Xamarin.Forms support for UWP

Problem to solve

Support UWP for Xamarin.Forms apps

Intended users

LibVLCSharp.Forms users

Proposal

Close to getting it working at https://github.com/mfkl/libvlcsharp/tree/uap-xf but:

• Retrieving the swapchain CLI options to give to libvlc through the Xamarin Forms abstraction layer is PITA and makes for an awkward API.
• Currently, due to Xamarin.Forms handling of native views, sharpdx initialization fails because the videoView is not fully loaded and sized. It needs to be worked around. This needs to be fixed for libvlc 3.x Xamarin.Forms UWP support.
• Note that Xamarin.Forms does not support uap10.0 target, so we actually need 2 uap builds of libvlcsharp.

With libvlc 4.0 (nightlies), we would not need this hackery because we'd not need the swapchain options. But

• There is no setup for nightlies build to be pushed on myget/nuget. edit: there is now.
• Those would be unstable builds.
• We'd need to implement d3d11/gl callbacks for this to work and adapt it with the swapchain.