From 52509e1f7d60c8d816fc89591d0a1c2a90a218dc Mon Sep 17 00:00:00 2001
From: Thomas White <taw@physics.org>
Date: Thu, 2 Jun 2022 19:37:45 +0200
Subject: Debounce "go" button on MIDI controller

---
 guile/starlet/midi-control/button-utils.scm | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

(limited to 'guile/starlet/midi-control')

diff --git a/guile/starlet/midi-control/button-utils.scm b/guile/starlet/midi-control/button-utils.scm
index 8462e3e..d9a3c1c 100644
--- a/guile/starlet/midi-control/button-utils.scm
+++ b/guile/starlet/midi-control/button-utils.scm
@@ -22,6 +22,7 @@
   #:use-module (starlet midi-control base)
   #:use-module (starlet state)
   #:use-module (starlet playback)
+  #:use-module (starlet utils)
   #:export (make-go-button
             make-stop-button
             make-back-button
@@ -31,11 +32,18 @@
 (define* (make-go-button controller pb button
                          #:key
                          (ready-note #f)
-                         (pause-note #f))
-  (register-midi-note-callback!
-    controller
-    #:note-number button
-    #:func (lambda () (go! pb)))
+                         (pause-note #f)
+                         (min-time-between-presses 0.2))
+  (let ((time-last-press 0))
+    (register-midi-note-callback!
+      controller
+      #:note-number button
+      #:func (lambda ()
+               (let ((time-this-press (hirestime)))
+                 (if (> time-this-press (+ time-last-press min-time-between-presses))
+                   (go! pb)
+                   (display "Too soon after last press!\n"))
+                 (set! time-last-press time-this-press)))))
 
   (when (or ready-note pause-note)
     (add-hook!
-- 
cgit v1.2.3