WebChromeClient not displaying the "message" parameter to the onJsPrompt function

I want my WebView to display a prompt just like a web browser would.

From other answers addressing alert(), I found that I must do something like this in my Java code:

myWebView = (WebView) findViewById(R.id.webview);
WebSettings webSettings = myWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
myWebView.addJavascriptInterface(new WebAppInterface(this), "Android");
// Next line was added 
myWebView.setWebChromeClient(new WebChromeClient());

This works, and the prompt pops up, but instead of displaying the message I pass to prompt(), it instead says:

The page at "https:..." says:

In javascript my call looks like this:

prompt("Test")

So I would expect the prompt to say "Test".

This totally breaks the immersion of the WebView being embedded in an app. How do I get the WebChromeClient to display the text I actually pass?

Solution

You need to create an AlertDialog in onJsPrompt under WebChromeClient and attach an EditText as its view like so:

@Override boolean onJsPrompt (WebView view, String url, String message, String defaultValue, JsPromptResult result) { 
    final EditText input = new EditText(main);
    input.setInputType(InputType.TYPE_CLASS_TEXT);
    input.setText(defaultValue);
    new AlertDialog.Builder(myApp) 
      .setTitle("App Titler")
      .setView(input)
      .setMessage(message)
      .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, int which) {
           result.confirm(input.getText().toString()); 
         } 
       })
      .setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, int which) {
           result.cancel(); 
         }
       })
     .create()
     .show();
     return true;
 }