I have a background with four different values. I have a wide shot, a close up shot, a beauty shot and a screen shot. It is basically the same background with different transform values. Instead of having to duplicate the background, I would like to have only one layer with checkbox that would activivate a specific transform keyframe. Is it possible?
Indeed, Dropdowns are a great application for this - just as Roland said.
But instead of applying the same expression on all properties, better use timeRemap and stick it to the selected keyframe time. You can use any of your properties, as long as the keyframes are not shifted to each other. This will also works with markers. You need as much keyframes as menu entries, but it doesn't matter where you place them.
And this effectively will stop the time on the layer, so if there are any animations going on, we need another approach.
The code looks like this:
prop = *pickwhip one of the properties with the keyframes here*