Add shortcuts for nextSong previousSong increaseVolume decreaseVolume…

[InteractiveNinja]

Code by @stankovictab Issue #1355

[khanhas]

Do these default keyboard shortcuts actually not work on all Linux distros or just yours? Can I get some more input?
Also wrap them in a if condition checking OS, I'm sure on Windows and MacOS they work just fine.

[stankovictab]

@khanhas That's right, they do work fine on Windows,
however I know from experience and from my friends that the shortcut doesn't work on Ubuntu, Kubuntu, Linux Mint or Manjaro.
It's been an active issue for a while now, you can see the issue here on the Spotify Community forum.
It appears to be the same on Mac, but I haven't experimented with it.
I'll add the OS check, it should work fine, but please correct it if it's wrong. 🙂

[stankovictab]

This should do the trick.

function nextSong() {
	if (window.navigator.userAgent.indexOf("Win") == -1) // Works only on Linux and Mac
		document.querySelector(".main-skipForwardButton-button").click();
	}

function previousSong() {
	if (window.navigator.userAgent.indexOf("Win") == -1) // Works only on Linux and Mac
		document.querySelector(".main-skipBackButton-button").click();
	}

function increaseVolume() {
	if (window.navigator.userAgent.indexOf("Win") == -1) // Works only on Linux and Mac
		Spicetify.Player.origin.setVolume(Spicetify.Player.getVolume() + 0.1);
	}

function decreaseVolume() {
	if (window.navigator.userAgent.indexOf("Win") == -1) // Works only on Linux and Mac
		Spicetify.Player.origin.setVolume(Spicetify.Player.getVolume() - 0.1);
	}

[khanhas]

Okay then.
But please wrap functions definitions and Spicetify.KeyboardShortcut calls in one if condition, not one of each in like stankovictab's code.
We don't need to add these shortcuts handler for Windows since they work out of the box.

[InteractiveNinja]

Do we really need to also check the function definitions?