From 6145b5cea22223f41aa16482d1d6f9a4c8fec892 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=9B=B7=E7=94=B5=E8=8A=BD=E8=A1=A3?=
 <zhangyanghaha0407@outlook.com>
Date: Fri, 9 Oct 2026 18:42:39 -0400
Subject: [PATCH] ElyTable: a large text file no longer freezes the window
 before its import dialog (T-09)

---
 apps/ely-table/src/text.rs | 15 +++++++++------
 tasks/BUGS.md              |  2 +-
 tasks/reviews/T-09-r1.md   |  1 +
 3 files changed, 11 insertions(+), 7 deletions(-)
 create mode 100644 tasks/reviews/T-09-r1.md

diff --git a/apps/ely-table/src/text.rs b/apps/ely-table/src/text.rs
index b517c4b..2b6a08d 100644
--- a/apps/ely-table/src/text.rs
+++ b/apps/ely-table/src/text.rs
@@ -235,13 +235,16 @@ impl Book {
         let reading = path.clone();
         let chinese = ely_ui::i18n::resolve(&ely_platform::locale::system()) == "zh-CN";
         cx.spawn(async move |this, cx| {
-            let bytes = cx
-                .background_spawn(async move { std::fs::read(&reading) })
+            // Guessing checks the whole file: off the window thread.
+            let pending = cx
+                .background_spawn(async move {
+                    std::fs::read(&reading).map(|bytes| Pending::new(reading, bytes, chinese))
+                })
                 .await;
-            in_window(&this, cx, |book, _, cx| match bytes {
-                Ok(bytes) => {
-                    log::info!("table: import asks for {} bytes", bytes.len());
-                    book.imports.push_back(Pending::new(path, bytes, chinese));
+            in_window(&this, cx, |book, _, cx| match pending {
+                Ok(pending) => {
+                    log::info!("table: import asks for {} bytes", pending.bytes.len());
+                    book.imports.push_back(pending);
                     book.next_import(cx);
                 }
                 Err(error) => book.failed_open(&path.display().to_string(), &error, cx),
diff --git a/tasks/BUGS.md b/tasks/BUGS.md
index e45637b..bfca13e 100644
--- a/tasks/BUGS.md
+++ b/tasks/BUGS.md
@@ -16,7 +16,7 @@
 - [x] T-06 滚轮向下被内核平铺区卡住 — 表格的可滚范围先行两屏、止于表尾；R1 PASS
 - [x] T-07 表头点选、行高列宽拖动是“按编号的命令”，而每次点击与拖选都推进修订，紧接着的表头操作被当作过期拒绝 — 行列号不再算作按编号的命令；R1 PASS
 - [x] T-08 自动筛选的列菜单对光标所在的表而不是按钮所在的表筛选、排序 — 先把光标移到按钮所在格再排序或筛选；R1 PASS
-- [ ] T-09 导入文本文件时整文件的 UTF-8 校验在界面线程跑
+- [x] T-09 导入文本文件时整文件的 UTF-8 校验在界面线程跑 — 编码与分隔符的猜测随读文件在后台；R1 PASS
 - [ ] T-10 CSV 导入对话框开着时打开任何别的对话框，待导入的文件静默消失
 - [ ] T-11 对话框比其标签活得久：导出、定义名称、重命名不可见却“开着”，挡住导入；名称表的“转到”激活已关闭的标签
 - [ ] T-12 打印区域是整列或整行时页面设置无法应用
diff --git a/tasks/reviews/T-09-r1.md b/tasks/reviews/T-09-r1.md
new file mode 100644
index 0000000..7ef22e9
--- /dev/null
+++ b/tasks/reviews/T-09-r1.md
@@ -0,0 +1 @@
+PASS