refactor: improve accessibility for audio settings

data/resources/src/commonMain/composeResources/values/strings.xml

@@ -24,9 +24,14 @@
     <string name="subtitle_marked_letters_description">Afficher les consonnes muettes et les liaisons</string>
 
     <string name="playback_speed_title">Vitesse de lecture</string>
+    <string name="playback_speed_value">%1$d %</string>
     <string name="playback_settings_action">Réglages de lecture</string>
     <string name="break_between_phrases_title">Pause entre les phrases</string>
     <string name="break_between_phrases_value">%1$d s</string>
+    <plurals name="break_between_phrases_value_description">
+        <item quantity="one">%1$d seconde</item>
+        <item quantity="other">%1$d secondes</item>
+    </plurals>
     <string name="auto_pause_title">Pause automatique</string>
     <string name="auto_pause_description">Mettre en pause après chaque phrase</string>
 

feature/records/src/commonMain/kotlin/bzh/ajaury/chombev/player/ui/PlaybackSpeedBottomSheet.kt

@@ -22,7 +22,10 @@ import bzh.ajaury.chombev.resources.generated.resources.auto_pause_description
 import bzh.ajaury.chombev.resources.generated.resources.auto_pause_title
 import bzh.ajaury.chombev.resources.generated.resources.break_between_phrases_title
 import bzh.ajaury.chombev.resources.generated.resources.break_between_phrases_value
+import bzh.ajaury.chombev.resources.generated.resources.break_between_phrases_value_description
 import bzh.ajaury.chombev.resources.generated.resources.playback_speed_title
+import bzh.ajaury.chombev.resources.generated.resources.playback_speed_value
+import org.jetbrains.compose.resources.pluralStringResource
 import org.jetbrains.compose.resources.stringResource
 import kotlin.math.roundToInt
 
@@ -85,6 +88,8 @@ private fun PlaybackSpeedContent(
         LabeledSlider(
             title = stringResource(Res.string.playback_speed_title),
             valueLabel = formatPlaybackSpeed(speed),
+            // "x0.7" reads poorly aloud: screen readers get "70 %" instead.
+            valueDescription = stringResource(Res.string.playback_speed_value, (speed * 100).roundToInt()),
             value = speed,
             valueRange = PlaybackPreferences.MIN_SPEED..PlaybackPreferences.MAX_SPEED,
             steps = speedSteps,
@@ -102,6 +107,12 @@ private fun PlaybackSpeedContent(
                 Res.string.break_between_phrases_value,
                 breakSeconds.roundToInt().toString(),
             ),
+            // "2 s" may be spelled out letter by letter: screen readers get "2 secondes" instead.
+            valueDescription = pluralStringResource(
+                Res.plurals.break_between_phrases_value_description,
+                breakSeconds.roundToInt(),
+                breakSeconds.roundToInt(),
+            ),
             value = breakSeconds,
             valueRange = 0f..maxBreakSeconds.toFloat(),
             steps = breakSteps,

feature/records/src/commonMain/kotlin/bzh/ajaury/chombev/player/ui/components/LabeledSlider.kt

@@ -10,8 +10,16 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.semantics.ProgressBarRangeInfo
+import androidx.compose.ui.semantics.clearAndSetSemantics
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.disabled
+import androidx.compose.ui.semantics.progressBarRangeInfo
+import androidx.compose.ui.semantics.setProgress
+import androidx.compose.ui.semantics.stateDescription
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import kotlin.math.roundToInt
 
 @Composable
 fun LabeledSlider(
@@ -20,13 +28,37 @@ fun LabeledSlider(
     value: Float,
     valueRange: ClosedFloatingPointRange<Float>,
     steps: Int,
+    valueDescription: String = valueLabel,
     onValueChange: (Float) -> Unit = {},
     enabled: Boolean = true,
 ) {
     // Dim the labels to match the Slider's disabled appearance.
     val contentAlpha = if (enabled) 1f else 0.38f
 
-    Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
+    Column(
+        // The whole block (title, value and slider) is a single adjustable element for screen
+        // readers, named by the title: swiping up or down moves one step and reads the new value.
+        modifier = Modifier.clearAndSetSemantics {
+            contentDescription = title
+            stateDescription = valueDescription
+            progressBarRangeInfo = ProgressBarRangeInfo(
+                current = value,
+                range = valueRange,
+                steps = steps,
+            )
+            if (enabled) {
+                setProgress { target ->
+                    val newValue = target.snapToSteps(valueRange, steps)
+                    if (newValue == value) return@setProgress false
+                    onValueChange(newValue)
+                    true
+                }
+            } else {
+                disabled()
+            }
+        },
+        verticalArrangement = Arrangement.spacedBy(4.dp),
+    ) {
         Row(
             modifier = Modifier.fillMaxWidth(),
             horizontalArrangement = Arrangement.SpaceBetween,
@@ -53,6 +85,17 @@ fun LabeledSlider(
     }
 }
 
+private fun Float.snapToSteps(
+    range: ClosedFloatingPointRange<Float>,
+    steps: Int,
+): Float {
+    val clamped = coerceIn(range)
+    if (steps <= 0) return clamped
+    val stepSize = (range.endInclusive - range.start) / (steps + 1)
+    val stepIndex = ((clamped - range.start) / stepSize).roundToInt()
+    return (range.start + stepIndex * stepSize).coerceIn(range)
+}
+
 @Preview
 @Composable
 private fun LabeledSliderPreview() {