I think that the main advantage of the spinbox over a generic field is that the spinbox is recognizable as input for inserting only numbers. So often the users of my wikis make mistakes and inserted values like "over 9000" or "9000 (approximately)" instead of just "9000". This usually leaded to problems in queries and the wiki produced not nice looking error notifications.
I usually solved these problems by adding explanations to the fields and use regex filtering. However I think that the amount or user errors will decrease if we use spinner for numbers.
I agree though that the the change in default look of the forms is very important and always must be done very carefully: I myself hated the switch to KDE4, Unity and most of all GMail's-barbarian-forced-switch-to-a-new-look.
Another thing is that wiki-admins may have attached some CSS and JS to html elements and the change will broke the appearance of their forms.
So I'll integrate the spinbox input to SFI.
02.07.2012 19:45 пользователь "Yaron Koren" <email@example.com> написал:
Alexey Klimovich from WikiVote developed great form input for spinners
(spinboxes). Should we integrate this input with SF or with SFI? In my
opinion spinner should be default input for number data: not because
those little buttons are handy but because the user recognizes
immediately that she have to put the number (not string) in the box.
You can see the input in action here  and this library  have been used.
The input supports the following parameters:
* min and max values
* showonfocus - show buttons on hover
We'll probably add these parameters soon:
* step - the step of a single increment/decrement
* prefix - text before the number
* suffix - text after the number
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