Detection of Retina (high-res) display

Hi,

how can I detect in Vaadin that a session is running on a high-res display?

I see that if I display images with double resolution it looks significantly better on a Retina display.
However, sending larger images to non-Retina displays makes no sense and may look even worse, for example with IE11.

How would this be handled best? 

Thanks in advance!
Andreas
 

Hi Andreas,

have a look here:

view-source:http://whatsmy.browsersize.com/

and at

http://stackoverflow.com/questions/19689715/what-is-the-best-way-to-detect-retina-support-on-a-device-using-javascript

to get an idea of how to query the browser for its resolution.

Once you know the resolution available, you could write a pure-JS (without GWT) add-on for Vaadin that relays the information to the server-side session. Some example for such small add-on is here:
https://github.com/enver-haase/NumberCaptcha

I didn't find a ready-made solution here: https://vaadin.com/directory
so it would be nice if you could publish your solution there when you're finished.

HTH, Best Regards,
Enver