Complete the Protocol Descriptor as the single home for per-protocol knowledge

sharingan/src/commonMain/kotlin/dev/sharingan/SharinganExport.kt

@@ -2,6 +2,7 @@ package dev.sharingan
 
 import dev.sharingan.internal.formatClockTime
 import dev.sharingan.ui.descriptorOf
+import dev.sharingan.ui.protocolCountsLine
 
 /**
  * Turns captured events into shareable text.
@@ -78,12 +79,8 @@ public object SharinganExport {
 
     // ── session assembly ─────────────────────────────────────────
 
-    private fun countsLine(events: List<SharinganEvent>): String {
-        val http = events.count { it is HttpEvent }
-        val mqtt = events.count { it is MqttEvent }
-        val ble = events.count { it is BleEvent }
-        return "${events.size} events · HTTP $http · MQTT $mqtt · BLE $ble"
-    }
+    private fun countsLine(events: List<SharinganEvent>): String =
+        "${events.size} events · ${protocolCountsLine(events)}"
 
     private fun eventJson(event: SharinganEvent, indent: String): String {
         val fields = mutableListOf<Pair<String, String>>()

sharingan/src/commonMain/kotlin/dev/sharingan/internal/NotificationContent.kt

@@ -1,9 +1,8 @@
 package dev.sharingan.internal
 
 import dev.sharingan.SharinganEvent
-import dev.sharingan.ui.Protocol
 import dev.sharingan.ui.descriptorOf
-import dev.sharingan.ui.protocolOf
+import dev.sharingan.ui.protocolCountsLine
 
 /**
  * What the capture notification should say — the platform-free half of the
@@ -29,9 +28,7 @@ internal fun notificationContentOf(
 ): NotificationContent? {
     if (events.isEmpty()) return null
     val stateLabel = if (recording) "Capturing" else "Paused"
-    val countsLine = Protocol.entries.joinToString(" · ") { protocol ->
-        "${protocol.name} ${events.count { protocolOf(it) == protocol }}"
-    }
+    val countsLine = protocolCountsLine(events)
     val ticker = events.takeLast(3).reversed().joinToString("\n") { descriptorOf(it).tickerLine(it) }
     return NotificationContent(
         title = "Sharingan — $stateLabel · ${events.size} events",

sharingan/src/commonMain/kotlin/dev/sharingan/ui/BleDescriptor.kt

@@ -1,6 +1,7 @@
 package dev.sharingan.ui
 
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.vector.ImageVector
 import dev.sharingan.BleEvent
 import dev.sharingan.BleOperation
 import dev.sharingan.formatBytes
@@ -11,6 +12,8 @@ internal object BleDescriptor : ProtocolDescriptor<BleEvent>() {
 
     override val protocol: Protocol = Protocol.BLE
     override val eventNoun: String = "operations"
+    override val tabIcon: ImageVector = SharinganIcons.Bluetooth
+    override val searchPlaceholder: String = "Filter characteristic, device…"
 
     override val chips: List<FilterChipSpec> = listOf(
         FilterChipSpec("all", "All"),

sharingan/src/commonMain/kotlin/dev/sharingan/ui/EventFilter.kt

@@ -18,6 +18,14 @@ internal data class FilterChipSpec(val key: String, val label: String)
 
 internal fun protocolOf(event: SharinganEvent): Protocol = descriptorOf(event).protocol
 
+/** `HTTP n · MQTT n · BLE n` — one segment per protocol, in tab order. The
+ *  single home for the cross-protocol counts line shared by the export header
+ *  and the capture notification. */
+internal fun protocolCountsLine(events: List<SharinganEvent>): String =
+    Protocol.entries.joinToString(" · ") { protocol ->
+        "${protocol.name} ${events.count { protocolOf(it) == protocol }}"
+    }
+
 /** The design's per-protocol chip rows. */
 internal fun chipsFor(protocol: Protocol): List<FilterChipSpec> = descriptorOf(protocol).chips
 

sharingan/src/commonMain/kotlin/dev/sharingan/ui/HomeScreen.kt

@@ -190,11 +190,7 @@ private fun TabBar(
     Row(Modifier.fillMaxWidth()) {
         Protocol.entries.forEach { protocol ->
             val on = protocol == selected
-            val icon = when (protocol) {
-                Protocol.HTTP -> SharinganIcons.Globe
-                Protocol.MQTT -> SharinganIcons.Waves
-                Protocol.BLE -> SharinganIcons.Bluetooth
-            }
+            val icon = descriptorOf(protocol).tabIcon
             Column(
                 Modifier.weight(1f).clickable { onSelect(protocol) },
                 horizontalAlignment = Alignment.CenterHorizontally,
@@ -255,11 +251,7 @@ private fun SearchField(
     modifier: Modifier = Modifier,
 ) {
     val colors = LocalSharinganColors.current
-    val placeholder = when (protocol) {
-        Protocol.HTTP -> "Filter path, status, header…"
-        Protocol.MQTT -> "Filter topic, payload…"
-        Protocol.BLE -> "Filter characteristic, device…"
-    }
+    val placeholder = descriptorOf(protocol).searchPlaceholder
     Row(
         modifier
             .fillMaxWidth()

sharingan/src/commonMain/kotlin/dev/sharingan/ui/HttpDescriptor.kt

@@ -19,6 +19,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
@@ -32,6 +33,8 @@ internal object HttpDescriptor : ProtocolDescriptor<HttpEvent>() {
 
     override val protocol: Protocol = Protocol.HTTP
     override val eventNoun: String = "requests"
+    override val tabIcon: ImageVector = SharinganIcons.Globe
+    override val searchPlaceholder: String = "Filter path, status, header…"
 
     override val chips: List<FilterChipSpec> = listOf(
         FilterChipSpec("all", "All"),

sharingan/src/commonMain/kotlin/dev/sharingan/ui/MqttDescriptor.kt

@@ -1,6 +1,7 @@
 package dev.sharingan.ui
 
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.vector.ImageVector
 import dev.sharingan.MqttDirection
 import dev.sharingan.MqttEvent
 import dev.sharingan.formatBytes
@@ -12,6 +13,8 @@ internal object MqttDescriptor : ProtocolDescriptor<MqttEvent>() {
 
     override val protocol: Protocol = Protocol.MQTT
     override val eventNoun: String = "messages"
+    override val tabIcon: ImageVector = SharinganIcons.Waves
+    override val searchPlaceholder: String = "Filter topic, payload…"
 
     override val chips: List<FilterChipSpec> = listOf(
         FilterChipSpec("all", "All"),

sharingan/src/commonMain/kotlin/dev/sharingan/ui/ProtocolDescriptor.kt

@@ -1,6 +1,7 @@
 package dev.sharingan.ui
 
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.vector.ImageVector
 import dev.sharingan.BleEvent
 import dev.sharingan.HttpEvent
 import dev.sharingan.MqttEvent
@@ -34,6 +35,12 @@ internal abstract class ProtocolDescriptor<E : SharinganEvent> {
     /** Quick-filter chips below the search field, in design order. */
     abstract val chips: List<FilterChipSpec>
 
+    /** Tab-bar icon for this protocol's tab. */
+    abstract val tabIcon: ImageVector
+
+    /** Placeholder hint shown in the search field on this protocol's tab. */
+    abstract val searchPlaceholder: String
+
     /** Chip matching; `"all"` is handled by the caller before dispatch. */
     protected abstract fun chipMatches(event: E, chipKey: String): Boolean
 

sharingan/src/commonTest/kotlin/dev/sharingan/ui/EventFilterTest.kt

@@ -5,6 +5,7 @@ import dev.sharingan.BleOperation
 import dev.sharingan.HttpEvent
 import dev.sharingan.MqttDirection
 import dev.sharingan.MqttEvent
+import dev.sharingan.SharinganEvent
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
@@ -87,6 +88,24 @@ internal class EventFilterTest {
         assertTrue(matchesQuery(http(), "   "))
     }
 
+    @Test
+    fun `Given a mix of events When the counts line is built Then it shows per-protocol counts`() {
+        val events: List<SharinganEvent> =
+            listOf(http(), http(), mqtt(MqttDirection.PUBLISH), ble(BleOperation.NOTIFY))
+        assertEquals("HTTP 2 · MQTT 1 · BLE 1", protocolCountsLine(events))
+    }
+
+    @Test
+    fun `When the counts line is built Then it has one segment for every protocol`() {
+        val events: List<SharinganEvent> =
+            listOf(http(), mqtt(MqttDirection.PUBLISH), ble(BleOperation.NOTIFY))
+        val line = protocolCountsLine(events)
+        assertEquals(Protocol.entries.size, line.split(" · ").size)
+        for (p in Protocol.entries) {
+            assertTrue(line.contains(p.name))
+        }
+    }
+
     @Test
     fun `When chips for a protocol are requested Then they match the design`() {
         assertEquals(listOf("all", "err", "2xx", "get", "post"), chipsFor(Protocol.HTTP).map { it.key })