# riverguile

Scripting layer for the [river](https://github.com/riverwm/river) Wayland
server using [Guile Scheme](https://www.gnu.org/software/guile/).

Send commands to river and install handlers for various events, inclusing
layout events.

Uppon launch, riverguile tries to load a scheme script and checks the following
paths for it in the given order:

* `layout.scm`
* `$XDG_CONFIG_HOME/river/layout.scm`
* `$HOME/.config/river/layout.scm`
* `/etc/riverguile/layout.scm`

In the context of this script, a special procedure `(install-handler key proc)`
is available, which can be used to install handlers to certain events.
Check the man page for more information.

Here is an example `layout.scm` file replicating rivertiles behavior of having
a main window and a stack of windows aside while also automatically locking
the screen after five minutes of inactivity.

```scheme
(install-handler 'idle:300 (lambda (event)
                             (cond ((eq? event 'idle) (system "swaylock &")
                                                      (system "backlight.sh set-to 40"))
                                   ((eq? event 'resume) (system "backlight.sh set-to 100")))))

(define split 0.55)

(define (layout:rows n x y w h)
        (letrec ((height (/ h n))
                 (rows (lambda (n)
                               (if (eq? n 0)
                                   '()
                                   (let ((Y (- (+ y h) (* n height))))
                                        (append (list (list x Y w height))
                                                (rows (- n 1))))))))
                (rows n)))

(define (layout:split n x y w h)
        (if (eq? n 1)
            (list (list x y w h))
            (letrec* ((left (* split w))
                      (right (- w left)))
                     (append (list (list x y left h))
                             (layout:rows (- n 1) (+ x left) y right h)))))

(install-handler 'layout-demand (lambda (view-count width height tags output)
                                  (layout:split view-count 0 0 width height)))
```