Add crop controls

[GoogleCodeExporter]

It would be very handy to be able to set image crop limits as we go rather than 
relying on the post-processing stages to do this correctly.

I'm undecided as to whether this should be spin boxes as with the previous 
version or a box with crop handles on the image preview view. The problem is 
that we're starting to mix paradigms from post-processing and tethered shooting 
-- should you be able to apply a crop retroactively to images? What if you 
over-crop?

For now I think we'll handle this by showing an uncropped image on the preview 
window and viewfinder but with marks showing where it gets cropped when it is 
saved to disk. You will be able to change the crop marks on the current image 
but they will only affect future images. We could get quite fancy and generate 
a scantailor project with cropping info but that seems like overkill.

Original issue reported on code.google.com by o...@andalso.net on 13 Apr 2012 at 9:04

[GoogleCodeExporter]

How about letting the crop handles update the spin-boxes and vice-versa ?

I personally find cropping in ST to be very cumbersome - in that respect BSW 
does a better job I think. Besides if you know for sure that you want to crop 
out a thumb or other object, it would probably help ST do a better job of 
selecting the edges.

TKR

Original comment by terence....@gmail.com on 18 Apr 2012 at 5:52

[GoogleCodeExporter]

That's a good idea. I'll get round do doing something sensible with cropping 
(it works now but spin boxes only) but it may have to wait while I rework the 
image viewer. I've been playing with Qt Quick (which lets you build lovely 
fluid UIs in a declarative way) and I'm thinking of moving thumbnails and image 
viewers to that paradigm.

Original comment by o...@andalso.net on 22 Apr 2012 at 7:41