implement as processing algorithm

[AlisterH]

This would be nice, but I am unlikely to do it; patches / pull requests are welcome.

[jdlom]

I would be glad to help. I'm on an other project for now but I may have time in the future.

[AlisterH]

That will be very helpful if you can - several improvements I've mentioned in other tickets would be easily addressed with processing models.

It would make sense for the algorithm only to generate the coverage rectangles:

• the user may want to add or remove rectangles before numbering
• they may want to number in a different order

There are probably several different tools we could use for the numbering - I'm adding this link for future reference: https://gis.stackexchange.com/questions/404177/qgis-3-16-vector-grid-number-generation

[AlisterH]

Just noting that we should also check whether any other tools are useful to reduce the amount of code we maintain.
e.g. mmqgis (which provides a library) has a tool for generating a grid of rectangles (or various other shapes), and there are probably several existing processing tools to do this.
This is especially relevant for "regular" grids.