Support input from the PS Vita's on-screen keyboard

[DvaMishkiLapa]

Would love to have this feature.

Main challenges:

• Is there functionality to transfer the selected keyboard character to VitaSDK?
• If there is no such functionality, what would be the maximum size of the string to be transferred? FlatBuffers might be able to handle passing an array of strings, dynamically determining the packet size allocated for them.
• What key combination should be used to call the on-screen keyboard?

[DvaMishkiLapa]

While I was implementing the transfer of battery information, I looked at how much space we had in the FlatBuffer for the sake of interest.

The results were good. I created a lot of garbage in the packet, eventually going from 144 bytes to 320 bytes. The sending delay did not increase in any way. The Vita was 1 meter away from the WiFi router, my PC was 5 meters away. My latency was 7-8 ms.

I think it makes sense to send strings via FB. It would be easier to implement and the Vita's WiFi adapter should be able to handle it.

[santarl]

What key combination should be used to call the on-screen keyboard?

I think we should have a config system that allows the user to specify their own key combination to trigger the keyboard as everyone plays differently. This can be combined with #13

If there is no such functionality, what would be the maximum size of the string to be transferred? FlatBuffers might be able to handle passing an array of strings, dynamically determining the packet size allocated for them.

I think a better approach would be to collect the string first from the vita after user presses Enter and closes the keyboard, and then break down the string into multiple chunks and send them through flatbuffers. This should be no problem as we send update once ever 10ms or so (or faster) and would prevent the packet from getting too big (or unpredictable)

The reason I suggest collecting the string first instead of sending every keycode realtime is so that we don't lose the auto correction feature in vita keyboard.