GUACAMOLE-2277: On-Screen Keyboard: incorrect Meta keysym generated.

[bbennett-ks]

Currently, the On-Screen Keyboard Meta key generates Super_L keysym. This works fine for RDP sessions:

• Linux, treats it as the Meta key.
• Windows interprets as Meta which is treated as the Windows key.

With VNC, inconsistent browser key events are generated

• Linux, pressing Meta emits an Alt/Shift sequence.
• macOS: pressing Meta emits AltLeft.

Emitting Meta_L instead:

• RDP, Windows and Linux: change in behavior.
• VNC, Linux macOS: Meta browser key events are generated.

See the Jira for more details: https://issues.apache.org/jira/browse/GUACAMOLE-2277

[necouchman]

Looking back at the history of this file, it seems we've gone back and forth about it:

8b5cdbb

We should probably discuss which one really makes the most sense so we're not swapping back and forth every few years...

@mike-jumper ?

[bbennett-ks]

Looking back at the history of this file, it seems we've gone back and forth about it:

8b5cdbb

We should probably discuss which one really makes the most sense so we're not swapping back and forth every few years...

@mike-jumper ?

Yep, it's definitely not black & white. Though I think Super_L is lightest shade of gray. :) I have a little more detail in the Jira (https://issues.apache.org/jira/browse/GUACAMOLE-2277). Also, we could make the behavior configurable. Or make it's behavior based on session type?

But without doing something, the Meta key is useless on macOS so no Meta short cuts.

[mike-jumper]

I'm unsure about this. The Meta key is the Mac Command key, and the opposite of this was part of 1.4.0:

https://issues.apache.org/jira/browse/GUACAMOLE-1386

[mike-jumper]

Looking at the GUACAMOLE-2277 issue, it looks like there may be some confusion: the Meta key is not Alt on a PC keyboard, it's the Windows key.

Some Linux editors refer to Alt as Meta, but that's just the terminology used by those editors. Windows key is Meta, Alt is Alt.

[bbennett-ks]

Looking at the GUACAMOLE-2277 issue, it looks like there may be some confusion: the Meta key is not Alt on a PC keyboard, it's the Windows key.

Some Linux editors refer to Alt as Meta, but that's just the terminology used by those editors. Windows key is Meta, Alt is Alt.

Apologies, I was referring to key events were generated and how they were interpreted by the OS. ! I've provided more detail and clarity (hopefully!).

[bbennett-ks]

@mike-jumper @necouchman I updated https://issues.apache.org/jira/browse/GUACAMOLE-2277 with more details, including before and after this fix for OSes & protocols.

Based on these results, I believe this is the correct fix.