How to implement multi-windowed layout (like the default browser) (Editor with several open files)
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I am writing an editor (of sorts) which I want to be able to have multiple windows open at the same time, and I want to be able to navigate between windows as can be done in the default browser (Internet) application.  See picture: http://i.imgur.com/LM6Nz.png for clarification.

My question is how to implement these windows;  Do I want each window to be an own (Editor) Activity, should I use Fragments (I am mainly designing for API 10, and Fragments arrived in API 11, but I read somewhere this should be fine).  Or do I simply hack together some different Views in a ViewGroup?

If I use Fragments, do I place them in a ViewGroup?