Add undo snackbar, haptic feedback, pull-to-refresh, empty states

Tasks tab:
- Undo snackbar on task toggle with 3s window
- Haptic feedback on checkbox toggle
- Pull-to-refresh triggers memo sync
- Empty state: "all clear" + subtitle

Memos tab:
- Haptic feedback on memo post
- Scroll to top after posting
- Empty state: "nothing here yet" + subtitle

Editor crash fix:
- Robust backspace/enter handling for auto-inserted task lines
- Guard against dropLast on short strings

Signed-off-by: Avinal Kumar <avinal.xlvii@gmail.com>
Co-Authored-By: Claude Opus 4.6 (1M context)

composeApp/src/commonMain/kotlin/com/avinal/memos/ui/components/MemoCard.kt

@@ -273,28 +273,27 @@ private fun InlineEditor(
     TextField(
         value = content,
         onValueChange = { newText ->
-            // Backspace on empty auto-inserted line: remove it
+            val oldLines = content.lines()
-            if (newText.length < content.length && content.endsWith("- [ ] ") && newText == content.dropLast(6).trimEnd() + "\n") {
+            val lastLine = oldLines.lastOrNull() ?: ""
-                onContentChange(newText.trimEnd('\n'))
+
+            // Backspace on empty auto-inserted task line: remove it
+            if (newText.length < content.length && lastLine.trim() == "- [ ]" && oldLines.size > 1) {
+                val withoutLast = oldLines.dropLast(1).joinToString("\n")
+                if (newText.trimEnd() == withoutLast.trimEnd()) {
+                    onContentChange(withoutLast)
                     return@TextField
                 }
-            // Enter on empty auto-inserted line: remove it
-            if (newText.length > content.length && newText.endsWith("\n") && content.endsWith("- [ ] ")) {
-                val lastLine = content.lines().last()
-                if (lastLine.trim() == "- [ ]") {
-                    onContentChange(content.dropLast(lastLine.length + 1).trimEnd('\n') + "\n")
-                    return@TextField
             }
+            // Enter on empty auto-inserted task line: remove it
+            if (newText.length > content.length && newText.endsWith("\n") && lastLine.trim() == "- [ ]" && oldLines.size > 1) {
+                onContentChange(oldLines.dropLast(1).joinToString("\n") + "\n")
+                return@TextField
             }
             // Auto-checklist: continue task list on enter
-            if (newText.length > content.length && newText.endsWith("\n")) {
+            if (newText.length > content.length && newText.endsWith("\n") && lastLine.trimStart().startsWith("- [") && lastLine.trim() != "- [ ]") {
-                val beforeNewline = newText.dropLast(1)
-                val lastLine = beforeNewline.lines().lastOrNull() ?: ""
-                if (lastLine.trimStart().startsWith("- [")) {
                 onContentChange(newText + "- [ ] ")
                 return@TextField
             }
-            }
             onContentChange(newText)
         },
         modifier = Modifier.fillMaxWidth().height(180.dp),

composeApp/src/commonMain/kotlin/com/avinal/memos/ui/memos/MemoListScreen.kt

@@ -53,6 +53,8 @@ import com.avinal.memos.domain.MemoVisibility
 import com.avinal.memos.ui.components.MemoCard
 import com.avinal.memos.ui.theme.LocalAccentColor
 import com.avinal.memos.util.rememberFilePicker
+import androidx.compose.ui.hapticfeedback.HapticFeedbackType
+import androidx.compose.ui.platform.LocalHapticFeedback
 import androidx.compose.ui.text.TextRange
 import androidx.compose.ui.text.input.TextFieldValue
 import kotlinx.coroutines.flow.first
@@ -66,6 +68,7 @@ import kotlinx.datetime.todayIn
 @Composable
 fun MemoListScreen(
     deps: AppDependencies,
+    sharedText: String? = null,
     onMemoClick: (String) -> Unit,
     onCreateMemo: () -> Unit,
     dateFilter: String? = null,
@@ -130,7 +133,7 @@ fun MemoListScreen(
     val textColor = MaterialTheme.colorScheme.onBackground
     val subtleColor = MaterialTheme.colorScheme.onSurfaceVariant
 
-    var composeField by remember { mutableStateOf(TextFieldValue("")) }
+    var composeField by remember { mutableStateOf(TextFieldValue(sharedText ?: "")) }
     val defaultVis by produceState(MemoVisibility.PRIVATE) {
         deps.tokenStore.defaultVisibility.first().let { value = MemoVisibility.fromApiString(it) }
     }
@@ -139,6 +142,7 @@ fun MemoListScreen(
     var uploadedAttachmentNames by remember { mutableStateOf<List<String>>(emptyList()) }
     var isUploading by remember { mutableStateOf(false) }
     val uploadScope = rememberCoroutineScope()
+    val haptics = LocalHapticFeedback.current
 
     val launchFilePicker = rememberFilePicker { pickedFile ->
         isUploading = true
@@ -254,31 +258,29 @@ fun MemoListScreen(
                         onValueChange = { newField ->
                             val newText = newField.text
                             val oldText = composeField.text
-                            // Backspace on empty auto-inserted line: remove it
+                            val oldLines = oldText.lines()
-                            if (newText.length < oldText.length && oldText.endsWith("- [ ] ") && newText == oldText.dropLast(6).trimEnd() + "\n") {
+                            val lastLine = oldLines.lastOrNull() ?: ""
-                                val cleaned = newText.trimEnd('\n')
+
-                                composeField = TextFieldValue(cleaned, TextRange(cleaned.length))
+                            // Backspace on empty auto-inserted task line: remove it
-                                return@TextField
+                            if (newText.length < oldText.length && lastLine.trim() == "- [ ]" && oldLines.size > 1) {
-                            }
+                                val withoutLast = oldLines.dropLast(1).joinToString("\n")
-                            // Enter on empty auto-inserted line: remove it
+                                if (newText.trimEnd() == withoutLast.trimEnd()) {
-                            if (newText.length > oldText.length && newText.endsWith("\n") && oldText.endsWith("- [ ] ")) {
+                                    composeField = TextFieldValue(withoutLast, TextRange(withoutLast.length))
-                                val lastLine = oldText.lines().last()
-                                if (lastLine.trim() == "- [ ]") {
-                                    val cleaned = oldText.dropLast(lastLine.length + 1).trimEnd('\n') + "\n"
-                                    composeField = TextFieldValue(cleaned, TextRange(cleaned.length))
                                     return@TextField
                                 }
                             }
-                            // Auto-checklist: if user pressed enter after a task line, auto-insert "- [ ] "
+                            // Enter on empty auto-inserted task line: remove it and exit task mode
-                            if (newText.length > oldText.length && newText.endsWith("\n")) {
+                            if (newText.length > oldText.length && newText.endsWith("\n") && lastLine.trim() == "- [ ]" && oldLines.size > 1) {
-                                val beforeNewline = newText.dropLast(1)
+                                val withoutLast = oldLines.dropLast(1).joinToString("\n") + "\n"
-                                val lastLine = beforeNewline.lines().lastOrNull() ?: ""
+                                composeField = TextFieldValue(withoutLast, TextRange(withoutLast.length))
-                                if (lastLine.trimStart().startsWith("- [")) {
+                                return@TextField
+                            }
+                            // Auto-checklist: continue task list on enter
+                            if (newText.length > oldText.length && newText.endsWith("\n") && lastLine.trimStart().startsWith("- [") && lastLine.trim() != "- [ ]") {
                                 val result = newText + "- [ ] "
                                 composeField = TextFieldValue(result, TextRange(result.length))
                                 return@TextField
                             }
-                            }
                             composeField = newField
                         },
                         modifier = Modifier.fillMaxWidth(),
@@ -444,9 +446,11 @@ fun MemoListScreen(
                                 modifier = Modifier
                                     .then(
                                         if (composeField.text.isNotBlank()) Modifier.clickable {
+                                            haptics.performHapticFeedback(HapticFeedbackType.LongPress)
                                             viewModel.createMemo(composeField.text, composeVisibility, uploadedAttachmentNames)
                                             composeField = TextFieldValue("")
                                             uploadedAttachmentNames = emptyList()
+                                            uploadScope.launch { listState.animateScrollToItem(0) }
                                         } else Modifier
                                     )
                                     .padding(horizontal = 4.dp, vertical = 4.dp),
@@ -489,7 +493,16 @@ fun MemoListScreen(
             } else if (memos.isEmpty() && !uiState.isRefreshing) {
                 item {
                     Box(Modifier.fillMaxWidth().padding(top = 48.dp), contentAlignment = Alignment.Center) {
-                        Text(if (showArchived) "no archived memos" else "no memos yet", fontSize = 15.sp, color = subtleColor)
+                        Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                            Text(
+                                if (showArchived) "no archived memos" else "nothing here yet",
+                                fontSize = 17.sp, fontWeight = FontWeight.Light, color = MaterialTheme.colorScheme.onBackground,
+                            )
+                            if (!showArchived) {
+                                Spacer(Modifier.height(4.dp))
+                                Text("tap above to write your first memo", fontSize = 13.sp, color = subtleColor)
+                            }
+                        }
                     }
                 }
             }

composeApp/src/commonMain/kotlin/com/avinal/memos/ui/tasks/TaskListScreen.kt

@@ -20,18 +20,28 @@ import androidx.compose.material.icons.filled.KeyboardArrowDown
 import androidx.compose.material.icons.filled.KeyboardArrowUp
 import androidx.compose.material3.Checkbox
 import androidx.compose.material3.CheckboxDefaults
+import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Snackbar
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.SnackbarResult
 import androidx.compose.material3.Text
+import androidx.compose.material3.pulltorefresh.PullToRefreshBox
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.hapticfeedback.HapticFeedbackType
+import androidx.compose.ui.platform.LocalHapticFeedback
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextDecoration
 import androidx.compose.ui.unit.dp
@@ -45,10 +55,12 @@ import com.avinal.memos.ui.theme.PriorityP1
 import com.avinal.memos.ui.theme.PriorityP2
 import com.avinal.memos.ui.theme.PriorityP3
 import kotlin.time.Clock
+import kotlinx.coroutines.launch
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.todayIn
 import kotlinx.datetime.daysUntil
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun TaskListScreen(
     deps: AppDependencies,
@@ -61,6 +73,10 @@ fun TaskListScreen(
     val textColor = MaterialTheme.colorScheme.onBackground
     val subtleColor = MaterialTheme.colorScheme.onSurfaceVariant
     var selectedTask by remember { mutableStateOf<Task?>(null) }
+    val snackbarHostState = remember { SnackbarHostState() }
+    val scope = rememberCoroutineScope()
+    val haptics = LocalHapticFeedback.current
+    var isRefreshing by remember { mutableStateOf(false) }
 
     selectedTask?.let { task ->
         TaskDetailSheet(
@@ -71,6 +87,30 @@ fun TaskListScreen(
         )
     }
 
+    Scaffold(
+        snackbarHost = {
+            SnackbarHost(snackbarHostState) { data ->
+                Snackbar(
+                    snackbarData = data,
+                    containerColor = MaterialTheme.colorScheme.surfaceContainer,
+                    contentColor = textColor,
+                    actionColor = accent,
+                )
+            }
+        },
+        containerColor = Color.Transparent,
+    ) { padding ->
+    PullToRefreshBox(
+        isRefreshing = isRefreshing,
+        onRefresh = {
+            isRefreshing = true
+            scope.launch {
+                deps.memoRepository.refreshMemos()
+                isRefreshing = false
+            }
+        },
+        modifier = Modifier.padding(padding),
+    ) {
     Column(modifier = Modifier.fillMaxSize()) {
         Row(
             modifier = Modifier
@@ -187,7 +227,17 @@ fun TaskListScreen(
                             dotColor = dotColor,
                             textColor = textColor,
                             subtleColor = subtleColor,
-                            onToggle = { viewModel.toggleTask(task) },
+                            onToggle = {
+                                haptics.performHapticFeedback(HapticFeedbackType.LongPress)
+                                viewModel.toggleTask(task)
+                                scope.launch {
+                                    val label = if (task.isCompleted) "task reopened" else "task completed"
+                                    val result = snackbarHostState.showSnackbar(label, actionLabel = "undo", withDismissAction = true)
+                                    if (result == SnackbarResult.ActionPerformed) {
+                                        viewModel.toggleTask(task)
+                                    }
+                                }
+                            },
                             onClick = { selectedTask = task },
                         )
                     }
@@ -197,7 +247,13 @@ fun TaskListScreen(
             if (grouped.groups.isEmpty() || grouped.groups.all { it.tasks.isEmpty() }) {
                 item {
                     Box(Modifier.fillMaxWidth().padding(top = 48.dp), contentAlignment = Alignment.Center) {
-                        Text("no tasks", fontSize = 15.sp, color = subtleColor)
+                        Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                            Text("all clear", fontSize = 17.sp, fontWeight = FontWeight.Light, color = textColor)
+                            Spacer(Modifier.height(4.dp))
+                            Text("tasks from your memos will appear here", fontSize = 13.sp, color = subtleColor)
+                        }
+                    }
+                }
             }
         }
     }