Akela-OneShot

One-shots are a new kind of behaviour for your standard modifier and momentary layer keys: instead of having to hold them while pressing other keys, they can be tapped and released, and will remain active until any other key is pressed. In short, they turn Shift, A into Shift+A, and Fn, 1 to Fn+1. The main advantage is that this allows us to place the modifiers and layer keys to positions that would otherwise be awkward when chording. Nevertheless, they still act as normal when held, that behaviour is not lost.

Furthermore, if a one-shot key is tapped two times in quick succession, it becomes sticky, and remains active until disabled with a third tap. This can be useful when one needs to input a number of keys with the modifier or layer active, and still does not wish to hold the key down.

To make multi-modifier, or multi-layer shortcuts possible, one-shot keys remain active if another one-shot of the same type is tapped, so Ctrl, Alt, b becomes Ctrl+Alt+b, and L1, L2, c is turned into L1+L2+c.

Using the plugin

There are two major ways in which the plugin can be used: one is to turn existing modifiers or momentary layer toggles into one-shot keys:

#include <Akela-OneShot.h>

void setup () {
  OneShot.enableAuto ();
  
  Keyboardio.setup (KEYMAP_SIZE);
  Keyboardio.use (&OneShot, NULL);
}

The other is to explicitly mark keys as one-shot in the keymap:

#include <Akela-OneShot.h>

// somewhere in the keymap...
OSM(LCtrl), OSL(_FN)

void setup () {
  Keyboardio.setup (KEYMAP_SIZE);
  Keyboardio.use (&OneShot, NULL);
}

Keymap markup

There are two macros the plugin provides:

OSM(mod)

A macro that takes a single argument, the name of the modifier: LCtrl, LShift, LAlt, LGUI or their right-side variant. When marked up with this macro, the modifier will act as a one-shot modifier.

OSL(layer)

Takes a layer number as argument, and sets up the key to act as a one-shot layer key.

Please note that while KeyboardioFirmware supports more, one-shot layers are limited to 24 layers only.

Plugin methods

The plugin provides one object, OneShot, which implements both one-shot modifiers and one-shot layer keys. It has the following methods:

.enableAuto()

Automatically turns modifiers and momentary layer switches into their one-shot variant. It will only turn keys on the keymap into one-shots: if any macro injects a modifier or a momentary layer switch key, those will be left alone, as-is.

This must be called before any Keyboardio.use() call in the setup() method of your Sketch.

.isActive()

Returns if any one-shot key is in flight. This makes it possible to differentiate between having a modifier or layer active, versus having them active only until after the next key getting pressed. And this, in turn, is useful for macros that need to fiddle with either modifier or layer state: if one-shots are not active, they need not restore the original state.

.isModifierActive(key)

Returns if the modifier key has a one-shot state active. Use this together with Keyboard.isModifierActive to catch cases where a one-shot modifier is active, but not registered yet.

.cancel([withStickies])

The cancel() method can be used to cancel any pending one-shot effects, useful when one changed their minds, and does not wish to wait for the timeout.

The optional withStickies argument, if set to true, will also cancel sticky one-shot effects. If omitted, it defaults to false, and not canceling stickies.

.on()

Turns the one-shot behaviour on. This method is idempotent, you can call it any number of times, at any time.

.off()

The counterpart of the on() method, this turns off one-shot behaviour. Modifiers will act as normal modifiers, and one-shot layer keys will act as momentary layer switchers. As on(), this method is idempotent, and can be called at any time, from anywhere.

.timeOut

The number of loop iterations to wait before timing out and cancelling the one-shot effect, unless interrupted or cancelled before by any other means.

Not strictly a method, it is a variable one can assign a new value to.

Defaults to 40.

.holdTimeOut

The number of loop iterations to wait before considering a held one-shot key as intentionally held. In this case, the one-shot effect will not trigger when the key is released. In other words, holding a one-shot key at least this long, and then releasing it, will not trigger the one-shot effect.

Not strictly a method, it is a variable one can assign a new value to.

Defaults to 5.

Further reading

Starting from the example is the recommended way of getting started with the plugin.