Receive all input events

[brianmay]

Hello,

I would like to be able to turn off the screen when there has not been any user interaction, say for the last 3 minutes. I can write the appropriate screen_on and screen_off functions here.

However I need to be able to receive any events that occur whenever a mouse event is received, so I can cancel and restart the timer. Is this possible?

I guess I could reset the timer in every callback, but this seems yuck, wondering if there is a better way.

Regards

[tronical]

Hm, what operating system / windowing system are you targeting? Perhaps what you're trying to do could be done with the platform api, but it really depends on the environment.

[brianmay]

Linux/Wayland. Running on Raspberry Pi 3.

At the moment using the cage compositor. But that was a bit of a pain to setup, requiring raspbian testing + wlroots from Debian experimental. Might try redoing this setup with https://swaywm.org/ which I think should work in Raspbian bullseye.

Is that enough details?

I think I have been fixated solving this at the application layer. But you are right, maybe there are other options here.

[brianmay]

There is one advantage doing this at the application layer: I have more control, and e.g. can turn on the display if my application receives a significant event. I don't think I can do this if I do it at a higher level.

[tronical]

I was thinking that perhaps this could be done inside the application if you use the slint::platform::Platform abstraction, but on a Pi with Wayland that limits you to using the software renderer (MinimalSoftwareWindow). If you're ok with that, then you could do that and combine it with your own use of winit and spin the event loop there. Then you'll receive every input event first and you can dispatch it to slint::Window::dispatch_event, and right before that you can reset your timer.

Otherwise we need to make the Skia or FemtoVG renderer crates public for hardware accelerated rendering. Something we plan to to do, but haven't done yet.

[brianmay]

Might need to think about this a bit more.

Ideally a solution would be platform independent...

I have been experimenting with swayidle to send sway commands to turn on/off the screen. But noticed another issue - if I touch the display to turn the screen on, I also invoke what ever option I just touched (but couldn't see). So perhaps someway to disable screen events when the screen is off might be useful too. I guess if I created my own event loop I could do that.

I probably do need hardware rendering, the RPI3 isn't exactly fast.

I am not sure how I would write an event loop. Presumably I would replace my ui.run() with some sort of event loop thing?