app/src/main/java/com/runicgateway/app/data/api/dto/RustDto.kt

@@ -176,6 +176,20 @@ data class RustLeaderboardRowDto(
     val structures: Int = 0,
     val playtimeSec: Long = 0,
     val lastSeen: String? = null,
+    /**
+     * The chat titles this player holds now (module-rust phase 17, M19) — the
+     * ones the game shows in chat, after the server's mode. They rank the
+     * CURRENT wipe whichever wipe the board is showing. Absent from an older
+     * module, which is why it defaults to empty: nothing is drawn.
+     */
+    val titles: List<RustTitleDto> = emptyList(),
+)
+
+/** One chat title: its text, and the operator's `#rrggbb` colour for it. */
+@Serializable
+data class RustTitleDto(
+    val text: String = "",
+    val color: String = "",
 )
 
 /** `GET /public/rust/servers/{id}/wipes` — every wipe this server has had, newest first. */

app/src/main/java/com/runicgateway/app/ui/rust/RustFormat.kt

@@ -175,3 +175,31 @@ fun shortSteamId(steamId: String?): String {
  */
 fun playerLabel(name: String?, steamId: String?): String =
     name?.takeIf { it.isNotBlank() } ?: shortSteamId(steamId)
+
+/**
+ * A chat title's `#rrggbb` colour as opaque ARGB, or null for anything else —
+ * a title with a colour this build cannot read is drawn in the theme's own chip
+ * colours rather than guessed at (M19).
+ */
+fun titleArgb(hex: String?): Long? {
+    val m = Regex("^#([0-9a-fA-F]{6})$").find(hex.orEmpty()) ?: return null
+    return 0xFF000000L or m.groupValues[1].toLong(16)
+}
+
+/**
+ * Whether a title chip of this colour needs DARK ink — the same rule as the
+ * website's `contrastInk`: black or white, whichever has the higher WCAG
+ * contrast. The colour is the operator's, chosen for a dark game chat, and the
+ * app draws in the reader's theme, so the colour becomes the chip and the ink is
+ * picked for it.
+ */
+fun titleInkIsDark(argb: Long): Boolean {
+    fun linear(channel: Long): Double {
+        val v = channel / 255.0
+        return if (v <= 0.03928) v / 12.92 else Math.pow((v + 0.055) / 1.055, 2.4)
+    }
+    val l = 0.2126 * linear((argb shr 16) and 0xFF) +
+        0.7152 * linear((argb shr 8) and 0xFF) +
+        0.0722 * linear(argb and 0xFF)
+    return (l + 0.05) / 0.05 >= 1.05 / (l + 0.05)
+}

app/src/main/java/com/runicgateway/app/ui/rust/RustServerScreen.kt

@@ -3,10 +3,13 @@
  */
 package com.runicgateway.app.ui.rust
 
+import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.horizontalScroll
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
@@ -15,6 +18,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.FilterChip
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ScrollableTabRow
@@ -25,6 +29,8 @@ import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
@@ -38,6 +44,7 @@ import com.runicgateway.app.data.api.dto.RustEventListDto
 import com.runicgateway.app.data.api.dto.RustLeaderboardRowDto
 import com.runicgateway.app.data.api.dto.RustOnlineDto
 import com.runicgateway.app.data.api.dto.RustServerDto
+import com.runicgateway.app.data.api.dto.RustTitleDto
 import com.runicgateway.app.data.api.dto.RustWipeDto
 import com.runicgateway.app.ui.ErrorKind
 import com.runicgateway.app.ui.PollWhileResumed
@@ -392,6 +399,7 @@ private val RUST_COLUMNS = listOf(
     RustColumn(R.string.rust_col_played, RustSort.PLAYTIME) { playtime(it.playtimeSec) },
 )
 
+@OptIn(ExperimentalLayoutApi::class)
 @Composable
 private fun LeaderboardPanel(
     state: UiState<List<RustLeaderboardRowDto>>,
@@ -452,13 +460,25 @@ private fun LeaderboardPanel(
                         // Five numeric columns beside an equal-weight name column
                         // left "Brannock" touching its own kill count, which the
                         // walk read as one field.
-                        Text(
-                            text = playerLabel(row.name, row.steamId),
-                            style = MaterialTheme.typography.bodyMedium,
-                            maxLines = 1,
-                            overflow = TextOverflow.Ellipsis,
-                            modifier = Modifier.weight(NAME_WEIGHT).padding(end = 8.dp),
-                        )
+                        Column(Modifier.weight(NAME_WEIGHT).padding(end = 8.dp)) {
+                            Text(
+                                text = playerLabel(row.name, row.steamId),
+                                style = MaterialTheme.typography.bodyMedium,
+                                maxLines = 1,
+                                overflow = TextOverflow.Ellipsis,
+                            )
+                            // M19: the chat titles this player holds now, under the
+                            // name — the column is too narrow to put them beside it.
+                            if (row.titles.isNotEmpty()) {
+                                FlowRow(
+                                    Modifier.padding(top = 2.dp),
+                                    horizontalArrangement = Arrangement.spacedBy(4.dp),
+                                    verticalArrangement = Arrangement.spacedBy(2.dp),
+                                ) {
+                                    row.titles.forEach { title -> TitleChip(title) }
+                                }
+                            }
+                        }
                         RUST_COLUMNS.forEach { column ->
                             Text(
                                 text = column.value(row),
@@ -475,6 +495,33 @@ private fun LeaderboardPanel(
     }
 }
 
+/**
+ * One chat title (M19): the operator's colour as the chip, and black or white
+ * ink chosen for it, as the website draws it. A colour this build cannot read
+ * falls back to the theme's own chip colours.
+ */
+@Composable
+private fun TitleChip(title: RustTitleDto) {
+    val argb = titleArgb(title.color)
+    val background = argb?.let { Color(it) } ?: MaterialTheme.colorScheme.secondaryContainer
+    val ink = when {
+        argb == null -> MaterialTheme.colorScheme.onSecondaryContainer
+        titleInkIsDark(argb) -> Color.Black
+        else -> Color.White
+    }
+    Text(
+        text = title.text,
+        style = MaterialTheme.typography.labelSmall,
+        color = ink,
+        maxLines = 1,
+        overflow = TextOverflow.Ellipsis,
+        modifier = Modifier
+            .clip(RoundedCornerShape(50))
+            .background(background)
+            .padding(horizontal = 6.dp, vertical = 1.dp),
+    )
+}
+
 // ── Online ────────────────────────────────────────────────────────────────
 
 @Composable

app/src/test/java/com/runicgateway/app/ui/rust/RustDtoTest.kt

@@ -4,6 +4,7 @@
 package com.runicgateway.app.ui.rust
 
 import com.runicgateway.app.data.api.dto.RustEventDto
+import com.runicgateway.app.data.api.dto.RustLeaderboardDto
 import com.runicgateway.app.data.api.dto.RustServerListDto
 import kotlinx.serialization.json.Json
 import org.junit.Assert.assertEquals
@@ -121,4 +122,28 @@ class RustDtoTest {
         assertNull(b.nextWipe)
         assertNull(c.nextWipe)
     }
+
+    @Test
+    fun `a leaderboard row carries its chat titles, and an older module's carries none`() {
+        // M19. The shape is module-rust's `listLeaderboard`: `titles` on every
+        // row, empty for a player with none; absent altogether from a module
+        // older than phase 17, which must decode to empty rather than fail.
+        val board = json.decodeFromString<RustLeaderboardDto>(
+            """
+            {"leaderboard":[
+              {"steamId":"1","name":"Brannock","kills":12,"deaths":3,"npcKills":0,"structures":0,"playtimeSec":3600,
+               "titles":[{"text":"Top Killer","color":"#ff8800"},{"text":"Regular","color":"#00aa55"}]},
+              {"steamId":"2","name":"Wren","kills":1,"deaths":0,"npcKills":0,"structures":0,"playtimeSec":60,"titles":[]}
+            ]}
+            """.trimIndent(),
+        )
+        assertEquals(listOf("Top Killer", "Regular"), board.leaderboard[0].titles.map { it.text })
+        assertEquals("#ff8800", board.leaderboard[0].titles[0].color)
+        assertTrue(board.leaderboard[1].titles.isEmpty())
+
+        val older = json.decodeFromString<RustLeaderboardDto>(
+            """{"leaderboard":[{"steamId":"1","name":"Brannock","kills":12}]}""",
+        )
+        assertTrue(older.leaderboard.single().titles.isEmpty())
+    }
 }

app/src/test/java/com/runicgateway/app/ui/rust/RustFormatTest.kt

@@ -4,6 +4,7 @@
 package com.runicgateway.app.ui.rust
 
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
 import org.junit.Assert.assertNull
 import org.junit.Assert.assertTrue
 import org.junit.Test
@@ -153,4 +154,19 @@ class RustFormatTest {
         assertNull(nextWipeWhen(null, now, utc, uk))
         assertNull(nextWipeWhen("soon", now, utc, uk))
     }
+
+    @Test
+    fun `a title colour is read only as #rrggbb, and its ink is whichever reads`() {
+        assertEquals(0xFFFFAA55L, titleArgb("#ffaa55"))
+        assertEquals(0xFFFFAA55L, titleArgb("#FFAA55"))
+        assertNull(titleArgb("red"))
+        assertNull(titleArgb(null))
+
+        // The same four the website's contrastInk test asserts, so the two
+        // clients draw a title the same way.
+        assertTrue(titleInkIsDark(titleArgb("#ffff00")!!))
+        assertTrue(titleInkIsDark(titleArgb("#ffaa55")!!))
+        assertTrue(titleInkIsDark(titleArgb("#ff0000")!!))
+        assertFalse(titleInkIsDark(titleArgb("#1a1a8c")!!))
+    }
 }