As Erel pointed out - the default B4A WebView does not support modal dialogs.
So if the javascript
navigator.geolocation returns false then the alert dialog will not be displayed.
And if the javascript use of navigator.geolocation would normally show a prompt (to allow/disallow) then that prompt will not be displayed either.
So you need to add the
WebChromeClient to your WebView to enable modal dialogs.
But WebViewExtras will i think need an update.
Take a look at the documentation:
WebChromeClient | Android Developers.
Scroll down that page to
onGeolocationPermissionsHidePrompt and
onGeolocationPermissionsShowPrompt.
It looks as though i'll need to implement those two methods in WebViewExtras so that the WebChromeClient properly asks the user for permission for the web page to use the Geolocation methods.
Can you try to simply use WebViewExtras and it's addWebChromeClient method and post with your results?
It may be that the default WebChromeClient already shows the required dialogs but i suspect not.
Post again with your results and if required i'll try and update the WebChromeClient to support the Geolocation prompts.
Martin.