Kap: Add "crop service" plugin support

[albinekb]

Awesome work with the plugin support 💯

It would be awesome plugins could supply a crop-service

• Add setting in preferences to choose crop-service (default to the current one)
• When you click the crop button, that module is run and outputs the cropArea sent to aperture

for example: "select app window", and "drag rectangle", the latter i have a prototype of:

(just like macOS still image capturing)

I'll make a PR if you think this is a good idea 🥇

[sindresorhus]

Can you elaborate on why? I'm curious why we can't just improve the default cropper. It seems like a lot of bloat for something that would result in not that many plugins. What potential is there really to innovate with cropper plugins?

[albinekb]

Yeah maybe, I'm working on a module that will emit events on window-focus, with the width, height, x, y for that window, which could be used in kap:

1. select "target window mode"
2. start checking windows
3. move the cropper window automatically to the focused window (do not receive click events)
4. have a button to say "ok" shown somewhere

But yeah, this should probably be in the core as there won't be many (if any) other needed ways to crop areas

[sindresorhus]

A "target window mode" would be super useful. I often have the need to only record a specific window. But I think that too is something that should just be in core.

[albinekb]

Agreed, there's only so much you can do with the crop rectangle 😄 Closing this.
I'll open PRs for some improvements to the cropping.