Emacs Hydra menu

It's been a while since I've written anything meaningful. I suppose I've just been feeling a bit lazy, but to my defense, I've spent a lot of time training on my bike 🚴. I needed a change of pace. Don’t get me wrong—I love programming and the exhilaration of being in the zone where everything flows effortlessly. But sometimes, I lose it all. Inspiration fades, and more than anything, I find it hard to sit down in front of the computer and actually get something done.

My daytime job as a software engineer often drains the energy right out of me. One way I try to cope is by taking deeper breaths—usually while cycling. Anyway, I realize I need to do something to kickstart my motivation. So here I am, trying to get myself moving again, having changed the spark plugs and added some starting fuel. Trying to jumpstart my writing once more… Honestly, it’s not going great yet.

One of my main problems when using emacs is remebering the key shortcuts or even functions that I need to run. Don't take wrong its both a benefit and a curse, maybe it boils down to me not having a perfect memory. Though I guess im not the only one. The reason for the last statement is based on all the different meta-menu shortcuts that you can build. So what do I mean by that? Well, there are several different menu system that can be used and several different ways of searching for the right functionality. For example hydra which maps a popup menu, and this can be mapped to certain major-mode, and each item is based on a key and a function. Lets make a really short example

(defhydra hydra-zoom (:color amarath :title fisk :separator "🪓")
  "🐛 zoom 🐛"
  ("g" text-scale-increase "in")
  ("l" text-scale-decrease "out")
  ("q" nil "quit"))

As the result shows it returns a hydra-zooom/body , which is a interactive function and shows a nice menu as in , the red frame outlines the popup.

This of course could be connected to a key-shortcut or run interactivly. Each of the defined hydra menu will automatically have a <name>/body function, which then can be bound to some key for example the above example could be bound to:

(bind-key "C-c c z" #'hydra-zoom/body)

Another nice way to deal with this, is to map a major mode to some hydra-popup, with a certain key-binding M-SPC. That means , we get a different popup depending on what major-mode is running. . This can be done using major-mode-hydra. The following example shows how to initialize major-mode-hydra

(use-package major-mode-hydra
:straight t
:config
    (global-set-key (kbd "M-SPC") #'major-mode-hydra)
    (setq hydra-hint-display-type 'posframe)
)

Lets make a simple example using the major mode: text-mode . The idea is to create a major mode that maps to M-SPC when in text-mode. I added some different options in the following example:

(major-mode-hydra-define text-mode
  (:color red :title "Ꙫ Text mode Ꙫ" :separator "⨝" :quit-key "q" :foreign-keys warn :hint t :timeout 15)
  (
   "🐛 zoom 🐛"
   (("g" text-scale-increase "in" :color blue :column "vertical")
    ("l" text-scale-decrease "out")
    ("d" whitespace-mode "Debug on error" :toggle (bound-and-true-p whitespace-mode ))
    ("q" nil "quit")
    )
   "Options"
   (("f" flyspell-mode "Flyspell mode" :toggle  (bound-and-true-p flyspell-mode))
    ("v" visual-line-mode "visual line mode" :toggle (bound-and-true-p visual-line-mode))
    ("b" abbrev-mode "abbrev mode" :toggle (bound-and-true-p abbrev-mode))
    ("a" auto-fill-mode "auto fill mode"  :toggle (and (boundp 'auto-fill-function) auto-fill-function))
    ("n" display-line-numbers-mode "line number" :toggle t)
    ("h" highlight-changes-mode "Highlight changes" :toggle t (bound-and-true-p highlight-changes-mode))
    )
   "Face"
   (("w" writeroom-mode "Writer room" :toggle ))
   ))

This creates a hydra function called: (major-mode-hydras/text-mode/body), which when called will bring up the popup, since we also are using major-mode-hydra which has mapped M-Spc, each time we use that shortcut it will bring up the menu. But if we want to use this menu in a different mode, for example org-mode we could do map a key to the function as in:

(add-hook 'org-mode-hook
          (lambda ()
            (local-set-key (kbd "<f6>") #'major-mode-hydras/text-mode/body)))

Now it is linked to M-Spc in text-mode and F6 in org-mode (noting that org-mode could have a different menu mapped to M-Spc).

major-mode-hydra also extends the possibility to use toggles, which can be very useful. In the above example I added a couple of differnt toggles for example whitespace-mode which shows the whitespaces in the current text. Its also possible to change the layout in the popup. The above creates three columns with headings Zoom, options ,/face/.

Some of the properties needs some explanation.

timeout

Timeout before the menu disappears

exit

After executing the command, the menu will dissapear

Color

Color actually have a side effect except for just coloring the field. It is an aggregation of foreign-keys and exit

red

blue

exit t

amaranth

Foreign-keys warn

teal

foreign-keys warn, exit t

pink

foreign-keys run

foreign-keys

If a key is hit that is not part of the defined, what will happen?

warn

A warning

nil

Hydra state will stop and the foreign key will do whatefer it was suppose to do.

run

Will not stop the hydra state, and try to run the foreign key, this can be somewhat confusing.

The template for creating a layout can be something like the following yas-snippets.

# -*- mode: snippet -*-
# name: major-mode-hydra menu
# key: <hydra
# group: col
# --
  (major-mode-hydra-define ${1:text-mode}
    (:color ${2:$$(yas-choose-value '("red" "blue" "amaranth" "teal" "pink"))} :title "${3:My title}" :separator "${4:―}")
    (
    ${5:<hydra-column}$0
     ));

Now for the column snippet

  # -*- mode: snippet -*-
# name: Hydra column
# key: <hydra-column
# group: col
# --

   "${1:Column header}"
     (("${2:key}" ${3:function} "${4:description}")
      ${5:("${6:key}" ${7:function} "${8:description}")}
      )
      ${9:<hydra-column}$0

This snippets are kind of neat, since it provides a recursive way of implement different columns.

Adding this and pressing M-<space>= will open the above popup-menu above if in text-mode. This of course can be chained with other menus. For example; you have a some options where you want to change the theme or font or something else, this could potentially be done in another menu with other option, more on this in the later section. But lets first take a look at how to extend this the hydra