Add MPRIS volume control

Fixes #776.

Author: foonathan

plugins/shortcuts/mpris.js

@@ -19,7 +19,7 @@ function setupMPRIS() {
 
 function registerMPRIS(win) {
 	const songControls = getSongControls(win);
-	const { playPause, next, previous } = songControls;
+	const { playPause, next, previous, volumeMinus10, volumePlus10 } = songControls;
 	try {
 		const secToMicro = n => Math.round(Number(n) * 1e6);
 		const microToSec = n => Math.round(Number(n) / 1e6);
@@ -93,6 +93,22 @@ function registerMPRIS(win) {
 		player.on('seek', seekBy);
 		player.on('position', seekTo);
 
+		ipcMain.on('volumeChanged', (_, value) => {
+			player.volume = value;
+		});
+		player.on('volume', (newVolume) => {
+			// With keyboard shortcuts we can only change the volume in increments of 10, so round it.
+			const deltaVolume = Math.round((newVolume - player.volume) / 10);
+
+			if (deltaVolume > 0) {
+				for (let i = 0; i < deltaVolume; i++)
+					volumePlus10();
+			} else {
+				for (let i = 0; i < -deltaVolume; i++)
+					volumeMinus10();
+			}
+		});
+
 		registerCallback(songInfo => {
 			if (player) {
 				const data = {

providers/song-info-front.js

@@ -23,6 +23,7 @@ module.exports = () => {
 			(is.linux() && config.plugins.isEnabled('shortcuts'))) {
 			setupTimeChangeListener();
 			setupRepeatChangeListener();
+			setupVolumeChangeListener();
 		}
 		const video = $('video');
 		// name = "dataloaded" and abit later "dataupdated"
@@ -74,3 +75,13 @@ function setupRepeatChangeListener() {
 	// Emit the initial value as well; as it's persistent between launches.
 	ipcRenderer.send('repeatChanged', $('#right-controls .repeat').title);
 }
+
+function setupVolumeChangeListener() {
+	const volumeObserver = new MutationObserver(mutations => {
+		ipcRenderer.send('volumeChanged', mutations[0].target.value);
+	});
+	volumeObserver.observe($('#right-controls .volume-slider'), { attributeFilter: ["value"] });
+
+	// Emit the initial value as well; as it's persistent between launches.
+	ipcRenderer.send('volumeChanged', $('#right-controls .volume-slider').value);
+}