title: get input type value from html to android
body: <p>I want to make a web view calculator. Let's I have an HTML base calculator UI.</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
  &lt;head&gt;
      &lt;meta charset="UTF-8"&gt;
      &lt;title&gt;Calculator&lt;/title&gt;
      &lt;link href='https://fonts.googleapis.com/css?family=Orbitron' rel='stylesheet' type='text/css'&gt;
  
  &lt;/head&gt;
  &lt;body&gt;
  &lt;form action="" name="calc"&gt;
      &lt;input type="text" name="screen" disabled&gt; &lt;br&gt;
      &lt;hr&gt;
      &lt;input type="button" value="&amp;radic;" onclick="calc.screen.value = Math.sqrt(calc.screen.value);"&gt;
      &lt;input type="button" value="CE" onclick="calc.screen.value = ''"&gt;
      &lt;input type="button" value="C" onclick="calc.screen.value = ''"&gt;
      &lt;input type="button" value="&amp;larr;" onclick="calc.screen.value = calc.screen.value.slice(0,-1);"&gt; &lt;br&gt;
  
      &lt;input type="button" value="7"&gt;
      &lt;input type="button" value="8"&gt;
      &lt;input type="button" value="9"&gt;
      &lt;input type="button" value="+"&gt;
  
      &lt;br&gt;
  
      &lt;input type="button" value="4"&gt;
      &lt;input type="button" value="5"&gt;
      &lt;input type="button" value="6"&gt;
      &lt;input type="button" value="-"&gt;
  
      &lt;br&gt;
  
      &lt;input type="button" value="1"&gt;
      &lt;input type="button" value="2"&gt;
      &lt;input type="button" value="3"&gt;
      &lt;input type="button" value="*"&gt;
  
      &lt;br&gt;
  
      &lt;input type="button" value="0"&gt;
      &lt;input type="button" value="."&gt;
      &lt;input type="button" value="="&gt;
      &lt;input type="button" value="/"&gt; &lt;br&gt;
  &lt;/form&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Now, I want to get value from a button and then I will calculate in an android java class. After this, the final result will show in HTML.</p>
  
  <p><strong>How can I get input typed value from HTML to android and pass back?</strong></p>