[plot] x-axis with category-like labels

[vallsv]

As i need to display channels values in plots, i expect to display in the x-axis the channel numbers.

I do not expect to see 0.5 or -1. But only positive integer values (from 0 to ...).

For example, Qt Chart provides QBarCategoryAxis. I do not expect an advanced object like that, but at least a way to force the labels to be integers-only (0, 1, 2, 3).

The time-axis implementation from silx could be used as reference, cause it should have the same kind of constrains on numbers.

[vallsv]

The use case here could be see as only displaying intger in the x-axis.

That's not really generic category feature.