implements RadioGroup .OnCheckedChangeListener

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout/*from  w  ww .j a  v a2s  .  com*/
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <RadioGroup android:id="@+id/orientation"
        android:orientation="horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="5px">
        <RadioButton
            android:id="@+id/horizontal"
            android:text="horizontal"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/vertical"
            android:text="vertical"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
    </RadioGroup>
    <RadioGroup android:id="@+id/gravity"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="5px">
        <RadioButton
            android:id="@+id/left"
            android:text="left"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/center"
            android:text="center"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/right"
            android:text="right"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
    </RadioGroup>
</LinearLayout>

package com.java2s.myapplication3.app;
//w  w  w  .  ja  v a  2 s.  c om
import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.text.TextWatcher;
import android.widget.LinearLayout;
import android.widget.RadioGroup;
import android.widget.EditText;

public class MainActivity extends Activity
        implements RadioGroup.OnCheckedChangeListener {
    RadioGroup orientation;
    RadioGroup gravity;

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.activity_main);

        orientation=(RadioGroup)findViewById(R.id.orientation);
        orientation.setOnCheckedChangeListener(this);
        gravity=(RadioGroup)findViewById(R.id.gravity);
        gravity.setOnCheckedChangeListener(this);
    }

    public void onCheckedChanged(RadioGroup group, int checkedId) {
        if (group==orientation) {
            if (checkedId==R.id.horizontal) {
                orientation.setOrientation(LinearLayout.HORIZONTAL);
            }
            else {
                orientation.setOrientation(LinearLayout.VERTICAL);
            }
        }
        else if (group==gravity) {
            if (checkedId==R.id.left) {
                gravity.setGravity(Gravity.LEFT);
            }
            else if (checkedId==R.id.center) {
                gravity.setGravity(Gravity.CENTER_HORIZONTAL);
            }
            else if (checkedId==R.id.right) {
                gravity.setGravity(Gravity.RIGHT);
            }
        }
    }
}