ElyPDF: page pictures stay through an edit until they repaint (P-02)

apps/ely-pdf/src/edits.rs

@@ -115,9 +115,14 @@ impl PdfView {
             // A page may now stand where another stood.
             self.retire_tiles();
             self.sizes = measured;
+            self.thumbs_stale.clear();
+            for (_, image) in self.thumbs.drain() {
+                self.retired.push(image);
+            }
         } else {
-            // Same pages: old tiles stay under them until repainted.
+            // Same pages: old pictures stay until repainted.
             self.keep_all();
+            self.thumbs_stale.extend(self.thumbs.keys().copied());
             let read = fresh.first.len();
             self.sizes[..read].copy_from_slice(&measured[..read]);
         }
@@ -125,9 +130,6 @@ impl PdfView {
         self.failed.clear();
         self.text.clear();
         self.asking_text.clear();
-        for (_, image) in self.thumbs.drain() {
-            self.retired.push(image);
-        }
         self.thumbs_failed.clear();
         // Indices shift with any edit; aims start over.
         (self.layers, self.aim, self.drag) = (Default::default(), None, None);

apps/ely-pdf/src/side.rs

@@ -1,6 +1,6 @@
 //! Page pictures, and bookmarks if any (PDF-01, PDF-02).
 
-use std::{collections::BTreeSet, ops::Range};
+use std::{collections::BTreeSet, ops::Range, sync::Arc};
 
 use ely_gpui_component::{
     buttons::SegmentedControl,
@@ -9,7 +9,7 @@ use ely_gpui_component::{
     theme::{ActiveTheme as _, ControlSize},
 };
 use gpui::{
-    Action, App, Context, Entity, InteractiveElement as _, IntoElement, ParentElement as _, Render, Role,
+    Action, App, Context, Entity, InteractiveElement as _, IntoElement, ParentElement as _, Render, RenderImage, Role,
     StatefulInteractiveElement as _, Styled as _, WeakEntity, Window, div, img, prelude::FluentBuilder as _, px,
     uniform_list,
 };
@@ -104,7 +104,8 @@ impl PdfView {
         if self.thumbing {
             return;
         }
-        let Some(page) = rows.clone().find(|page| !self.thumbs.contains_key(&(*page, dark)) && !self.thumbs_failed.contains(page)) else {
+        let due = |page: &usize| !self.thumbs.contains_key(&(*page, dark)) || self.thumbs_stale.contains(&(*page, dark));
+        let Some(page) = rows.clone().find(|page| due(page) && !self.thumbs_failed.contains(page)) else {
             return;
         };
         let (w, h) = self.sizes[page];
@@ -127,6 +128,7 @@ impl PdfView {
                 });
                 match painted.map(|bgra| crate::pages::picture((tile[2] as u32, tile[3] as u32), bgra)) {
                     Ok(Some(image)) => {
+                        view.thumbs_stale.remove(&(page, dark));
                         if let Some(old) = view.thumbs.insert((page, dark), image) {
                             view.retired.push(old);
                         }
@@ -145,13 +147,20 @@ impl PdfView {
     }
 }
 
+impl PdfView {
+    /// The picture a row draws; an old one until repainted.
+    pub fn picture(&self, page: usize, dark: bool) -> Option<Arc<RenderImage>> {
+        self.thumbs.get(&(page, dark)).cloned()
+    }
+}
+
 /// One row: the page number and its picture.
 fn row(view: &Entity<PdfView>, page: usize, dark: bool, cx: &App) -> gpui::AnyElement {
     let read = view.read(cx);
     let colors = &cx.theme().colors;
     let (w, h) = read.sizes[page];
     let picked = read.picked.contains(&page);
-    let picture = read.thumbs.get(&(page, dark)).cloned();
+    let picture = read.picture(page, dark);
     let count = read.sizes.len();
     let label = Viewer::text(cx, "pdf.page.label", &[("n", &(page + 1).to_string())]);
     let (clicked, pressed, dropped) = (view.clone(), view.clone(), view.clone());

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

@@ -326,3 +326,31 @@ fn old_tiles_are_painted_and_freed_with_their_tab() {
     cx.update(|_, app| view.update(app, |view, _| view.retire_all()));
     assert!(cx.update(|_, app| view.read(app).backdrop.is_empty()), "closing hands every old tile over");
 }
+
+#[test]
+fn an_edit_keeps_page_pictures_until_they_repaint() {
+    let dir = tempfile::tempdir().expect("a temp dir");
+    let mut cx = TestAppContext::single();
+    let (viewer, cx) = windowed(&mut cx, dir.path(), &[file(dir.path(), "one.pdf", &[(612.0, 792.0, &["Hello"])])], true);
+    let view = shown(cx, &viewer);
+    let dark = cx.update(|_, app| ely_gpui_component::theme::ActiveTheme::theme(app).is_dark());
+    settle(cx, |app| view.read(app).picture(0, dark).is_some() && repainted(view.read(app)));
+    let old = cx.update(|_, app| view.read(app).picture(0, dark).expect("a picture"));
+    // A picture on its way holds back the repaint.
+    cx.update(|_, app| view.update(app, |view, _| view.thumbing = true));
+    cx.update(|_, app| view.update(app, |view, cx| view.annotate("adding a note", vec![note()], cx)));
+    settle(cx, |app| view.read(app).edited == 1 && repainted(view.read(app)));
+    // Dropped from the atlas, it returns only if drawn.
+    cx.update(|window, _| window.drop_image(old.clone())).expect("drops");
+    super::frames(cx);
+    assert!(cx.update(|window, _| window.has_image_atlas_entry(&old)), "the old picture shows meanwhile");
+    cx.update(|_, app| view.update(app, |view, cx| {
+        view.thumbing = false;
+        cx.notify()
+    }));
+    settle(cx, |app| view.read(app).thumbs_stale.is_empty());
+    let new = cx.update(|_, app| view.read(app).picture(0, dark).expect("a picture"));
+    assert!(!std::sync::Arc::ptr_eq(&new, &old), "the new picture replaces it");
+    super::frames(cx);
+    assert!(cx.update(|window, _| window.has_image_atlas_entry(&new)), "and is drawn");
+}

apps/ely-pdf/src/view.rs

@@ -71,6 +71,8 @@ pub struct PdfView {
     /// Page pictures for the side panel, by page and darkness.
     pub thumbs: HashMap<(usize, bool), Arc<RenderImage>>,
     pub thumbs_failed: HashSet<usize>,
+    /// Pictures from before an edit; shown until repainted.
+    pub thumbs_stale: HashSet<(usize, bool)>,
     /// A picture is on its way from the worker.
     pub thumbing: bool,
     /// Pages picked in the side panel, and the anchor.
@@ -188,6 +190,7 @@ impl PdfView {
             mark: loaded.mark,
             thumbs: HashMap::new(),
             thumbs_failed: HashSet::new(),
+            thumbs_stale: HashSet::new(),
             thumbing: false,
             picked: BTreeSet::new(),
             anchor: None,