implement onSelectionChanged

packages/svelte/src/lib/hooks/useSelectionChanged.svelte.ts

@@ -0,0 +1,15 @@
+import type { OnSelectionChanged } from '$lib/types';
+import { useStore } from '$lib/hooks/useStore';
+
+export function useSelectionChanged(onselectionchanged: OnSelectionChanged) {
+  const store = $derived(useStore());
+  const symbol = Symbol();
+
+  $effect(() => {
+    store.selectionChangedHandlers.set(symbol, onselectionchanged);
+
+    return () => {
+      store.selectionChangedHandlers.delete(symbol);
+    };
+  });
+}