Android Throttled Search

ThrottledSearch.java

import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.SearchView;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;

import java.util.Timer;
import java.util.TimerTask;

/**
 * Throttles a search action by an amount of milliseconds.
 *
 * @author Aleksandar Gotev
 */

public class ThrottledSearch {

    public interface Delegate {
        void onThrottledSearch(String searchTerm);
    }

    private static final int DEFAULT_DELAY = 400;

    private int mDelayMilliseconds;
    private final Delegate mDelegate;
    private String mSearchTerm;
    private Timer mTimer;
    private AppCompatActivity mActivity;

    public ThrottledSearch(AppCompatActivity activity, Delegate delegate, int milliseconds) {
        mActivity = activity;
        mDelayMilliseconds = milliseconds;
        mDelegate = delegate;
        mSearchTerm = "";
    }

    public ThrottledSearch(AppCompatActivity activity, Delegate delegate) {
        this(activity, delegate, DEFAULT_DELAY);
    }

    public void onTextChanged(CharSequence charSequence) {
        if (mTimer != null)
            mTimer.cancel();

        mTimer = new Timer();
        mSearchTerm = charSequence.toString();

        mTimer.schedule(new TimerTask() {
            @Override
            public void run() {
                mActivity.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        mDelegate.onThrottledSearch(mSearchTerm);
                    }
                });
            }
        }, mDelayMilliseconds);
    }

    public void attachTo(final EditText editText) {
        editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                ThrottledSearch.this.onTextChanged(charSequence);
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        });
    }

    public void attachTo(final SearchView searchView) {
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return true;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                ThrottledSearch.this.onTextChanged(newText);
                return true;
            }
        });
    }
}

Usage:

new ThrottledSearch(this, new ThrottledSearch.Delegate() {
    @Override
    public void onThrottledSearch(String searchTerm) {
        // do something with the search term
    }
}).attachTo(EditText or SearchView);

alternatively, you can create a new object:

ThrottledSearch search = new ThrottledSearch(activity, new ThrottledSearch.Delegate() {
    @Override
    public void onThrottledSearch(String searchTerm) {
        // do something
    }
});

and then call search.onTextChanged("something"); in your own edit text listener.

You can also set the throttle amount in milliseconds in the constructor (by default it's 400ms):

new ThrottledSearch(activity, delegate, milliseconds);