fix(select): a picked picture that is edited away no longer leaves its highlight behind

crates/ui-egui/src/canvas.rs

@@ -3275,6 +3275,7 @@ pub fn document_area(app: &mut PdfCraftApp, index: usize, ui: &mut egui::Ui) {
             if tool == QuickTool::Select && !consumed {
                 crate::image_pick::page_input(&resp, &xf, i, info, doc, pointer, view);
             }
+            crate::image_pick::drop_stale(doc, view);
             crate::image_pick::paint(painter, &xf, i, info, view);
             comments::page_after_text(&resp, &pcx, view);
             if tool == QuickTool::Redact && can_modify {

crates/ui-egui/src/editing.rs

@@ -52,6 +52,12 @@ impl PdfCraftApp {
                 let Some(doc) = self.session.get(id) else { return true };
                 let info = &doc.info;
                 let view = &mut self.views[i];
+                // A picture picked with the Select tool may be the one this edit removed or moved:
+                // drop its highlight now, not on the next frame (which only comes with the next input).
+                view.picked_image = None;
+                if let Some(ctx) = &self.ctx {
+                    ctx.request_repaint();
+                }
                 if !matches!(edit, Edit::AddAnnotation(_)) {
                     // Only a new drawing waits on its raster; any other edit may remove or move it.
                     view.comments.settling.clear();

crates/ui-egui/src/image_pick.rs

@@ -9,12 +9,14 @@ use crate::PdfCraftApp;
 use crate::canvas::{DocView, PageXform};
 use pdfcraft_render::DocInfo;
 
-/// The selected picture: page, index in `page_images` and its box in user space.
+/// The selected picture: page, index in `page_images` and its box in user space, and the
+/// document's edit generation when it was picked (any later edit may have removed or renumbered it).
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct PickedImage {
     pub page: usize,
     pub index: usize,
     pub rect: [f64; 4],
+    pub generation: u64,
 }
 
 const BLUE: Color32 = Color32::from_rgb(0x3A, 0x7B, 0xF0);
@@ -43,8 +45,18 @@ pub(crate) fn page_input(
     let (vx, vy) = xf.screen_to_view(p);
     let u = info_page.view_to_user(vx, vy);
     let at = [f64::from(u[0]), f64::from(u[1])];
+    let generation = doc.edit_generation();
     view.picked_image =
-        doc.page_image_at(page, at).and_then(|index| doc.page_images(page).get(index).map(|i| PickedImage { page, index, rect: i.rect }));
+        doc.page_image_at(page, at).and_then(|index| doc.page_images(page).get(index).map(|i| PickedImage { page, index, rect: i.rect, generation }));
+}
+
+/// Forget the selected picture once the document has been edited since it was picked: Edit text &
+/// images (or Undo) may have deleted or moved it, and its highlight would stay behind on an empty
+/// spot of the page.
+pub(crate) fn drop_stale(doc: &pdfcraft_engine::Document, view: &mut DocView) {
+    if view.picked_image.is_some_and(|p| p.generation != doc.edit_generation()) {
+        view.picked_image = None;
+    }
 }
 
 /// The selected picture's highlight on page `page`.

crates/ui-egui/tests/viewer.rs

@@ -1384,6 +1384,55 @@ fn a_clicked_picture_is_selected_and_copied_in_its_original_format() {
     assert_eq!(h.state().views[i].picked_image, None);
 }
 
+/// A picture picked with the Select tool, then deleted in Edit text & images, leaves no highlight
+/// behind on the empty spot where it was.
+#[test]
+fn a_picked_picture_that_is_deleted_in_edit_mode_loses_its_highlight() {
+    let (_, mut h) = picture_harness();
+    let i = h.state().active.unwrap();
+    let id = h.state().views[i].id;
+    let at = h.state().views[i].page_screen_rect(0).expect("on screen").center();
+    h.hover_at(at);
+    h.run_steps(1);
+    h.event(egui::Event::PointerButton { pos: at, button: egui::PointerButton::Primary, pressed: true, modifiers: Default::default() });
+    h.event(egui::Event::PointerButton { pos: at, button: egui::PointerButton::Primary, pressed: false, modifiers: Default::default() });
+    h.run_steps(2);
+    assert!(h.state().views[i].picked_image.is_some(), "picked with the Select tool");
+    // Edit text & images: click the picture, delete it with the Delete key.
+    assert!(h.state_mut().execute("edit.edit_text"));
+    h.run_steps(2);
+    h.hover_at(at);
+    h.run_steps(1);
+    h.drag_at(at);
+    h.run_steps(1);
+    h.drop_at(at);
+    h.run_steps(2);
+    h.key_press(egui::Key::Delete);
+    // One frame, no more input: the highlight goes at once, it does not wait for a click.
+    h.run_steps(1);
+    assert!(h.state().session.get(id).unwrap().page_images(0).is_empty(), "the picture is gone");
+    assert_eq!(h.state().views[i].picked_image, None, "and so is its highlight");
+}
+
+/// The highlight goes in the very edit that removes the picture, not on a later frame: the window
+/// only redraws on the next input, so waiting for one leaves the highlight on screen until a click.
+#[test]
+fn an_edit_clears_the_picked_picture_at_once() {
+    let (_, mut h) = picture_harness();
+    let i = h.state().active.unwrap();
+    let at = h.state().views[i].page_screen_rect(0).expect("on screen").center();
+    h.hover_at(at);
+    h.run_steps(1);
+    h.event(egui::Event::PointerButton { pos: at, button: egui::PointerButton::Primary, pressed: true, modifiers: Default::default() });
+    h.event(egui::Event::PointerButton { pos: at, button: egui::PointerButton::Primary, pressed: false, modifiers: Default::default() });
+    h.run_steps(2);
+    assert!(h.state().views[i].picked_image.is_some(), "picked with the Select tool");
+    let delete = pdfcraft_engine::Edit::EditPageImage { page: 0, index: 0, change: pdfcraft_engine::ImageEdit::Delete };
+    assert!(h.state_mut().apply_edit(delete));
+    // No frame has run since the edit.
+    assert_eq!(h.state().views[i].picked_image, None);
+}
+
 #[test]
 fn right_click_on_a_picture_copies_it_at_full_size() {
     let (px, mut h) = picture_harness();