combobox: default icon support, smart icon width

src/lib/Combobox.svelte

@@ -24,7 +24,7 @@
 	import { Portal } from '@jsrob/svelte-portal';
 	import { browser } from '$app/environment';
 	import { scale } from 'svelte/transition';
-	import { generateIdentifier } from './util';
+	import { generateIdentifier, type IconDef } from './util';
 	import type { ClassValue } from 'svelte/elements';
 	import { matchSorter } from 'match-sorter';
 	import Spinner from './Spinner.svelte';
@@ -40,6 +40,8 @@
 		invalidMessage?: string | null;
 		label?: string;
 		placeholder?: string;
+		/** displayed by default if no item is selected that has its own icon */
+		icon?: IconDef;
 		/**
 		 * enables loading spinner and fallback text if no items are found. may be changed
 		 * internally if lazy is enabled. loading is, however, not bindable, so don't expect
@@ -76,6 +78,7 @@
 		invalidMessage = 'Please select an option',
 		label,
 		placeholder,
+		icon,
 		loading = false,
 		lazy = false,
 		compact = false,
@@ -98,6 +101,7 @@
 	let searchValue = $state('');
 	let pickerPosition = $state<'top' | 'bottom'>('bottom');
 	let searching = $state(false);
+	let iconWidth = $state<number | undefined>(undefined);
 
 	let searchInput = $state<HTMLInputElement | null>(null);
 	let searchContainer = $state<HTMLDivElement | null>(null);
@@ -121,13 +125,12 @@
 	});
 
 	/** controls whether an icon should be displayed */
-	let iconVisible = $derived.by(() => {
-		return (
-			(open && highlighted && highlighted.icon) ||
+	let iconVisible = $derived(
+		(open && highlighted && highlighted.icon) ||
 			(value && value.icon && searchValue === '') ||
-			loading
-		);
-	});
+			loading ||
+			icon !== undefined
+	);
 
 	/** controls whether the highlighted option should be used in the selection preview  */
 	let useHighlighted = $derived.by(() => {
@@ -494,9 +497,11 @@
 		{#if iconVisible}
 			<div
 				class={[
+					(iconWidth === undefined || iconWidth === 0) && 'opacity-0',
 					'pointer-events-none absolute top-1/2 left-3.5 -translate-y-1/2 transform select-none'
 				]}
 				transition:scale
+				bind:clientWidth={iconWidth}
 			>
 				{#if loading}
 					<Spinner class="stroke-sui-accent! -mt-0.5" size="1em" />
@@ -504,6 +509,8 @@
 					{@render highlighted.icon(highlighted)}
 				{:else if value?.icon}
 					{@render value.icon(value)}
+				{:else if icon}
+					<icon.component {...icon.props} />
 				{:else}
 					❌
 				{/if}
@@ -511,7 +518,8 @@
 		{/if}
 
 		<StyledRawInput
-			class={[iconVisible && 'pl-10', caret && 'pr-9', !valid && 'border-red-500!']}
+			style={iconWidth && iconVisible ? `padding-left: ${iconWidth + 14 + 10}px` : undefined}
+			class={[caret && 'pr-9', !valid && 'border-red-500!']}
 			{compact}
 			type="text"
 			name={name + '_search'}

src/routes/+page.svelte

@@ -151,6 +151,12 @@
 		/>
 
 		<Combobox
+			icon={{
+				component: Plus,
+				props: {
+					size: '1.2em'
+				}
+			}}
 			label="Lazy combobox"
 			placeholder="Choose..."
 			options={lazyOptions}