SetCtlValue

Set a control's value; check/uncheck boxes, etc.

#include <Controls.h> Control Manager

void SetCtlValue( theControl, theValue );

ControlHandle theControl ; handle of control to update

short theValue ; desired new value for the control

SetCtlValue updates the current value of a control. It is used to draw/erase

Xs in check boxes and dots in radio buttons and it causes the thumb of a scroll

bar (or other indicator) to be re positioned.

theControl is a handle leading to a variable-length ControlRecord structure. It

specifies which control to update.

theValue specifies the desired new value. For check boxes and radio buttons,

use 1 to indicate "selected" and 0 to indicate "deselected". Values that

are either too low or too high are pinned to the control's minimum or

maximum settings, respectively.

Notes: SetCtlValue must be called to reflect the user's choices in check boxes

and radio buttons-the X's and •'s ARE NOT drawn or erased automatically.

For instance, it is up to the application to use SetCtlValue to erase all

radio-button dots (•'s) except for the new choice.

When the user drags the thumb of a scroll bar, its contrlValue is

automatically updated to correspond to the thumb's new position. On other

document motions (such as when the user presses the "page down" key), you

must use this function to reposition the indicator (thumb).

Note that an out-of-range value for theValue is coerced to the maximum or

minimum to make it valid. The result is stored into the contrlValue field of

the ControlRecord structure. See GetCtlMin and GetCtlMax. Use

GetCtlValue to obtain the current setting.

Referenced by (31):