title: Enabling Button when EditText has text (RxAndroid)
body: <p>New to RxJava/RxAndroid and am finding the lack of examples disturbing. As a way to jump into using Rx, id like to try to get something small working. Basically, if an <code>EditText</code> has text entered into it, then enable a <code>Button</code> below it.</p>
  
  <p>I came across <a href="https://stackoverflow.com/questions/32263773/rxjava-rxandroid-handle-multiple-edittext-changes">this</a> answer, but the authors edit doesnt really show how to completely implement something like this.</p>
  
  <p>From what I've gathered, I can use <a href="https://github.com/JakeWharton/RxBinding" rel="nofollow noreferrer">RxBindings</a> to create an <code>Observable</code> like:</p>
  
  <pre><code>Observable&lt;CharSequence&gt; observable = RxTextView.textChanges(mEditText);
  </code></pre>
  
  <p>Supposedly I would now need to <code>.subcribe()</code> an <code>Observer</code> to watch for changes in <code>observable</code>, but am unsure how this would be done.</p>
  
  <p>Also, how would you create the EditTexts Observable without using RxBindings if needed?</p>
  
  <p><strong>Edit:</strong> Although <a href="https://github.com/evant/gradle-retrolambda" rel="nofollow noreferrer">Retrolambda</a> exists, answers showing how to implement this without lambdas (or both) would be helpful.</p>