Is this different than the existing cursor coord readout? I far prefer a readout in the corner to a data tooltip because it doesn't cover my data more than the mouse already does....

This is different because you can show arbitrary data, not just the coordinates.

My instinct is a HoverEvent (and an UnHoverEvent?) and add a generic show_tooltip / hide_tooltip methods on the Canvas classes

How does this interact with the existing mouseover / get_cursor_data functionality?

How does this interact with the existing mouseover / get_cursor_data functionality?

T.b.d. I think get_cursor_data is quite limited in its output because it has to fit in a single line in the gui.

I'm looking for things like this:

https://docs.bokeh.org/en/latest/docs/user_guide/tools.html#hovertool
https://plotly.com/python/hover-text-and-formatting/

in particular also the ability to show context information on data points, which get_cursor_data currently does not have.

How does this differ from how https://mplcursors.readthedocs.io/ and https://github.com/joferkington/mpldatacursor implement hovering/would it make those libraries way simpler?

This should, btw, also be possible to support in the PDF and SVG backends.

I think we even have a demo of post-processing an SVG to add tooltips.

https://matplotlib.org/devdocs/gallery/user_interfaces/svg_tooltip_sgskip.html

Slightly related: #9957

Hi there,

Some group members and I are working on implementing tooltip support for this issue, and we're looking for guidance on the most efficient way to handle the high-level API.

Rather than modifying each plotting function individually (e.g., plot(), scatter(), bar(), etc.) to accept a hover parameter, is there a preferred approach for applying this functionality across all plotting functions?

We’re wondering if there’s:

A shared wrapper, internal dispatcher, or base function we could hook into,

A decorator pattern that could be reused,

Or perhaps an existing mechanism (like how data or label are handled) that we could align with?

Our goal is to avoid duplicating logic while ensuring consistent behavior and maintaining backward compatibility. Any suggestions on where best to integrate this or references to similar patterns used in the codebase would be appreciated.

Thanks in advance!

You can and probably should add this to the Artist base class - get/set_tooltip. This will be propagated though **kwargs by most plotting functions, just like label. Though you'll likely need per-Artist-subclass specific implementation of data mapping, i.e. what is the tooltip for a given data coordinate.

That said, you don't have to implement all Artists right away. I suggest starting with Line2D. If you manage to to do 1., 2. and a specific version of 3. for Line2D, you've come quite far. We can generalize the high level API subsequently.

@Dil003 to follow on Tim's comment, you may also want to look at the data cursor mechanism/API folks have been discussing b/c it's got somewhat similar functionality and possibly look at how some of the third party packages implement it.