Made it possible to pause.

Kyome22 · Aug 12, 2024 · 05393a7 · 05393a7
1 parent 3d708dc
commit 05393a7
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Showing 4 changed files with 55 additions and 27 deletions.
diff --git a/Examples/Example_for_iOS/MusicView.swift b/Examples/Example_for_iOS/MusicView.swift
@@ -17,7 +17,8 @@ struct MusicView: View {
         .navigationBarTitleDisplayMode(.inline)
         .onAppear {
             do {
-                try audioAnalyzer.play(url: musicItem.url)
+                try audioAnalyzer.prepare(url: musicItem.url)
+                try audioAnalyzer.play()
             } catch {
                 print(error.localizedDescription)
             }

diff --git a/Examples/Example_for_macOS/MusicListView.swift b/Examples/Example_for_macOS/MusicListView.swift
@@ -6,7 +6,7 @@ struct MusicListView: View {
 
     var body: some View {
         VStack {
-            Text("Title: \(model.playingMusicItem?.title ?? "unknown")")
+            Text("Title: \(model.selectedMusicItem?.title ?? "-")")
             AmplitudeSpectrumView(
                 shapeType: .straight,
                 magnitudes: model.audioAnalyzer.magnitudes,
@@ -19,21 +19,18 @@ struct MusicListView: View {
                     HStack {
                         Text(musicItem.title)
                         Spacer()
-                        if musicItem == model.playingMusicItem {
+                        if musicItem == model.selectedMusicItem, model.isPlaying {
                             Button {
-                                model.playingMusicItem = nil
-                                model.stop()
+                                model.pause()
                             } label: {
-                                Image(systemName: "stop.fill")
+                                Image(systemName: "pause.fill")
                             }
                         } else {
                             Button {
-                                model.playingMusicItem = musicItem
                                 model.play(musicItem: musicItem)
                             } label: {
                                 Image(systemName: "play.fill")
                             }
-                            .disabled(model.playingMusicItem != nil)
                         }
                     }
                 }

diff --git a/Examples/Example_for_macOS/MusicListViewModel.swift b/Examples/Example_for_macOS/MusicListViewModel.swift
@@ -3,10 +3,11 @@ import iTunesLibrary
 import Observation
 import SwiftUI
 
-@Observable 
+@Observable
 final class MusicListViewModel {
     var musicItems = [MusicItem]()
-    var playingMusicItem: MusicItem?
+    var selectedMusicItem: MusicItem?
+    var isPlaying = false
     let audioAnalyzer = AudioAnalyzer(fftSize: 2048, windowType: .hammingWindow)
 
     func loadMusicItems() {
@@ -27,20 +28,29 @@ final class MusicListViewModel {
     }
 
     func play(musicItem: MusicItem) {
-        let url = musicItem.url
-        if url.startAccessingSecurityScopedResource() {
-            defer {
-                url.stopAccessingSecurityScopedResource()
-            }
-            do {
-                try audioAnalyzer.play(url: url)
-            } catch {
-                Swift.print(error.localizedDescription)
+        do {
+            if musicItem != selectedMusicItem {
+                if selectedMusicItem != nil {
+                    audioAnalyzer.stop()
+                }
+                let url = musicItem.url
+                if url.startAccessingSecurityScopedResource() {
+                    defer {
+                        url.stopAccessingSecurityScopedResource()
+                    }
+                    try audioAnalyzer.prepare(url: url)
+                    selectedMusicItem = musicItem
+                }
             }
+            try audioAnalyzer.play()
+            isPlaying = true
+        } catch {
+            Swift.print(error.localizedDescription)
         }
     }
 
-    func stop() {
-        audioAnalyzer.stop()
+    func pause() {
+        audioAnalyzer.pause()
+        isPlaying = false
     }
 }
diff --git a/Sources/AudioVisualizerKit/AudioAnalyzer.swift b/Sources/AudioVisualizerKit/AudioAnalyzer.swift
@@ -3,7 +3,8 @@ import Observation
 
 protocol AudioAnalyzerProtocol: AnyObject {
     init(fftSize: Int, windowType: WindowType)
-    func play(url: URL) throws
+    func prepare(url: URL) throws
+    func play() throws
     func stop()
 }
 
@@ -13,6 +14,7 @@ public final class AudioAnalyzer: AudioAnalyzerProtocol {
     private let audioEngine = AVAudioEngine()
     private let playerNode = AVAudioPlayerNode()
     private let fft: FFT
+    private var isPrepared = false
 
     public var magnitudes: [Magnitude]
     public var rms: Float = .zero
@@ -23,7 +25,8 @@ public final class AudioAnalyzer: AudioAnalyzerProtocol {
         magnitudes = .init(repeating: .zero, count: fftSize / 2)
     }
 
-    public func play(url: URL) throws {
+    public func prepare(url: URL) throws {
+        stop()
         let audioFile = try AVAudioFile(forReading: url)
         let sampleRate = Float(audioFile.processingFormat.sampleRate)
         audioEngine.attach(playerNode)
@@ -40,24 +43,41 @@ public final class AudioAnalyzer: AudioAnalyzerProtocol {
             self?.calculate(sampleRate: sampleRate, buffer: buffer)
         }
         playerNode.scheduleFile(audioFile, at: nil)
-        try audioEngine.start()
-        playerNode.play()
+        isPrepared = true
+    }
+
+    public func play() throws {
+        guard isPrepared else { return }
+        if !audioEngine.isRunning {
+            try audioEngine.start()
+        }
+        if !playerNode.isPlaying {
+            playerNode.play()
+        }
+    }
+
+    public func pause() {
+        if playerNode.isPlaying {
+            playerNode.pause()
+        }
     }
 
     public func stop() {
+        guard isPrepared else { return }
         if playerNode.isPlaying {
             playerNode.stop()
         }
-        playerNode.removeTap(onBus: 0)
+        playerNode.removeTap(onBus: .zero)
         if audioEngine.isRunning {
             audioEngine.stop()
         }
         audioEngine.disconnectNodeOutput(playerNode)
         audioEngine.detach(playerNode)
+        isPrepared = false
     }
 
     func calculate(sampleRate: Float, buffer: AVAudioPCMBuffer) {
-        if let data = buffer.floatChannelData {
+        if let data = buffer.floatChannelData, playerNode.isPlaying {
             magnitudes = fft.compute(sampleRate: sampleRate, audioData: data.pointee)
             rms = fft.rms(audioData: data.pointee)
         }