Table of Contents
14.1.2 Special keys - constants
Some articles in the Internet illustrate the surprises you have to deal with in connection with keyboards and their construction, the assignments of the keys under different operating systems as well as the different designations on the keys:
14.1.2.1 Keyboard constants
In addition to the keyboard constants described in chapter 14.1.1, Gambas also has constants for special keys:
Escape BackTab Help Menu ScrollLock SysReq
Key. Escape - synonym for Key. Esc. * Key. BackTab - A tab is undone and can be emulated with the Shift+Tab key combination.
- Key. help - Some keyboards have a special help key, others bind the help function to the F1 key.
- Key. menu - Some keyboards have a menu button. What it does depends on the program that interprets the keystroke.ScrollLock key - Some keyboards have a ScrollLock key that acts as a switch. * Key. SysReq - as SystemRequest - is the second assignment of the' Print' key.
14.1.2.2.2 Super key
The super key is the so-called Windows key between the Ctrl key and the Alt key. The key code is 133 and the symbol is 'Super_L'. Under Ubuntu and Unity you can call up the dashboard directly by pressing the Super key.
14.1.2.3 Program xev
Start the xev program in a console. It gives you detailed information about a pressed key:
KeyPress event, serial 33, synthetic NO, window 0x3600001,
root 0xbc, subw 0x3600002, time 4714461, (45,34), root:(161,563),
state 0x10, keycode 133 (keysym 0xffeb, Super_L), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False
A variant of xev with a filter:
hans@linux:~$ xev | grep -A2 --line-buffered '^KeyRelease' | sed -n '/keycode /s/^.*keycode \([0-9]*\).* (.*, \(.*\)).*$/\1 \2/p'
50 Shift_L 37 Control_L 64 Alt_L 108 ISO_Level3_Shift 105 Control_R 62 Shift_R 36 Return 104 KP_Enter 20 ssharp
Under the link: https://wiki.archlinux.org/index.php/Extra_Keyboard_Keys, from which the filter example for xev was taken, can be found with showkey/ another keyboard analysis program, which you have to call in a login console.
Certain media keys, the' FN' key or the touch pad are not (yet) referred to in this chapter.