The FILTERKEYS structure contains information about the FilterKeys accessibility feature, which allow a user with disabilities to set the keyboard repeat rate (RepeatKeys), acceptance delay (SlowKeys), and bounce rate (BounceKeys).
typedef struct tagFILTERKEYS { // fk
UINT cbSize;
DWORD dwFlags;
DWORD iWaitMSec;
DWORD iDelayMSec;
DWORD iRepeatMSec;
DWORD iBounceMSec;
} FILTERKEYS;
Members
cbSize
Specifies the structure size, in bytes.
dwFlags
A set of bit flags that specify properties of the FilterKeys feature. The following bit-flag values are defined:
| Value | Meaning |
| FKF_AVAILABLE | The FilterKeys features are available. |
| FKF_CLICKON | The computer makes a click sound when a key is pressed or accepted, that is, if SlowKeys is on, the acceptance is separated from the press and gets a separate click.. |
| FKF_FILTERKEYSON | The FilterKeys features are on. |
| FKF_HOTKEYACTIVE | The user can turn the FilterKeys feature on and off by holding down the SHIFT key for eight seconds. |
| FKF_HOTKEYSOUND | 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_CONFIRMHOTKEY | Windows 95 only: A confirmation dialog box appears when the the FilterKeys features are activated by using the hot key. |
| FKF_INDICATOR | Windows 95 only: A visual indicator is displayed when the FilterKeys features are on. |
iWaitMSec
Specifies the length of time, in milliseconds, that the user must hold down a key before it is accepted by the computer.
iDelayMSec
Specifies the length of time, in milliseconds, that the user must hold down a key before it begins to repeat.
iRepeatMSec
Specifies the length of time, in milliseconds, between each repetition of the keystroke.
iBounceMSec
Specifies the amount 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 wAction 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.
Either iDelayMSec or iBounceMSec, or both, must be zero; they cannot both be nonzero at the same time.
If iBounceMSec is nonzero, the BounceKeys feature is on and the SlowKeys feature is off (the iDelayMSec value is ignored). If iBounceMSec is zero, the BounceKeys feature is off.
If iDelayMSec is nonzero and iBounceMSec is zero, the SlowKeys feature is on; otherwise, it is off.
See Also