Android Hybrid Webview: Wait for webview to load completely to fetch webview elements


I want to know how do i fetch webview elements in a hybrid android application. My webview loads and takes time to load the page. It is a simple authentication page. I want to get the username & password fields.
So, how do i wait for webview to load completely and fetch elements inside webview ?

Just wait for the context and an element inside the view, just like a user would do.