new: display current playback position and implement cross-platform position tracking

core/audioplayer/src/androidMain/kotlin/fr/ajaury/gwenedeg/player/AndroidAudioPlayer.kt

@@ -7,6 +7,8 @@ import androidx.media3.exoplayer.ExoPlayer
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.milliseconds
 
 class AndroidAudioPlayer(
     context: Context,
@@ -36,6 +38,8 @@ class AndroidAudioPlayer(
         )
     }
 
+    override fun currentPosition(): Duration = player.currentPosition.coerceAtLeast(0).milliseconds
+
     override fun load(uri: String) {
         val mediaItem = MediaItem.fromUri(uri)
         player.setMediaItem(mediaItem)

core/audioplayer/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/AudioPlayer.kt

@@ -1,10 +1,13 @@
 package fr.ajaury.gwenedeg.player
 
 import kotlinx.coroutines.flow.StateFlow
+import kotlin.time.Duration
 
 interface AudioPlayer {
     val playbackState: StateFlow<PlaybackState>
 
+    fun currentPosition(): Duration
+
     fun play()
 
     fun pause()

core/audioplayer/src/iosMain/kotlin/fr/ajaury/gwenedeg/player/IosAudioPlayer.kt

@@ -7,13 +7,18 @@ import kotlinx.coroutines.flow.asStateFlow
 import platform.AVFoundation.AVPlayer
 import platform.AVFoundation.AVPlayerItem
 import platform.AVFoundation.AVPlayerItemDidPlayToEndTimeNotification
+import platform.AVFoundation.currentTime
 import platform.AVFoundation.pause
 import platform.AVFoundation.play
 import platform.AVFoundation.replaceCurrentItemWithPlayerItem
+import platform.CoreMedia.CMTimeGetSeconds
 import platform.Foundation.NSNotificationCenter
 import platform.Foundation.NSOperationQueue
 import platform.Foundation.NSURL
 import platform.darwin.NSObjectProtocol
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.Duration.Companion.seconds
 
 class IosAudioPlayer : AudioPlayer {
     private var player: AVPlayer? = null
@@ -22,6 +27,13 @@ class IosAudioPlayer : AudioPlayer {
     private val _playbackState = MutableStateFlow(PlaybackState.IDLE)
     override val playbackState: StateFlow<PlaybackState> = _playbackState.asStateFlow()
 
+    @OptIn(ExperimentalForeignApi::class)
+    override fun currentPosition(): Duration {
+        val player = player ?: return 0.milliseconds
+        val seconds = CMTimeGetSeconds(player.currentTime()).takeIf { !it.isNaN() }
+        return seconds?.seconds ?: 0.milliseconds
+    }
+
     @OptIn(ExperimentalForeignApi::class)
     override fun load(uri: String) {
         release()

core/audioplayer/src/jvmMain/kotlin/fr/ajaury/gwenedeg/player/JvmAudioPlayer.kt

@@ -9,6 +9,8 @@ import javax.sound.sampled.AudioFormat
 import javax.sound.sampled.AudioSystem
 import javax.sound.sampled.Clip
 import javax.sound.sampled.LineEvent
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.microseconds
 
 /**
  * Desktop [AudioPlayer] backed by [javax.sound.sampled].
@@ -25,6 +27,8 @@ class JvmAudioPlayer : AudioPlayer {
     private val _playbackState = MutableStateFlow(PlaybackState.IDLE)
     override val playbackState: StateFlow<PlaybackState> = _playbackState.asStateFlow()
 
+    override fun currentPosition(): Duration = (clip?.microsecondPosition ?: 0L).microseconds
+
     override fun load(uri: String) {
         release()
 

core/audioplayer/src/webMain/kotlin/fr/ajaury/gwenedeg/player/WebAudioPlayer.kt

@@ -5,6 +5,8 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import org.w3c.dom.HTMLAudioElement
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.seconds
 
 class WebAudioPlayer : AudioPlayer {
     private var audio: HTMLAudioElement? = null
@@ -12,6 +14,8 @@ class WebAudioPlayer : AudioPlayer {
     private val _playbackState = MutableStateFlow(PlaybackState.IDLE)
     override val playbackState: StateFlow<PlaybackState> = _playbackState.asStateFlow()
 
+    override fun currentPosition(): Duration = (audio?.currentTime ?: 0.0).seconds
+
     override fun load(uri: String) {
         release()