to_if_alone

to_if_alone posts events when the from key is pressed alone.
The events are posted at the from key is released.

Example

The following json changes left_control to sending escape when left_control is pressed alone.

{
    "description": "Send the escape key when the left control key is tapped",
    "manipulators": [
        {
            "type": "basic",
            "from": {
                "key_code": "left_control",
                "modifiers": { "optional": ["any"] }
            },
            "to": [
                {
                    "key_code": "left_control"
                }
            ],
            "to_if_alone": [{ "key_code": "escape" }]
        }
    ]
}

About cancellation

to_if_alone is canceled if other events (keys, buttons or scroll wheel) is happen while the from key is pressed down.

Cancellation also occurs when you press the from key for a long time. (The default timeout is 1000 milliseconds.)

You can adjust the timeout milliseconds by parameters > basic.to_if_alone_timeout_milliseconds.
The following example sets the timeout 200 milliseconds.

💡 How to use this example

{
    "description": "Send the escape key when the left control key is tapped",
    "manipulators": [
        {
            "type": "basic",
            "from": {
                "key_code": "left_control",
                "modifiers": { "optional": ["any"] }
            },
            "to": [
                {
                    "key_code": "left_control"
                }
            ],
            "to_if_alone": [{ "key_code": "escape" }],
            "parameters": { "basic.to_if_alone_timeout_milliseconds": 200 }
        }
    ]
}

About keyboard repeat

to_if_alone posts both key_down and key_up events at the same time. Thus, you cannot use key repeat for to_if_alone events.

About sending caps lock

to_if_alone posts both key_down and key_up events at the same time. Since the caps_lock key needs to be held down for a certain duration, you need to specify hold_down_milliseconds.

{
    "description": "Change caps_lock to left_control",
    "manipulators": [
        {
            "type": "basic",
            "from": {
                "key_code": "caps_lock",
                "modifiers": { "optional": ["any"] }
            },
            "to": [
                {
                    "key_code": "left_control"
                }
            ],
            "to_if_alone": [
                {
                    "key_code": "caps_lock",
                    "hold_down_milliseconds": 200
                }
            ]
        }
    ]
}

With the lazy flag

When changing a key to a modifier and sending the key only when pressed alone, there may be cases where you do not want to send the modifier in that situation. In such cases, add lazy to to. This ensures that the modifier is sent only when pressed together with another key. Additionally, by combining this with to_if_held_down, you can send the modifier when the key is held down for a certain duration, ensuring that cases where the modifier needs to be sent alone are also covered.

{
    "description": "Post escape if left_control is tapped",
    "manipulators": [
        {
            "type": "basic",
            "from": {
                "key_code": "left_control",
                "modifiers": { "optional": ["any"] }
            },
            "to": [
                {
                    "key_code": "left_control",
                    "lazy": true
                }
            ],
            "to_if_alone": [{ "key_code": "escape" }],
            "to_if_held_down": [{ "key_code": "left_control" }],
            "parameters": {
                "basic.to_if_alone_timeout_milliseconds": 100,
                "basic.to_if_held_down_threshold_milliseconds": 100
            }
        }
    ]
}