LR-BEHAV-ACCESS: an alert dialog carries what it says as its accessible description

crates/ui-egui/src/panels/library_problem.rs

@@ -28,6 +28,10 @@ use crate::widgets::register;
 /// windows and their dim.
 const DIM_ID: &str = "library-problem-dim";
 const ERROR_WINDOW_ID: &str = "library-problem";
+/// What the error window says about the library's safety and the way on (drawn as it is, not translated).
+const EXPLANATION: &str = "Your photos and edits in it are untouched. You can try again (e.g. after closing another program that has it open \
+                            or reconnecting its drive), open a different library or create a new one, or continue without a library — \
+                            then nothing you do is saved.";
 const CHOOSER_WINDOW_ID: &str = "library-chooser";
 
 /// The named `Foreground` layer used by the dim and the two blocking library windows.
@@ -1016,6 +1020,12 @@ pub fn show(app: &mut LightcraftApp, ctx: &egui::Context, blocked: bool) {
     dim(ctx);
     let mut choice = None;
     let frame = egui::Frame::window(&ctx.global_style()).inner_margin(egui::Margin::symmetric(18, 14));
+    // what the window says, in one piece, for a screen reader: the labels below are separate nodes
+    let description = if problem.path.is_empty() {
+        format!("{} {} {EXPLANATION}", crate::i18n::tr("LightCraft couldn't find where to keep your library."), problem.error)
+    } else {
+        format!("{} {}. {} {EXPLANATION}", crate::i18n::tr("LightCraft couldn't open the library at"), problem.path, problem.error)
+    };
     let shown = egui::Window::new(crate::i18n::tr("Your library couldn't be opened"))
         .id(egui::Id::unique(ERROR_WINDOW_ID))
         .order(egui::Order::Foreground)
@@ -1035,14 +1045,7 @@ pub fn show(app: &mut LightcraftApp, ctx: &egui::Context, blocked: bool) {
                 ui.label(RichText::new(&problem.path).font(t.semibold(12.5)).color(t.text));
             }
             ui.add(egui::Label::new(RichText::new(&problem.error).color(t.caution)).wrap());
-            ui.label(
-                RichText::new(
-                    "Your photos and edits in it are untouched. You can try again (e.g. after closing another program that has it open \
-                     or reconnecting its drive), open a different library or create a new one, or continue without a library — \
-                     then nothing you do is saved.",
-                )
-                .color(t.text_dim),
-            );
+            ui.label(RichText::new(EXPLANATION).color(t.text_dim));
             ui.add_space(4.0);
             ui.horizontal(|ui| {
                 let mut button = |ui: &mut egui::Ui, id: &str, label: &str, enabled: bool, c: Choice| {
@@ -1060,6 +1063,7 @@ pub fn show(app: &mut LightcraftApp, ctx: &egui::Context, blocked: bool) {
         });
     if let Some(w) = &shown {
         crate::widgets::announce_dialog(ctx, &w.response, crate::widgets::Modal::Alert);
+        crate::widgets::describe_dialog(ctx, &w.response, &description);
         // A press on the dim raises its area; keep this window (and its own buttons) above it.
         ctx.move_to_top(w.response.layer_id);
     }

crates/ui-egui/src/panels/notices.rs

@@ -513,6 +513,7 @@ fn window(ctx: &egui::Context, id: &str, title: &str, text: &str, buttons: &[(&s
     // A backdrop press can raise its area; keep the prompt buttons above it.
     if let Some(window) = shown {
         crate::widgets::announce_dialog(ctx, &window.response, crate::widgets::Modal::Alert);
+        crate::widgets::describe_dialog(ctx, &window.response, text);
         ctx.move_to_top(window.response.layer_id);
     }
     input.button_ids = seen;

crates/ui-egui/src/widgets.rs

@@ -1186,6 +1186,13 @@ pub(crate) fn announce_dialog(ctx: &egui::Context, response: &Response, kind: Mo
     });
 }
 
+/// Gives the dialog `response` drew the words it says as its accessible description, for an alert
+/// whose content (the task names, the error) is drawn as separate labels: a screen reader then
+/// has what the alert is about when it announces the alert, not only its title.
+pub(crate) fn describe_dialog(ctx: &egui::Context, response: &Response, text: &str) {
+    ctx.accesskit_node_builder(response.id, |node| node.set_description(text));
+}
+
 /// The same for one that is on or off (a toggle, a selected row or swatch).
 pub(crate) fn announce_selected(resp: &egui::Response, name: impl Into<String>, selected: bool) {
     let name = name.into();

crates/ui-egui/tests/it/dialog_role.rs

@@ -85,3 +85,30 @@ fn a_library_that_could_not_be_opened_is_a_modal_alert_dialog() {
         assert_eq!((role, modal), (Role::AlertDialog, true), "{title:?} is a modal alert dialog");
     }
 }
+
+/// The description of every alert dialog in the tree.
+fn alert_descriptions(h: &Harness<'_, LightcraftApp>) -> Vec<String> {
+    h.root()
+        .children_recursive()
+        .map(|n| n.accesskit_node())
+        .filter(|n| n.role() == Role::AlertDialog)
+        .map(|n| n.data().description().unwrap_or_default().to_string())
+        .collect()
+}
+
+#[test]
+fn an_alert_carries_what_it_says_as_its_description() {
+    let mut h = harness();
+    h.state_mut().quit_prompt = Some(lightcraft_ui_egui::QuitPrompt::Tasks("1 task is still running: Import. Quitting stops it.".into()));
+    h.run_steps(6);
+    let said = alert_descriptions(&h);
+    assert!(said.iter().any(|d| d.contains("1 task is still running: Import")), "the quit prompt names the task: {said:?}");
+    let mut h = harness();
+    h.state_mut().library_problem = Some(lightcraft_ui_egui::panels::library_problem::LibraryProblem::new("/no/such/library", "No catalog here."));
+    h.run_steps(6);
+    let said = alert_descriptions(&h);
+    assert!(
+        said.iter().any(|d| d.contains("/no/such/library") && d.contains("No catalog here.") && d.contains("untouched")),
+        "the library alert has its path, error and explanation: {said:?}"
+    );
+}