Add offline-mode protocol adapters, session manager, UI connect flow and launcher branding

README.md

@@ -12,8 +12,9 @@ Implemented now:
 
 - Kotlin + Jetpack Compose Android project,
 - dark crimson / neon design system,
+- branded launcher, adaptive and in-app logo assets,
 - saved server browser,
-- direct offline-mode connection using Minecraft Java 1.8.x protocol 47,
+- direct offline-mode connection using Minecraft Java 26.1 protocol 775,
 - chat and command surface,
 - online player list,
 - settings screen,
@@ -24,10 +25,10 @@ Implemented now:
 - GitHub Actions Android CI,
 - repository guidance in `AGENTS.md`.
 
-The first networking slice supports direct TCP login to an offline-mode server using
-Minecraft Java 1.8.x protocol 47, compression negotiation, keep-alive replies and the
-initial position acknowledgement. Modern servers need a compatibility layer such as
-ViaVersion until a current protocol adapter is implemented.
+The default networking adapter supports direct TCP login to an offline-mode server using
+Minecraft Java 26.1 protocol 775, including the login, configuration and play states,
+compression negotiation, keep-alive replies and position acknowledgement. The older
+protocol 47 adapter remains isolated for later explicit version selection.
 
 The client sends only the selected nickname. In offline mode the server or proxy owns
 identity assignment and returns the UUID during login; CraftConnect does not allow an

app/src/main/AndroidManifest.xml

@@ -3,7 +3,9 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <application
         android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.CraftConnect">
         <activity

app/src/main/java/pl/syntaxdevteam/craftconnect/CraftConnectApp.kt

@@ -37,6 +37,7 @@ fun CraftConnectApp(sessionManagerFactory: SessionManagerFactory) {
     var activeServer by remember { mutableStateOf<ServerProfile?>(null) }
     var sessionManager by remember { mutableStateOf<SessionManager?>(null) }
     var connectionState by remember { mutableStateOf(ConnectionState.DISCONNECTED) }
+    var connectionError by remember { mutableStateOf<String?>(null) }
     val coroutineScope = rememberCoroutineScope()
 
     CraftBackground {
@@ -55,13 +56,16 @@ fun CraftConnectApp(sessionManagerFactory: SessionManagerFactory) {
                 when (destination) {
                     AppDestination.Servers -> ServersScreen(
                         connectionState = connectionState,
+                        connectionError = connectionError,
                         onConnect = { server, username ->
                             coroutineScope.launch {
                                 val manager = sessionManagerFactory.create()
                                 sessionManager = manager
                                 connectionState = ConnectionState.CONNECTING
+                                connectionError = null
                                 manager.connect(server, username)
                                 connectionState = manager.session.value.connectionState
+                                connectionError = manager.session.value.lastError?.serverMessage
                                 if (connectionState == ConnectionState.CONNECTED) {
                                     activeServer = server.copy(online = true)
                                     destination = AppDestination.Chat

app/src/main/java/pl/syntaxdevteam/craftconnect/data/session/DefaultSessionManager.kt

@@ -105,7 +105,7 @@ class DefaultSessionManager(
 }
 
 private fun MinecraftConnectionException.toSessionError(): SessionError = when (this) {
-    is MinecraftConnectionException.Network -> SessionError.Network(diagnosticCode)
-    is MinecraftConnectionException.Authentication -> SessionError.Authentication(diagnosticCode)
-    is MinecraftConnectionException.Protocol -> SessionError.Protocol(diagnosticCode)
+    is MinecraftConnectionException.Network -> SessionError.Network(diagnosticCode, serverMessage)
+    is MinecraftConnectionException.Authentication -> SessionError.Authentication(diagnosticCode, serverMessage)
+    is MinecraftConnectionException.Protocol -> SessionError.Protocol(diagnosticCode, serverMessage)
 }

app/src/main/java/pl/syntaxdevteam/craftconnect/data/session/DefaultSessionManagerFactory.kt

@@ -2,8 +2,8 @@ package pl.syntaxdevteam.craftconnect.data.session
 
 import pl.syntaxdevteam.craftconnect.domain.session.SessionManager
 import pl.syntaxdevteam.craftconnect.domain.session.SessionManagerFactory
-import pl.syntaxdevteam.craftconnect.protocol.legacy.LegacyOfflineMinecraftConnection
+import pl.syntaxdevteam.craftconnect.protocol.modern.ModernOfflineMinecraftConnection
 
 class DefaultSessionManagerFactory : SessionManagerFactory {
-    override fun create(): SessionManager = DefaultSessionManager(LegacyOfflineMinecraftConnection())
+    override fun create(): SessionManager = DefaultSessionManager(ModernOfflineMinecraftConnection())
 }

app/src/main/java/pl/syntaxdevteam/craftconnect/domain/session/SessionModels.kt

@@ -25,11 +25,27 @@ data class SessionSnapshot(
 
 sealed interface SessionError {
     val diagnosticCode: String
+    val serverMessage: String?
 
-    data class Network(override val diagnosticCode: String) : SessionError
-    data class Authentication(override val diagnosticCode: String) : SessionError
-    data class Protocol(override val diagnosticCode: String) : SessionError
-    data class Disconnected(override val diagnosticCode: String) : SessionError
+    data class Network(
+        override val diagnosticCode: String,
+        override val serverMessage: String? = null,
+    ) : SessionError
+
+    data class Authentication(
+        override val diagnosticCode: String,
+        override val serverMessage: String? = null,
+    ) : SessionError
+
+    data class Protocol(
+        override val diagnosticCode: String,
+        override val serverMessage: String? = null,
+    ) : SessionError
+
+    data class Disconnected(
+        override val diagnosticCode: String,
+        override val serverMessage: String? = null,
+    ) : SessionError
 }
 
 sealed interface SessionEvent {

app/src/main/java/pl/syntaxdevteam/craftconnect/protocol/MinecraftConnection.kt

@@ -21,9 +21,11 @@ interface MinecraftConnection {
 
 sealed class MinecraftConnectionException(
     val diagnosticCode: String,
+    val serverMessage: String? = null,
     cause: Throwable? = null,
 ) : Exception(diagnosticCode, cause) {
-    class Network(code: String, cause: Throwable? = null) : MinecraftConnectionException(code, cause)
-    class Authentication(code: String, cause: Throwable? = null) : MinecraftConnectionException(code, cause)
-    class Protocol(code: String, cause: Throwable? = null) : MinecraftConnectionException(code, cause)
+    class Network(code: String, cause: Throwable? = null) : MinecraftConnectionException(code, cause = cause)
+    class Authentication(code: String, serverMessage: String? = null) :
+        MinecraftConnectionException(code, serverMessage)
+    class Protocol(code: String, cause: Throwable? = null) : MinecraftConnectionException(code, cause = cause)
 }

app/src/main/java/pl/syntaxdevteam/craftconnect/protocol/legacy/LegacyOfflineMinecraftConnection.kt

@@ -57,6 +57,7 @@ class LegacyOfflineMinecraftConnection(
             })
             val session = awaitLoginSuccess()
             connectedSocket.soTimeout = 0
+            sendClientIdentity()
             readerJob = scope.launch { playLoop() }
             session
         } catch (failure: MinecraftConnectionException) {
@@ -102,8 +103,8 @@ class LegacyOfflineMinecraftConnection(
             val packetInput = readPacket(requireInput(), compressionThreshold)
             when (val packetId = packetInput.readVarInt()) {
                 LOGIN_DISCONNECT_PACKET -> {
-                    packetInput.readProtocolString(MAX_JSON_LENGTH)
-                    throw MinecraftConnectionException.Authentication("login_rejected")
+                    val reason = packetInput.readProtocolString(MAX_JSON_LENGTH).minecraftText()
+                    throw MinecraftConnectionException.Authentication("login_rejected", reason)
                 }
                 LOGIN_SUCCESS_PACKET -> return ConnectedSession(
                     protocolVersion = PROTOCOL_VERSION,
@@ -124,7 +125,7 @@ class LegacyOfflineMinecraftConnection(
             while (open.get()) {
                 val packetInput = readPacket(requireInput(), compressionThreshold)
                 when (packetInput.readVarInt()) {
-                    CLIENTBOUND_KEEP_ALIVE_PACKET -> respondToKeepAlive(packetInput.readInt())
+                    CLIENTBOUND_KEEP_ALIVE_PACKET -> respondToKeepAlive(packetInput.readVarInt())
                     CLIENTBOUND_POSITION_PACKET -> respondToPosition(packetInput)
                     CLIENTBOUND_DISCONNECT_PACKET -> {
                         packetInput.readProtocolString(MAX_JSON_LENGTH)
@@ -140,7 +141,23 @@ class LegacyOfflineMinecraftConnection(
     private fun respondToKeepAlive(id: Int) {
         sendPacket(packet {
             writeVarInt(SERVERBOUND_KEEP_ALIVE_PACKET)
-            writeInt(id)
+            writeVarInt(id)
+        })
+    }
+
+    private fun sendClientIdentity() {
+        sendPacket(packet {
+            writeVarInt(SERVERBOUND_CLIENT_SETTINGS_PACKET)
+            writeProtocolString("en_US")
+            writeByte(2)
+            writeByte(0)
+            writeBoolean(true)
+            writeByte(0x7F)
+        })
+        sendPacket(packet {
+            writeVarInt(SERVERBOUND_CUSTOM_PAYLOAD_PACKET)
+            writeProtocolString("MC|Brand")
+            writeProtocolString("CraftConnect")
         })
     }
 
@@ -237,6 +254,8 @@ class LegacyOfflineMinecraftConnection(
         const val SERVERBOUND_KEEP_ALIVE_PACKET = 0x00
         const val SERVERBOUND_CHAT_PACKET = 0x01
         const val SERVERBOUND_POSITION_LOOK_PACKET = 0x06
+        const val SERVERBOUND_CLIENT_SETTINGS_PACKET = 0x15
+        const val SERVERBOUND_CUSTOM_PAYLOAD_PACKET = 0x17
         const val RELATIVE_X = 0x01
         const val RELATIVE_Y = 0x02
         const val RELATIVE_Z = 0x04
@@ -245,3 +264,13 @@ class LegacyOfflineMinecraftConnection(
         val USERNAME = Regex("[A-Za-z0-9_]{3,16}")
     }
 }
+
+private fun String.minecraftText(): String {
+    val text = Regex("\"text\"\\s*:\\s*\"((?:\\\\.|[^\"\\\\])*)\"").find(this)?.groupValues?.get(1)
+        ?: return take(512)
+    return text
+        .replace("\\n", "\n")
+        .replace("\\\"", "\"")
+        .replace("\\\\", "\\")
+        .take(512)
+}