web-greeter-theme-basealt/wallpapper.js

const DEFAULT_WALLPAPPER = "defaultWallpapper";
const WALLPAPPER_ELEMENT = "wallpappers";


function setWallpapper(wallpapper) {
    console.log(wallpapper)
    var body = document.getElementsByTagName('body')[0];
    body.style.backgroundImage = wallpapper;
}

function updateWallpapper(wallpapper) {
    let wall_file = `url(wallpappers/${wallpapper})`
    if (wallpapper === 'User') {
        setWallpapper(`url(wallpappers/Rosatomflot.jpg)`)
        theme_utils.dirlist(`/usr/share/web-greeter/themes/basealt/wallpappers`, true, (images) => {
	        if(images) {
	            console.log(images)
		        for (let i = 0; i < images.length; i++) {
			        let image = images[i]
			        if(image.indexOf("/wallpapper.png") == image.length - 15) {
				        setWallpapper(`url(${image})`)
			            console.log(wall_file)
			        }
		        }
	        }
        });
    } else {
       setWallpapper(`url(wallpappers/${wallpapper})`)
    }
}