android, use camera as a background for an activity

I have a request that background for my activi开发者_StackOverflow中文版ty must be "transparent", ie. background of an activity should be camera's current view. What is the easiest way to implemet this? I have all the activities already implemented, with all the logic already implemented. Ideally, solution wouldn't include a lot of modification of an existing code.

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Normally this is done with SurfaceView. Use it via camera.setPreviewDisplay(surfaceView)

To use it in your app, the simplest way would be to use FrameLayout as a top layout of your Activity and then put SurfaceView any you current top layout inside it.

`FrameLayout`
    `SurfaceView`
    `yourExistingLayout`

Of course your existing layout must be transparent to see the underlying SurfaceView. Note also that this alpha blending takes a lot of processor power so it will eat battery.