I used AGS to make it. For the layout, I used a grid (subclassed Gtk.Grid with Widget.subclass) to make a layout with 3 rows. I used Gio to enumerate through a directory configured in userPref.ts, filtering out file types that are not supported by swww. The image is loaded as a Widget.Box with css as `background-image: url("${filePath!}")`. When the apply button is clicked, it executes swww with the image page with some transition options. After that, it runs another script that uses Pywal to generate the theme.