feat: add combobox filter

examples/gallery/src/main.rs

@@ -1146,6 +1146,7 @@ fn combo_option(label: &'static str) -> ComboboxOption<SharedString> {
 struct ComboboxDemo {
     branch: Entity<ComboboxState<SharedString>>,
     label: Entity<ComboboxState<SharedString>>,
+    fuzzy: Entity<ComboboxState<SharedString>>,
     label_created: Option<SharedString>,
     _subscriptions: Vec<gpui::Subscription>,
 }
@@ -1199,15 +1200,43 @@ impl ComboboxDemo {
             });
         });
         let label = cx.new(|cx| ComboboxState::new(label_builder, window, cx));
+        // A caller-owned matcher: characters in order, so "md" finds "markdown".
+        let fuzzy = cx.new(|cx| {
+            ComboboxState::new(
+                Combobox::new(
+                    "combo-demo-fuzzy",
+                    "Module",
+                    vec![
+                        combo_option("combobox"),
+                        combo_option("dock"),
+                        combo_option("editor"),
+                        combo_option("markdown"),
+                    ],
+                )
+                .placeholder("Filter modules…")
+                .filter(|query, _value, label| {
+                    let label = label.to_lowercase();
+                    let mut letters = label.chars();
+                    query
+                        .to_lowercase()
+                        .chars()
+                        .all(|letter| letters.any(|found| found == letter))
+                }),
+                window,
+                cx,
+            )
+        });
         // The panel is a cached view in the dock: the value readouts re-render
         // only when the picker states it reads are notified.
         let subscriptions = vec![
             cx.observe(&branch, |_, _, cx| cx.notify()),
             cx.observe(&label, |_, _, cx| cx.notify()),
+            cx.observe(&fuzzy, |_, _, cx| cx.notify()),
         ];
         Self {
             branch,
             label,
+            fuzzy,
             label_created: None,
             _subscriptions: subscriptions,
         }
@@ -1266,6 +1295,17 @@ impl Render for ComboboxDemo {
                             .child(format!("label: {label_value}")),
                     ),
             ))
+            .child(demo_section(
+                "custom matcher",
+                colors,
+                v_flex().gap_2().child(
+                    Field::new("combo-demo-fuzzy-field", "Module")
+                        .description(
+                            "The matcher is caller-owned: this one matches characters in order.",
+                        )
+                        .child(self.fuzzy.clone()),
+                ),
+            ))
     }
 }