From cfb10a04f5141fa10bbecce5dc9046207c3c13f7 Mon Sep 17 00:00:00 2001
From: Rinde van Lon <rindevanlon@gmail.com>
Date: Wed, 11 Jun 2025 11:01:34 +0100
Subject: [PATCH] Improve `ComboBox` doc example (#7116)
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Improves the `ComboBox` example with some code that shows how to handle
changes in the `ComboBox`’s selection. The approach is based on the
advice given in https://github.com/emilk/egui/discussions/923 . I hope
this saves future me (and hopefully others) a web search for how to do
this.

* [x] I have followed the instructions in the PR template
---
 crates/egui/src/containers/combo_box.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/crates/egui/src/containers/combo_box.rs b/crates/egui/src/containers/combo_box.rs
index ab89c435..3ae8344b 100644
--- a/crates/egui/src/containers/combo_box.rs
+++ b/crates/egui/src/containers/combo_box.rs
@@ -16,9 +16,10 @@ pub type IconPainter = Box<dyn FnOnce(&Ui, Rect, &WidgetVisuals, bool)>;
 ///
 /// ```
 /// # egui::__run_test_ui(|ui| {
-/// # #[derive(Debug, PartialEq)]
+/// # #[derive(Debug, PartialEq, Copy, Clone)]
 /// # enum Enum { First, Second, Third }
 /// # let mut selected = Enum::First;
+/// let before = selected;
 /// egui::ComboBox::from_label("Select one!")
 ///     .selected_text(format!("{:?}", selected))
 ///     .show_ui(ui, |ui| {
@@ -27,6 +28,10 @@ pub type IconPainter = Box<dyn FnOnce(&Ui, Rect, &WidgetVisuals, bool)>;
 ///         ui.selectable_value(&mut selected, Enum::Third, "Third");
 ///     }
 /// );
+///
+/// if selected != before {
+///     // Handle selection change
+/// }
 /// # });
 /// ```
 #[must_use = "You should call .show*"]