title: click on a button and change the color on half of the screen
body: <p>So, i have 1 screen that is cut in 2 parts. First part contain 4 buttons(red, blue, green, purple) and the second is an empty space.
  What i want is, when i press 1 of the button, i want to color that corresponds to show up in the empty space.</p>
  
  <p>how do i create the connection between the buttons and the empty space</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><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:weightSum="2"
      android:orientation="vertical"&gt;
  
      &lt;RelativeLayout
          android:layout_width="match_parent"
          android:layout_height="0dp"
          android:layout_weight="0.5"&gt;
      &lt;Button
          android:layout_width="200sp"
          android:layout_height="50sp"
          android:id="@+id/button1"
          android:text="Red"/&gt;
  
  
      &lt;Button
          android:layout_width="200sp"
          android:layout_height="50sp"
          android:id="@+id/button2"
          android:layout_toRightOf="@+id/button1"
          android:text="Blue"/&gt;
      &lt;Button
          android:layout_width="200sp"
          android:layout_height="50sp"
          android:id="@+id/button3"
          android:layout_below="@+id/button1"
          android:text="Green"/&gt;
      &lt;Button
          android:layout_width="200sp"
          android:layout_height="50sp"
          android:id="@+id/button4"
          android:layout_toRightOf="@+id/button3"
          android:layout_below="@+id/button2"
          android:text="Purple"/&gt;
      &lt;/RelativeLayout&gt;
  
  &lt;RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="0dp"
      android:layout_weight="1.5"
      android:id="@+id/bg2"
      android:background="@drawable/selector"&gt;
  
  
  &lt;/RelativeLayout&gt;
  &lt;/LinearLayout&gt;</code></pre>
  </div>
  </div>
  </p>