title: ViewGroup clip children can not be set false
body: <p>i am trying to implement a swipeable card effect, just like the app Tinder :
  <a href="https://play.google.com/store/apps/details?id=com.tinder&amp;hl=en_GB" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=com.tinder&amp;hl=en_GB</a></p>
  
  <p>When I swipe my card, the child view is always clipped by its container even if I set clipchildren and cliptopadding to false. Any idea why????</p>
  
  <p>The CardStack is my custom container Layout extends RelativeLayout
  xml: </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"&gt;
  
  &lt;com.wenchao.cardstack.CardStack
      android:id="@+id/container"
      android:layout_width="match_parent"
      android:layout_height="0dp"
      android:padding="20dp"
      android:clipChildren="false" &lt;!--- false --&gt;
      android:clipToPadding="false"
      android:layout_weight="3"
      /&gt;
  
  
  &lt;RelativeLayout
  
      android:layout_weight="1"
      android:layout_width="match_parent"
      android:layout_height="0dp"
      android:orientation="horizontal"
      android:background="#FF00FF"
      &gt;
      &lt;Button
          android:layout_centerHorizontal="true"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="B"
          android:id="@+id/info"
          /&gt;
      &lt;Button
          android:id="@+id/like"
          android:layout_toLeftOf="@+id/info"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="A"
          /&gt;
      &lt;Button
          android:id="@+id/dislike"
          android:layout_toRightOf="@+id/info"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="C"
          /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>before swipe </p>
  
  <p><img src="https://i.stack.imgur.com/ugkhHm.png" alt="enter image description here"></p>
  
  <p>after swipe, the buttom of the child view is clipped :(</p>
  
  <p><img src="https://i.stack.imgur.com/I3P5Cm.png" alt="enter image description here"></p>
  
  <p>----------------Edit-----------------------</p>
  
  <p>I found the problem is that in linear layout , the last child is always displayed on top (larger z-index). so even if cardstack container do not clip chirdren, its children are still displayed underneath the next view below. So It would better to switch to Relative layout . </p>
  
  <p>But I do not really want to, because RelativeLayout do not have a nice "layout_weight" feature to specify height percentage. So the situation is that I want a way to easily control z-index (something impossible for a linearlayout) and also want to keep "layout_weight" feature (seems to be only feasible with linearlayout).  Any idea??</p>