preloadImages.js

            preloadPhotographs() {
                let photos = this.photographs;
                let preloaded = new Array();
                photos.forEach(photo => {
                    let image = new Image();
                    image.src = photo.source;
                    image.onload = () => {
                        preloaded.push(image);
                        if (preloaded.length === photos.length) {
                            this.loading = false;
                            // Event.$emit('loading', false);
                        }
                    };
                });
            },