new: add navigation guards for previous/next sentence in player controls

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/PlayerControl.kt

@@ -39,6 +39,8 @@ fun PlayerControl(
     onMainPlayActionButtonClicked: () -> Unit = {},
     onPreviousSentenceClicked: () -> Unit = {},
     onNextSentenceClicked: () -> Unit = {},
+    canGoToPreviousSentence: Boolean = true,
+    canGoToNextSentence: Boolean = true,
 ) {
     Column(
         modifier = modifier.fillMaxWidth(),
@@ -66,6 +68,7 @@ fun PlayerControl(
         ) {
             IconButton(
                 modifier = Modifier.size(60.dp),
+                enabled = canGoToPreviousSentence,
                 onClick = onPreviousSentenceClicked,
             ) {
                 Icon(
@@ -87,6 +90,7 @@ fun PlayerControl(
 
             IconButton(
                 modifier = Modifier.size(60.dp),
+                enabled = canGoToNextSentence,
                 onClick = onNextSentenceClicked,
             ) {
                 Icon(
@@ -122,3 +126,27 @@ private fun PlayerControlPreview() {
         )
     }
 }
+
+@Preview
+@Composable
+private fun PlayerControlFirstSentencePreview() {
+    GwenedegTheme {
+        PlayerControl(
+            playbackState = PlaybackState.PLAYING,
+            playbackTiming = PlaybackTiming(positionMs = 1234, durationMs = 5000),
+            canGoToPreviousSentence = false,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PlayerControlLastSentencePreview() {
+    GwenedegTheme {
+        PlayerControl(
+            playbackState = PlaybackState.PLAYING,
+            playbackTiming = PlaybackTiming(positionMs = 1234, durationMs = 5000),
+            canGoToNextSentence = false,
+        )
+    }
+}

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/PlayerScreen.kt

@@ -150,6 +150,8 @@ fun PlayerScreen(
                 onMainPlayActionButtonClicked = onMainPlayActionButtonClicked,
                 onPreviousSentenceClicked = onPreviousSentenceClicked,
                 onNextSentenceClicked = onNextSentenceClicked,
+                canGoToPreviousSentence = uiState.canGoToPreviousSentence,
+                canGoToNextSentence = uiState.canGoToNextSentence,
             )
         }
 

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/viewmodel/PlayerUiState.kt

@@ -8,4 +8,10 @@ data class PlayerUiState(
     val recordTitle: Phrase = Phrase(transcription = ""),
     val playerState: PlayerState = PlayerState(),
     val subtitlePreferences: SubtitlePreferences = SubtitlePreferences(),
-)
+) {
+    val canGoToPreviousSentence: Boolean
+        get() = playerState.playbackTiming.positionMs > 2000
+
+    val canGoToNextSentence: Boolean
+        get() = (playerState.currentSubtitleIndex ?: Int.MAX_VALUE) < playerState.subtitleLines.lastIndex
+}