I need to build an application that will register all participants of a sportsevent race (swimming or running a fixed distance). Every participant will have a registrationnumber to identify the person.
At the finish the registrationnumber of the finished participant will be registrered in the application and the endtime will be set.
Based on the number of participants, buttons will be created and placed on a form showing the registrationnumber. Clicking the individual button will set the endtime for the participant.
The form must be organised in such a way that alle buttons will be presented in increasing registrationnumber (1 -> 999).
The form has a vertical scrollbar to access currently non visible buttons.
Clicking a button will make it invisible on the from, so only remaining buttons (of non-finished participants) are available. Remaining buttons will be reorganised, so the buttons are presented as compact as possible (less scrolling).
What would be a good approach to accomplish this?
In stead of buttons any other approach is welcome (maybe a grid).
Maybe there is also some free open source that already has this functionality?