feature(sticky_keys): add quick-release

when quick-release is enabled, the sticky key is released immediately after another key is pressed

app/dts/behaviors/sticky_key.dtsi

@@ -19,6 +19,7 @@
 			#binding-cells = <1>;
 			release-after-ms = <1000>;
 			bindings = <&mo>;
+			quick-release;
 		};
 	};
 

app/dts/bindings/behaviors/zmk,behavior-sticky-key.yaml

@@ -13,3 +13,5 @@ properties:
     required: true
   release-after-ms:
     type: int
+  quick-release:
+    type: boolean

app/src/behaviors/behavior_sticky_key.c

@@ -29,6 +29,7 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 
 struct behavior_sticky_key_config {
     uint32_t release_after_ms;
+    bool quick_release;
     struct zmk_behavior_binding behavior;
 };
 
@@ -209,10 +210,12 @@ static int sticky_key_keycode_state_changed_listener(const zmk_event_t *eh) {
             }
             if (sticky_key->timer_started) {
                 stop_timer(sticky_key);
+                if (sticky_key->config->quick_release) {
+                    release_sticky_key_behavior(sticky_key, ev->timestamp);
+                }
             }
             sticky_key->modified_key_usage_page = ev->usage_page;
             sticky_key->modified_key_keycode = ev->keycode;
-
         } else { // key up
             if (sticky_key->timer_started &&
                 sticky_key->modified_key_usage_page == ev->usage_page &&
@@ -269,6 +272,7 @@ static struct behavior_sticky_key_data behavior_sticky_key_data;
 #define KP_INST(n)                                                                                 \
     static struct behavior_sticky_key_config behavior_sticky_key_config_##n = {                    \
         .behavior = _TRANSFORM_ENTRY(0, n).release_after_ms = DT_INST_PROP(n, release_after_ms),   \
+        .quick_release = DT_INST_PROP(n, quick_release),                                           \
     };                                                                                             \
     DEVICE_AND_API_INIT(behavior_sticky_key_##n, DT_INST_LABEL(n), behavior_sticky_key_init,       \
                         &behavior_sticky_key_data, &behavior_sticky_key_config_##n, APPLICATION,   \

app/tests/sticky-keys/2-sl-dn-up-kcdn-kcup/events.patterns

@@ -0,0 +1 @@
+s/.*hid_listener_keycode_//p

app/tests/sticky-keys/2-sl-dn-up-kcdn-kcup/keycode_events.snapshot

@@ -0,0 +1,8 @@
+pressed: usage_page 0x07 keycode 0x1b implicit_mods 0x00 explicit_mods 0x00
+pressed: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00
+released: usage_page 0x07 keycode 0x1b implicit_mods 0x00 explicit_mods 0x00
+released: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00
+pressed: usage_page 0x07 keycode 0x1b implicit_mods 0x00 explicit_mods 0x00
+pressed: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00
+released: usage_page 0x07 keycode 0x1b implicit_mods 0x00 explicit_mods 0x00
+released: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00

app/tests/sticky-keys/2-sl-dn-up-kcdn-kcup/native_posix.keymap

@@ -0,0 +1,52 @@
+#include <dt-bindings/zmk/keys.h>
+#include <behaviors.dtsi>
+#include <dt-bindings/zmk/kscan-mock.h>
+
+/*
+ sticky layers should quick-release.
+ Thus, the second keypress should be on the default layer, not on the lower_layer.
+*/
+
+/ {
+	keymap {
+		compatible = "zmk,keymap";
+		label ="Default keymap";
+
+		default_layer {
+			bindings = <
+				&sk E &sl 1
+				&kp A &kp B>;
+		};
+
+		lower_layer {
+			bindings = <
+				&sk LEFT_CONTROL &kp X
+				&kp Y  &kp Z>;
+		};
+	};
+};
+
+&kscan {
+	events = <
+		/* press sl 1 */
+		ZMK_MOCK_PRESS(0,1,10) 
+		ZMK_MOCK_RELEASE(0,1,10) 
+		/* press X */
+		ZMK_MOCK_PRESS(0,1,10)
+		/* press A */
+		ZMK_MOCK_PRESS(1,0,10)
+		ZMK_MOCK_RELEASE(0,1,10)
+		ZMK_MOCK_RELEASE(1,0,10)
+
+		/* repeat test to check if cleanup is done correctly */
+		/* press sl 1 */
+		ZMK_MOCK_PRESS(0,1,10) 
+		ZMK_MOCK_RELEASE(0,1,10) 
+		/* press X */
+		ZMK_MOCK_PRESS(0,1,10)
+		/* press Y */
+		ZMK_MOCK_PRESS(1,0,10)
+		ZMK_MOCK_RELEASE(0,1,10)
+		ZMK_MOCK_RELEASE(1,0,10)
+	>;
+};

app/tests/sticky-keys/8-lsk-osk-combination/keycode_events.snapshot

@@ -1,8 +1,8 @@
 pressed: usage_page 0x07 keycode 0xe0 implicit_mods 0x00 explicit_mods 0x00
-pressed: usage_page 0x07 keycode 0x1c implicit_mods 0x00 explicit_mods 0x00
+pressed: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00
 released: usage_page 0x07 keycode 0xe0 implicit_mods 0x00 explicit_mods 0x00
-released: usage_page 0x07 keycode 0x1c implicit_mods 0x00 explicit_mods 0x00
+released: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00
 pressed: usage_page 0x07 keycode 0xe0 implicit_mods 0x00 explicit_mods 0x00
-pressed: usage_page 0x07 keycode 0x1c implicit_mods 0x00 explicit_mods 0x00
+pressed: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00
 released: usage_page 0x07 keycode 0xe0 implicit_mods 0x00 explicit_mods 0x00
-released: usage_page 0x07 keycode 0x1c implicit_mods 0x00 explicit_mods 0x00
+released: usage_page 0x07 keycode 0x04 implicit_mods 0x00 explicit_mods 0x00

app/tests/sticky-keys/8-lsk-osk-combination/native_posix.keymap

@@ -29,7 +29,7 @@
 		/* tap sk LEFT_CONTROL */
 		ZMK_MOCK_PRESS(0,0,10)
 		ZMK_MOCK_RELEASE(0,0,10)
-		/* tap Y */
+		/* tap A */
 		ZMK_MOCK_PRESS(1,0,10) 
 		ZMK_MOCK_RELEASE(1,0,10) 
 		
@@ -40,7 +40,7 @@
 		/* tap sk */
 		ZMK_MOCK_PRESS(0,0,10)
 		ZMK_MOCK_RELEASE(0,0,10)
-		/* tap Y */
+		/* tap A */
 		ZMK_MOCK_PRESS(1,0,10) 
 		ZMK_MOCK_RELEASE(1,0,10) 
 	>;