using ivy completion on a hydra

Question

I'd like to use ivy completion to select items from my hydra rather than using the specified keymap. The use case would be for a very large hydra. I could create nested hydras, but I want to be lazy and just keep adding stuff to one large hydra without spending time organizing or formatting it. Technically, a hydra isn't required for the solution. Could also just be a list of functions, preferably with hints, and a method to select them via ivy. Thanks.

Answer 1

Instead of starting from hydra, I would start from counsel-M-x. This function uses ivy-read, which wants a list of possible inputs, and a function to run once you've chosen one. You can provide it a list of the commands you want to run, and use counsel-M-x-action as the function to run. Here's an example:

(defvar my/commands '(shell scroll-down text-mode))

(defun my/commands ()
  (interactive)
  (ivy-read "Command: " my/commands
            :caller 'my-commands
            :require-match t
            :action #'counsel-M-x-action))

For customization, Ivy has "display transformers", which let you display something other than the command name. You could use this to add hints. First, add :caller 'my-commands to the ivy-read, so that this command has a name. Then, use ivy-configure to tell Ivy to use your function for displaying text:

(defun my/commands-display (candidate)
  (format "%s - add hint here" candidate))
 
(ivy-configure 'my-commands
  :display-transformer-fn #'my/commands-display)