title: nip4 progress

libvips.org OpenCollective has generously given me a year of funding [to

complete nip4](https://github.com/jcupitt/nip4). This is an update of [the

libvips GUI, nip2](https://github.com/libvips/nip2), to the gtk4 toolkit,

and to the vips8 API.

nip2 was written between about 1997 and 2003 and depends on a lot of

frameworks from the period. These are becoming extremely elderly now,

and nip2 is becoming difficult to maintain. It's also looking increasingly

old-fashioned.


nip4 is hoping to fix this. It has the following goals:

1. Update from the gtk2 GUI toolkit to gtk4, the current version. This is a

lot of work -- the drawing model is completely different, and there are many,

many changes in best practice. As a test, I updated vipsdisp to gtk4. The

image display widget in this viewer is the thing that will display images

in nip4.

2. Switch to the vips8 API. We rewrote libvips to make vips8 between about

2010 and 2015, but nip2 was obviously stuck on the old vips7 API. nip4

has removed all the old vips7 code and redesigned for vips8. It's the last

large-scale user of vips7, as far as I know, so completing nip4 will let

us build libvips with deprecated code removed by default.

3. Complete backwards compatibility. nip4 aims to be able to run the whole

of the nip2 test suite unmodified. 

4. Prettier, simpler, faster, modernised.

nip4 is now loading the first 5 test workspaces correctly. The big change

from the UI point of view is full animation for interactions. Everything

slides around as you work:

<iframe width="560" height="315" src="https://www.youtube.com/embed/Z4TpOLh2Lno?si=5F-SEp3wS37SYBDv" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

Next steps:

1. Get all the old nip2 test workspaces loading. This will involve

implementing a few more workspace widgets. Plotting is probably the most work.

2. Finish drag - drop and copy - paste. It's only half-there right now.

3. Add the toolkit menu and browser. This will probably be a bar down the left.

4. Perhaps implement a cut down and polished version of the programming

and debugging interface from nip2.

5. UI for per-workspace definitions needs to go in.

6. The image processing menus are all currently designed around vips7. A

new set of vips8 menus could be a useful simplification.

7. Do windows and mac builds. We have win and mac builds for vipsdisp

done already.

And I think that would be enough for a release, hopefully in the first half

of 2025.