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FILTERKEYS structure (winuser.h)

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Contains information about the FilterKeys accessibility feature, which enables a user with disabilities to set the keyboard repeat rate (RepeatKeys), acceptance delay (SlowKeys), and bounce rate (BounceKeys).

Syntax

typedef struct tagFILTERKEYS {
  UINT  cbSize;
  DWORD dwFlags;
  DWORD iWaitMSec;
  DWORD iDelayMSec;
  DWORD iRepeatMSec;
  DWORD iBounceMSec;
} FILTERKEYS, *LPFILTERKEYS;

Members

cbSize

Type: UINT

Specifies the structure size, in bytes.

dwFlags

Type: DWORD

A set of bit flags that specify properties of the FilterKeys feature. The following bit-flag values are defined:

Value Meaning
FKF_AVAILABLE
0x00000002
 The FilterKeys features are available.
FKF_CLICKON
0x00000040
 The computer makes a click sound when a key is pressed or accepted. If SlowKeys is on, a click is generated when the key is pressed and again when the keystroke is accepted.
FKF_CONFIRMHOTKEY
0x00000008
 Windows 95/98, Windows 2000: A confirmation dialog box appears when the FilterKeys features are activated by using the hot key.
FKF_FILTERKEYSON
0x00000001
 The FilterKeys features are on.
FKF_HOTKEYACTIVE
0x00000004
 The user can turn the FilterKeys feature on and off by holding down the RIGHT SHIFT key for eight seconds.
FKF_HOTKEYSOUND
0x00000010
 If this flag is set, the computer plays a siren sound when the user turns the FilterKeys feature on or off by using the hot key.
FKF_INDICATOR
0x00000020
 Windows 95, Windows 2000: A visual indicator is displayed when the FilterKeys features are on.

iWaitMSec

Type: DWORD

Specifies the length of time, in milliseconds, that the user must hold down a key before it is accepted by the computer.

iDelayMSec

Type: DWORD

Specifies the length of time, in milliseconds, that the user must hold down a key before it begins to repeat.

iRepeatMSec

Type: DWORD

Specifies the length of time, in milliseconds, between each repetition of the keystroke.

iBounceMSec

Type: DWORD

Specifies the length of time, in milliseconds, that must elapse after releasing a key before the computer will accept a subsequent press of the same key.

Remarks

Use a FILTERKEYS structure when calling the SystemParametersInfo function with the uiAction parameter set to the SPI_GETFILTERKEYS or SPI_SETFILTERKEYS value. When using SPI_GETFILTERKEYS, you must specify the cbSize member of the FILTERKEYS structure; the SystemParametersInfo function fills the remaining members. Specify all structure members when using the SPI_SETFILTERKEYS value.

The iBounceMSec member controls the BounceKeys feature, and the iWaitMSec, iDelayMSec, and iRepeatMSec members work together to control the RepeatKeys and SlowKeys features. If BounceKeys is on (that is, iBounceMSec is nonzero), the RepeatKeys and SlowKeys features are off (that is, the iWaitMSec, iDelayMSec, and iRepeatMSec members must all be zero). Similarly, if BounceKeys is off (iBounceMSec is zero), the iWaitMSec, iDelayMSec, and iRepeatMSec must all be nonzero.

The maximum value of the iBounceMSec, iWaitMSec, iDelayMSec, and iRepeatMSec members is 20,000 milliseconds.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Header winuser.h (include Windows.h)

See also

Accessibility Structures

SystemParametersInfo