title: How to modify content before rendering in Android WebView?
body: <p>I am making a custom simple web browser for Android and needed to capture the content of every page the user browses and manipulate it <strong>before rendering</strong> so that it displays as expected.</p>
  
  <p>I don't want to break user login state and interaction, so I don't want to intercept the POST request or cookies.</p>
  
  <p>So far as I know, I can put the content with <code>loadDataWithBaseURL()</code>.
  However, to make a better user experience, I wan to get the content and manipulate before the user sees it, and if possible, before images being downloaded (like <code>DOMReady</code> in JS), but had no clue how to do it.</p>
  
  <p>What is the best place to listen to, and how can I get the current <code>webview</code> content?</p>
  
  <p>Since I am new to Android development, I was looking for a good advice for the solution.
  Thanks.</p>