Function to show documentation for thing at point

[rrudakov]

Hi! Is it possible to disable showing hover information in the minibuffer and implement a function to show it in a new window?

I have the following problems:

• For java projects with jdtls I only see signatures in the minibuffer

• For rust-analyzer I mostly see hover information and minibuffer is being resized every time I move point to another symbol:

I've tried:

• To set (setq eldoc-documentation-strategy #'eldoc-documentation-compose) in the eglot-managed-mode-hook, but it's still distracting to see hover information when I don't need it.
• To set

(setq eldoc-documentation-functions
                    (thread-last
                      eldoc-documentation-functions
                      (remove #'eglot-hover-eldoc-function)))

in the eglot-managed-mode-hook, but in this case I don't know how to see hover information when I need to.

P. S. I used lsp-mode before and there were a function lsp-describe-thing-at-point to show the documentation in a new window, I think I'm looking for an alternative for this functionality.

[manuel-uberti]

I am not sure whether this is the proper way to do it, but if you set eldoc-display-functions to something like:

(setq eldoc-display-functions '(eldoc-display-in-buffer))

And then do M-x eldoc-print-current-symbol-info (or just M-x eldoc) you should get the window you're looking for.

Personally, I'd recommend not to change eldoc-display-functions globally though.

[manuel-uberti]

I see, then you need something different. My answer was related to your question:

Is it possible to disable showing hover information in the minibuffer and implement a function to show it in a new window?

[rrudakov]

Yeah, the question was specifically about hover information. Eglot sets eldoc-documentation-functions to '(eglot-signature-eldoc-function eglot-hover-eldoc-function flymake-eldoc-function), so if signature is available, hover won't be ever shown.

[joaotavora]

You still need a function to put in eldoc-display-functions, something that is smart enough to display only some types of documentation in a separate window. There's no such thing built-in, but if you do that sort of thing, be sure to propose it here and then we can consider it for inclusion in Emacs (eldoc.el).

You may need Eglot to mark different types of documentation so you can sort through them. It doesn't do this at the moment. But this is a second step. If you're interested in this functionality you should tackle the elements of eldoc-display-functions first.

[rrudakov]

I was able to achieve the desired behaviour using the following code:

  (add-hook 'eglot-managed-mode-hook
            (lambda ()
              (setq eldoc-documentation-functions
                    (thread-last
                      eldoc-documentation-functions
                      (remove #'eglot-hover-eldoc-function)))))

  (defun rr/eglot-describe-thing-at-point ()
    (interactive)
    (when (eglot--server-capable :hoverProvider)
      (let ((buf (current-buffer)))
        (jsonrpc-async-request
         (eglot--current-server-or-lose)
         :textDocument/hover (eglot--TextDocumentPositionParams)
         :success-fn (eglot--lambda ((Hover) contents range)
                       (eglot--when-buffer-window buf
                         (when-let ((info (unless (seq-empty-p contents)
                                            (eglot--hover-info contents range))))
                           (with-help-window (help-buffer)
                             (with-current-buffer (help-buffer)
                               (insert info))))))
         :deferred :textDocument/hover))))

Does it make sense to include it in eglot? IMO, it's more consistent with default emacs behaviour: for example for emacs lisp eldoc shows only signature, and if you need a documentation you should call describe-* function.

[joaotavora]

Does it make sense to include it in eglot?

Not really, in my opinion. One should use eldoc.el's API so that simply M-x eldoc can be used for this. If that API is insufficient, it can be extended.