Add dedicated task list screen — view and manage all tasks

Author: SysAdminDoc

app/src/main/java/com/opentasker/ui/screens/TaskListScreen.kt

@@ -0,0 +1,160 @@
+package com.opentasker.ui.screens
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Delete
+import androidx.compose.material3.*
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.viewmodel.compose.viewModel
+import androidx.lifecycle.viewModelScope
+import com.opentasker.core.model.Task
+import com.opentasker.core.storage.AppDatabase
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.flow.SharingStarted
+
+/**
+ * ViewModel for task list screen — loads and manages task list from database.
+ */
+class TaskListScreenViewModel(private val db: AppDatabase) : ViewModel() {
+    val tasks: StateFlow<List<Task>> = db.taskDao()
+        .getAllAsFlow()
+        .map { entities -> entities.map { it.toDomain() } }
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.Lazily,
+            initialValue = emptyList()
+        )
+}
+
+class TaskListScreenViewModelFactory(private val db: AppDatabase) : ViewModelProvider.Factory {
+    @Suppress("UNCHECKED_CAST")
+    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+        return TaskListScreenViewModel(db) as T
+    }
+}
+
+/**
+ * Screen to display all tasks in a list with add/edit/delete options.
+ */
+@OptIn(androidx.compose.material3.ExperimentalMaterial3Api::class)
+@Composable
+fun TaskListScreen(
+    db: AppDatabase,
+    onCreateTask: () -> Unit,
+    onEditTask: (Task) -> Unit,
+    onDeleteTask: (Task) -> Unit,
+    onBack: () -> Unit,
+) {
+    val viewModel: TaskListScreenViewModel = viewModel(
+        factory = TaskListScreenViewModelFactory(db)
+    )
+    val tasks by viewModel.tasks.collectAsState()
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Tasks") },
+            )
+        },
+        floatingActionButton = {
+            Button(onClick = onCreateTask) {
+                Icon(Icons.Filled.Add, contentDescription = "Add")
+                Text("New Task")
+            }
+        }
+    ) { inner ->
+        Column(modifier = Modifier
+            .fillMaxSize()
+            .padding(inner)
+            .padding(16.dp)
+        ) {
+            if (tasks.isEmpty()) {
+                Text(
+                    "No tasks yet. Create one to get started!",
+                    style = MaterialTheme.typography.bodyLarge,
+                    modifier = Modifier.padding(bottom = 16.dp)
+                )
+            } else {
+                LazyColumn {
+                    items(tasks, key = { it.id }) { task ->
+                        TaskCardItem(
+                            task = task,
+                            onEdit = { onEditTask(task) },
+                            onDelete = { onDeleteTask(task) }
+                        )
+                    }
+                }
+            }
+
+            Spacer(modifier = Modifier.weight(1f))
+            
+            Button(
+                onClick = onBack,
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(top = 16.dp)
+            ) {
+                Text("Back to Profiles")
+            }
+        }
+    }
+}
+
+@Composable
+fun TaskCardItem(
+    task: Task,
+    onEdit: () -> Unit,
+    onDelete: () -> Unit,
+) {
+    Card(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(vertical = 8.dp),
+        shape = MaterialTheme.shapes.medium,
+    ) {
+        Column(modifier = Modifier
+            .fillMaxWidth()
+            .padding(12.dp)
+        ) {
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween,
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                Column(modifier = Modifier.weight(1f)) {
+                    Text(task.name, style = MaterialTheme.typography.titleSmall)
+                    Text(
+                        "Actions: ${task.actions.size} | Priority: ${task.priority}",
+                        style = MaterialTheme.typography.bodySmall
+                    )
+                }
+                IconButton(onClick = onDelete) {
+                    Icon(Icons.Filled.Delete, contentDescription = "Delete")
+                }
+            }
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(top = 8.dp),
+                horizontalArrangement = Arrangement.End
+            ) {
+                Button(onClick = onEdit) {
+                    Text("Edit")
+                }
+            }
+        }
+    }
+}