Further improve the chat page

app/build.gradle.kts

@@ -57,6 +57,7 @@ dependencies {
     implementation(libs.hilt.android)
     implementation(libs.retrofit)
     implementation(libs.retrofit.converter.gson)
+    implementation(libs.androidx.material3.window.size.class1)
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)

app/src/main/AndroidManifest.xml

@@ -13,12 +13,14 @@
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/Theme.ChatApp" >
+        android:theme="@style/Theme.ChatApp"
+        android:enableOnBackInvokedCallback="true">
         <activity
             android:name=".activity.chat.ChatActivity"
             android:exported="true"
             android:label="@string/title_activity_chat"
-            android:theme="@style/Theme.ChatApp" >
+            android:theme="@style/Theme.ChatApp"
+            android:windowSoftInputMode="adjustNothing">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

app/src/main/java/eu/m724/chatapp/activity/chat/ChatActivity.kt

@@ -8,10 +8,12 @@ import androidx.activity.enableEdgeToEdge
 import androidx.activity.viewModels
 import androidx.compose.animation.animateColorAsState
 import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -20,6 +22,7 @@ import androidx.compose.foundation.layout.imePadding
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.foundation.shape.RoundedCornerShape
@@ -31,132 +34,362 @@ import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.IconButtonDefaults
+import androidx.compose.material3.LocalTextStyle
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
-import androidx.compose.material3.TextField
+import androidx.compose.material3.windowsizeclass.ExperimentalMaterial3WindowSizeClassApi
-import androidx.compose.material3.TextFieldDefaults
+import androidx.compose.material3.windowsizeclass.WindowSizeClass
+import androidx.compose.material3.windowsizeclass.WindowWidthSizeClass
+import androidx.compose.material3.windowsizeclass.calculateWindowSizeClass
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.rememberCoroutineScope
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
-import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalSoftwareKeyboardController
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import dagger.hilt.android.AndroidEntryPoint
-import eu.m724.chatapp.activity.chat.compose.AnimatedChangingText
+import eu.m724.chatapp.activity.chat.ChatState.Companion.rememberChatState
-import eu.m724.chatapp.activity.chat.compose.LanguageModelMistakeWarning
+import eu.m724.chatapp.activity.chat.composable.AnimatedChangingText
+import eu.m724.chatapp.activity.chat.composable.LanguageModelMistakeWarning
+import eu.m724.chatapp.activity.chat.composable.NestedScrollKeyboardHider
+import eu.m724.chatapp.activity.chat.composable.SimpleTextFieldWithPadding
+import eu.m724.chatapp.activity.chat.composable.disableBringIntoViewOnFocus
 import eu.m724.chatapp.activity.ui.theme.ChatAppTheme
+import eu.m724.chatapp.api.data.ChatMessage
+import kotlinx.coroutines.launch
 
 @AndroidEntryPoint
 class ChatActivity : ComponentActivity() {
     private val viewModel: ChatActivityViewModel by viewModels()
 
+    @OptIn(ExperimentalMaterial3WindowSizeClassApi::class)
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
         enableEdgeToEdge()
         setContent {
-            Content(viewModel)
+            val windowSizeClass = calculateWindowSizeClass(this)
+            val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+            val softwareKeyboardController = LocalSoftwareKeyboardController.current
+            val context = LocalContext.current
+            val coroutineScope = rememberCoroutineScope()
+
+            val chatState = rememberChatState(
+                requestInProgress = uiState.requestInProgress,
+                onSend = { message ->
+                    viewModel.sendMessage(message)
+                }
+            )
+
+            val threadViewLazyListState = rememberLazyListState()
+
+            ChatScreen(
+                windowSizeClass = windowSizeClass,
+                uiState = uiState,
+                chatState = chatState,
+                threadViewLazyListState = threadViewLazyListState,
+                onRequestFocus = {
+                    coroutineScope.launch {
+                        if (threadViewLazyListState.layoutInfo.visibleItemsInfo.find { it.key == "composer" } == null) {
+                            if (uiState.messages.isNotEmpty()) {
+                                threadViewLazyListState.animateScrollToItem(uiState.messages.size)
+                            }
+                        }
+
+                        chatState.requestFocus()
+                        softwareKeyboardController?.show()
+                    }
+                }
+            )
+
+            LaunchedEffect(Unit) {
+                viewModel.uiEvents.collect { event ->
+                    when (event) {
+                        is ChatActivityUiEvent.ProcessingRequest -> {
+                            threadViewLazyListState.animateScrollToItem(uiState.messages.size)
+                        }
+                        is ChatActivityUiEvent.SuccessfulResponse -> {
+                            chatState.composerValue = ""
+
+                            if (uiState.messages.isNotEmpty()) {
+                                threadViewLazyListState.animateScrollToItem(uiState.messages.size - 2)
+                            }
+
+                            threadViewLazyListState.layoutInfo.visibleItemsInfo.firstOrNull {
+                                it.key == "composer"
+                            }?.let {
+                                chatState.requestFocus()
+                                softwareKeyboardController?.show() // TODO perhaps it's pointless to focus since we can click on the toolbar?
+                            }
+                        }
+                        is ChatActivityUiEvent.Error -> {
+                            Toast.makeText(context, event.error, Toast.LENGTH_SHORT)
+                                .show() // TODO better way of showing this. snackbar?
+                        }
+                    }
+                }
+            }
         }
     }
 }
 
 @Composable
-fun Content(
+fun ChatScreen(
-    viewModel: ChatActivityViewModel // = viewModel() doesn't work
+    windowSizeClass: WindowSizeClass,
+    uiState: ChatActivityUiState,
+    chatState: ChatState,
+    threadViewLazyListState: LazyListState,
+    onRequestFocus: () -> Unit
 ) {
-    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    val isTablet = windowSizeClass.widthSizeClass > WindowWidthSizeClass.Compact
-    val localSoftwareKeyboardController = LocalSoftwareKeyboardController.current
-    val context = LocalContext.current
-
-    var composerValue by remember { mutableStateOf("") }
-    val composerFocusRequester = remember { FocusRequester() }
-
-    val lazyListState = rememberLazyListState()
-
-    LaunchedEffect(uiState.requestInProgress) { // TODO probably not the best way
-        if (!uiState.requestInProgress) {
-            if (uiState.requestLastError == null) {
-                composerValue = ""
-                composerFocusRequester.requestFocus() // TODO maybe make toggleable? or smart?
-            } else {
-                Toast.makeText(context, uiState.requestLastError, Toast.LENGTH_SHORT).show() // TODO better way of showing this
-            }
-        } else {
-            if (!uiState.messageHistory.isEmpty()) {
-                lazyListState.animateScrollToItem(uiState.messageHistory.size)
-            }
-        }
-    }
 
     ChatAppTheme {
         Scaffold(
-            modifier = Modifier.fillMaxSize().imePadding(),
+            modifier = Modifier.fillMaxSize(),
             topBar = {
                 ChatTopAppBar(uiState.chatTitle ?: "Start a new conversation")
             }
         ) { innerPadding ->
-            Column(
+            ChatScreenContent(
                 modifier = Modifier.fillMaxSize().padding(innerPadding),
+                isTablet = isTablet,
+                messages = uiState.messages,
+                liveResponse = uiState.liveResponse,
+                chatState = chatState,
+                threadViewLazyListState = threadViewLazyListState,
+                onRequestFocus = onRequestFocus
+            )
+        }
+    }
+}
+
+@Composable
+fun ChatScreenContent(
+    modifier: Modifier = Modifier,
+    isTablet: Boolean,
+    messages: List<ChatMessage>,
+    liveResponse: String,
+    chatState: ChatState,
+    threadViewLazyListState: LazyListState,
+    onRequestFocus: () -> Unit
+) {
+    val layout: @Composable (@Composable () -> Unit, @Composable () -> Unit) -> Unit =
+        if (isTablet) {
+            { thread, composer ->
+                Row(
+                    modifier = modifier,
+                    verticalAlignment = Alignment.Bottom
+                ) {
+                    Box(modifier = Modifier.weight(1f)) { thread() }
+                    Box(modifier = Modifier.width(500.dp)) { composer() }
+                }
+            }
+        } else {
+            { thread, composer ->
+                Column(
+                    modifier = modifier,
+                    horizontalAlignment = Alignment.CenterHorizontally
+                ) {
+                    Box(modifier = Modifier.weight(1f)) { thread() }
+                    composer()
+                }
+            }
+        }
+
+    layout(
+        {
+            ThreadView(
+                modifier = Modifier.fillMaxSize().padding(horizontal = 24.dp),
+                lazyListState = threadViewLazyListState,
+                messages = messages,
+                liveResponse = liveResponse,
+                chatState = chatState
+            )
+        },
+        {
+            Column(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .imePadding()
+                    .padding(horizontal = 10.dp),
                 horizontalAlignment = Alignment.CenterHorizontally
             ) {
-                LazyColumn(
+                ChatToolBar(
-                    modifier = Modifier.fillMaxSize().weight(1f),
+                    chatState = chatState,
-                    state = lazyListState
+                    onEmptySpaceClick = onRequestFocus
-                ) {
+                )
-                    items(uiState.messageHistory) { message ->
-                        MessageExchange(
-                            modifier = Modifier.padding(5.dp),
-                            isComposing = false,
-                            composerValue = message.prompt,
-                            responseValue = message.response
-                        )
-                    }
 
-                    item {
+                LanguageModelMistakeWarning(
-                        MessageExchange(
+                    modifier = Modifier
-                            modifier = Modifier.padding(5.dp).fillParentMaxHeight(),
+                        .padding(vertical = 10.dp) // TODO this is troublesome if there's navigation bar below or any kind of padding
-                            isComposing = !uiState.requestInProgress,
+                )
-                            composerValue = composerValue,
+            }
-                            onComposerValueChange = { composerValue = it },
+        }
-                            composerFocusRequester = composerFocusRequester,
+    )
-                            responseValue = uiState.currentMessageResponse // TODO animate this
+}
-                        )
-                    }
-                }
 
-                Box(
+@Composable
-                    modifier = Modifier.fillMaxWidth(),
+fun ThreadView(
-                    contentAlignment = Alignment.CenterEnd
+    lazyListState: LazyListState,
-                ) {
+    messages: List<ChatMessage>,
-                    Column(
+    liveResponse: String,
-                        horizontalAlignment = Alignment.CenterHorizontally
+    chatState: ChatState,
-                    ) {
+    modifier: Modifier = Modifier
-                        ComposerToolBar(
+) {
-                            modifier = Modifier.width(500.dp).padding(horizontal = 10.dp),
+    val localSoftwareKeyboardController = LocalSoftwareKeyboardController.current
-                            canSend = composerValue.isNotBlank() && !uiState.requestInProgress,
-                            onSend = {
-                                viewModel.sendMessage(composerValue)
-                            },
-                            onEmptySpaceClick = {
-                                composerFocusRequester.requestFocus()
-                                localSoftwareKeyboardController?.show()
-                            }
-                        )
 
-                        LanguageModelMistakeWarning(
+    val composerValue = if (chatState.requestInProgress) {
-                            modifier = Modifier.padding(vertical = 10.dp)
+        chatState.lastPrompt
-                        )
+    } else {
-                    }
+        chatState.composerValue
-                }
+    }
+
+    LazyColumn(
+        modifier = modifier
+            .nestedScroll( // Hides the keyboard when scrolling
+                NestedScrollKeyboardHider(localSoftwareKeyboardController)
+            ),
+        state = lazyListState
+    ) {
+        items(messages) { message ->
+            if (message.role == ChatMessage.Role.User) {
+                ChatMessagePrompt(
+                    content = message.content,
+                    modifier = Modifier.padding(vertical = 10.dp)
+                )
+            } else if (message.role == ChatMessage.Role.Assistant) {
+                ChatMessageResponse(
+                    content = message.content
+                )
+            }
+        }
+
+        item(key = "composer") {
+            ChatMessageComposer(
+                modifier = Modifier
+                    .fillParentMaxHeight() // so that you can click anywhere on the screen to focus the text field
+                    .disableBringIntoViewOnFocus()
+                    .focusRequester(chatState.focusRequester),
+                value = composerValue,
+                onValueChange = {
+                    chatState.composerValue = it
+                },
+                submitted = chatState.requestInProgress
+            )
+        }
+
+        if (chatState.requestInProgress) {
+            item {
+                ChatMessageResponse(
+                    content = liveResponse
+                )
+            }
+        }
+    }
+}
+
+@Composable
+fun ChatMessagePrompt(
+    content: String,
+    modifier: Modifier = Modifier
+) {
+    Text(
+        text = content,
+        modifier = modifier
+            .padding(horizontal = 16.dp),
+        color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
+    )
+}
+
+@Composable
+fun ChatMessageResponse(
+    content: String,
+    modifier: Modifier = Modifier
+) {
+    Text(
+        text = content,
+        modifier = modifier
+    )
+}
+
+@Composable
+fun ChatMessageComposer(
+    value: String,
+    onValueChange: (String) -> Unit,
+    submitted: Boolean,
+    modifier: Modifier = Modifier
+) {
+    val textPadding by animateDpAsState(
+        targetValue = if (submitted) 16.dp else 0.dp,
+        label = "composerTextPaddingAnimation"
+    )
+
+    val textOpacity by animateFloatAsState(
+        targetValue = if (submitted) 0.7f else 1.0f,
+        label = "composerTextOpacityAnimation"
+    )
+
+    SimpleTextFieldWithPadding(
+        modifier = modifier,
+        value = value,
+        onValueChange = onValueChange,
+        enabled = !submitted,
+        placeholder = {
+            Text("Type your message...") // TODO hide when just browsing history?
+        },
+        padding = PaddingValues(vertical = 10.dp, horizontal = textPadding),
+        textStyle = LocalTextStyle.current.copy(
+            color = MaterialTheme.colorScheme.onSurface.copy(alpha = textOpacity)
+        )
+    )
+}
+
+@Composable
+fun ChatToolBar(
+    modifier: Modifier = Modifier,
+    chatState: ChatState,
+    onEmptySpaceClick: () -> Unit
+) {
+    val sendButtonColor by animateColorAsState(
+        targetValue = if (chatState.canSend) {
+            IconButtonDefaults.iconButtonColors().contentColor
+        } else {
+            IconButtonDefaults.iconButtonColors().disabledContentColor
+        }, label = "sendButtonColor"
+    )
+
+    ElevatedCard(
+        modifier = modifier,
+        shape = RoundedCornerShape(24.dp)
+    ) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onEmptySpaceClick),
+            horizontalArrangement = Arrangement.End
+        ) {
+            IconButton(
+                onClick = chatState::performSend,
+                modifier = Modifier
+                    .height(48.dp)
+                    .padding(horizontal = 8.dp),
+                enabled = chatState.canSend,
+                colors = IconButtonDefaults.iconButtonColors(
+                    contentColor = sendButtonColor,
+                    disabledContentColor = sendButtonColor
+                )
+            ) {
+                Icon(
+                    imageVector = Icons.AutoMirrored.Filled.Send,
+                    contentDescription = "Send"
+                )
             }
         }
     }
@@ -175,136 +408,8 @@ fun ChatTopAppBar(
             ) {
                 AnimatedChangingText(
                     text = title,
-                )  // TODO fade
-            }
-        }
-    )
-}
-
-@Composable
-fun MessageExchange(
-    isComposing: Boolean,
-    composerValue: String,
-    modifier: Modifier = Modifier,
-    onComposerValueChange: (String) -> Unit = {},
-    composerFocusRequester: FocusRequester = FocusRequester(),
-    responseValue: String = "",
-) {
-
-    Column(
-        modifier = modifier.padding(horizontal = 10.dp)
-    ) {
-        MessageComposer(
-            value = composerValue,
-            onValueChange = onComposerValueChange,
-            enabled = isComposing,
-            focusRequester = composerFocusRequester
-        )
-
-        if (!isComposing) {
-            Text(
-                text = responseValue,
-                modifier = Modifier
-                    .padding(horizontal = 16.dp)
-            )
-        }
-
-    }
-}
-
-@Composable
-fun MessageComposer(
-    value: String,
-    onValueChange: (String) -> Unit,
-    enabled: Boolean,
-    focusRequester: FocusRequester,
-    modifier: Modifier = Modifier
-) {
-    val textFieldPadding by animateDpAsState(
-        targetValue = if (enabled) {
-            0.dp
-        } else {
-            16.dp
-        }
-    )
-
-    val textFieldTextColor by animateColorAsState(
-        targetValue = if (enabled) {
-            TextFieldDefaults.colors().focusedTextColor
-        } else {
-            TextFieldDefaults.colors().disabledTextColor
-        }
-    )
-
-    TextField(
-        value = value,
-        onValueChange = onValueChange,
-        modifier = modifier
-            .fillMaxWidth()
-            .padding(horizontal = textFieldPadding)
-            .focusRequester(focusRequester),
-            // .animateContentSize()
-        placeholder = {
-            Text("Type your message...")
-        },
-        colors = TextFieldDefaults.colors(
-            unfocusedContainerColor = Color.Transparent,
-            focusedContainerColor = Color.Transparent,
-            disabledContainerColor = Color.Transparent,
-            unfocusedIndicatorColor = Color.Transparent,
-            focusedIndicatorColor = Color.Transparent,
-            disabledIndicatorColor = Color.Transparent,
-            disabledTextColor = textFieldTextColor
-        ),
-        enabled = enabled
-    )
-}
-
-@Composable
-fun ComposerToolBar(
-    modifier: Modifier = Modifier,
-    canSend: Boolean,
-    onSend: () -> Unit,
-    onEmptySpaceClick: () -> Unit
-) {
-    val sendButtonColor by animateColorAsState(
-        targetValue = if (canSend) {
-            IconButtonDefaults.iconButtonColors().contentColor
-        } else {
-            IconButtonDefaults.iconButtonColors().disabledContentColor
-        }
-    )
-
-    ElevatedCard(
-        modifier = modifier.clickable(
-            onClick = onEmptySpaceClick
-        ),
-        shape = RoundedCornerShape(100)
-    ) {
-        Row(
-            modifier = Modifier.fillMaxWidth(),
-            horizontalArrangement = Arrangement.End
-        ) {
-            IconButton(
-                onClick = {
-                    onSend()
-                },
-                modifier = Modifier.height(48.dp).padding(horizontal = 8.dp),
-                enabled = canSend,
-                colors = IconButtonDefaults.iconButtonColors(
-                    contentColor = sendButtonColor,
-                    disabledContentColor = sendButtonColor
                 )
-            ) {
-                Column (
-                    horizontalAlignment = Alignment.CenterHorizontally
-                ) {
-                    Icon(
-                        imageVector = Icons.AutoMirrored.Filled.Send,
-                        contentDescription = "Send"
-                    )
-                }
             }
         }
-    }
+    )
 }

app/src/main/java/eu/m724/chatapp/activity/chat/ChatActivityUiEvent.kt

@@ -0,0 +1,7 @@
+package eu.m724.chatapp.activity.chat
+
+sealed interface ChatActivityUiEvent {
+    data object ProcessingRequest : ChatActivityUiEvent
+    data class SuccessfulResponse(val message: String): ChatActivityUiEvent
+    data class Error(val error: String): ChatActivityUiEvent
+}

app/src/main/java/eu/m724/chatapp/activity/chat/ChatActivityUiState.kt

@@ -1,5 +1,7 @@
 package eu.m724.chatapp.activity.chat
 
+import eu.m724.chatapp.api.data.ChatMessage
+
 data class ChatActivityUiState(
     /**
      * The title of the current chat
@@ -14,20 +16,10 @@ data class ChatActivityUiState(
     /**
      * The response right now, updates when streaming
      */
-    val currentMessageResponse: String = "",
+    val liveResponse: String = "",
 
     /**
      * All the messages of this chat
      */
-    val messageHistory: List<ChatMessageExchange> = listOf(),
+    val messages: List<ChatMessage> = listOf()
-
-    /**
-     * Error, if any, of the last request
-     */
-    val requestLastError: String? = null
-)
-
-data class ChatMessageExchange(
-    val prompt: String,
-    var response: String
 )

app/src/main/java/eu/m724/chatapp/activity/chat/ChatActivityViewModel.kt

@@ -6,9 +6,11 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import eu.m724.chatapp.api.AiApiService
 import eu.m724.chatapp.api.data.ChatMessage
 import eu.m724.chatapp.api.data.request.ChatCompletionRequest
+import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import javax.inject.Inject
@@ -17,32 +19,36 @@ import javax.inject.Inject
 class ChatActivityViewModel @Inject constructor(
     private val aiApiService: AiApiService
 ) : ViewModel() {
+    private val messages = mutableListOf<ChatMessage>()
+
     private val _uiState = MutableStateFlow(ChatActivityUiState())
     val uiState: StateFlow<ChatActivityUiState> = _uiState.asStateFlow()
 
-    private val messages = mutableListOf<ChatMessage>()
+    private val _uiEvents = Channel<ChatActivityUiEvent>()
+    val uiEvents = _uiEvents.receiveAsFlow()
 
     fun sendMessage(message: String) {
         _uiState.update {
-            it.copy(
+            var uiState = it.copy(
                 requestInProgress = true,
-                currentMessageResponse = ""
+                liveResponse = "",
             )
-        }
 
-        if (_uiState.value.chatTitle == null) {
+            if (it.chatTitle == null) {
-            _uiState.update {
+                uiState = uiState.copy(chatTitle = message)
-                it.copy(chatTitle = "User says \"$message\"") // TODO
             }
+
+            uiState
         }
 
         messages.add(ChatMessage(
-            role = ChatMessage.Role.USER,
+            role = ChatMessage.Role.User,
             content = message
         ))
 
-
         viewModelScope.launch {
+            _uiEvents.send(ChatActivityUiEvent.ProcessingRequest)
+
             val response = aiApiService.chatComplete(ChatCompletionRequest(
                 model = "free-model",
                 messages = messages,
@@ -53,13 +59,16 @@ class ChatActivityViewModel @Inject constructor(
             ))
 
             if (!response.isSuccessful || response.body() == null) {
+                messages.removeLast()
+
                 _uiState.update {
                     it.copy(
-                        requestInProgress = false,
+                        requestInProgress = false
-                        requestLastError = response.code().toString()
                     )
                 }
 
+                _uiEvents.send(ChatActivityUiEvent.Error(response.code().toString()))
+
                 // TODO launch toast or something
                 return@launch
             }
@@ -72,11 +81,11 @@ class ChatActivityViewModel @Inject constructor(
             _uiState.update {
                 it.copy(
                     requestInProgress = false,
-                    messageHistory = it.messageHistory.plus(
+                    messages = messages.toList()
-                        ChatMessageExchange(message, choice.message.content)
-                    )
                 )
             }
+
+            _uiEvents.send(ChatActivityUiEvent.SuccessfulResponse(message))
         }
     }
 }

app/src/main/java/eu/m724/chatapp/activity/chat/ChatState.kt

@@ -0,0 +1,59 @@
+package eu.m724.chatapp.activity.chat
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.focus.FocusRequester
+
+class ChatState(
+    val focusRequester: FocusRequester,
+    private val onSend: (String) -> Unit, // Store the lambda
+    initialRequestInProgress: Boolean
+) {
+    var composerValue by mutableStateOf("")
+    var lastPrompt by mutableStateOf("")
+    var requestInProgress by mutableStateOf(initialRequestInProgress)
+
+    val canSend: Boolean
+        get() = composerValue.isNotBlank() && !requestInProgress
+
+    // This method will be called by the UI (e.g., the send button)
+    fun performSend() {
+        if (canSend) {
+            lastPrompt = composerValue
+            onSend(composerValue)
+            composerValue = ""
+        }
+    }
+
+    fun requestFocus() {
+        focusRequester.requestFocus()
+    }
+
+    companion object {
+        @Composable
+        fun rememberChatState(
+            requestInProgress: Boolean,
+            onSend: (String) -> Unit, // Takes the message string as a parameter
+            focusRequester: FocusRequester = remember { FocusRequester() }
+        ): ChatState {
+            val state = remember {
+                ChatState(
+                    focusRequester = focusRequester,
+                    onSend = onSend, // Pass the lambda directly
+                    initialRequestInProgress = requestInProgress
+                )
+            }
+
+            LaunchedEffect(requestInProgress) {
+                state.requestInProgress = requestInProgress
+            }
+
+            return state
+        }
+    }
+}
+

app/src/main/java/eu/m724/chatapp/activity/chat/composable/AnimatedChangingText.kt

@@ -1,4 +1,4 @@
-package eu.m724.chatapp.activity.chat.compose
+package eu.m724.chatapp.activity.chat.composable
 
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.core.tween

app/src/main/java/eu/m724/chatapp/activity/chat/composable/DisableBringIntoViewOnFocusNode.kt

@@ -0,0 +1,44 @@
+package eu.m724.chatapp.activity.chat.composable
+
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Rect
+import androidx.compose.ui.layout.LayoutCoordinates
+import androidx.compose.ui.node.ModifierNodeElement
+import androidx.compose.ui.platform.InspectorInfo
+import androidx.compose.ui.relocation.BringIntoViewModifierNode
+
+private class DisableBringIntoViewOnFocusNode : Modifier.Node(), BringIntoViewModifierNode {
+    // When a child of this modifier requests to be brought into view, this method is called.
+    // By providing an empty implementation, we effectively "swallow" the request
+    // and prevent it from propagating up to the LazyColumn, which would otherwise scroll.
+    override suspend fun bringIntoView(
+        childCoordinates: LayoutCoordinates,
+        boundsProvider: () -> Rect?
+    ) {
+
+    }
+}
+
+private class DisableBringIntoViewOnFocusElement : ModifierNodeElement<DisableBringIntoViewOnFocusNode>() {
+    override fun create() = DisableBringIntoViewOnFocusNode()
+
+    override fun equals(other: Any?): Boolean {
+        return other === this
+    }
+
+    override fun hashCode(): Int {
+        return "disableBringIntoViewOnFocus".hashCode()
+    }
+
+    override fun update(node: DisableBringIntoViewOnFocusNode) {
+
+    }
+
+    override fun InspectorInfo.inspectableProperties() {
+        name = "disableBringIntoViewOnFocus"
+    }
+
+}
+
+// This is the public Modifier function you will use in your code.
+fun Modifier.disableBringIntoViewOnFocus(): Modifier = this.then(DisableBringIntoViewOnFocusElement())

app/src/main/java/eu/m724/chatapp/activity/chat/composable/LanguageModelMistakeWarning.kt

@@ -1,4 +1,4 @@
-package eu.m724.chatapp.activity.chat.compose
+package eu.m724.chatapp.activity.chat.composable
 
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text

app/src/main/java/eu/m724/chatapp/activity/chat/composable/NestedScrollKeyboardHider.kt

@@ -0,0 +1,16 @@
+package eu.m724.chatapp.activity.chat.composable
+
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
+import androidx.compose.ui.input.nestedscroll.NestedScrollSource
+import androidx.compose.ui.platform.SoftwareKeyboardController
+
+class NestedScrollKeyboardHider(
+    private val softwareKeyboardController: SoftwareKeyboardController?
+) : NestedScrollConnection {
+    override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
+        if (available.y > 0) // if scrolling up (content up, finger down)
+            softwareKeyboardController?.hide()
+        return Offset.Companion.Zero
+    }
+}

app/src/main/java/eu/m724/chatapp/activity/chat/composable/SimpleTextFieldWithPadding.kt

@@ -0,0 +1,55 @@
+package eu.m724.chatapp.activity.chat.composable
+
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.text.BasicTextField
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.TextFieldDefaults
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.input.VisualTransformation
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun SimpleTextFieldWithPadding(
+    value: String,
+    onValueChange: (String) -> Unit,
+    enabled: Boolean,
+    placeholder: @Composable () -> Unit,
+    padding: PaddingValues,
+    textStyle: TextStyle,
+    modifier: Modifier = Modifier
+) {
+    val interactionSource = remember { MutableInteractionSource() }
+
+    BasicTextField(
+        value = value,
+        onValueChange = onValueChange,
+        modifier = modifier,
+        enabled = enabled,
+        textStyle = textStyle,
+        cursorBrush = SolidColor(MaterialTheme.colorScheme.onSurface)
+    ) { innerTextField ->
+        TextFieldDefaults.DecorationBox(
+            value = value,
+            visualTransformation = VisualTransformation.None,
+            innerTextField = innerTextField,
+            singleLine = false,
+            enabled = true, // to make things easier
+            interactionSource = interactionSource,
+            contentPadding = padding,
+            placeholder = placeholder,
+            colors = TextFieldDefaults.colors(
+                unfocusedContainerColor = Color.Transparent,
+                focusedContainerColor = Color.Transparent,
+                unfocusedIndicatorColor = Color.Transparent,
+                focusedIndicatorColor = Color.Transparent,
+            )
+        )
+    }
+}

app/src/main/java/eu/m724/chatapp/api/data/ChatMessage.kt

@@ -1,12 +1,19 @@
 package eu.m724.chatapp.api.data
 
+import com.google.gson.annotations.SerializedName
+
 data class ChatMessage(
     val role: Role,
     val content: String
 ) {
     enum class Role {
-        SYSTEM,
+        @SerializedName("system")
-        USER,
+        System,
-        ASSISTANT
+
+        @SerializedName("user")
+        User,
+
+        @SerializedName("assistant")
+        Assistant
     }
 }

app/src/main/java/eu/m724/chatapp/api/data/response/ChatCompletionResponse.kt

@@ -49,17 +49,20 @@ enum class CompletionFinishReason {
     /**
      * The response has stopped, because the model said so
      */
-    STOP,
+    @SerializedName("stop")
+    Stop,
 
     /**
      * The response has stopped, because it got too long
      */
-    LENGTH,
+    @SerializedName("length")
+    Length,
 
     /**
      * The response has stopped, because the content got flagged
      */
-    CONTENT_FILTER
+    @SerializedName("content_filter")
+    ContentFilter
 }
 
 data class CompletionTokenUsage(

gradle/libs.versions.toml

@@ -15,6 +15,7 @@ ksp = "2.1.21-2.0.2"
 retrofit = "3.0.0"
 secrets = "2.0.1"
 loggingInterceptor = "4.12.0"
+material3WindowSizeClass = "1.3.2"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -38,6 +39,7 @@ hilt-compiler = { group = "com.google.dagger", name = "hilt-compiler", version.r
 retrofit = { group = "com.squareup.retrofit2", name = "retrofit", version.ref = "retrofit" }
 retrofit-converter-gson = { group = "com.squareup.retrofit2", name = "converter-gson", version.ref = "retrofit"}
 logging-interceptor = { group = "com.squareup.okhttp3", name = "logging-interceptor", version.ref = "loggingInterceptor" }
+androidx-material3-window-size-class1 = { group = "androidx.compose.material3", name = "material3-window-size-class", version.ref = "material3WindowSizeClass" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }