Consider how connections could be made in Rust

[ahayzen-kdab]

Problem

On the Rust side you cannot connect to a signal from the QObject or other QObjects.

Proposed Solution

Use a closure + the signals enum + existing signals ( #286 ) to allow Rust to connect to a signal, then run a closure with the enum of the signal.

self.connect(|qobject, signal| {
  match signal {
    SignalsEnum::Signal(...) => {
      ... // do work
    }
  }
});

Discussion points

• This doesn't connect to a single signal and would require us to connect to all signals in the enum and proxy them to any closures
  • Can we pass the SignalsEnum::Signal(...) as a parameter to the connection so it knows which signals to connect to on the C++ side and which to trigger in Rust?
• Do we need to consider Queued vs Direct vs Auto connection modes?
• Or do we generate a method for every signal to allow you to connect self.my_signal_connect(|| { ... }) ? This then means that the C++ side would know which signal to connect to and the Rust side can just take the qobject + signal enum so it can read any args

[ahayzen-kdab]

#485 solves this with the route described in #473 which allows for adding a closure to the signal, specifying auto/queued etc, and disconnecting.