feat: add arrow key support to Selector

webui/src/components/utils/Input.svelte

@@ -29,6 +29,7 @@
     on:input={onInput}
     on:focus={() => (focused = true)}
     on:blur={() => (focused = false)}
+    on:keydown
     {disabled}
   />
 </div>

webui/src/components/utils/Selector.svelte

@@ -182,14 +182,59 @@
     visible = false;
   }
 
-  let inputFocused = false;
-  let hover = false;
-  $: visible = (inputFocused || hover) && Boolean(options.length);
+  let listEl: HTMLUListElement;
+  let optionFocusIndex: number = -1;
+  function handleArrowKeys(ev: KeyboardEvent) {
+    if (!options.length) {
+      return;
+    }
+
+    const optionEls = Array.from(listEl.children) as HTMLLIElement[];
+    const currentIndex = optionEls.findIndex(
+      (el) => document.activeElement === el
+    );
+
+    let targetIndex = currentIndex;
+    switch (ev.key) {
+      case "ArrowDown":
+        targetIndex += 1;
+        
+        // pressed down on last
+        if (targetIndex >= optionEls.length) {
+          targetIndex = 0;
+        }
+        break;
+      case "ArrowUp":
+        targetIndex -= 1;
+
+        // pressed up on input
+        if (targetIndex == -2) {
+          targetIndex = optionEls.length - 1;
+        }
+
+        // pressed up on first
+        if (targetIndex == -1) {
+          focus();
+          return;
+        }
+        break;
+      default:
+        return; // early return, stop processing
+    }
+
+    if (optionEls[targetIndex]) {
+      optionEls[targetIndex].focus();
+    }
+  }
 
   let input: Input;
   export function focus() {
     input.focus();
   }
+
+  let inputFocused = false;
+  $: visible =
+    (inputFocused || optionFocusIndex > -1) && Boolean(options.length);
 </script>
 
 <div class="selector">
@@ -206,18 +251,28 @@
       bind:value={inputValue}
       on:input={onInput}
       on:focusChange={(ev) => (inputFocused = ev.detail)}
+      on:keydown={handleArrowKeys}
       {disabled}
       {placeholder}
     />
   {/if}
-  <ul
-    class="options"
-    class:visible
-    on:mouseenter={() => (hover = true)}
-    on:mouseleave={() => (hover = false)}
-  >
-    {#each options.slice(0, MAX_OPTIONS) as option}
-      <li on:click={() => set(option)}>
+  <ul class="options" class:visible bind:this={listEl}>
+    {#each options.slice(0, MAX_OPTIONS) as option, idx}
+      <!-- svelte-ignore a11y-no-noninteractive-tabindex -->
+      <li
+        tabindex="0"
+        on:click={() => set(option)}
+        on:mousemove={() => focus()}
+        on:focus={() => (optionFocusIndex = idx)}
+        on:blur={() => (optionFocusIndex = -1)}
+        on:keydown={(ev) => {
+          if (ev.key === "Enter") {
+            set(option);
+          } else {
+            handleArrowKeys(ev);
+          }
+        }}
+      >
         {#if option.attribute}
           {option.attribute}
         {:else if option.value}
@@ -282,11 +337,16 @@
       cursor: pointer;
       padding: 0.5em;
 
-      transition: background-color 0.2s;
+      transition: background-color 0.1s;
       &:hover {
         background-color: var(--background-lighter);
       }
 
+      &:focus {
+        background-color: var(--background-lighter);
+        outline: none;
+      }
+
       .type,
       .content {
         display: inline-block;