feel free to keep it strictly simple...

BE-Theme Templates

If you want to adapt the BE-Theme templates of your addon to the look and feel of the Standard Themes (LEPSem and Talgos) you can make them automatically available in all Backend Themes. Just follow these steps (starting with L* 5.4.0):

1. put all matching templates in addon-folder, for instance  /backendthemes/talgos/backend

2. put following line in the install.php and upgrade.php of your addon

LEPTON_handle::moveThemeFiles( __FILE__ );

3. put following line in the uninstall.php of your addon 

LEPTON_handle::removeAllThemeFiles(__FILE__);

and you are done.

See for example code and files of foldergallery.