ElyShow: switching slides repaints the canvas (R2.4)

crates/ely-lok/src/view/lane.rs

@@ -23,7 +23,8 @@ pub(super) struct Job {
 
 /// What came back from the lane.
 enum Landed {
-    Input(u64, bool, (io::Result<Option<String>>, Option<u64>)),
+    /// Sequence, whether it edits, whether it switched part, outcome.
+    Input(u64, bool, bool, (io::Result<Option<String>>, Option<u64>)),
     Tile(Job, io::Result<Tile>),
 }
 
@@ -46,6 +47,7 @@ impl LokView {
                         input = input_queue.next() => {
                             let Some((seq, input, sent)) = input else { break };
                             let (waited, edits) = (sent.elapsed().as_millis(), input.edits());
+                            let switched = matches!(input, super::input::Input::Part(_));
                             let outcome = super::input::run(&worker, &doc, input);
                             let took = sent.elapsed().as_millis();
                             if took > SLOW_MS {
@@ -53,7 +55,7 @@ impl LokView {
                             } else {
                                 log::debug!("lok: input {seq} waited {waited}, took {took} ms");
                             }
-                            Landed::Input(seq, edits, outcome)
+                            Landed::Input(seq, edits, switched, outcome)
                         }
                         job = tile_queue.next() => {
                             let Some(job) = job else { break };
@@ -96,8 +98,12 @@ impl LokView {
         let mut reported = false;
         for landed in batch {
             match landed {
-                Landed::Input(seq, edits, outcome) => {
+                Landed::Input(seq, edits, switched, outcome) => {
                     self.applied = seq;
+                    // Same tile keys, another slide or sheet.
+                    if switched {
+                        self.invalidate(cx);
+                    }
                     self.edited += u64::from(edits);
                     let (outcome, now) = outcome;
                     if edits {

crates/ely-lok/src/view/tests/input.rs

@@ -269,3 +269,44 @@ fn the_clipboard_moves_html_tables_and_images() {
     let xml = std::fs::read_to_string(&out).expect("the save reads");
     assert!(xml.contains("<draw:image"), "the image lands");
 }
+
+/// Two slides, each with one line of text.
+const DECK: &str = r#"<?xml version="1.0" encoding="UTF-8"?>
+<office:document xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0"
+ xmlns:draw="urn:oasis:names:tc:opendocument:xmlns:drawing:1.0"
+ xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0"
+ xmlns:svg="urn:oasis:names:tc:opendocument:xmlns:svg-compatible:1.0"
+ office:version="1.3" office:mimetype="application/vnd.oasis.opendocument.presentation">
+ <office:body><office:presentation>
+  <draw:page draw:name="one"><draw:frame svg:x="2cm" svg:y="2cm" svg:width="10cm" svg:height="3cm"><draw:text-box><text:p>One</text:p></draw:text-box></draw:frame></draw:page>
+  <draw:page draw:name="two"><draw:frame svg:x="2cm" svg:y="8cm" svg:width="10cm" svg:height="3cm"><draw:text-box><text:p>Two</text:p></draw:text-box></draw:frame></draw:page>
+ </office:presentation></office:body>
+</office:document>"#;
+
+#[test]
+fn switching_slides_repaints_the_shown_tiles() {
+    let Some(install) = crate::client::tests::install() else {
+        eprintln!("SKIP: no pinned LOK build");
+        return;
+    };
+    let mut cx = TestAppContext::single();
+    let (view, _) = cx.update(|app| live_view_of(app, &install, "deck.fodp", DECK));
+    let before = cx.update(|app| {
+        view.update(app, |view, cx| {
+            let side = view.geom.tile_pixels() as usize;
+            let tile = crate::Tile { generation: view.generation, pixels: vec![0; side * side * 4] };
+            view.finish_tile((0, 0), view.geom, Ok(tile), cx);
+            let image = Arc::clone(&view.tiles[&(0, 0)].image);
+            view.show_part(1);
+            image
+        })
+    });
+    flush(&cx);
+    cx.update(|app| {
+        let entry = &view.read(app).tiles[&(0, 0)];
+        assert!(
+            entry.stale || !Arc::ptr_eq(&entry.image, &before),
+            "the first slide's tile must not stay"
+        );
+    });
+}