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FILTERKEYS

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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 {  
    UINT   cbSize; 
    DWORD  dwFlags; 
    DWORD  iWaitMSec; 
    DWORD  iDelayMSec; 
    DWORD  iRepeatMSec; 
    DWORD  iBounceMSec; 
} FILTERKEYS *LPFILTERKEYS;

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. If SlowKeys is on, a click is generated when the key is pressed and again when the keystroke is accepted.
    FKF_FILTERKEYSON The FilterKeys features are on.
    FKF_HOTKEYACTIVE The user can turn the FilterKeys feature on and off by holding down the RIGHT 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 95/98, Windows 2000: A confirmation dialog box appears when the FilterKeys features are activated by using the hot key.
    FKF_INDICATOR Windows 95/98, Windows 2000: 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 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.

At least one of the iDelayMSec and iBounceMSec members 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.

Requirements

**  Windows NT/2000/XP:** Included in Windows NT 3.5 or later.
**  Windows 95/98/Me:** Included in Windows 95 or later.
**  Header:** Declared in Winuser.h; include Windows.h.

See Also

Accessibility Structures, SystemParametersInfo