Fragment animation question

In the Honeycomb sample gallery app, there's a layout that uses a two-fragment setup: one on the left of the screen showing titles, and one on the right showing the selected content. The titles fragment can be hidden with an animation.

During the hiding animation, the app asks the framework to recalculate the layout on every single frame. This way the content-fragment can take up the empty space that the titles-fragment leaves behind w开发者_开发问答hile it moves off-screen. This produces a great, dynamic effect, but is terribly inefficient I think.

I have fairly complex layouts, and I'd rather not ask the system to re-layout on every single frame. But I'd like a smooth transition animation like in the sample. Are there any alternative solutions to this problem?

P.s.: Just to be clear, I'm not asking how to do basic fragment-transaction animations. I know those, and AFAIK, those animations can't produce the behaviour found in that sample gallery app (another example would be the Honeycomb Gmail app, it has similar transitions that I'd like to achieve).

You can provide custom animations to the fragment system that do whatever you want. You can move the fragments around, fade them, etc. If these animations do not explicitly or implicitly cause layout (by changing properties that trigger a layout), then you should not get a layout on each animation frame. There maybe still be a layout call at the beginning/end as the fragments are added/removed, but the layout/invalidation process during the animation is up to your animations and what they do.