Label genes

[alimanfoo]

It would be useful to be able to label some genes of interest in a genes plot.

The bokeh LabelSet feature looks potentially useful here, see also bokeh labels docs.

[alimanfoo]

Perhaps a label_genes parameter which takes a mapping of gene IDs to gene labels, allowing customisation of the labels to appear.

Perhaps also a label_loci parameter which takes an instance of LabelSet allowing arbitrary labelling of the genes track.

[leehart]

While trying this out, I encountered an amusing problem, which arises if I put a label on every gene, e.g. using its gene ID... When zoomed out the gene tracks become long smears of incoherent overlapping text, where the labels go beyond the limits of their gene and overlap each other. So I need to devise some way to avoid this... 🤔

[alimanfoo]

Maybe something like this...?

From here.

[leehart]

Assuming we don't get too many genes to label, we can do something like this:

[leehart]

It's not yet clear to me how we want to accept a custom LabelSet, but we could do something like this:

Note: there is a general problem accommodating labels within the default plot height and current layout.