ElyPDF: a preview overtaken by an edit says so (P-10)

apps/ely-pdf/src/tests/editing.rs

@@ -397,3 +397,33 @@ fn a_small_picture_on_text_under_a_page_form_still_aims() {
     click(cx, &view, (140.0, 66.0));
     assert!(matches!(cx.update(|_, app| view.read(app).aim), Some(Aim::Text { .. })), "the text, not the form around it");
 }
+
+#[test]
+fn a_preview_overtaken_by_an_edit_says_so() {
+    use ely_gpui_component::primitives::Severity;
+    let dir = tempfile::tempdir().expect("a temp dir");
+    let mut cx = TestAppContext::single();
+    let (viewer, cx, view) = editing(&mut cx, dir.path());
+    // The window's toasts live on its root.
+    let root = cx.update(|window, app| {
+        let root = ely_ui::document_root(ely_platform::AppId::Pdf, viewer.clone().into(), &ely_ui::commands::FILE, Vec::new(), window, app);
+        viewer.update(app, |viewer, _| viewer.core.root = root.downgrade());
+        root
+    });
+    click(cx, &view, (80.0, 66.0));
+    type_in(cx, &viewer, "Hi world\nSecond line");
+    cx.update(|_, app| viewer.update(app, |viewer, cx| {
+        // A new font asks for a preview first.
+        viewer.edit_panel.update(cx, |panel, _| panel.font = "times".into());
+        viewer.write_text(false, cx);
+        // An edit lands before the preview answers.
+        if let Some(view) = viewer.active_view() {
+            view.update(cx, |view, _| view.version += 1);
+        }
+    }));
+    let changed = cx.update(|_, app| Viewer::text(app, "pdf.object.changed", &[]));
+    settle(cx, |app| root.read(app).toasts(app).iter().any(|(text, severity)| *severity == Some(Severity::Warning) && *text == changed));
+    frames(cx);
+    assert!(cx.update(|_, app| viewer.read(app).preview.is_none()), "no stale preview");
+    assert_eq!(cx.update(|_, app| view.read(app).edited), 0, "nothing written");
+}

apps/ely-pdf/src/writes.rs

@@ -71,7 +71,8 @@ impl Viewer {
         let (asked, viewer) = (writing.clone(), cx.weak_entity());
         view.update(cx, |view, cx| {
             let doc = view.doc;
-            view.read(
+            // A stale answer still reaches `previewed`, which says so.
+            view.off(
                 move |worker| worker.put_text(doc, page, &asked, PREVIEW),
                 move |_, answer, cx| {
                     // The viewer edits this view; wait until it is free.
@@ -95,6 +96,11 @@ impl Viewer {
         replacing: bool,
         cx: &mut Context<Self>,
     ) {
+        let same = self.tab(tab).is_some_and(|open| open.view.read(cx).version == version);
+        if !same {
+            let text = Self::text(cx, "pdf.object.changed", &[]);
+            return self.toast(text, Severity::Warning, cx);
+        }
         match answer {
             Ok(Wrote::Unwritable) => {
                 let note = Self::text(cx, "pdf.text.unwritable", &[]);

tasks/BUGS.md

@@ -42,7 +42,7 @@
 - [x] P-07 含连字的文字块永远不可编辑 — 字形按 stext 的写法展开（多字字形、连字码点），整页、单块与删除同一判法；R3 PASS
 - [x] P-08 页面读取失败后每帧重试、每帧弹提示 — 失败的读取按页或种类记下，编辑后重读；签名读取以保存计数判过期
 - [x] P-09 识别文字的写入被拒后仍弹“成功” — on_same 回报是否执行；被拒时只有警告
-- [ ] P-10 预览回复被丢弃时“应用”静默无事
+- [x] P-10 预览回复被丢弃时“应用”静默无事 — 预览回复照常交回，版本已变即提示，不显示过期预览
 - [ ] P-11 撤销或重做在 MuPDF 侧失败后 worker 的步数不再同步
 - [ ] P-12 `unhook` 中途抛出时泄漏保留的对象
 - [ ] P-13 优化导出的“之前”大小取磁盘文件而非当前文档