I have written an AppleScript which, among other things, sets my desktop background. However, using AppleScript's "set picture" changes the background abruptly - it doesn't look too good. Is there a way to get the nice fade effect that is used when you cycle the background via the Desktop & Screen Saver preferences' "Change Picture" setting?
Ideally, I'd like to do this in AppleScript, but if it's possible in Cocoa (or something else), please do let me know! Thanks!
Answering my own question!
It's not exactly what I was looking for, but close enough:
set picture rotation to 1 -- turn on wallpaper cycling
set change interval to -1 -- force a change to happen right now
delay 1.5 -- wait a bit to allow for the fade transition - you may want to play w/ this #
set picture of item N of theDesktops to POSIX file ("yourfilenamehere.png") -- set wallpaper to wallpaper you want
set picture rotation to 0 -- turn off wallpaper cycling
By taking advantage of Apple's built-in wallpaper changer, you can get the fade effect in AppleScript, but you'll need to put whatever images you want to change between in a directory together and select it either in the Desktop & Screen Saver preferences or programmatically.
Also, set picture rotation to 1 seems to automatically change the wallpaper to what I think is the first image (alphabetically) in that directory - I didn't bother to test this, though, it didn't matter for my purposes. The delay of 1.5 allows for a bit of blinking, but since the image I was using was a TARDIS, that's acceptable and actually made for a cool effect (so long as we watch out for weeping angels!)