How would I implement a swipe-based circular control like this?

Question

I am working on an Android application, and I have a TextView where I display a price (for example 50$).

I would like to have a circular control similar to this picture:

Answer 1

You can use the Android Gesture Builder from the Android SDK samples.

I can't test it right now, but you should be able to create the app from the sample, run it, create the custom gestures you want (circular clockwise and circular counter clockwise), and then get the gestures raw file from the device/emulator internal storage (it is created by the app after you make the gestures).

With that, you can import it to your project and use the Gesture Library to intercept, register and recognize the specific gestures. You basically add an overlay layout where you want the gesture to be captured and then you decide what to do with it.

See more in depth, step-by-step guide in the following link: http://www.techotopia.com/index.php/Implementing_Android_Custom_Gesture_and_Pinch_Recognition