Do extensions use jar files also? Or did you mean

Do extensions use jar files also? Or did you mean themes? Extensions are downloaded with xpi but I don't know if the xpi file will generate jar files. Thanks for explaining. I will see and try this method also. Anyway, I think that perhaps you could explain on the text that this will not work on local files unless if bundled to a content folder of the jar of an extension (theme whatever), converted to data:URI or if the image is loaded from a server. Anyway, good job on this style.