I've used xfce off and on for a few years and I'm back. I'm hoping there's a way to set an image as wallpaper from Thunar, or some command to add to gthumb or geeqie to allow me to do the same without having to go through the settings manager and browsing for the image?
Since xfdesktop doesn't accept an image file as an argument, I set up a custom action in Thunar.
In the Desktop Preferences of the Settings Manager, set the file to use as the image; I used /home/me/xfcewall. This will actually be a symlink to the actual image you want to use.
In Thunar, configure a custom action:
Name: Set as wallpaper
Description: Use this image as the desktop wallpaper
Command: ln -sf %f /home/me/xfcewall; xfdesktop --reload
Icon: I'm using the "background" icon under application icons
If you're using a list, obviously this won't work. I suppose it would be trivial to append an image to the list, but you wouldn't be able to choose it since the reload selects a random image from the list.