Tracking container focus

[markgardner10]

When you click into a container with the mouse and it gets focus, can other containers poll some event table to track that ?

Im trying to figure out how a container can do some work based on which other container gets focus

Thanks

[mum4k]

Hi @markgardner10, thank you for reaching out. I believe that the functionality you re describing isn't currently available, but shouldn't be too hard to implement it.

To confirm - you would like to have an event subscriber at a particular container? I.e. something similar to this:

termdash/termdash.go

Lines 74 to 81 in 9ed3713

	// KeyboardSubscriber registers a subscriber for Keyboard events. Each
	// keyboard event is forwarded to the container and the registered subscriber.
	// The provided function must be thread-safe.
	func KeyboardSubscriber(f func(*terminalapi.Keyboard)) Option {
	return option(func(td *termdash) {
	td.keyboardSubscriber = f
	})
	}

But with an ability to select a specific container by id and with an ability to receive the same events the container is getting (i.e. both keyboard and mouse)?

It would help me if you could describe what this will be used for, so that we can better shape the feature.

[markgardner10]

Best described with a diagram I think

[mum4k]

Thank you, that indeed helps. I have one more question - are you planning to display anything in the "Display log A", "Display log B" and "Display log C" containers?

One solution that comes to mind is to implement a widget that will display what you want (or nothing if that is desired). However this widget will also react to the focus and any keyboard / mouse events in the containers and perform the functionality you describe. Let me know if this sounds doable, if you are going to go in this direction I would give you some additional advice related to deadlock avoidance, since the infrastructure holds a container level lock while the widgets are drawing their content (which is when you can react to focus changes).

You could model this widget closely after the Button widget, which essentially does the same thing. Except the button widget does it when the button is pressed, while your widget would also do it when it receives focus.

If this doesn't sounds like a good idea, we could also add a container level subscriber to events.