Implement player list

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/Netplay.kt

@@ -5,11 +5,17 @@ package org.dolphinemu.dolphinemu.features.netplay
 
 import androidx.annotation.Keep
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.asSharedFlow
+import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.withContext
 import org.dolphinemu.dolphinemu.features.netplay.model.ConnectionType
+import org.dolphinemu.dolphinemu.features.netplay.model.Player
 
 object Netplay {
     @Keep
@@ -27,6 +33,12 @@ object Netplay {
     private val _connectionErrors = Channel<String>(Channel.BUFFERED)
     val connectionErrors = _connectionErrors.receiveAsFlow()
 
+    private val _players = MutableSharedFlow<List<Player>>(
+        replay = 1,
+        onBufferOverflow = BufferOverflow.DROP_OLDEST
+    )
+    val players = _players.asSharedFlow().distinctUntilChanged()
+
     suspend fun join(): Boolean = withContext(Dispatchers.IO) {
         netPlayClientPointer = Join()
         val isConnected = netPlayClientPointer != 0L && isClientConnected()
@@ -48,6 +60,7 @@ object Netplay {
         releaseNetplayClient()
     }
 
+    @OptIn(ExperimentalCoroutinesApi::class)
     private fun releaseNetplayClient() {
         if (netPlayClientPointer != 0L) {
             ReleaseNetplayClient()
@@ -55,6 +68,7 @@ object Netplay {
         }
         _launchGame.flush()
         _connectionErrors.flush()
+        _players.resetReplayCache()
     }
 
     @JvmStatic
@@ -79,6 +93,11 @@ object Netplay {
         _connectionErrors.trySend(message)
     }
 
+    @JvmStatic
+    fun onUpdate(players: Array<Player>) {
+        _players.tryEmit(players.toList())
+    }
+
     // Settings
 
     @JvmStatic

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/NetplayViewModel.kt

@@ -3,11 +3,14 @@
 package org.dolphinemu.dolphinemu.features.netplay.model
 
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.Channel.Factory.CONFLATED
+import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import org.dolphinemu.dolphinemu.features.netplay.Netplay
 
@@ -17,6 +20,9 @@ class NetplayViewModel : ViewModel() {
     private val _goBack = Channel<Unit>(CONFLATED)
     val goBack = _goBack.receiveAsFlow()
 
+    val players = Netplay.players
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(), emptyList())
+
     init {
         if (!Netplay.isClientConnected()) {
             _goBack.trySend(Unit)

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/Player.kt

@@ -0,0 +1,13 @@
+// Copyright 2003 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package org.dolphinemu.dolphinemu.features.netplay.model
+
+data class Player(
+    val pid: Int,
+    val name: String,
+    val revision: String,
+    val ping: Int,
+    val isHost: Boolean,
+    val mapping: String,
+)

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplayActivity.kt

@@ -8,6 +8,7 @@ import android.os.Bundle
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.appcompat.app.AppCompatActivity
+import androidx.compose.runtime.collectAsState
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.flowWithLifecycle
@@ -15,7 +16,6 @@ import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import org.dolphinemu.dolphinemu.activities.EmulationActivity
-import org.dolphinemu.dolphinemu.features.netplay.Netplay
 import org.dolphinemu.dolphinemu.features.netplay.model.NetplayViewModel
 import org.dolphinemu.dolphinemu.ui.main.ThemeProvider
 import org.dolphinemu.dolphinemu.ui.theme.DolphinTheme
@@ -44,6 +44,7 @@ class NetplayActivity : AppCompatActivity(), ThemeProvider {
             DolphinTheme {
                 NetplayScreen(
                     onBackClicked = { finish() },
+                    players = viewModel.players.collectAsState().value,
                 )
             }
         }

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplayScreen.kt

@@ -2,23 +2,46 @@
 
 package org.dolphinemu.dolphinemu.features.netplay.ui
 
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.consumeWindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.MediumTopAppBar
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
 import org.dolphinemu.dolphinemu.R
+import org.dolphinemu.dolphinemu.features.netplay.model.Player
+import org.dolphinemu.dolphinemu.ui.theme.DolphinTheme
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun NetplayScreen(
     onBackClicked: () -> Unit,
+    players: List<Player>,
 ) {
     Scaffold(
         topBar = {
@@ -34,7 +57,81 @@ fun NetplayScreen(
                 },
             )
         },
-    ) { _ -> }
+    ) { innerPadding ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .consumeWindowInsets(innerPadding)
+                .verticalScroll(rememberScrollState())
+                .padding(innerPadding)
+                .padding(horizontal = DolphinTheme.scaffoldPadding)
+        ) {
+            PlayersTable(
+                rows = buildList {
+                    add(listOf("Player", "Ping", "Mapping"))
+                    addAll(players.map { listOf(it.name, it.ping.toString(), it.mapping) })
+                },
+                modifier = Modifier.fillMaxWidth()
+            )
+        }
+    }
+}
+
+/**
+ * A table arranged into columns sized to wrap the largest item. Except the
+ * first column which takes up the remaining space left by the other columns.
+ * The first row is treated as the column titles.
+ */
+@Composable
+private fun PlayersTable(
+    rows: List<List<String>>,
+    modifier: Modifier = Modifier,
+) {
+    rows.zipWithNext { a, b -> if (a.size != b.size) throw IllegalArgumentException("Rows must all contain the same number of elements.") }
+    val maxWidths = remember { List(rows.first().size) { mutableIntStateOf(0) } }
+    val density = LocalDensity.current
+
+    Column(
+        verticalArrangement = Arrangement.spacedBy(6.dp),
+        modifier = modifier
+    ) {
+        rows.forEachIndexed { rowIndex, row ->
+            Row(
+                horizontalArrangement = Arrangement.spacedBy(16.dp),
+            ) {
+                row.forEachIndexed { itemIndex, text ->
+                    Box(
+                        modifier = Modifier
+                            .then(
+                                when {
+                                    itemIndex == 0 -> Modifier.weight(1f)
+
+                                    maxWidths[itemIndex].intValue > 0 -> Modifier
+                                        .width(with(density) { maxWidths[itemIndex].intValue.toDp() })
+
+                                    else -> Modifier
+                                }
+                            )
+                            .onGloballyPositioned { coordinates ->
+                                val width = coordinates.size.width
+                                if (width > maxWidths[itemIndex].intValue) {
+                                    maxWidths[itemIndex].intValue = width
+                                }
+                            }
+                    ) {
+                        Text(
+                            text = text,
+                            fontWeight = if (rowIndex == 0) FontWeight.Medium else FontWeight.Normal,
+                            style = MaterialTheme.typography.bodyMedium,
+                        )
+                    }
+                }
+            }
+            if (rowIndex == 0) {
+                HorizontalDivider()
+            }
+        }
+    }
 }
 
 @Preview
@@ -42,5 +139,23 @@ fun NetplayScreen(
 private fun NetplayScreenPreview() {
     NetplayScreen(
         onBackClicked = {},
+        players = listOf(
+            Player(
+                pid = 1,
+                name = "Player 1",
+                revision = "123",
+                ping = 2,
+                isHost = true,
+                mapping = "m1"
+            ),
+            Player(
+                pid = 2,
+                name = "Player 2",
+                revision = "123",
+                ping = 23,
+                isHost = false,
+                mapping = "m2"
+            ),
+        ),
     )
-}
+}