fix: Show signal strength as bar indicator instead of percent

app/src/main/java/eu/darken/capod/main/ui/overview/cards/DualPodsCard.kt

@@ -47,7 +47,6 @@ import eu.darken.capod.common.compose.PreviewWrapper
 import eu.darken.capod.common.compose.preview.MockPodDataProvider
 import eu.darken.capod.monitor.core.PodDevice
 import eu.darken.capod.monitor.core.cachedBatteryFormatted
-import eu.darken.capod.monitor.core.getSignalQuality
 import eu.darken.capod.pods.core.apple.aap.protocol.AapSetting
 import eu.darken.capod.pods.core.apple.ble.devices.DualApplePods
 import eu.darken.capod.pods.core.apple.ble.devices.DualApplePods.LidState
@@ -91,12 +90,23 @@ fun DualPodsCard(
                 Spacer(modifier = Modifier.width(8.dp))
 
                 Column(modifier = Modifier.weight(1f)) {
-                    Text(
-                        text = device.label ?: "?",
-                        style = MaterialTheme.typography.titleMedium,
-                        maxLines = 1,
-                        overflow = TextOverflow.Ellipsis,
-                    )
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        verticalAlignment = Alignment.CenterVertically,
+                    ) {
+                        Text(
+                            text = device.label ?: "?",
+                            style = MaterialTheme.typography.titleMedium,
+                            maxLines = 1,
+                            overflow = TextOverflow.Ellipsis,
+                            modifier = Modifier.weight(1f, fill = false),
+                        )
+                        SignalIndicator(
+                            signalQuality = device.signalQuality,
+                            isLive = device.isLive,
+                            modifier = Modifier.padding(start = 6.dp),
+                        )
+                    }
                     val deviceLabel = buildString {
                         append(device.getLabel(context))
                         val podStyle = device.ble as? HasPodStyle
@@ -109,6 +119,7 @@ fun DualPodsCard(
                         }
                     }
                     Row(
+                        modifier = Modifier.fillMaxWidth(),
                         verticalAlignment = Alignment.CenterVertically,
                     ) {
                         Text(
@@ -119,12 +130,10 @@ fun DualPodsCard(
                             overflow = TextOverflow.Ellipsis,
                             modifier = Modifier.weight(1f, fill = false),
                         )
-                        Spacer(modifier = Modifier.width(6.dp))
-                        SignalBadge(
-                            signalText = device.getSignalQuality(context),
+                        DeviceConnectionBadge(
                             bleKeyState = device.bleKeyState,
                             isAapConnected = device.isAapConnected,
-                            isLive = device.isLive,
+                            modifier = Modifier.padding(start = 6.dp),
                         )
                     }
                 }

app/src/main/java/eu/darken/capod/main/ui/overview/cards/PodCardComponents.kt

@@ -1,9 +1,11 @@
 package eu.darken.capod.main.ui.overview.cards
 
+import androidx.annotation.VisibleForTesting
 import androidx.compose.animation.animateContentSize
 import androidx.compose.animation.core.FastOutSlowInEasing
 import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.tween
+import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -20,14 +22,13 @@ import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.twotone.BatteryChargingFull
-import androidx.compose.material.icons.twotone.Hearing
-import androidx.compose.material.icons.twotone.KeyboardVoice
 import androidx.compose.material.icons.outlined.Key
+import androidx.compose.material.icons.twotone.BatteryChargingFull
 import androidx.compose.material.icons.twotone.Bluetooth
+import androidx.compose.material.icons.twotone.Hearing
 import androidx.compose.material.icons.twotone.Key
+import androidx.compose.material.icons.twotone.KeyboardVoice
 import androidx.compose.material.icons.twotone.LinkOff
-import androidx.compose.material.icons.twotone.SettingsInputAntenna
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.SegmentedButton
@@ -41,8 +42,13 @@ import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.geometry.CornerRadius
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import eu.darken.capod.R
@@ -159,14 +165,90 @@ fun StatusChipRow(
     }
 }
 
+@VisibleForTesting
+internal enum class SignalLevel { DISCONNECTED, BARS_0, BARS_1, BARS_2, BARS_3, BARS_4 }
+
+@VisibleForTesting
+internal fun signalLevelOf(signalQuality: Float, isLive: Boolean): SignalLevel {
+    if (!isLive) return SignalLevel.DISCONNECTED
+    if (!signalQuality.isFinite()) return SignalLevel.BARS_0
+    val q = signalQuality.coerceIn(0f, 1f)
+    return when {
+        q >= 0.80f -> SignalLevel.BARS_4
+        q >= 0.60f -> SignalLevel.BARS_3
+        q >= 0.40f -> SignalLevel.BARS_2
+        q >= 0.20f -> SignalLevel.BARS_1
+        else -> SignalLevel.BARS_0
+    }
+}
+
 @Composable
-fun SignalBadge(
-    signalText: String,
-    bleKeyState: BleKeyState = BleKeyState.NONE,
-    isAapConnected: Boolean = false,
-    isLive: Boolean = true,
+fun SignalIndicator(
+    signalQuality: Float,
+    isLive: Boolean,
     modifier: Modifier = Modifier,
 ) {
+    val level = signalLevelOf(signalQuality, isLive)
+    val description = when (level) {
+        SignalLevel.DISCONNECTED -> stringResource(R.string.signal_indicator_disconnected_cd)
+        SignalLevel.BARS_0 -> stringResource(R.string.signal_indicator_bars_cd, 0)
+        SignalLevel.BARS_1 -> stringResource(R.string.signal_indicator_bars_cd, 1)
+        SignalLevel.BARS_2 -> stringResource(R.string.signal_indicator_bars_cd, 2)
+        SignalLevel.BARS_3 -> stringResource(R.string.signal_indicator_bars_cd, 3)
+        SignalLevel.BARS_4 -> stringResource(R.string.signal_indicator_bars_cd, 4)
+    }
+    val tint = MaterialTheme.colorScheme.onSurfaceVariant
+    val rootModifier = modifier
+        .size(12.dp)
+        .semantics(mergeDescendants = true) { contentDescription = description }
+
+    if (level == SignalLevel.DISCONNECTED) {
+        Icon(
+            imageVector = Icons.TwoTone.LinkOff,
+            contentDescription = null,
+            modifier = rootModifier,
+            tint = tint,
+        )
+        return
+    }
+
+    val activeBars = when (level) {
+        SignalLevel.BARS_0 -> 0
+        SignalLevel.BARS_1 -> 1
+        SignalLevel.BARS_2 -> 2
+        SignalLevel.BARS_3 -> 3
+        SignalLevel.BARS_4 -> 4
+        SignalLevel.DISCONNECTED -> 0 // unreachable; handled above
+    }
+    val inactiveColor = tint.copy(alpha = 0.3f)
+    Canvas(modifier = rootModifier) {
+        val barCount = 4
+        val gapWidth = size.width * 0.12f
+        val totalGap = gapWidth * (barCount - 1)
+        val barWidth = (size.width - totalGap) / barCount
+        val corner = CornerRadius(barWidth * 0.4f, barWidth * 0.4f)
+        for (i in 0 until barCount) {
+            val heightFraction = (i + 1).toFloat() / barCount
+            val barHeight = size.height * heightFraction
+            val x = i * (barWidth + gapWidth)
+            val y = size.height - barHeight
+            drawRoundRect(
+                color = if (i < activeBars) tint else inactiveColor,
+                topLeft = Offset(x, y),
+                size = Size(barWidth, barHeight),
+                cornerRadius = corner,
+            )
+        }
+    }
+}
+
+@Composable
+fun DeviceConnectionBadge(
+    bleKeyState: BleKeyState,
+    isAapConnected: Boolean,
+    modifier: Modifier = Modifier,
+) {
+    if (bleKeyState == BleKeyState.NONE && !isAapConnected) return
     Surface(
         modifier = modifier,
         shape = RoundedCornerShape(8.dp),
@@ -176,47 +258,25 @@ fun SignalBadge(
             modifier = Modifier.padding(horizontal = 6.dp, vertical = 2.dp),
             verticalAlignment = Alignment.CenterVertically,
         ) {
-            if (!isLive) {
+            if (bleKeyState != BleKeyState.NONE) {
                 Icon(
-                    imageVector = Icons.TwoTone.LinkOff,
-                    contentDescription = null,
+                    imageVector = if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) Icons.TwoTone.Key else Icons.Outlined.Key,
+                    contentDescription = stringResource(
+                        if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) R.string.signal_badge_key_encrypted_cd
+                        else R.string.signal_badge_key_irk_cd
+                    ),
                     modifier = Modifier.size(12.dp),
                     tint = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
-            } else {
-                if (bleKeyState != BleKeyState.NONE) {
-                    Icon(
-                        imageVector = if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) Icons.TwoTone.Key else Icons.Outlined.Key,
-                        contentDescription = stringResource(
-                            if (bleKeyState == BleKeyState.IRK_AND_ENCRYPTED) R.string.signal_badge_key_encrypted_cd
-                            else R.string.signal_badge_key_irk_cd
-                        ),
-                        modifier = Modifier.size(12.dp),
-                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
-                    )
-                    Spacer(modifier = Modifier.width(3.dp))
-                }
-                if (isAapConnected) {
-                    Icon(
-                        imageVector = Icons.TwoTone.Bluetooth,
-                        contentDescription = stringResource(R.string.signal_badge_aap_cd),
-                        modifier = Modifier.size(12.dp),
-                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
-                    )
-                    Spacer(modifier = Modifier.width(3.dp))
-                }
+                if (isAapConnected) Spacer(modifier = Modifier.width(3.dp))
+            }
+            if (isAapConnected) {
                 Icon(
-                    imageVector = Icons.TwoTone.SettingsInputAntenna,
-                    contentDescription = null,
+                    imageVector = Icons.TwoTone.Bluetooth,
+                    contentDescription = stringResource(R.string.signal_badge_aap_cd),
                     modifier = Modifier.size(12.dp),
                     tint = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
-                Spacer(modifier = Modifier.width(3.dp))
-                Text(
-                    text = signalText,
-                    style = MaterialTheme.typography.labelSmall,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                )
             }
         }
     }
@@ -307,18 +367,36 @@ fun ConversationAwarenessToggle(
 
 @Preview2
 @Composable
-private fun SignalBadgeDefaultPreview() = PreviewWrapper {
-    SignalBadge(signalText = "85%")
+private fun DeviceConnectionBadgeIrkPreview() = PreviewWrapper {
+    DeviceConnectionBadge(bleKeyState = BleKeyState.IRK_ONLY, isAapConnected = false)
 }
 
 @Preview2
 @Composable
-private fun SignalBadgeIrkOnlyPreview() = PreviewWrapper {
-    SignalBadge(signalText = "85%", bleKeyState = BleKeyState.IRK_ONLY)
+private fun DeviceConnectionBadgeAllIconsPreview() = PreviewWrapper {
+    DeviceConnectionBadge(bleKeyState = BleKeyState.IRK_AND_ENCRYPTED, isAapConnected = true)
 }
 
 @Preview2
 @Composable
-private fun SignalBadgeAllIconsPreview() = PreviewWrapper {
-    SignalBadge(signalText = "85%", bleKeyState = BleKeyState.IRK_AND_ENCRYPTED, isAapConnected = true)
+private fun DeviceConnectionBadgeEmptyPreview() = PreviewWrapper {
+    DeviceConnectionBadge(bleKeyState = BleKeyState.NONE, isAapConnected = false)
+}
+
+@Preview2
+@Composable
+private fun SignalIndicatorPreviewsGroup() = PreviewWrapper {
+    Row(
+        horizontalArrangement = Arrangement.spacedBy(8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        SignalIndicator(signalQuality = 0.10f, isLive = true)
+        SignalIndicator(signalQuality = 0.35f, isLive = true)
+        SignalIndicator(signalQuality = 0.55f, isLive = true)
+        SignalIndicator(signalQuality = 0.75f, isLive = true)
+        SignalIndicator(signalQuality = 0.95f, isLive = true)
+        SignalIndicator(signalQuality = Float.NaN, isLive = true)
+        SignalIndicator(signalQuality = -0.3f, isLive = true)
+        SignalIndicator(signalQuality = 0.85f, isLive = false)
+    }
 }

app/src/main/java/eu/darken/capod/main/ui/overview/cards/SinglePodsCard.kt

@@ -47,7 +47,6 @@ import eu.darken.capod.common.compose.PreviewWrapper
 import eu.darken.capod.common.compose.preview.MockPodDataProvider
 import eu.darken.capod.monitor.core.PodDevice
 import eu.darken.capod.monitor.core.cachedBatteryFormatted
-import eu.darken.capod.monitor.core.getSignalQuality
 import eu.darken.capod.pods.core.apple.aap.protocol.AapSetting
 import eu.darken.capod.pods.core.apple.ble.formatBatteryPercent
 import java.time.Instant
@@ -101,13 +100,25 @@ fun SinglePodsCard(
                 Spacer(modifier = Modifier.width(8.dp))
 
                 Column(modifier = Modifier.weight(1f)) {
-                    Text(
-                        text = device.label ?: "?",
-                        style = MaterialTheme.typography.titleMedium,
-                        maxLines = 1,
-                        overflow = TextOverflow.Ellipsis,
-                    )
                     Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        verticalAlignment = Alignment.CenterVertically,
+                    ) {
+                        Text(
+                            text = device.label ?: "?",
+                            style = MaterialTheme.typography.titleMedium,
+                            maxLines = 1,
+                            overflow = TextOverflow.Ellipsis,
+                            modifier = Modifier.weight(1f, fill = false),
+                        )
+                        SignalIndicator(
+                            signalQuality = device.signalQuality,
+                            isLive = device.isLive,
+                            modifier = Modifier.padding(start = 6.dp),
+                        )
+                    }
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
                         verticalAlignment = Alignment.CenterVertically,
                     ) {
                         Text(
@@ -118,12 +129,10 @@ fun SinglePodsCard(
                             overflow = TextOverflow.Ellipsis,
                             modifier = Modifier.weight(1f, fill = false),
                         )
-                        Spacer(modifier = Modifier.width(6.dp))
-                        SignalBadge(
-                            signalText = device.getSignalQuality(context),
+                        DeviceConnectionBadge(
                             bleKeyState = device.bleKeyState,
                             isAapConnected = device.isAapConnected,
-                            isLive = device.isLive,
+                            modifier = Modifier.padding(start = 6.dp),
                         )
                     }
                 }

app/src/main/java/eu/darken/capod/main/ui/overview/cards/UnknownPodDeviceCard.kt

@@ -6,12 +6,7 @@ import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.width
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.twotone.SettingsInputAntenna
 import androidx.compose.material3.Card
-import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -19,13 +14,13 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import eu.darken.capod.R
 import eu.darken.capod.common.compose.Preview2
 import eu.darken.capod.common.compose.PreviewWrapper
 import eu.darken.capod.common.compose.preview.MockPodDataProvider
 import eu.darken.capod.monitor.core.PodDevice
-import eu.darken.capod.monitor.core.getSignalQuality
 import eu.darken.capod.pods.core.apple.ble.devices.ApplePods
 
 @Composable
@@ -43,7 +38,7 @@ fun UnknownPodDeviceCard(
         Column(
             modifier = Modifier.padding(16.dp),
         ) {
-            // Header with signal in top-right
+            // Header: label + signal indicator (sits right after the text)
             Row(
                 verticalAlignment = Alignment.CenterVertically,
                 modifier = Modifier.fillMaxWidth(),
@@ -51,20 +46,14 @@ fun UnknownPodDeviceCard(
                 Text(
                     text = device.getLabel(context),
                     style = MaterialTheme.typography.titleMedium,
-                    modifier = Modifier.weight(1f),
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                    modifier = Modifier.weight(1f, fill = false),
                 )
-
-                Text(
-                    text = device.getSignalQuality(context),
-                    style = MaterialTheme.typography.bodySmall,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                )
-                Spacer(modifier = Modifier.width(4.dp))
-                Icon(
-                    imageVector = Icons.TwoTone.SettingsInputAntenna,
-                    contentDescription = null,
-                    modifier = Modifier.size(16.dp),
-                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                SignalIndicator(
+                    signalQuality = device.signalQuality,
+                    isLive = device.isLive,
+                    modifier = Modifier.padding(start = 6.dp),
                 )
             }
 

app/src/main/java/eu/darken/capod/monitor/core/DeviceMonitorExtensions.kt

@@ -1,23 +1,16 @@
 package eu.darken.capod.monitor.core
 
-import android.content.Context
 import android.icu.text.RelativeDateTimeFormatter
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
 import java.time.Duration
 import java.time.Instant
-import kotlin.math.roundToInt
 
 fun DeviceMonitor.devicesWithProfiles(): Flow<List<PodDevice>> = devices
     .map { devices -> devices.filter { it.profileId != null } }
 
 fun DeviceMonitor.primaryDevice(): Flow<PodDevice?> = devicesWithProfiles().map { it.firstOrNull() }
 
-fun PodDevice.getSignalQuality(context: Context): String {
-    val multiplier = 100 * signalQuality
-    return "${multiplier.roundToInt()}%"
-}
-
 fun PodDevice.lastSeenFormatted(now: Instant): String {
     val lastAt = seenLastAt ?: return ""
     val formatter = RelativeDateTimeFormatter.getInstance()

app/src/main/java/eu/darken/capod/pods/core/apple/ble/PodDeviceExtensions.kt

@@ -18,11 +18,6 @@ fun formatBatteryPercent(context: Context, percent: Float?): String =
     percent?.let { "${(it * 100).roundToInt()}%" }
         ?: context.getString(R.string.general_value_not_available_label)
 
-fun BlePodSnapshot.getSignalQuality(context: Context): String {
-    val multiplier = 100 * signalQuality
-    return "${multiplier.roundToInt()}%"
-}
-
 @DrawableRes
 fun getBatteryDrawable(percent: Float?): Int = when {
     percent == null -> R.drawable.ic_baseline_battery_unknown_24

app/src/main/java/eu/darken/capod/reaction/ui/popup/PopUpContent.kt

@@ -12,8 +12,6 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.twotone.SignalCellularAlt
 import androidx.compose.material3.Button
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
@@ -34,8 +32,8 @@ import eu.darken.capod.R
 import eu.darken.capod.common.compose.Preview2
 import eu.darken.capod.common.compose.PreviewWrapper
 import eu.darken.capod.common.compose.preview.MockPodDataProvider
+import eu.darken.capod.main.ui.overview.cards.SignalIndicator
 import eu.darken.capod.monitor.core.PodDevice
-import eu.darken.capod.monitor.core.getSignalQuality
 import eu.darken.capod.pods.core.apple.PodModel
 import eu.darken.capod.pods.core.apple.ble.formatBatteryPercent
 import eu.darken.capod.pods.core.apple.ble.getBatteryDrawable
@@ -63,7 +61,7 @@ fun PopUpContent(
                     .padding(top = 20.dp, bottom = 16.dp),
                 horizontalAlignment = Alignment.CenterHorizontally,
             ) {
-                // Header: label + signal quality
+                // Header: label + signal indicator (sits right after the text)
                 Row(
                     modifier = Modifier.fillMaxWidth(),
                     verticalAlignment = Alignment.CenterVertically,
@@ -76,21 +74,11 @@ fun PopUpContent(
                         overflow = TextOverflow.Ellipsis,
                         modifier = Modifier.weight(1f, fill = false),
                     )
-
-                    val signalText = device.getSignalQuality(context)
-                    if (signalText.isNotBlank()) {
-                        Spacer(modifier = Modifier.width(4.dp))
-                        Icon(
-                            imageVector = Icons.TwoTone.SignalCellularAlt,
-                            contentDescription = null,
-                            modifier = Modifier.size(12.dp),
-                        )
-                        Spacer(modifier = Modifier.width(4.dp))
-                        Text(
-                            text = signalText,
-                            style = MaterialTheme.typography.labelSmall,
-                        )
-                    }
+                    SignalIndicator(
+                        signalQuality = device.signalQuality,
+                        isLive = device.isLive,
+                        modifier = Modifier.padding(start = 6.dp),
+                    )
                 }
 
                 Spacer(modifier = Modifier.height(16.dp))

app/src/main/res/values/strings.xml

@@ -273,6 +273,8 @@
     <string name="signal_badge_key_irk_cd">Identity verified</string>
     <string name="signal_badge_key_encrypted_cd">Encrypted connection</string>
     <string name="signal_badge_aap_cd">Direct connection active</string>
+    <string name="signal_indicator_bars_cd">Signal strength: %1$d of 4 bars</string>
+    <string name="signal_indicator_disconnected_cd">Signal: disconnected</string>
     <string name="pods_yours">Yours</string>
     <string name="headset_being_worn_label">Being worn</string>
     <string name="headset_not_being_worn_label">Not being worn</string>

app/src/test/java/eu/darken/capod/main/ui/overview/cards/SignalLevelTest.kt

@@ -0,0 +1,57 @@
+package eu.darken.capod.main.ui.overview.cards
+
+import io.kotest.matchers.shouldBe
+import org.junit.jupiter.api.Test
+import testhelpers.BaseTest
+
+class SignalLevelTest : BaseTest() {
+
+    @Test
+    fun `not live always returns DISCONNECTED regardless of quality`() {
+        signalLevelOf(signalQuality = 1.0f, isLive = false) shouldBe SignalLevel.DISCONNECTED
+        signalLevelOf(signalQuality = 0.5f, isLive = false) shouldBe SignalLevel.DISCONNECTED
+        signalLevelOf(signalQuality = 0.0f, isLive = false) shouldBe SignalLevel.DISCONNECTED
+        signalLevelOf(signalQuality = Float.NaN, isLive = false) shouldBe SignalLevel.DISCONNECTED
+    }
+
+    @Test
+    fun `exact boundaries map upward`() {
+        signalLevelOf(signalQuality = 0.20f, isLive = true) shouldBe SignalLevel.BARS_1
+        signalLevelOf(signalQuality = 0.40f, isLive = true) shouldBe SignalLevel.BARS_2
+        signalLevelOf(signalQuality = 0.60f, isLive = true) shouldBe SignalLevel.BARS_3
+        signalLevelOf(signalQuality = 0.80f, isLive = true) shouldBe SignalLevel.BARS_4
+    }
+
+    @Test
+    fun `just below boundaries fall into lower bucket`() {
+        signalLevelOf(signalQuality = 0.199f, isLive = true) shouldBe SignalLevel.BARS_0
+        signalLevelOf(signalQuality = 0.399f, isLive = true) shouldBe SignalLevel.BARS_1
+        signalLevelOf(signalQuality = 0.599f, isLive = true) shouldBe SignalLevel.BARS_2
+        signalLevelOf(signalQuality = 0.799f, isLive = true) shouldBe SignalLevel.BARS_3
+    }
+
+    @Test
+    fun `zero quality maps to BARS_0`() {
+        signalLevelOf(signalQuality = 0.0f, isLive = true) shouldBe SignalLevel.BARS_0
+    }
+
+    @Test
+    fun `full quality maps to BARS_4`() {
+        signalLevelOf(signalQuality = 1.0f, isLive = true) shouldBe SignalLevel.BARS_4
+    }
+
+    @Test
+    fun `non-finite live inputs fall back to BARS_0`() {
+        signalLevelOf(signalQuality = Float.NaN, isLive = true) shouldBe SignalLevel.BARS_0
+        signalLevelOf(signalQuality = Float.POSITIVE_INFINITY, isLive = true) shouldBe SignalLevel.BARS_0
+        signalLevelOf(signalQuality = Float.NEGATIVE_INFINITY, isLive = true) shouldBe SignalLevel.BARS_0
+    }
+
+    @Test
+    fun `out of range values are clamped`() {
+        signalLevelOf(signalQuality = -0.5f, isLive = true) shouldBe SignalLevel.BARS_0
+        signalLevelOf(signalQuality = -0.001f, isLive = true) shouldBe SignalLevel.BARS_0
+        signalLevelOf(signalQuality = 1.7f, isLive = true) shouldBe SignalLevel.BARS_4
+        signalLevelOf(signalQuality = 99f, isLive = true) shouldBe SignalLevel.BARS_4
+    }
+}