Not firing key-up when layer shift is released out of order.

[mythmon]

I have a key that triggers layerShift( 1 ). On the associated layer, I have a key to press the left arrow key. If I hold the layerShift key, then hold the left arrow key, then release the layerShift key, and then release the left arrow key, the left arrow keyup event is not sent, and the key repeats until any other key is pressed.

I'm using an Infinity keyboard.

[haata]

Interesting. I believe I've run into the same problem as well (though I wasn't quite sure how it happened).

What would you think the correct behaviour would be?

I'm sort've leaning towards sending all release codes for anything that is being triggered by that layer.
I'll have to check how easy it is to do this.

[tmk]

It is exaclty what my firmware does. It unregisters all of hold down keys every time changing layers. But except for modifiers, keeping modifier state is useful for most case. So modifiers can be still stuck in unusual keymap in my firmware. Though, this behaviour rarely bother users.

[mythmon]

To be concrete, the key that has the left arrow is H normally. So if I pressed Fn+H, I'd get left arrow. I'd expect that if I released Fn, the left arrow would still be repeated until I released H. I could also live with sending the key up when Fn was released. As long as the key release gets sent when one of the keys is released, I think the bug would be fixed.

[cucook]

The HHKB works in the same manner that @mythmon describes, where the key-up for the layer-shifted button is only sent when that physical key is released, not when the layer is released.

[haata]

I've had a chance to think about this for a few days, and I think I have a good way to fix this now.

When a key is pressed, there is a "pending keys" buffer. This is used to process all possible key input events (just think of this like a giant regex). Right now, on each processing loop the layer is checked right before evaluating a step in the regex.
The planned change is to evaluate and track the layer when each key is "pressed" in the "pending keys" buffer.

This way the layer stays constant, even if it has been unset.

Pending other issues, I'll try to get a fix in for this in the next week or so.

[dumle29]

I didn't quite understand that last comment of yours haata :/ Will this mean my delete key wont keep deleting the rest of my document if I let go of the fn key before I let go of the delete key? :P

If you want to keep this behaviour for anyone making a feature out of it, maybe you could have a switch per layer that can be set to true or false, as in "KEY_UP all keys on layer exit?

[haata]

Yeah, I think the current behaviour is a bug.

However, "locking" a key might be useful in some cases. So I'm going to add a feature like this in future revisions of the kll spec.

[haata]

I nearly have a fix written. Should have at least a feature branch to test this evening.

[haata]

Fixed: f07e934

Because it made the most sense, I am doing what the HHKB does and assign a key to layer it was first pressed on. Any layer changes that happen while the key is held will have no effect until the key is released.

Let me know if there are still any issues.