Set Threshold for AutoCompleteTextView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Name of President" />

<AutoCompleteTextView android:id="@+id/txtCountries"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

</LinearLayout>

package com.java2s.myapplication3.app;
/*from   w  w w  .ja va 2s  .  c  o  m*/
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;

public class MainActivity extends Activity {
    String[] presidents = {
            "Dwight D. Eisenhower",
            "John F. Kennedy",
            "Lyndon B. Johnson",
            "Richard Nixon",
            "Gerald Ford",
            "Jimmy Carter",
            "Ronald Reagan",
            "George H. W. Bush",
            "Bill Clinton",
            "George W. Bush",
            "Barack Obama"
    };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_dropdown_item_1line, presidents);

        AutoCompleteTextView textView = (AutoCompleteTextView)
                findViewById(R.id.txtCountries);

        textView.setThreshold(3);
        textView.setAdapter(adapter);
    }
}