Add a third `active' state to a camera object

[Matthias Vogelgesang]

In order to implement a "polling" uca node, we need a way to distinguish between a stopped camera (that is able to acquire frames after a start command) and an inactive camera which is not yet ready to take frames.

Thus, we need three states S = { inactive, started, stopped } and four commands C = { activate, deactivate, start, stop } and the following transitions:

• activate({inactive}) = stopped
• start({inactive, stopped}) = started
• stop({started}) = stopped
• deactivate({started, stopped}) = inactive

All other transitions are illegal.

[Matthias Vogelgesang]

Data acquisition is triggered from outside, so we don't have to wait in a polling mode.

[Matthias Vogelgesang]

Milestone libuca-wishlist deleted