title: How to add subview of some view in xml layout
body: <p>I am a beginner programming android. I am searching for info how to create transparent sub view  on current window layout.</p>
  
  <p>I have created simple layout this is source:</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;TextView
          android:id="@+id/textView1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="Simple text" /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>Now i want to create a View when navigation button is pressed. That View i want to add on top of this layout with transparent about 40%. It should look something like this:</p>
  
  <p><img src="https://i.stack.imgur.com/S99cM.png" alt="enter image description here"></p>
  
  <p>Also it should be easy to add Buttons, Drop box or else and i could easy remove this View.</p>
  
  <p>Maybe someone did this and could me share ideas, how do do this ?</p>
  
  <p>Thanks.</p>