I feel like you don't have much confidence in what the Android framework can or cannot do in the first place. All controls we are currently developing are only extending this network, so I feel like you will benefit much more from them, by first getting familiar with the Android framework basics.
I would recommend you to look at the official documentation available here - Android Developers Docs
It will prepare you to start thinking the Android way and you will have much more confidence using the platform, and far less struggles.
The approach of checking something every 10 milliseconds , in my opinion, should not be used in any scenario. It is far better to simply override the setZoom() method of the chart and apply your validation logic there. It will only be triggered when needed and it will not do any futile work on your thread.
Also, the RadLegendView is a View, and you don't need to ask yourself, can I rotate the RadLegendView, but rather, can I rotate a View in Android. Here is an article on the subject that might prove useful - How to Rotate View in Android 90 degrees
. There are many articles on the subject in the net, so I feel you will be fine with this one.
Thank you for using Telerik support and happy coding!
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