Node Hotkeys

Handle hotkeys on NodeJS easily.

Registering hotkeys

Simple use

const hotkeys = require('node-hotkeys');

hotkeys.on({
	hotkeys: 'ctrl + a',
	matchAllModifiers: true,
	callback: function (hotkey) {
		console.log("Activated:", hotkey);
	}
});

If ctrl + a is pressed, the output will be:

Activated: ctrl + a

Multiple hotkeys

Separate the hotkeys using comma:

hotkeys.on({
	hotkeys: 'alt + a, shift + a, ctrl + a',
	matchAllModifiers: true,
	callback: function (hotkey) {
		console.log("Activated:", hotkey);
	}
});

If any of the registered hotkeys are pressed, the output will be:

Activated: alt + a, shift + a, ctrl + a

Triggering multiple hotkeys

By adding the option triggerAll we can call the callback function for each of the hotkeys pressed:

hotkeys.on({
	hotkeys: 'alt + a, shift + a, ctrl + a',
	matchAllModifiers: true,
	triggerAll: true,
	callback: function (hotkey) {
		console.log("Activated:", hotkey);
	}
});

If shift + a is pressed and then alt + a, the output will be:

Activated: shift + a
Activated: alt + a

Matching only the required modifiers

If we set matchAllModifiers to false then we'll be able to detect hotkeys that may have been pressed accompanied by other modifiers:

hotkeys.on({
	hotkeys: 'ctrl + a, a',
	matchAllModifiers: false,
	triggerAll: true,
	callback: function (hotkey) {
		console.log("Activated:", hotkey);
	}
});

If ctrl + a is pressed, the output will be:

Activated: ctrl + a
Activated: a

And if shift + a is pressed, the output will be:

Activated: a

PS: the modifiers are alt, shift and ctrl.

Matching capitalization

If you would like to differentiate uppercase and lowercase letters, add the capitalization option:

hotkeys.on({
	hotkeys: 'ctrl + a, ctrl + A',
	capitalization: true,
	triggerAll: true,
	callback: function (hotkey) {
		console.log("Activated:", hotkey);
	}
});

If you have caps lock disabled and press ctrl + a, the output will be:

Activated: ctrl + a

If you have caps lock disabled and press ctrl + shift + a, the output will be:

Activated: ctrl + A

If you have caps lock enabled and press ctrl + a, the output will be:

Activated: ctrl + A

And if you have caps lock enabled and press ctrl + shift + a, the output will be:

Activated: ctrl + a

Special cases

hotkeys.on({
	hotkeys: 'shift + plus, enter, space, tab, esc, backspace',
	triggerAll: true,
	callback: function (hotkey) {
		console.log("Activated:", hotkey);
	}
});

If we press those keys in that order, the output will be:

Activated: shift + plus
Activated: enter
Activated: space
Activated: tab
Activated: esc
Activated: backspace

Detecting special keys

Some keys do not have a character representation, thus they can only be detected using keydown events, which you can turn on by setting the option useKeyDown to true:

hotkeys.on({
	hotkeys: 'left, up, right, down',
	matchAllModifiers: true,
	triggerAll: true,
	useKeyDown: true,
	callback: function (hotkey) {
		console.log("Arrow:", hotkey);
	}
});

If we press those keys in that order, the output will be:

Arrow: left
Arrow: up
Arrow: right
Arrow: down

Other special keys: capslock, pgup, pgdn, end, home, prtsc, insert, delete, cmd, F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12.

Split key

The split key is used to combine keys in order to define the hotkey, the default split key is +. But it can be changed using the splitKey option:

hotkeys.on({
	hotkeys: 'shift - +',
	splitKey: '-',
	callback: function (hotkey) {
		console.log("Activated:", hotkey);
	}
});

If we press shift and +, the output will be:

Activated: shift - +

Removing hotkeys

The following method has support to the same options of the method on() used to register the hotkeys.

hotkeys.remove({ hotkeys: "ctrl + a" });

PS: when removing hotkeys all modifiers will always be checked and only if they match that the hotkey will be removed. So matchAllModifiers is automatically set true.

Detecting any hotkeys

It is also possible to detect what combination of keys the user pressed by using the method getNextHotkey:

(async () => {
	while (true) {
		let hotkeyStr = await hotkeys.getNextHotkey(false);
		console.log("Detected:", hotkeyStr);
	}
})();

The code above prints in the console every hotkey pressed by the user, it can be used, for instance, when asking for the user to choose a custom hotkey. The method getNextHotkey receives a boolean parameter that determines whether to listen to hotkeys from keydown events (when true) or only keypress events (when false). It also returns a Promise that will be resolved with the hotkey string definition that the user chose. So if you press alt + shift + y with caps lock disabled, the output will be:

Detected: alt + shift + Y

Access the IOHook instance

hotkeys.iohook

More information about IOHook on this link.

Debug hotkeys being used

Example of use:

hotkeys.on({
	hotkeys: 'alt + a, shift + a',
	matchAllModifiers: true,
	triggerAll: true,
	callback: function (hotkey) { }
});

hotkeys.on({
	hotkeys: 'ctrl + h, H',
	capitalization: true,
	callback: function (hotkey) { }
});

hotkeys.logRegisteredHotkeys();

Output:

[{
	"hotkeyStr": "alt + a",
	"shiftKey": false,
	"altKey": true,
	"ctrlKey": false,
	"matchAllModifiers": true,
	"rawcode": 65
}, {
	"hotkeyStr": "shift + a",
	"shiftKey": true,
	"altKey": false,
	"ctrlKey": false,
	"matchAllModifiers": true,
	"rawcode": 65
}, {
	"hotkeys": [{
		"hotkeyStr": "ctrl + h",
		"shiftKey": false,
		"altKey": false,
		"ctrlKey": true,
		"matchAllModifiers": false,      
		"keychar": 104
	}, {
		"hotkeyStr": "H",
		"shiftKey": false,
		"altKey": false,
		"ctrlKey": false,
		"matchAllModifiers": false,
		"keychar": 72
	}],
	"hotkeyStr": "ctrl + h, H"
}]

Using Debounce Listeners

The debounce method can register a callback to be called whenever the user presses keys or types some text. You must define a debounce time in milliseconds and the callback that will receive the content typed as a string and the KeypressEvents array with each key pressed. The string returned by this method is a key that identifies the registered debounce listener so that you can remove it later using removeDebounce.

Definition:

debounce (ms: number, callback: (string, KeypressEvent[]) => void): string

Example of use:

const hotkeys = require('node-hotkeys');

const key = hotkeys.debounce(500, (value, events) => {
	console.log("INPUT:", value);
});

Removing debounce listeners:

hotkeys.removeDebounce(key);