From 30c02dc99042ef74d6249bb40c46373b0adf0947 Mon Sep 17 00:00:00 2001
From: Michael Tyson <michael@atastypixel.com>
Date: Mon, 12 May 2025 18:58:26 +1000
Subject: [PATCH] =?UTF-8?q?feat(behaviors):=20Added=20=E2=80=98fire-hold-a?=
 =?UTF-8?q?s-tap=E2=80=99=20option=20for=20hold-tap=20behavior?=
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This adds a new optional property `fire-hold-as-tap` to the hold-tap behavior.

When enabled, if the hold condition is met, the hold behavior sends both a press and immediate release (simulating a tap) instead of sending the hold press on hold and release on key-up.

This prevents OS key repeat behavior and allows safe assignment of normal keys (or other simple behaviors) to the hold action of hold-tap bindings. It is particularly useful for sending keyboard shortcuts on hold without unwanted repeats.

The option is fully backwards compatible. It defaults to off.
---
 .../behaviors/zmk,behavior-hold-tap.yaml         |  2 ++
 app/src/behaviors/behavior_hold_tap.c            | 16 ++++++++++++++++
 docs/docs/keymaps/behaviors/hold-tap.mdx         | 15 +++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/app/dts/bindings/behaviors/zmk,behavior-hold-tap.yaml b/app/dts/bindings/behaviors/zmk,behavior-hold-tap.yaml
index 76f14d12d..ea1bd8732 100644
--- a/app/dts/bindings/behaviors/zmk,behavior-hold-tap.yaml
+++ b/app/dts/bindings/behaviors/zmk,behavior-hold-tap.yaml
@@ -43,6 +43,8 @@ properties:
     type: boolean
   retro-tap:
     type: boolean
+  fire-hold-as-tap:
+    type: boolean
   hold-trigger-key-positions:
     type: array
     required: false
diff --git a/app/src/behaviors/behavior_hold_tap.c b/app/src/behaviors/behavior_hold_tap.c
index 3df3bc864..a5647e447 100644
--- a/app/src/behaviors/behavior_hold_tap.c
+++ b/app/src/behaviors/behavior_hold_tap.c
@@ -41,6 +41,7 @@ enum status {
     STATUS_TAP,
     STATUS_HOLD_INTERRUPT,
     STATUS_HOLD_TIMER,
+    STATUS_HOLD_TAP_SENT,
 };
 
 enum decision_moment {
@@ -62,6 +63,7 @@ struct behavior_hold_tap_config {
     bool hold_while_undecided;
     bool hold_while_undecided_linger;
     bool retro_tap;
+    bool fire_hold_as_tap;
     bool hold_trigger_on_release;
     int32_t hold_trigger_key_positions_len;
     int32_t hold_trigger_key_positions[];
@@ -379,6 +381,8 @@ static inline const char *status_str(enum status status) {
         return "hold-interrupt";
     case STATUS_TAP:
         return "tap";
+    case STATUS_HOLD_TAP_SENT:
+        return "hold-tap-sent";
     default:
         return "UNKNOWN STATUS";
     }
@@ -467,6 +471,12 @@ static int press_binding(struct active_hold_tap *hold_tap) {
         if (hold_tap->config->hold_while_undecided) {
             // the hold is already active, so we don't need to press it again
             return 0;
+        } else if (hold_tap->config->fire_hold_as_tap) {
+            // send press followed immediately by release to simulate a tap
+            press_hold_binding(hold_tap);
+            release_hold_binding(hold_tap);
+            hold_tap->status = STATUS_HOLD_TAP_SENT;
+            return 0;
         } else {
             return press_hold_binding(hold_tap);
         }
@@ -485,6 +495,11 @@ static int release_binding(struct active_hold_tap *hold_tap) {
         return 0;
     }
 
+    if (hold_tap->config->fire_hold_as_tap && hold_tap->status == STATUS_HOLD_TAP_SENT) {
+        // Already sent tap/release for hold
+        return 0;
+    }
+
     if (hold_tap->status == STATUS_HOLD_TIMER || hold_tap->status == STATUS_HOLD_INTERRUPT) {
         return release_hold_binding(hold_tap);
     } else {
@@ -870,6 +885,7 @@ static int behavior_hold_tap_init(const struct device *dev) {
         .hold_while_undecided = DT_INST_PROP(n, hold_while_undecided),                             \
         .hold_while_undecided_linger = DT_INST_PROP(n, hold_while_undecided_linger),               \
         .retro_tap = DT_INST_PROP(n, retro_tap),                                                   \
+        .fire_hold_as_tap = DT_INST_PROP(n, fire_hold_as_tap),                                     \
         .hold_trigger_on_release = DT_INST_PROP(n, hold_trigger_on_release),                       \
         .hold_trigger_key_positions = DT_INST_PROP(n, hold_trigger_key_positions),                 \
         .hold_trigger_key_positions_len = DT_INST_PROP_LEN(n, hold_trigger_key_positions),         \
diff --git a/docs/docs/keymaps/behaviors/hold-tap.mdx b/docs/docs/keymaps/behaviors/hold-tap.mdx
index 755230a29..7ade35456 100644
--- a/docs/docs/keymaps/behaviors/hold-tap.mdx
+++ b/docs/docs/keymaps/behaviors/hold-tap.mdx
@@ -460,3 +460,18 @@ For example, if you press `&mt LEFT_SHIFT A` and then release it without pressin
     retro-tap;
 };
 ```
+
+### `fire-hold-as-tap`
+
+If `fire-hold-as-tap` is enabled, the hold behavior will send both press and release immediately when the hold condition is met, instead of waiting for key release.  
+This prevents operating system key repeat behavior for hold actions that are intended to be momentary, such as triggering shortcut key combinations.
+
+For example, if you press and hold `&mt KC_PGUP KC_PGDN` with `fire-hold-as-tap` enabled, it will send a single `KC_PGUP` event when the hold condition triggers, and will not repeat or send additional events on key release.
+
+```dts
+&mt {
+    fire-hold-as-tap;
+};
+```
+
+**Note:** This option has no effect on the tap behavior. It only changes the way the hold action is sent.
\ No newline at end of file