fix(screen-reader): disable FileDropZone area-label for models withou…

…t file upload (huggingface#1295)

Co-authored-by: Nathan Sarrazin <sarrazin.nathan@gmail.com>

src/lib/components/chat/ChatWindow.svelte

@@ -163,6 +163,8 @@
 			: []),
 		...(currentModel.multimodal ? ["image/*"] : []),
 	];
+
+	$: isFileUploadEnabled = activeMimeTypes.length > 0;
 </script>
 
 <div class="relative min-h-0 min-w-0">
@@ -312,7 +314,7 @@
 					/>
 				{:else}
 					<div class="ml-auto gap-2">
-						{#if activeMimeTypes.length > 0}
+						{#if isFileUploadEnabled}
 							<UploadBtn bind:files mimeTypes={activeMimeTypes} classNames="ml-auto" />
 						{/if}
 						{#if messages && lastMessage && lastMessage.interrupted && !isReadOnly}
@@ -334,12 +336,12 @@
 				on:dragenter={onDragEnter}
 				on:dragleave={onDragLeave}
 				tabindex="-1"
-				aria-label="file dropzone"
+				aria-label={isFileUploadEnabled ? "file dropzone" : undefined}
 				on:submit|preventDefault={handleSubmit}
 				class="relative flex w-full max-w-4xl flex-1 items-center rounded-xl border bg-gray-100 focus-within:border-gray-300 dark:border-gray-600 dark:bg-gray-700 dark:focus-within:border-gray-500
 			{isReadOnly ? 'opacity-30' : ''}"
 			>
-				{#if onDrag && activeMimeTypes.length > 0}
+				{#if onDrag && isFileUploadEnabled}
 					<FileDropzone bind:files bind:onDrag mimeTypes={activeMimeTypes} />
 				{:else}
 					<div class="flex w-full flex-1 border-none bg-transparent">