[wearable_rotary] Add a `RotatoryDetector` widget

[alestiago]

Description

As a Flutter developer I'm used to using a GestureDetector to listen to user gesture inputs. Where I pass callbacks and I don't have to deal with disposing controllers.

I would like to have a RotatoryDetector widget or similar that allows me listening to events with an API similar to the one offered by GestureDetector.

For example:

RotatoryDetector(
  onRotate: (details) => {},
);

I would expect the details to have information such as RotatoryDirection and other values available with a RotatoryScrollController.

I think the API is opened for discussion. I'm willing to contribute once agreed on a solution. Thanks for this plugin.

[Issue opened on wearable_rotary 2.0.0]

[renancaraujo]

Rather than a Gesture detector, this should be more like a keyboard input since focus could affect the targeting of the input rather than HitTesting.
In other words, the proposed widget should contain/receive a FocusNode to define if it should accept the input.

[swift-kim]

Hi. I like the idea of creating a dedicated widget to treat rotation events like key events.

cc @Rexios80 Do you happen to have any specific comments on this?

[Rexios80]

What's the use-case for this that a StreamBuilder can't handle?

[renancaraujo]

Cases in which rotary events shouldn't trigger a widget rebuild directly.
It is an event semantically closer to gesture and keyboard events, not network or things coming from state management layers.

[Rexios80]

I strongly disagree with putting things like this in the widget tree, but it's not my place to tell other developers how to write their code. If other developers are going to want this, I don't have an issue with adding it.

[renancaraujo]

User input logic IS user interface logic. I'm afraid I have to disagree with putting things like this outside the widget tree.

[swift-kim]

I don't have a specific opinion but if you think it's appropriate, please feel free to contribute.