hover-mode
hover-mode: marks the hover popup buffer so it auto-dismisses when the document cursor moves. Content is markdown; markdown-mode renders it.
The minor mode on the hover popup buffer — the floating window that shows a symbol's documentation and type.
You don't invoke it. It comes with the popup, which comes from lsp-mode when you ask for hover information.
What it's for
One behaviour hangs off it today: a hover popup that was opened but never focused dismisses itself when the document cursor moves. That is the right instinct for a hover — you asked about the symbol you were on, so moving off it makes the answer stale — and the mode is what tells the dispatcher which popups that rule applies to.
Rendering
Hover content is markdown, and the popup's major mode is markdown-mode — so the same renderer, the same syntax highlighting, and the same link handling as any other markdown buffer. hover-mode layers on top as the minor; it doesn't reimplement any of that.
Behaviour worth knowing
- It's a marker mode. Its value is that hover-only behaviour has somewhere to attach without special-casing the popup code — an auto-close timer,
<Esc>-to-dismiss, or signature-help fan-in would land here. Today only the auto-dismiss rule reads it.