’re invoking the filter method that’s defined in the adapter class every time the search query text changes. The ListAdapter.java class looks like this.

package com.journaldev.searchview;

import android.content.Context;
import android.databinding.DataBindingUtil;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import com.journaldev.searchview.databinding.RowItemBinding;
import java.util.ArrayList;
import java.util.List;

public class ListAdapter extends BaseAdapter implements Filterable {

    List<String> mData;
    List<String> mStringFilterList;
    ValueFilter valueFilter;
    private LayoutInflater inflater;

    public ListAdapter(List<String> cancel_type) {
        mData=cancel_type;
        mStringFilterList = cancel_type;
    }


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

    @Override
    public String getItem(int position) {
        return mData.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

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

        if (inflater == null) {
            inflater = (LayoutInflater) parent.getContext()
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }
        RowItemBinding rowItemBinding = DataBindingUtil.inflate(inflater, R.layout.row_item, parent, false);
        rowItemBinding.stringName.setText(mData.get(position));


        return rowItemBinding.getRoot();
    }

    @Override
    public Filter getFilter() {
        if (valueFilter == null) {
            valueFilter = new ValueFilter();
        }
        return valueFilter;
    }

    private class ValueFilter extends Filter {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults results = new FilterResults();

            if (constraint != null && constraint.length() > 0) {
                List<String> filterList = new ArrayList<>();
                for (int i = 0; i < mStringFilterList.size(); i++) {
                    if ((mStringFilterList.get(i).toUpperCase()).contains(constraint.toString().toUpperCase())) {
                        filterList.add(mStringFilterList.get(i));
                    }
                }
                results.count = filterList.size();
                results.values = filterList;
            } else {
                results.count = mStringFilterList.size();
                results.values = mStringFilterList;
            }
            return results;

        }

        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) {
            mData = (List<String>) results.values;
            notifyDataSetChanged();
        }

    }

}

As you can see in the above code we’re performing filtering using an inner class ValueFilter that extends the Filter class. It filters the list by checking if the search query text matches the strings given in the ArrayList. The XML layout for the ListView row is given below. row_item.xml

<layout xmlns:android="https://schemas.android.com/apk/res/android">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/stringName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_centerVertical="true"
            android:padding="@dimen/activity_horizontal_margin"
            android:textAllCaps="false"
            android:textAppearance="?android:attr/textAppearanceMedium" />

    </RelativeLayout>

</layout>

The output of the android search view application in action is given below. The SearchView shown above requires us to press the search icon to activate the text field. Also, it doesn’t contain any hint/placeholder text. Add the following code in the MainActivity to enable the SearchView by default and display a hint.

activityMainBinding.search.setActivated(true);
        activityMainBinding.search.setQueryHint("Type your keyword here");
        activityMainBinding.search.onActionViewExpanded();
        activityMainBinding.search.setIconified(false);
        activityMainBinding.search.clearFocus();

The SearchView after customising as above looks like this. This brings an end to android SearchView tutorial. We’ll dive into the advanced features of SearchView in a later tutorial. You can download the Android SearchView Project from the link given below.

Download Android SearchView Example Project