feat: add audio devices event source

Package.resolved

@@ -9,6 +9,15 @@
         "version" : "2.3.0"
       }
     },
+    {
+      "identity" : "simplycoreaudio",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/rnine/SimplyCoreAudio.git",
+      "state" : {
+        "revision" : "35cc0e6eac5c2ee5049431f4238b0e333cf79869",
+        "version" : "4.1.1"
+      }
+    },
     {
       "identity" : "swift-argument-parser",
       "kind" : "remoteSourceControl",
@@ -18,6 +27,15 @@
         "version" : "1.2.3"
       }
     },
+    {
+      "identity" : "swift-atomics",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-atomics.git",
+      "state" : {
+        "revision" : "cd142fd2f64be2100422d658e7411e39489da985",
+        "version" : "1.2.0"
+      }
+    },
     {
       "identity" : "yams",
       "kind" : "remoteSourceControl",

Package.swift

@@ -11,15 +11,17 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.2.0"),
         .package(url: "https://github.com/JohnSundell/ShellOut.git", from: "2.0.0"),
-        .package(url: "https://github.com/jpsim/Yams.git", from: "5.0.6")
+        .package(url: "https://github.com/jpsim/Yams.git", from: "5.0.6"),
+        .package(url: "https://github.com/rnine/SimplyCoreAudio.git", from: "4.1.1"),
     ],
     targets: [
         .executableTarget(
             name: "runif",
             dependencies: [
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
                 .product(name: "ShellOut", package: "ShellOut"),
-                .product(name: "Yams", package: "Yams")
+                .product(name: "Yams", package: "Yams"),
+                .product(name: "SimplyCoreAudio", package: "SimplyCoreAudio")
             ]
         )
     ]

README.md

@@ -37,6 +37,5 @@ If you want to run a command on an event, regardless of the input (`with`), then
 
 The following event sources can be subscribed to:
 
-* `screen` — change connected displays. declares `connected` and `disconnected` events. In `with` takes the display name.
-
-
+* `screen` — connected displays list change. declares `connected` and `disconnected` events. In `with` takes the display name.
+* `audio`  — connected audio device list change. declares `connected` and `disconnected` events. In `with` takes the audio device name. Handles both input and output devices.

Sources/Events/AudioSource.swift

@@ -0,0 +1,40 @@
+import Cocoa
+import SimplyCoreAudio
+
+class AudioSource: EventSource {
+    let coreAudio = SimplyCoreAudio()
+    var name = "audio"
+    var listener: EventListener?
+    var lastScreens: [String]?
+    var updating = false
+
+    func emitAll(kind: String, devices: [AudioDevice]) {
+        var names: [String] = []
+        for device in devices where !names.contains(device.name) {
+            emit(kind: kind, target: device.name)
+            names.append(device.name)
+        }
+    }
+
+    @objc
+    func handleDeviceListChanged(notification: Notification) {
+        let addedDevices = notification.userInfo?["addedDevices"] as? [AudioDevice]
+        if addedDevices != nil && !addedDevices!.isEmpty {
+            emitAll(kind: "connected", devices: addedDevices!)
+        }
+
+        let removedDevices = notification.userInfo?["removedDevices"] as? [AudioDevice]
+        if removedDevices != nil && !removedDevices!.isEmpty {
+            emitAll(kind: "disconnected", devices: removedDevices!)
+        }
+    }
+
+    func subscribe() {
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(self.handleDeviceListChanged),
+            name: Notification.Name.deviceListChanged,
+            object: nil
+        )
+    }
+}

Sources/Events/Event.swift

@@ -15,14 +15,10 @@ protocol EventProvider {
 protocol EventSource: EventProvider {
     var name: String { get }
 
-    func handle()
+    func subscribe()
 }
 
 extension EventSource {
-    func handle() {
-        // Do nothing by default
-    }
-
     func emit(kind: String, target: String) {
         if listener == nil {
             return

Sources/Events/EventObserver.swift

@@ -6,8 +6,8 @@ class EventObserver: EventListener, EventProvider {
     var sources: [EventSource] = []
 
     init(sources: [EventSource]) {
-        for var provider in sources {
-            provider.listener = self
+        for var source in sources {
+            source.listener = self
         }
         self.sources = sources
     }
@@ -19,20 +19,19 @@ class EventObserver: EventListener, EventProvider {
         }
     }
 
+    func subscribeSources() {
+        for source in sources {
+            source.subscribe()
+        }
+    }
+
     func runLoop() {
+        subscribeSources()
         _ = NSApplication.shared
         let ticket = Timer.publish(every: 5, on: .main, in: .common)
             .autoconnect()
-            .sink { _ in
-                self.run()
-            }
+            .sink { _ in }
         RunLoop.main.run()
         ticket.cancel()
     }
-
-    func run() {
-        for provider in sources {
-            provider.handle()
-        }
-    }
 }

Sources/Events/ScreenSource.swift

@@ -7,23 +7,19 @@ class ScreenSource: EventSource {
     var lastScreens: [String]?
     var updating = false
 
-    init() {
-        subscribeChange()
-        refreshScreens()
-    }
-
     @objc
     func handleDisplayConnection(notification _: Notification) {
         refreshScreens()
     }
 
-    func subscribeChange() {
+    func subscribe() {
         NotificationCenter.default.addObserver(
             self,
             selector: #selector(handleDisplayConnection),
             name: NSApplication.didChangeScreenParametersNotification,
             object: nil
         )
+        refreshScreens()
     }
 
     func getScreenNames() -> [String] {

Sources/RunIf.swift

@@ -15,17 +15,21 @@ struct RunIf: ParsableCommand {
     var configPath: String?
 
     mutating func run() throws {
+        let sources: [EventSource] = [
+            ScreenSource(),
+            AudioSource()
+        ]
         let config = ConfigLoader.read(handlersOf: configPath)
         if config == nil {
             throw ValidationError("Can't open config file.")
         }
+        let activeSources = sources.filter { source in
+            config!.keys.contains(source.name)
+        }
         let runner = CommandRunner(with: config!)
-        let sources: [EventSource] = [
-            ScreenSource()
-        ]
-        let observer = EventObserver(sources: sources)
+        let observer = EventObserver(sources: activeSources)
         observer.listener = runner
-        print("starting with \(sources.count) event sources")
+        print("starting with \(activeSources.count) event sources")
         observer.runLoop()
     }
 }