12.6 Keyboard and Pointer Settings
Xlib provides functions that you can use to
change the keyboard control, obtain a list of the auto-repeat keys,
turn keyboard auto-repeat on or off, ring the bell,
set or obtain the pointer button or keyboard mapping,
and obtain a bit vector for the keyboard.
This section discusses
the user-preference options of bell, key click,
pointer behavior, and so on.
The default values for many of these options are server dependent.
Not all implementations will actually be able to control all of these
parameters.
The
XChangeKeyboardControl()
function changes control of a keyboard and operates on a
XKeyboardControl
structure:
/* Mask bits for ChangeKeyboardControl */
#define KBKeyClickPercent (1L<<0)
#define KBBellPercent (1L<<1)
#define KBBellPitch (1L<<2)
#define KBBellDuration (1L<<3)
#define KBLed (1L<<4)
#define KBLedMode (1L<<5)
#define KBKey (1L<<6)
#define KBAutoRepeatMode (1L<<7)
/* Values */
typedef struct {
int key_click_percent;
int bell_percent;
int bell_pitch;
int bell_duration;
int led;
int led_mode; /* LedModeOn, LedModeOff */
int key;
int auto_repeat_mode; /* AutoRepeatModeOff, AutoRepeatModeOn,
AutoRepeatModeDefault */
} XKeyboardControl;
The key_click_percent member sets the volume for key clicks between 0 (off)
and 100 (loud) inclusive, if possible.
A setting of -1 restores the default.
Other negative values generate a
BadValue
error.
The bell_percent sets the base volume for the bell between 0 (off) and 100
(loud) inclusive, if possible.
A setting of -1 restores the default.
Other negative values generate a
BadValue
error.
The bell_pitch member sets the pitch (specified in Hz) of the bell, if possible.
A setting of -1 restores the default.
Other negative values generate a
BadValue
error.
The bell_duration member sets the duration of the
bell specified in milliseconds, if possible.
A setting of -1 restores the default.
Other negative values generate a
BadValue
error.
If both the led_mode and led members are specified,
the state of that LED is changed, if possible.
The led_mode member can be set to
LedModeOn
or
LedModeOff.
If only led_mode is specified, the state of
all LEDs are changed, if possible.
At most 32 LEDs numbered from one are supported.
No standard interpretation of LEDs is defined.
If led is specified without led_mode, a
BadMatch
error results.
If both the auto_repeat_mode and key members are specified,
the auto_repeat_mode of that key is changed (according to
AutoRepeatModeOn,
AutoRepeatModeOff,
or
AutoRepeatModeDefault),
if possible.
If only auto_repeat_mode is
specified, the global auto_repeat_mode for the entire keyboard is
changed, if possible, and does not affect the per key settings.
If a key is specified without an auto_repeat_mode, a
BadMatch
error results.
Each key has an individual mode of whether or not it should auto-repeat
and a default setting for the mode.
In addition,
there is a global mode of whether auto-repeat should be enabled or not
and a default setting for that mode.
When global mode is
AutoRepeatModeOn,
keys should obey their individual auto-repeat modes.
When global mode is
AutoRepeatModeOff,
no keys should auto-repeat.
An auto-repeating key generates alternating
KeyPress
and
KeyRelease
events.
When a key is used as a modifier,
it is desirable for the key not to auto-repeat,
regardless of its auto-repeat setting.
A bell generator connected with the console but not directly on a
keyboard is treated as if it were part of the keyboard.
The order in which controls are verified and altered is server-dependent.
If an error is generated, a subset of the controls may have been altered.
To obtain the current control values for the keyboard, use
XGetKeyboardControl().
To turn on keyboard auto-repeat, use
XAutoRepeatOn().
To turn off keyboard auto-repeat, use
XAutoRepeatOff().
To ring the bell, use
XBell().
To obtain a bit vector that describes the state of the keyboard, use
XQueryKeymap().
To set the mapping of the pointer buttons, use
XSetPointerMapping().
To get the pointer mapping, use
XGetPointerMapping().
To control the pointer's interactive feel, use
XChangePointerControl().
To get the current pointer parameters, use
XGetPointerControl().
Christophe Tronche, [email protected]
