Allow arbitrary scancodes

[mondalaci]

Let's allow users to provide custom scancodes. There are 3 types of scancodes according to the USB interfaces that the UHK exposes:

• The basic keyboard interface implements the Keyboard/Keypad Page. See chapter 10, page 53 of HID Usage Tables. Scancode type abbreviation is B for basic.
• The media keyboard interface implements the Consumer Page. See chapter 15, page 75 of HID Usage Tables. Scancode type abbreviation is M for media.
• The system keyboard interface implements the Generic Desktop Page. See chapter 4, page 26 of HID Usage Tables. Scancode type abbreviation is S for system.

As for the valid numeric intervals of the scancodes, it's 1-255 for basic and system scancodes and 1-65535 for media scancodes.

Users will be able to write a string composed of the scancode type and scancode number into the scancode field of the key action popover and the macro editor to specify the desired scancode. Examples are B62, M180, and S10.

The scancode select2 widget won't contain custom scancodes because they're of no use for most. This way, the feature will be available for advanced users, but it won't confuse regular users.

When entering a custom scancode, Agent will look up the scancode.

• If the scancode is already part of the scancodes that Agent exposes in the scancode select2 widget then choose the relevant select2 item, and render its key as such.
• Otherwise, display the custom scancode as it is, like B62 in the select2 widget, and render its key as such.

Currently, Agent replaces unknown scancodes that are not part of the select2 widget with none actions when encountering with them. For this feature to work correctly, Agent must not replace such scancodes anymore, but leave them as they are.

[luteijn]

Great news, thanks for coming up with this way of making it workable.

[laxu]

Can we find if there is some software that could deduce the scancodes needed, e.g. by using the custom keys on a laptop and the software telling the scancodes received? We could then recommend this software for finding out the scancodes needed as that can be an endeavour in itself because a lot of manufacturers don't document them anywhere.

E.g. "To add custom scancode, run this software, press the custom key on your laptop and use the received scancode in UHK Agent".

[mondalaci]

@laxu To my knowledge, every OS does some sort of abstraction under the hood that makes user space applications unable to retrieve this information, and so, no such software exists.

[kareltucek]

On linux there's showkey (showkey --scancodes). It has to be run from tty.

Of course, if some sort of laptop firmware translates its specific scancodes on too low abstraction level, it might not tell you anything.

[luteijn]

The technique explained at https://jacksautohotkeyblog.wordpress.com/2016/04/14/understanding-autohotkey-keyboard-scan-codes-and-virtual-key-codes-beginning-hotkeys-part-12/ might be helpful for windows - especially if you plan to use AHK to receive special scancodes and act on them.

[skaldesh]

May I ask, what is the status of this issue?

[mondalaci]

No progress has been made with this issue yet. We don't have an ETA for GitHub issues, and we'll update them when progress is made.

[debbiev]

Will this let me add a handful of emojis?

[mondalaci]

No, emojis can be implemented with macros, not with special scancodes. See https://ultimatehackingkeyboard.com/blog/2018/06/23/how-can-i-type-accented-characters-with-my-uhk

[DDzwiedziu]

I'd like this quite much. As I've tried to generate a XF86XK_AudioMicMute keysym to capture it in the agent. The agent just went "None" for the scancode, but the mic mute toggled.

[FatBoyXPC]

I was just looking for XF86XK_AudioMicMute and realized I might need to do the scancode option. I'll be trying it soon!

Edit - I hit capture and it didn't seem to see that capture that keypress for me. Were you able to make this work @DDzwiedziu?

Edit again: Apparently F20 works to send that keycode for me, see this tweet for details

[mondalaci]

This feature has been implemented, and it will be included in the next Agent release.

[FatBoyXPC]

I've downloaded the latest release but I'm unsure how to input said arbitrary scancode?

[kareltucek]

As stated above, entering a code like B24 in the scancode field (tested with 1.5.17, works fine). Agent tries to lookup the scancode and if found, it will show just the actual entry. E.g., for "b24" it will show "letter U", which is confusing, but sort-of correct.

It might be a good idea to always show custom-scancode entry when custom code is entered - @mondalaci, @ert78gb?

Also, custom scancodes could be mentioned in the "?" popover.

[ert78gb]

It depends from Laci. I am fine with both solution

[mondalaci]

The scancode of B24 and U is the same, and from Agent's standpoint, they're identical. Also, from a usability standpoint, it's better to show the symbolic name of the scancode whenever possible, so we won't change the current behavior.

I'll document the custom scancode feature and mention it in the scancode tooltip according to #1642.