Popular Eye Candy idea...

People often suggest that it would be nice if GDM supported the ability to have animation transitions between states (starting to requesting for username, username entry to password entry, authentication to session startup, etc.).  For example, the MacOS login program makes the login experience appear as a cube that rotates as you complete each step.

Since people often ask for this feature in GDM, I'm submitting this enhancement request in case someone who has an idea of how to implement such animations wants to get involved and make GDM look more flashy.  I'd be happy to help explain how the gdmgreeter code works.  Currently it uses libgnomecanvas to render the theme and puts some GtkWidgets on the canvas.

To do something like this, GDM would probably need some code to pre-render the next screen in the background so that it can be sent into some animation engine if the transition were to work like MacOS where the next screen seems to move into place.  However, we could probably do some interesting transitions without needing to do such pre-rendering and just draw the next screen after some flash,
perhaps using alpha to fade in/out the animation effect.

The hard part for me is to imagine how the GDM theme would specify the transitions.  Perhaps it would be necessary to define what the transitions are and add a tag where the specific transitions could be specified.  Maybe they would be Theora videos that just get played full screen or something?  The code for parsing the XML file is gui/greeter/greeter_parser.c so it would likely need to be modified to support this.  I suppose the transitions could be coded in the GDM configuration file or installed to specific file locsations.  It would probably be cool if the transitions could be defined differently for each theme.  Perhaps a specific filename in the theme directory would work so you wouldn't have to modify the XML format to specify the filenames.

Not sure, but some ideas to play with.