XChangeKeyboardControl(3X1XLIB FUNCTIXChangeKeyboardControl(3X11)NAME
XChangeKeyboardControl, XGetKeyboardControl, XAutoRe-
peatOn, XAutoRepeatOff, XBell, XQueryKeymap, XKeyboardCon-
trol - manipulate keyboard settings and keyboard control
structure
SYNTAX
XChangeKeyboardControl(display, value_mask, values)
Display *display;
unsigned long value_mask;
XKeyboardControl *values;
XGetKeyboardControl(display, values_return)
Display *display;
XKeyboardState *values_return;
XAutoRepeatOn(display)
Display *display;
XAutoRepeatOff(display)
Display *display;
XBell(display, percent)
Display *display;
int percent;
XQueryKeymap(display, keys_return)
Display *display;
char keys_return[32];
ARGUMENTS
display Specifies the connection to the X server.
keys_return
Returns an array of bytes that identifies which
keys are pressed down. Each bit represents one
key of the keyboard.
percent Specifies the volume for the bell, which can
range from -100 to 100 inclusive.
value_mask
Specifies which controls to change. This mask
is the bitwise inclusive OR of the valid control
mask bits.
values Specifies one value for each bit set to 1 in the
mask.
values_return
Returns the current keyboard controls in the
specified XKeyboardState structure.
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XChangeKeyboardControl(3X1XLIB FUNCTIXChangeKeyboardControl(3X11)DESCRIPTION
The XChangeKeyboardControl function controls the keyboard
characteristics defined by the XKeyboardControl structure.
The value_mask argument specifies which values are to be
changed.
XChangeKeyboardControl can generate BadMatch and BadValue
errors.
The XGetKeyboardControl function returns the current con-
trol values for the keyboard to the XKeyboardState struc-
ture.
The XAutoRepeatOn function turns on auto-repeat for the
keyboard on the specified display.
The XAutoRepeatOff function turns off auto-repeat for the
keyboard on the specified display.
The XBell function rings the bell on the keyboard on the
specified display, if possible. The specified volume is
relative to the base volume for the keyboard. If the
value for the percent argument is not in the range -100 to
100 inclusive, a BadValue error results. The volume at
which the bell rings when the percent argument is nonnega-
tive is:
base - [(base * percent) / 100] + percent
The volume at which the bell rings when the percent argu-
ment is negative is:
base + [(base * percent) / 100]
To change the base volume of the bell, use
XChangeKeyboardControl.
XBell can generate a BadValue error.
The XQueryKeymap function returns a bit vector for the
logical state of the keyboard, where each bit set to 1
indicates that the corresponding key is currently pressed
down. The vector is represented as 32 bytes. Byte N
(from 0) contains the bits for keys 8N to 8N + 7 with the
least significant bit in the byte representing key 8N.
Note that the logical state of a device (as seen by client
applications) may lag the physical state if device event
processing is frozen.
STRUCTURES
The XKeyboardControl structure contains:
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/* 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 possi-
ble. A setting of -1 restores the default. Other nega-
tive 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 gener-
ate a BadValue error. The bell_pitch member sets the
pitch (specified in Hz) of the bell, if possible. A set-
ting 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 sup-
ported. 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 speci-
fied, the auto_repeat_mode of that key is changed (accord-
ing 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
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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.
The XKeyboardState structure contains:
typedef struct {
int key_click_percent;
int bell_percent;
unsigned int bell_pitch, bell_duration;
unsigned long led_mask;
int global_auto_repeat;
char auto_repeats[32];
} XKeyboardState;
For the LEDs, the least significant bit of led_mask corre-
sponds to LED one, and each bit set to 1 in led_mask indi-
cates an LED that is lit. The global_auto_repeat member
can be set to AutoRepeatModeOn or AutoRepeatModeOff. The
auto_repeats member is a bit vector. Each bit set to 1
indicates that auto-repeat is enabled for the correspond-
ing key. The vector is represented as 32 bytes. Byte N
(from 0) contains the bits for keys 8N to 8N + 7 with the
least significant bit in the byte representing key 8N.
DIAGNOSTICS
BadMatch Some argument or pair of arguments has the cor-
rect type and range but fails to match in some
other way required by the request.
BadValue Some numeric value falls outside the range of
values accepted by the request. Unless a spe-
cific range is specified for an argument, the
full range defined by the argument's type is
accepted. Any argument defined as a set of
alternatives can generate this error.
SEE ALSOXChangeKeyboardMapping(3X11), XSetPointerMapping(3X11)
Xlib - C Language X Interface
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