what does defStyleAttr and defStyleRes in context.obtainStyledAttributes used for
<p>When i check QuickContactBadge in FrameLayout, i found following code</p>

<pre><code> public QuickContactBadge(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);

    TypedArray a =
        context.obtainStyledAttributes(attrs,
                com.android.internal.R.styleable.QuickContactBadge, defStyle, 0);

    mMode = a.getInt(com.android.internal.R.styleable.QuickContactBadge_quickContactWindowSize,
            QuickContact.MODE_MEDIUM);

    a.recycle();

    init();

    mBadgeBackground = getBackground();
}
</code></pre>

<p>I don't really catch the meaning of defstyle and 0 parameter in obtainStyledAttributes. I have looked up reference. but still don't know what it used for.</p>
