web/src/lib/components/Listbox.svelte

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<script lang="ts">
  import { createEventDispatcher } from 'svelte';
  import { createListbox } from 'svelte-headlessui';
  import { fade } from 'svelte/transition';
  import Icon from './Icon.svelte';
  import { twMerge } from 'tailwind-merge';

  type GenericOption = { value: string; name: string };

  interface Props<T extends GenericOption> {
    options: readonly T[];
    selectedValue: T['value'];
    selectedOptionPrefix?: string;
    label?: string | undefined;
    id?: string | undefined;
    errorMessage?: string | undefined;
  }

  let {
    options,
    selectedValue = $bindable(),
    selectedOptionPrefix = '',
    label = undefined,
    id = undefined,
    errorMessage = undefined
  }: Props<GenericOption> = $props();

  let listbox = $state(
    createListbox({
      label: 'Actions',
      selected: options.find((option) => option.value === selectedValue) ?? options[0]
    })
  );

  $effect(() => {
    const newSelectedOption = options.find((option) => option.value === selectedValue);
    if (newSelectedOption) {
      listbox.set({ selected: newSelectedOption });
    }
  });

  const dispatch = createEventDispatcher<{ selectedValue: string }>();

  function onSelect(e: Event) {
    const selected = (e as CustomEvent).detail.selected.value;
    selectedValue = selected;
    dispatch('selectedValue', selected);
  }
</script>

<div class="flex flex-col gap-2">
  {#if label}
    <label for={id} class="text-sm ml-1 text-color">
      {label}
    </label>
  {/if}

  <div class="relative w-full">
    <button
      use:listbox.button
      onselect={onSelect}
      class={twMerge(
        'rounded-md dark:bg-shade-d400 w-full px-4  ring-1 ring-gray-300 dark:ring-gray-500 flex items-center h-[40px] text-color focus-within:ring-2 focus-within:ring-gray-400 transition group relative',
        $listbox.expanded && 'ring-creator-gray4',
        errorMessage && 'ring-red-600! ring-2'
      )}
    >
      <span class="block truncate text-sm">{selectedOptionPrefix} {$listbox.selected.name}</span>
      <Icon
        name="chevronDown"
        class={twMerge(
          ' pointer-events-none absolute right-3 top-1/2 -translate-y-1/2  w-[18px] transition-transform',
          $listbox.expanded && '-rotate-180'
        )}
      />
    </button>

    {#if $listbox.expanded}
      <ul
        use:listbox.items
        transition:fade={{ duration: 100 }}
        class="absolute mt-1 max-h-60 py-1 z-20 w-full border overflow-auto dark:bg-shade-d400 bg-shade-l200 rounded-md text-sm shadow-lg text-color"
      >
        {#each options as option, idx (idx)}
          {@const selected = $listbox.selected === option}
          <li
            class={twMerge(
              'relative cursor-default select-none py-2 pr-4 transition-colors p-[10px]  hoverable',
              selected && 'dark:!bg-shade-d170 !bg-shade-l600'
            )}
            use:listbox.item={{ value: option }}
          >
            <span class="block truncate {selected ? 'font-medium' : 'font-normal'}"
              >{option.name}</span
            >
          </li>
        {/each}
      </ul>
    {/if}
  </div>

  {#if errorMessage}
    <span class="text-red-600 text-xs font-medium ml-1">
      {errorMessage}
    </span>
  {/if}
</div>