title: Could not click on the buttons in SlidingDrawer
body: <p>I have a problem with SlidingDrawer. All buttons in it could not be click.</p>
  
  <p>Here is my xml file for SlidingDrawer:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;SlidingDrawer xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="110dp"
      android:content="@+id/content"
      android:handle="@+id/handle"&gt;
  
      &lt;Button
          android:id="@+id/handle"
          android:layout_width="wrap_content"
          android:layout_height="30dp"
          android:text="@string/menu" /&gt;
  
      &lt;LinearLayout
          android:id="@+id/content"
          android:layout_width="match_parent"
          android:layout_height="80dp"
          android:layout_gravity="center"
          &gt;
  
          &lt;Button
              android:id="@+id/btn_video"
              style="@style/button_menu_bottom"
              android:drawableTop="@drawable/mnu_video"
              android:text="@string/video" /&gt;
  
          ...
          ...
  
      &lt;/LinearLayout&gt;
  
  &lt;/SlidingDrawer&gt;
  </code></pre>
  
  <p>Here is my java file extended from SlidingDrawer</p>
  
  <p>package com.example;</p>
  
  <pre><code>import android.content.Context;
  import android.util.AttributeSet;
  import android.view.LayoutInflater;
  import android.widget.Button;
  import android.widget.LinearLayout;
  import android.widget.SlidingDrawer;
  import com.example.R;
  
  public class BottomMenuBar extends SlidingDrawer {
  
      private SlidingDrawer mSlidingDrawer;
      private Button mButtonSlidingDrawer;
      private LinearLayout mLayoutContent;
      private Button mButtonVideo;
      private Button mButtonPhoto;
      private Button mButtonChat;
      private Button mButtonSetting;
  
      public BottomMenuBar2(Context context, AttributeSet attrs) {
          super(context, attrs);
          String infService = Context.LAYOUT_INFLATER_SERVICE;
          LayoutInflater li;
          li = (LayoutInflater) getContext().getSystemService(infService);
          li.inflate(R.layout.bar_bottom_menu, this, true);
          mSlidingDrawer=(SlidingDrawer)findViewById(R.id.sld_bottom_menu);
          mButtonSlidingDrawer=(Button)findViewById(R.id.handle);
          mLayoutContent=(LinearLayout)findViewById(R.id.content);
          mButtonVideo=(Button)findViewById(R.id.btn_video);
          mButtonSetting=(Button)findViewById(R.id.btn_setting);
      }
  
      public Button getmButtonSlidingDrawer() {
          return mButtonSlidingDrawer;
      }
      public void setmButtonSlidingDrawer(Button mButtonSlidingDrawer) {
          this.mButtonSlidingDrawer = mButtonSlidingDrawer;
      }
  
      ...
      Setter &amp; Getter methods
      ...     
  }
  </code></pre>
  
  <p>Here is my main.xml file:</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:background="@drawable/bg_main"
      android:orientation="vertical" &gt;
  
      &lt;RelativeLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_weight="0.1" &gt;
  
          ...
          Any content
          ...
  
      &lt;/RelativeLayout&gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content" &gt;
  
          &lt;com.example.BottomMenuBar
              android:id="@+id/sld_bottom_menu"
              android:layout_width="wrap_content"
              android:layout_height="110dp"
              android:handle="@+id/handle"
              android:content="@+id/content"
              /&gt;
  
      &lt;/LinearLayout&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>