Systems that display multiple video sources across multiple screens often allow
the video feed from any computer to be redirected to any screen. In such systems,
typically only the control screen is touch-sensitive, because every other
screen would need to be physically wired to a single, predetermined computer,
which is impractical when the displayed video is redirected dynamically. This
thesis therefore presents a solution that exports the touchscreen device over
the network via the USB/IP protocol to whichever computer’s content is
currently shown on that screen, relying on the existing video-routing system
to determine which computer that is. This makes every screen touch-sensitive,
not just the control screen. Software running on the target computer remaps
or blocks touch events via the evdev interface according to the screen region
they belong to, which works both when a screen shows a single computer and
when it shows content from multiple computers. As the solution must also
operate reliably in the event of failures, it is designed to recover automatically
after a device or network outage without any user intervention. Measurements
on the finished prototype show that the additional latency the solution
introduces for touch input is negligible; across every tested type of failure,
the system consistently recovered automatically to a working state.
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