带有子菜单动画效果的Android菜单

Question

我需要创建菜单的子菜单。当我点击菜单时，子菜单应显示如下图所示，当我点击调整菜单时，它应该打开子菜单。

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch(item.getItemId()){
    case R.id.phone:
        Toast.makeText(getBaseContext(), "You selected Phone", Toast.LENGTH_SHORT).show();
        break;

    case R.id.computer:
        Toast.makeText(getBaseContext(), "You selected Computer", Toast.LENGTH_SHORT).show();
        break;

    case R.id.gamepad:
        Toast.makeText(getBaseContext(), "You selected Gamepad", Toast.LENGTH_SHORT).show();
        break;

    case R.id.camera:
        Toast.makeText(getBaseContext(), "You selected Camera", Toast.LENGTH_SHORT).show();
        break;

    case R.id.video:
        Toast.makeText(getBaseContext(), "You selected Video", Toast.LENGTH_SHORT).show();
        break;

    case R.id.email:
        Toast.makeText(getBaseContext(), "You selected EMail", Toast.LENGTH_SHORT).show();
        break;

    }
    return true;        
}

menu xml

    <item
        android:id="@+id/phone"
        android:title="phone"
        android:icon="@drawable/phone"
        myapp:showAsAction="ifRoom" />

    <item
        android:id="@+id/computer"
        android:title="computer"
        android:icon="@drawable/computer"
        myapp:showAsAction="ifRoom"  />

    <item
        android:id="@+id/gamepad"
        android:title="gamepad"
        android:icon="@drawable/gamepad"
        myapp:showAsAction="ifRoom|withText" />

    <item
        android:id="@+id/camera"
        android:title="camera"
        android:icon="@drawable/camera"
        myapp:showAsAction="ifRoom|withText" />

    <item
        android:id="@+id/video"
        android:title="video"
        android:icon="@drawable/video"
        myapp:showAsAction="ifRoom|withText" />

    <item
        android:id="@+id/email"
        android:title="email"
        android:icon="@drawable/email"
        myapp:showAsAction="ifRoom|withText" />

</menu>