As I understand it, one reason for the design of the Gimp spinbox is to make it easier to use with a graphics tablet stylus - hence the dragging of the bar. Personally I find it awkward to use whether with a mouse or a stylus, and particularly dislike the problems with dragging from the right that you mentioned. As for accidentally setting blur to 100% when trying to focus the text at the right... that's the bane of my Inkscape life! I would love to see them replaced with something else.


* Do you want the progress bar?

I do like the presence of the progress bar. It provides immediate feedback that plain numbers don't. If the box says 9, is that 9 out of 10 or 9 out of 100? A progress bar immediately gives you a sense of scale.
 
 
* If so, should it be the full height of the widget (quite a bit more
complicated)?

I don't necessarily think it should be full height, but it should be clear and obvious. It should also be clear that it's a progress bar, not an underline or other decoration - so perhaps also ensure the "unfilled" portion of the bar is visible.
 

* Do you want to be able to drag the bar? With one/two methods?

Dragging the bar is a nice feature which makes the widget a lot more immediate to use - great for just playing around.

I don't like the current two-method implementation, as I often end up activating the wrong one. That said, there are definite advantages to allowing both coarse and fine control. Perhaps some other approach could be used to still provide that capability - here are some possibilities off the top of my head:

* Make the amount of change proportional to the speed of the pointer movement, so that fast drags make coarse changes, whilst slow drags provide fine adjustment.

* Once the mouse button is held down, use left/right movements for coarse and up/down movements for fine adjustments.

* Left mouse button for coarse changes, right for fine. (Perhaps not so great for tablet users)

 
* Any other changes?

* One great feature in many Inkscape spinboxes is the context menu to let you select from a list of pre-defined values. The Gimp spinboxes lack these. Ideally I'm sure you would want a means for the developer to provide specific values (with comments), but having a standard fallback that lists, say, 10 evenly spaced values would be useful.

* The ability to do basic maths in Inkscape spinboxes is another useful feature that the Gimp ones lack.

* Mousewheel support almost goes without saying. But I'm saying it anyway, just in case ;)

* When dragging with the left button, clicking the right one should cancel the change and revert back to the previous value.



Regards,

Mark