key logger

So I"m building a web based application that can interact with a barcode scanner. Barcode scanners that I’m using have the ability to dump the id they read somewhere via keyboard input. So I can click on a text box scan something and the ID would get put in the text box.

What I want to do is scan something and have an event fired without need for the text box. In order to do that I’d need to be able to keep track of keyboard input. Scanners I’m using can prefix and postfix the data it scans with any keyboard input I tell it to. So the data I’d be taking in would be

Unique begin key - data - unique end key
or
^$@# 00000001 !(%$

Basically I would need to either listen for all keyboard input and send it to the server, or listen for some start key and end key and send the in the middle stuff to the server. Does Vaadin have any key logger stuff like this in existence either addons or not? If not do you think it’d be all that difficult to make an addon myself to do this? Are there any good guides out there for writing your own addon?

Hi,

Vaadin doesn’t have this kind of functionality/component built-in and I don’t know any add-on that would do that for you. If you really need a keylogger, you have to create a widget that listens keyboard events and somehow communicates them to the server. Book of Vaadin has a chapter about
developing widgets
.

Maybe the new TextChangeEvent in Vaadin 6.5.0 will help you? You can configure it to send the input from a TextField immediately when it changes or after a given delay. See
http://demo.vaadin.com/sampler#TextFieldTextChangeEvent