René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[ENH]: Data tooltip support","articleBody":"### Problem\n\nTo better support interactivity and contextual data, we should support data tooltips.\r\n\n\n### Proposed solution\n\nThings to be done:\r\n\r\n1) Add tooltip API to `backend_bases`. This should be similar to the picker functionality, only with hover instead of click. T.b.d.: Do we want a `TooltipEvent` or a more general `HoverEvent`?\r\n2) Implement that API for the backends. As a first step or prove of concept one could start with one backend, e.g. Qt and add the other backends later. ipympl could/should follow at some point as well.\r\n3) Add high-level API to support setting tooltips.\r\n   We likely want at least:\r\n   - explicit strings: `plt.plot(x, y, tooltip=['A', 'B', 'C', 'D'])`\r\n   - `data` support: `plt.plot('x', 'y', tooltip='label', data=data)`\r\n   - functions: `plt.plot(x, y, tooltip=lambda x, y: f'({x}, {y})')`\r\n ","author":{"url":"https://github.com/timhoffm","@type":"Person","name":"timhoffm"},"datePublished":"2022-07-01T15:12:53.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":12},"url":"https://github.com/23378/matplotlib/issues/23378"}