feat: 支持多选和删除待办（后续优化逻辑）

app/src/main/kotlin/cn/super12138/todo/logic/Repository.kt

@@ -19,6 +19,14 @@ object Repository {
     }
 
     suspend fun deleteTodo(toDo: TodoEntity) {
-        toDoDao.delete(toDo.id)
+        toDoDao.delete(toDo)
     }
+
+    suspend fun deleteTodoFromIds(toDoItems: List<Int>) {
+        toDoDao.deleteFromIds(toDoItems.toSet())
+    }
+
+    /*suspend fun deleteAllTodo() {
+        toDoDao.deleteAllTodo()
+    }*/
 }

app/src/main/kotlin/cn/super12138/todo/logic/database/TodoDao.kt

@@ -1,6 +1,7 @@
 package cn.super12138.todo.logic.database
 
 import androidx.room.Dao
+import androidx.room.Delete
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
 import androidx.room.Query
@@ -18,6 +19,12 @@ interface TodoDao {
     @Update
     suspend fun update(toDo: TodoEntity)
 
-    @Query("DELETE FROM todo WHERE id = :toDoId")
+    @Delete
-    suspend fun delete(toDoId: Int)
+    suspend fun delete(toDo: TodoEntity)
+
+    @Query("DELETE FROM todo WHERE id in (:toDoIds)")
+    suspend fun deleteFromIds(toDoIds: Set<Int>)
+
+    /*@Query("DELETE FROM todo")
+    suspend fun deleteAllTodo()*/
 }

app/src/main/kotlin/cn/super12138/todo/ui/components/FloatingActionButton.kt

@@ -10,7 +10,6 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
-import cn.super12138.todo.ui.TodoDefaults
 
 /**
  * 带动画且比 Material 3 内置组件动画好看的的可扩展 FAB
@@ -36,7 +35,7 @@ fun AnimatedExtendedFloatingActionButton(
         modifier = modifier
     ) {
         Row(
-            modifier = Modifier.padding(horizontal = TodoDefaults.screenPadding),
+            modifier = Modifier.padding(horizontal = 16.dp),
             verticalAlignment = Alignment.CenterVertically
         ) {
             icon()

app/src/main/kotlin/cn/super12138/todo/ui/pages/main/MainPage.kt

@@ -1,18 +1,31 @@
 package cn.super12138.todo.ui.pages.main
 
+import androidx.activity.compose.BackHandler
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.animateColorAsState
+import androidx.compose.animation.expandIn
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.shrinkOut
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Close
+import androidx.compose.material.icons.outlined.Delete
+import androidx.compose.material.icons.outlined.SelectAll
 import androidx.compose.material.icons.outlined.Settings
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.material3.adaptive.currentWindowAdaptiveInfo
 import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.runtime.Composable
@@ -44,36 +57,100 @@ fun MainPage(viewModel: MainViewModel, modifier: Modifier = Modifier) {
         }
     }
 
-    val selectedEditTodoItem = viewModel.selectedEditTodoItem
+    val selectedEditTodoItem = viewModel.selectedEditTodo
+    val selectedTodoIds = viewModel.selectedTodoIds.collectAsState()
     var openBottomSheet by rememberSaveable { mutableStateOf(false) }
     val bottomSheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
     val scope = rememberCoroutineScope()
 
     val windowSizeClass = currentWindowAdaptiveInfo().windowSizeClass
 
+    val isSelectedIdsEmpty by remember {
+        derivedStateOf {
+            selectedTodoIds.value.isEmpty()
+        }
+    }
+
+    val animatedTopAppBarColors by animateColorAsState(
+        targetValue = if (isSelectedIdsEmpty) MaterialTheme.colorScheme.surface else MaterialTheme.colorScheme.surfaceContainerHighest
+    )
+
+    BackHandler(enabled = !isSelectedIdsEmpty) {
+        // 当按下返回键（或进行返回操作）时清空选择
+        viewModel.clearAllTodoSelection()
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
+                navigationIcon = {
+                    AnimatedVisibility(!isSelectedIdsEmpty) {
+                        IconButton(onClick = { viewModel.clearAllTodoSelection() }) {
+                            Icon(
+                                imageVector = Icons.Outlined.Close,
+                                contentDescription = stringResource(R.string.tip_clear_selected_items)
+                            )
+                        }
+                    }
+                },
                 title = {
-                    Text(stringResource(R.string.app_name))
+                    Text(
+                        text = if (isSelectedIdsEmpty) {
+                            stringResource(R.string.app_name)
+                        } else {
+                            stringResource(
+                                R.string.title_selected_count,
+                                selectedTodoIds.value.size
+                            )
+                        }
+                    )
                 },
                 actions = {
-                    IconButton(
+                    AnimatedContent(isSelectedIdsEmpty) { isEmpty ->
-                        onClick = {}
+                        if (isEmpty) {
-                    ) {
+                            IconButton(
-                        Icon(
+                                onClick = {}
-                            imageVector = Icons.Outlined.Settings,
+                            ) {
-                            contentDescription = stringResource(R.string.page_settings)
+                                Icon(
-                        )
+                                    imageVector = Icons.Outlined.Settings,
+                                    contentDescription = stringResource(R.string.page_settings)
+                                )
+                            }
+                        } else {
+                            Row {
+                                IconButton(onClick = { viewModel.toggleAllSelected() }) {
+                                    Icon(
+                                        imageVector = Icons.Outlined.SelectAll,
+                                        contentDescription = stringResource(R.string.tip_select_all)
+                                    )
+                                }
+                                IconButton(onClick = { viewModel.deleteSelectedTodo() }) {
+                                    Icon(
+                                        imageVector = Icons.Outlined.Delete,
+                                        contentDescription = stringResource(R.string.action_delete)
+                                    )
+                                }
+                            }
+                        }
                     }
-                }
+
+                },
+                colors = TopAppBarDefaults.largeTopAppBarColors().copy(
+                    containerColor = animatedTopAppBarColors
+                )
             )
         },
         floatingActionButton = {
-            TodoFAB(
+            AnimatedVisibility(
-                expanded = isExpanded,
+                visible = isSelectedIdsEmpty,
-                onClick = { openBottomSheet = true }
+                enter = fadeIn() + expandIn(),
-            )
+                exit = shrinkOut() + fadeOut()
+            ) {
+                TodoFAB(
+                    expanded = isExpanded,
+                    onClick = { openBottomSheet = true }
+                )
+            }
         },
         modifier = modifier
     ) { innerPadding ->
@@ -91,8 +168,15 @@ fun MainPage(viewModel: MainViewModel, modifier: Modifier = Modifier) {
                     state = listState,
                     list = toDoList.value.filter { item -> !item.isCompleted },
                     onItemClick = { item ->
-                        openBottomSheet = true
+                        if (isSelectedIdsEmpty) {
-                        viewModel.setEditTodoItem(item)
+                            openBottomSheet = true
+                            viewModel.setEditTodoItem(item)
+                        } else {
+                            viewModel.toggleTodoSelection(item)
+                        }
+                    },
+                    onItemLongClick = { item ->
+                        viewModel.toggleTodoSelection(item)
                     },
                     onItemChecked = { item ->
                         item.apply {
@@ -107,6 +191,7 @@ fun MainPage(viewModel: MainViewModel, modifier: Modifier = Modifier) {
                             viewModel.playConfetti()
                         }
                     },
+                    selectedTodoIds = selectedTodoIds.value,
                     modifier = Modifier
                         .weight(3f)
                         .fillMaxSize()
@@ -126,8 +211,15 @@ fun MainPage(viewModel: MainViewModel, modifier: Modifier = Modifier) {
                     state = listState,
                     list = toDoList.value.filter { item -> !item.isCompleted },
                     onItemClick = { item ->
-                        openBottomSheet = true
+                        if (isSelectedIdsEmpty) {
-                        viewModel.setEditTodoItem(item)
+                            openBottomSheet = true
+                            viewModel.setEditTodoItem(item)
+                        } else {
+                            viewModel.toggleTodoSelection(item)
+                        }
+                    },
+                    onItemLongClick = { item ->
+                        viewModel.toggleTodoSelection(item)
                     },
                     onItemChecked = { item ->
                         item.apply {
@@ -142,6 +234,7 @@ fun MainPage(viewModel: MainViewModel, modifier: Modifier = Modifier) {
                             viewModel.playConfetti()
                         }
                     },
+                    selectedTodoIds = selectedTodoIds.value,
                     modifier = Modifier
                         .weight(3f)
                         .fillMaxSize()

app/src/main/kotlin/cn/super12138/todo/ui/pages/main/ManagerFragment.kt

@@ -29,7 +29,9 @@ fun ManagerFragment(
     state: LazyListState,
     list: List<TodoEntity>,
     onItemClick: (TodoEntity) -> Unit = {},
+    onItemLongClick: (TodoEntity) -> Unit = {},
     onItemChecked: (TodoEntity) -> Unit = {},
+    selectedTodoIds: List<Int>,
     modifier: Modifier = Modifier
 ) {
     val context = LocalContext.current
@@ -67,10 +69,12 @@ fun ManagerFragment(
                         content = item.content,
                         subject = Subjects.fromId(item.subject).getDisplayName(context),
                         onCardClick = { onItemClick(item) },
+                        onCardLongClick = { onItemLongClick(item) },
                         onChecked = { onItemChecked(item) },
+                        selected = selectedTodoIds.contains(item.id),
                         modifier = Modifier
                             .padding(vertical = 5.dp)
-                            .animateItem()
+                            .animateItem() // TODO: 设置动画时间
                     )
                 }
             }

app/src/main/kotlin/cn/super12138/todo/ui/pages/main/components/TodoCard.kt

@@ -1,13 +1,19 @@
 package cn.super12138.todo.ui.pages.main.components
 
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.background
 import androidx.compose.foundation.basicMarquee
+import androidx.compose.foundation.combinedClickable
 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.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.outlined.Check
 import androidx.compose.material3.ElevatedCard
@@ -18,31 +24,53 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import cn.super12138.todo.R
 
+@OptIn(ExperimentalFoundationApi::class)
 @Composable
 fun TodoCard(
     content: String,
     subject: String,
     onCardClick: () -> Unit = {},
+    onCardLongClick: () -> Unit = {},
     onChecked: () -> Unit = {},
+    selected: Boolean,
     modifier: Modifier = Modifier
 ) {
     ElevatedCard(
         modifier = modifier
             .fillMaxWidth()
-            .height(80.dp),
+            .height(80.dp)
-        onClick = onCardClick
     ) {
         Row(
             verticalAlignment = Alignment.CenterVertically,
             modifier = Modifier
                 .fillMaxSize()
+                .combinedClickable(
+                    onClick = onCardClick,
+                    onLongClick = onCardLongClick
+                )
                 .padding(horizontal = 15.dp)
         ) {
+            AnimatedVisibility(selected) {
+                Box(
+                    Modifier
+                        .padding(end = 15.dp)
+                        .clip(CircleShape)
+                        .background(MaterialTheme.colorScheme.onSecondaryContainer)
+                        .padding(5.dp)
+                ) {
+                    Icon(
+                        imageVector = Icons.Outlined.Check,
+                        tint = MaterialTheme.colorScheme.onSecondary,
+                        contentDescription = stringResource(R.string.tip_select_this)
+                    )
+                }
+            }
             Column(
                 verticalArrangement = Arrangement.Center,
                 modifier = Modifier
@@ -63,12 +91,14 @@ fun TodoCard(
                 )
             }
 
-            IconButton(onClick = onChecked) {
+            AnimatedVisibility(!selected) {
-                Icon(
+                IconButton(onClick = onChecked) {
-                    imageVector = Icons.Outlined.Check,
+                    Icon(
-                    tint = MaterialTheme.colorScheme.primary,
+                        imageVector = Icons.Outlined.Check,
-                    contentDescription = stringResource(R.string.tip_mark_completed)
+                        tint = MaterialTheme.colorScheme.primary,
-                )
+                        contentDescription = stringResource(R.string.tip_mark_completed)
+                    )
+                }
             }
 
             /*Box(

app/src/main/kotlin/cn/super12138/todo/ui/viewmodels/MainViewModel.kt

@@ -8,14 +8,22 @@ import androidx.lifecycle.viewModelScope
 import cn.super12138.todo.logic.Repository
 import cn.super12138.todo.logic.database.TodoEntity
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.firstOrNull
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 
 class MainViewModel : ViewModel() {
     val toDos: Flow<List<TodoEntity>> = Repository.getAllTodos()
-    var selectedEditTodoItem by mutableStateOf<TodoEntity?>(null)
+    var selectedEditTodo by mutableStateOf<TodoEntity?>(null)
         private set
     val showConfetti = mutableStateOf(false)
 
+    // 多选逻辑参考：https://github.com/X1nto/Mauth
+    private val _selectedTodoIds = MutableStateFlow(listOf<Int>())
+    val selectedTodoIds = _selectedTodoIds.asStateFlow()
+
     fun addTodo(toDo: TodoEntity) {
         viewModelScope.launch {
             Repository.insertTodo(toDo)
@@ -28,17 +36,75 @@ class MainViewModel : ViewModel() {
         }
     }
 
-    fun playConfetti() {
-        showConfetti.value = true
-    }
-
-    fun setEditTodoItem(toDo: TodoEntity?) {
-        selectedEditTodoItem = toDo
-    }
-
     fun deleteTodo(toDo: TodoEntity) {
         viewModelScope.launch {
             Repository.deleteTodo(toDo)
         }
     }
+
+    /*fun deleteAllTodo() {
+        viewModelScope.launch {
+            Repository.deleteAllTodo()
+        }
+    }*/
+
+    fun setEditTodoItem(toDo: TodoEntity?) {
+        selectedEditTodo = toDo
+    }
+
+    /**
+     * 切换待办的选择状态
+     */
+    fun toggleTodoSelection(toDo: TodoEntity) {
+        _selectedTodoIds.update { idList ->
+            if (idList.contains(toDo.id)) {
+                // 若已经选择取消选择
+                idList - toDo.id
+            } else {
+                // 若未选择添加到列表中，立即选中
+                idList + toDo.id
+            }
+        }
+    }
+
+    /**
+     * 切换是否全选
+     */
+    fun toggleAllSelected() {
+        viewModelScope.launch {
+            toDos.firstOrNull()?.let { todos ->
+                val allIds = todos.map { it.id }
+                _selectedTodoIds.update { currentSelectedIds ->
+                    if (currentSelectedIds.containsAll(allIds)) {
+                        // 如果当前是全选状态，取消所有选择（切换为全不选）
+                        emptyList()
+                    } else {
+                        // 如果当前不是全选状态，选中所有项
+                        allIds
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * 清除全部已选择的待办
+     */
+    fun clearAllTodoSelection() {
+        _selectedTodoIds.update { emptyList() }
+    }
+
+    /**
+     * 删除选择的待办
+     */
+    fun deleteSelectedTodo() {
+        viewModelScope.launch {
+            Repository.deleteTodoFromIds(selectedTodoIds.value)
+            clearAllTodoSelection()
+        }
+    }
+
+    fun playConfetti() {
+        showConfetti.value = true
+    }
 }

app/src/main/res/values-night/themes.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+
     <style name="Theme.ToDo" parent="android:Theme.Material.NoActionBar">
         <item name="android:statusBarColor">@android:color/transparent</item>
         <item name="android:navigationBarColor">@android:color/transparent</item>

app/src/main/res/values-zh-rCN/strings.xml

@@ -26,4 +26,7 @@
     <string name="tip_no_crash_logs">没有日志传入</string>
     <string name="action_exit_app">退出应用</string>
     <string name="action_delete">删除</string>
+    <string name="tip_clear_selected_items">清除已选择的项目</string>
+    <string name="tip_select_all">全选</string>
+    <string name="title_selected_count">已选择 %s 项</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -25,4 +25,7 @@
     <string name="tip_no_crash_logs">No crash logs</string>
     <string name="action_exit_app">Exit app</string>
     <string name="action_delete">Delete</string>
+    <string name="tip_clear_selected_items">Clear selected items</string>
+    <string name="tip_select_all">Select all</string>
+    <string name="title_selected_count">%s selected</string>
 </resources>

app/src/main/res/values/themes.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+
     <style name="Theme.ToDo" parent="android:Theme.Material.Light.NoActionBar">
         <item name="android:statusBarColor">@android:color/transparent</item>
         <item name="android:navigationBarColor">@android:color/transparent</item>