Background Eraser: a Tolerance set elsewhere wins over an interrupted edit (#11909)

The typed-text draft remembers the setting it was stored with and is only
used while that setting is unchanged, so a value set meanwhile (a tool
preset while the options bar was hidden) shows from the first frame.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/background_eraser_tolerance_field_tests.rs

@@ -112,6 +112,35 @@ fn a_leading_zero_typed_key_by_key_keeps_the_text() {
     assert_eq!(alert(&h), None, "05 is in range");
 }
 
+#[test]
+fn a_tolerance_set_elsewhere_during_an_edit_wins_over_the_typed_text() {
+    let mut h = app_harness();
+    h.query_all_by_role(egui::accesskit::Role::SpinButton)
+        .find(|n| n.accesskit_node().label().as_deref() == Some("Tolerance:"))
+        .expect("the Tolerance field")
+        .click();
+    h.run_steps(1);
+    h.key_press_modifiers(egui::Modifiers::COMMAND, egui::Key::A);
+    h.event(egui::Event::Text("150".into()));
+    h.run_steps(1);
+    // The bar goes away mid-edit and a preset sets the Tolerance meanwhile.
+    h.state_mut().ui.panels.options_bar = false;
+    h.run_steps(2);
+    h.state_mut().ui.tool_options.bg_tolerance = 30.0;
+    h.state_mut().ui.panels.options_bar = true;
+    h.run_steps(1);
+    // From the first frame back, the field shows the preset's value.
+    let shown = h
+        .query_all_by_role(egui::accesskit::Role::SpinButton)
+        .find(|n| n.accesskit_node().label().as_deref() == Some("Tolerance:"))
+        .expect("the Tolerance field")
+        .accesskit_node()
+        .numeric_value();
+    assert_eq!(shown, Some(30.0), "the field shows the preset's value, not the typed 150");
+    h.run_steps(2);
+    assert_eq!(tolerance(&h), 30.0, "the preset's value, not the typed 150");
+}
+
 #[test]
 fn an_expression_committed_with_enter_past_the_range_alerts() {
     let mut h = app_harness();

crates/ui-egui/src/tools/eraser_ui.rs

@@ -155,7 +155,10 @@ fn tolerance_field(ui: &mut egui::Ui, value: &mut f32) -> bool {
     // its text is left alone mid-entry (`0` on the way to `05` must not turn into `1`).
     let draft_id = ui.make_persistent_id(egui::IdSalt::new("bg-eraser-tolerance-typed"));
     // The field's own range is wide, so the typed value reaches here unclamped.
-    let mut typed = ui.ctx().data(|d| d.get_temp::<f32>(draft_id)).unwrap_or(*value);
+    // A draft only stands while the setting is still the one it stored: a value set elsewhere
+    // meanwhile (a tool preset while the bar was hidden) wins.
+    let draft = ui.ctx().data(|d| d.get_temp::<(f32, f32)>(draft_id));
+    let mut typed = draft.filter(|(_, stored)| *stored == *value).map_or(*value, |(typed, _)| typed);
     let r = widgets::value_field(ui, &mut typed, -1.0e9..=1.0e9, "%", 62.0).on_hover_text(tl!("Erase range of similar colors"));
     let out_id = r.id.with("out-of-range");
     // An edit the field never got to finish (the options bar was hidden while it had the
@@ -172,13 +175,13 @@ fn tolerance_field(ui: &mut egui::Ui, value: &mut f32) -> bool {
         let out = typing && !(1.0..=100.0).contains(&typed);
         ui.ctx().data_mut(|d| d.insert_temp(out_id, out));
         if typing && r.has_focus() {
-            ui.ctx().data_mut(|d| d.insert_temp(draft_id, typed));
+            ui.ctx().data_mut(|d| d.insert_temp(draft_id, (typed, *value)));
         } else {
-            ui.ctx().data_mut(|d| d.remove_temp::<f32>(draft_id));
+            ui.ctx().data_mut(|d| d.remove_temp::<(f32, f32)>(draft_id));
         }
     }
     if !r.has_focus() {
-        ui.ctx().data_mut(|d| d.remove_temp::<f32>(draft_id));
+        ui.ctx().data_mut(|d| d.remove_temp::<(f32, f32)>(draft_id));
     }
     r.lost_focus() && ui.ctx().data_mut(|d| d.remove_temp::<bool>(out_id)).unwrap_or(false)
 }