Add ability to toggle/hold key

docs/keyd.scdoc

@@ -694,6 +694,10 @@ A key may optionally be bound to an _action_ which accepts zero or more argument
 *clearm(<macro>)*
 	Identical to *clear*, but executes the supplied macro before clearing layers.
 
+*togglekey(<key>)*
+	Toggle whether the key is pressed. Effectively holds the key down until
+	togglekey is performed again.
+
 ## Key overloading
 
 *overload(<layer>, <action>)*

src/config.c

@@ -74,12 +74,14 @@ static struct {
 		ARG_TIMEOUT,
 		ARG_SENSITIVITY,
 		ARG_DESCRIPTOR,
+		ARG_KEYCODE,
 	} args[MAX_DESCRIPTOR_ARGS];
 } actions[] =  {
 	{ "swap", 	NULL,	OP_SWAP,	{ ARG_LAYER } },
 	{ "clear", 	NULL,	OP_CLEAR,	{} },
 	{ "oneshot", 	NULL,	OP_ONESHOT,	{ ARG_LAYER } },
 	{ "toggle", 	NULL,	OP_TOGGLE,	{ ARG_LAYER } },
+	{ "togglekey", 	NULL,	OP_TOGGLEKEY,	{ ARG_KEYCODE } },
 
 	{ "clearm", 	NULL,	OP_CLEARM,	{ ARG_MACRO } },
 	{ "swapm", 	NULL,	OP_SWAPM,	{ ARG_LAYER, ARG_MACRO } },
@@ -753,6 +755,13 @@ static int parse_descriptor(char *s,
 						arg->idx = config->nr_macros;
 						config->nr_macros++;
 
+						break;
+					case ARG_KEYCODE:
+						arg->code = lookup_keycode(argstr);
+						if (arg->code == 0) {
+							err("%s is not a valid keycode", argstr);
+							return -1;
+						}
 						break;
 					default:
 						assert(0);

src/config.h

@@ -44,6 +44,7 @@ enum op {
 	OP_OVERLOAD_IDLE_TIMEOUT,
 	OP_TOGGLE,
 	OP_TOGGLEM,
+	OP_TOGGLEKEY,
 
 	OP_MACRO,
 	OP_MACRO2,

src/keyboard.c

@@ -729,6 +729,17 @@ static long process_descriptor(struct keyboard *kbd, uint8_t code,
 			clear_oneshot(kbd);
 		}
 
+		break;
+	case OP_TOGGLEKEY:
+		new_code = d->args[0].code;
+
+		if (pressed) {
+			if (kbd->keystate[new_code]) {
+				send_key(kbd, new_code, 0);
+			} else {
+				send_key(kbd, new_code, 1);
+			}
+		}
 		break;
 	case OP_TIMEOUT:
 		struct pending_timeout *pt = &kbd->pending_timeout;

t/test.conf

@@ -33,6 +33,7 @@ p = layerm(shift, macro(on))
 1+2 = oneshot(test)
 l = layer(test)
 m = macro(C-h one)
+n = togglekey(q)
 c = oneshot(control)
 s = layer(shift)
 o = overloadt(control, a, 10)

t/togglekey.t

@@ -0,0 +1,11 @@
+n down
+n up
+a down
+a up
+n down
+n up
+
+q down
+a down
+a up
+q up