[macOS] Fix keyboard shortcuts on non QWERTY keyboard layouts.

[bruvzg]

Hopefully fix shortcuts on all non QWERTY layouts, gets key mapping from os keyboard layout instead of hardcoded maps.

Fixes (on macOS) #11777

Please test this with physical non-QWERTY keyboards before merging, I have tested it with software layouts only.

[Calinou]

Does this pull request affect running projects? Also, will this fix be ported to other platforms as well?

[bruvzg]

Yes this will affect projects, but macOS already had remapping for main layout (AZERTY, QWERTZ, Colemak, Dvorak and Neo), this PR just extends remapping to all possible layouts.

No idea about other platforms, I didn't look how layouts work on Windows/X11, currently there's not any remapping on other platform. (see comment below)

[green-coder]

It works!

I compiled that version on my computer and tested it. The editor works, both the text input and the shortcuts are correct. Nice !

For the record, my computer runs on OSX 10.13.3, the keyboard was a QWERTY which I use as a Programmer Dvorak via software remapping (in the macOS' settings).

[bruvzg]

I have removed some of the previous comments and consolidated all testing data from different platforms in this one.

Notes:

• Text input is NOT affected by this PR in any way, only scancodes.
• Other platforms are not affected by this PR (latin_keyboard_keycode_convert was only used on macOS).
• With this PR non-QWERTY latin layouts works similar on all platforms.
• Layouts w/o latin letters at all does not work correctly on Linux.

Testing process:

Test code:

func _unhandled_input(event):
	if event is InputEventKey:
		if event.pressed:
			print("%d %s" % [event.scancode, OS.get_scancode_string(event.scancode)])

Steps to reproduce:

1. Select specified keyboard layout in OS settings.
2. Press all keys in top letter row (QWERTYUIOP[] on QWERTY keyboard) left-to-right one by one.

Layout: DVORAK L (Left handed)

macOS without PR	macOS with PR	Debian GNU/Linux 9, Xfce 4	Manjaro Linux 17, KDE	Windows 10
81 Q	59 Semicolon	59 Semicolon	59 Semicolon	59 Semicolon
87 W	81 Q	81 Q	81 Q	81 Q
69 E	66 B	66 B	66 B	66 B
82 R	89 Y	89 Y	89 Y	89 Y
84 T	85 U	85 U	85 U	85 U
89 Y	82 R	82 R	82 R	82 R
85 U	83 S	83 S	83 S	83 S
73 I	79 O	79 O	79 O	79 O
79 O	46 Period	46 Period	46 Period	46 Period
80 P	16777356 Kp 6	54 6	54 6	54 6
123 BraceLeft	16777355 Kp 5	53 5	53 5	53 5
125 BraceRight	61 Equal	61 Equal	61 Equal	61 Equal

Layout: Crimean Tatar (Turkish F)

macOS without PR	macOS with PR	Debian GNU/Linux 9, Xfce 4	Manjaro Linux 17, KDE	Windows 10
81 Q	70 F	70 F	70 F	70 F
87 W	71 G	71 G	71 G	71 G
69 E	69 E	0	0	59 Semicolon
82 R	82 R	0	0	73 I
84 T	79 O	79 O	79 O	79 O
89 Y	68 D	68 D	68 D	68 D
85 U	82 R	82 R	82 R	82 R
73 I	78 N	78 N	78 N	78 N
79 O	72 H	72 H	72 H	72 H
80 P	80 P	80 P	80 P	80 P
123 BraceLeft	81 Q	81 Q	81 Q	81 Q
125 BraceRight	87 W	87 W	87 W	87 W

Layout: Russian (Phonetic)

macOS without PR	macOS with PR	Debian GNU/Linux 9, Xfce 4	Manjaro Linux 17, KDE	Windows 10
81 Q	81 Q	0	0	81 Q
87 W	87 W	0	0	87 W
69 E	69 E	0	0	69 E
82 R	82 R	0	0	82 R
84 T	84 T	0	0	84 T
89 Y	89 Y	0	0	89 Y
85 U	85 U	0	0	85 U
73 I	73 I	0	0	73 I
79 O	79 O	0	0	79 O
80 P	80 P	0	0	80 P
123 BraceLeft	123 BraceLeft	0	0	123 BraceLeft
125 BraceRight	125 BraceRight	0	0	125 BraceRight

[akien-mga]

Thanks for the very thorough test matrix @bruvzg, this shows that it's definitely a good improvement.

Let's merge and maybe open an issue about the non-working Russian layout on Linux?