feat(editor): 在编辑模式下用户修改待办后阻止返回

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

@@ -0,0 +1,73 @@
+package cn.super12138.todo.ui.components
+
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.Icon
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.vector.ImageVector
+
+@Composable
+fun BasicDialog(
+    visible: Boolean,
+    icon: ImageVector,
+    title: String,
+    text: @Composable (() -> Unit)? = null,
+    confirmButton: String,
+    dismissButton: String,
+    onConfirm: () -> Unit,
+    onDismiss: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    BasicDialog(
+        visible = visible,
+        icon = {
+            Icon(
+                imageVector = icon,
+                contentDescription = null // 会跟下面的文本重复，所以设置为 null
+            )
+        },
+        title = {
+            Text(title)
+        },
+        text = text,
+        confirmButton = {
+            FilledTonalButton(onClick = onConfirm) {
+                Text(confirmButton)
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(dismissButton)
+            }
+        },
+        onDismissRequest = onDismiss,
+        modifier = modifier
+    )
+}
+
+@Composable
+fun BasicDialog(
+    visible: Boolean,
+    icon: @Composable (() -> Unit)? = null,
+    title: @Composable () -> Unit,
+    text: @Composable (() -> Unit)? = null,
+    confirmButton: (@Composable () -> Unit),
+    dismissButton: (@Composable () -> Unit)? = null,
+    onDismissRequest: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    if (visible) {
+        AlertDialog(
+            icon = icon,
+            title = title,
+            text = text,
+            confirmButton = confirmButton,
+            dismissButton = dismissButton,
+            onDismissRequest = onDismissRequest,
+            modifier = modifier
+        )
+    }
+}

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

@@ -20,6 +20,7 @@ import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.outlined.Delete
+import androidx.compose.material.icons.outlined.ErrorOutline
 import androidx.compose.material.icons.outlined.Save
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
@@ -52,6 +53,7 @@ import cn.super12138.todo.logic.model.Priority
 import cn.super12138.todo.logic.model.Subjects
 import cn.super12138.todo.ui.TodoDefaults
 import cn.super12138.todo.ui.components.AnimatedExtendedFloatingActionButton
+import cn.super12138.todo.ui.components.BasicDialog
 import cn.super12138.todo.ui.components.FilterChipGroup
 import cn.super12138.todo.ui.components.LargeTopAppBarScaffold
 
@@ -66,8 +68,35 @@ fun TodoEditorPage(
     animatedVisibilityScope: AnimatedVisibilityScope,
     modifier: Modifier = Modifier
 ) {
-    BackHandler { // TODO: 实现用户更改后的阻止返回
-        onNavigateUp()
+    var showConfirmDialog by rememberSaveable { mutableStateOf(false) }
+
+    fun checkModifiedBeforeBack() {
+        if (toDo !== null) {
+            val newTodo = TodoEntity(
+                content = toDo.content,
+                subject = toDo.subject,
+                isCompleted = toDo.isCompleted,
+                priority = toDo.priority,
+                id = toDo.id
+            )
+            /*val newTodo = TodoEntity( // TODO: 只要用户有修改就阻止返回（当前是在编辑状态下检测）
+                content = toDo?.content ?: "",
+                subject = toDo?.subject ?: 0,
+                isCompleted = toDo?.isCompleted ?: false,
+                priority = toDo?.priority ?: 0f,
+                id = toDo?.id ?: 0
+            )*/
+            if (newTodo !== toDo) {
+                showConfirmDialog = true
+            } else {
+                onNavigateUp()
+            }
+        } else {
+            onNavigateUp()
+        }
+    }
+    BackHandler {
+        checkModifiedBeforeBack()
     }
     val context = LocalContext.current
     val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior()
@@ -131,7 +160,9 @@ fun TodoEditorPage(
                 }
             }
         },
-        onBack = onNavigateUp,
+        onBack = {
+            checkModifiedBeforeBack()
+        },
         modifier = modifier
     ) { innerPadding ->
         Column(
@@ -225,4 +256,18 @@ fun TodoEditorPage(
             Spacer(Modifier.size(40.dp))
         }
     }
+
+    BasicDialog(
+        visible = showConfirmDialog,
+        icon = Icons.Outlined.ErrorOutline,
+        title = stringResource(R.string.title_warning),
+        text = { Text(stringResource(R.string.tip_discard_changes)) },
+        confirmButton = stringResource(R.string.action_confirm),
+        dismissButton = stringResource(R.string.action_cancel),
+        onConfirm = {
+            showConfirmDialog = false
+            onNavigateUp()
+        },
+        onDismiss = { showConfirmDialog = false }
+    )
 }

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

@@ -81,4 +81,5 @@
     <string name="pref_category_todo_list">待办列表</string>
     <string name="pref_view_on_github">在 GitHub 上查看</string>
     <string name="pref_view_on_github_desc">查看源代码、提交错误报告和改进建议</string>
+    <string name="tip_discard_changes">退出编辑后将无法找回你修改过的数据。确定退出编辑吗？</string>
 </resources>

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

@@ -82,4 +82,5 @@
     <string name="pref_category_todo_list">To-Do List</string>
     <string name="pref_view_on_github">View On GitHub</string>
     <string name="pref_view_on_github_desc">View source code, submit bug reports, and improvement suggestions</string>
+    <string name="tip_discard_changes">After exiting edit mode, you will not be able to retrieve the data you have modified. Are you sure you want to exit editing?</string>
 </resources>