When editing a document in Google Docs, the enter key does not work, so you cannot generate new lines.

Also there is something strange going on with the selection range and caret selection - if you click around in the text of the document you can see the caret ends up in the middle of letters rather than between them.  The selection also appears off sometimes half a character to the left or right of where it is supposed to be.  The caret and selection issues can be seen most clearly by simultaneously opening a document for editing in both google docs and firefox.

The enter processing appears to be a WebView bug.  The selection could be a google bug, but it really looks more like a webview bug to me due to the slightly differing font processing in each browser.

Here is a link which can be used to test this out the editing, selection range and caret display  - just paste the link into a webview.

https://docs.google.com/document/d/16I-h8nzOziZSYncFVVzU_G--cHGItzg8yH6ikpCS3K8/edit?hl=en_US

To test while simultaneously editing in firefox, log into google (e.g. using a gmail account) in firefox and open the same url - any edits made will show up in the webview with the username attached, but the selection and carets will be slightly out of synch between the two browsers.

Sample test program

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class WebViewGoogleDocs extends Application {
  public static void main(String[] args) throws Exception { launch(args); }
  public void start(final Stage stage) throws Exception {
    WebView webView = new WebView(); webView.getEngine().load("https://docs.google.com/document/d/16I-h8nzOziZSYncFVVzU_G--cHGItzg8yH6ikpCS3K8/edit?hl=en_US");
    stage.setScene(new Scene(webView)); stage.show();
  }
}