refactor(frontent): move components and ts to lib folder

control/frontend/src/lib/ts/stores/thumbnails.ts

@@ -0,0 +1,43 @@
+import { get, writable, type Writable } from 'svelte/store';
+import { get_thumbnail_blob } from '../api_handler';
+import { type Inode } from '../types';
+import { db } from '../files_display.db';
+import { get_file_type } from '../utils';
+
+export const active_thumbnail_urls: Writable<string[]> = writable<string[]>([]);
+
+export async function generate_thumbnail(
+	display_ip: string,
+	path: string,
+	folder_element: Inode
+): Promise<void> {
+	const supported_file_type = get_file_type(folder_element);
+	if (!supported_file_type) return;
+
+	const thumbnail_blob = await get_thumbnail_blob(display_ip, path + folder_element.name);
+	if (!thumbnail_blob) return;
+
+	folder_element.thumbnail = thumbnail_blob;
+
+	await db.files.put(folder_element); // save
+}
+
+export async function get_thumbnail_url(file: Inode): Promise<string | null> {
+	if (!file.thumbnail) return null;
+	const new_url = URL.createObjectURL(file.thumbnail);
+	active_thumbnail_urls.update((current: string[]) => {
+		current.push(new_url);
+		return current;
+	});
+	return new_url;
+}
+
+export function deactivate_old_thumbnail_urls() {
+	const current_urls = get(active_thumbnail_urls);
+	for (const url of current_urls) {
+		URL.revokeObjectURL(url);
+	}
+	active_thumbnail_urls.update(() => {
+		return [];
+	});
+}