feat(gs): Bind a push-to-talk key r/1784

Bind a key, which I've located at the top-left of my right keyboard, to
a momentary push-to-talk by muting and unmuting my pulseaudio source
using xbindkeys. I had been putting this off for a while because i3
doesn't support binding different commands to keyup than to keydown
events, but the xbindkeys support appears to have solved that reasonably
well, plus it's got Scheme in it so that's cool.

If there's demand for it I'll gladly expose this as a reusable,
configurable home-manager module outside my users dir in the depot.

Change-Id: Ie591c93037dbdac364d5d8a718d99edb70780789
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1975
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>

3 files changed, 46 insertions, 1 deletions

diff --git a/users/glittershark/keyboard/keymap.c b/users/glittershark/keyboard/keymap.c
index 9ffa6fe9eb..fbb28c9aac 100644
--- a/users/glittershark/keyboard/keymap.c
+++ b/users/glittershark/keyboard/keymap.c
@@ -37,7 +37,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
                                                                     KC_LBRACKET,
                                         GUI_T(KC_NO), LSFT_T(KC_BSPACE),    KC_COLN,
 
-      KC_RIGHT,     KC_6,   KC_7,   KC_8,       KC_9,       KC_0,               KC_MINUS,
+      KC_MY_COMPUTER, KC_6,   KC_7,   KC_8,       KC_9,       KC_0,               KC_MINUS,
       KC_RALT,      KC_Y,   KC_U,   KC_I,       KC_O,       KC_P,               KC_BSLASH,
                     KC_H,   KC_J,   KC_K,       KC_L,       LT(2,KC_SCOLON),    LT(1,KC_QUOTE),
       KC_MINUS,     KC_N,   KC_M,   KC_COMMA,   KC_DOT,     CTL_T(KC_SLASH),    KC_RSFT,
diff --git a/users/glittershark/system/home/machines/chupacabra.nix b/users/glittershark/system/home/machines/chupacabra.nix
index 66531e9d7f..b6940dc831 100644
--- a/users/glittershark/system/home/machines/chupacabra.nix
+++ b/users/glittershark/system/home/machines/chupacabra.nix
@@ -11,6 +11,7 @@ in {
     ../modules/games.nix
     ../modules/rtlsdr.nix
     ../modules/urbint.nix
+    ../modules/ptt.nix
   ];
 
   # for when hacking
diff --git a/users/glittershark/system/home/modules/ptt.nix b/users/glittershark/system/home/modules/ptt.nix
new file mode 100644
index 0000000000..436c8f2617
--- /dev/null
+++ b/users/glittershark/system/home/modules/ptt.nix
@@ -0,0 +1,44 @@
+{ config, lib, pkgs, ... }:
+
+let
+
+  pttKeycode = "152";
+  sourceID = "3";
+
+  mute = pkgs.writeShellScript "mute-mic" ''
+    xset -r ${pttKeycode}
+    ${pkgs.pulseaudio}/bin/pactl set-source-mute ${sourceID} 1
+  '';
+
+  unmute = pkgs.writeShellScript "unmute-mic" ''
+    xset -r ${pttKeycode}
+    ${pkgs.pulseaudio}/bin/pactl set-source-mute ${sourceID} 0
+  '';
+
+in
+
+{
+  home.packages = with pkgs; [
+    xbindkeys
+  ];
+
+
+  home.file.".xbindkeysrc.scm".text = ''
+    (xbindkey '("c:${pttKeycode}") "${unmute}")
+    (xbindkey '(release "c:${pttKeycode}") "${mute}")
+  '';
+
+  systemd.user.services."xbindkeys" = {
+    Unit = {
+      Description = "Keybind daemon for push-to-talk";
+      After = [ "graphical-session-pre.target" ];
+      PartOf = [ "graphical-session.target" ];
+    };
+
+    Install = { WantedBy = [ "graphical-session.target" ]; };
+
+    Service = {
+      ExecStart = "${pkgs.xbindkeys}/bin/xbindkeys -n -v";
+    };
+  };
+}