Inside Macintosh: More Macintosh Toolbox /

Chapter 3 - Help Manager / Help Manager Reference

Help Manager Routines / Determining the Size of a Help Balloon

HMBalloonRect

To get information about the size of a help balloon before the Help Manager displays it, you can use the HMBalloonRect function.

FUNCTION HMBalloonRect (aHelpMsg: HMMessageRecord; 
                        VAR coolRect: Rect): OSErr;

aHelpMsg

The help message for the help balloon.

coolRect

The coordinates of the rectangle that encloses the help message. The upper-left corner of the rectangle has the coordinates (0,0).

DESCRIPTION

The HMBalloonRect function calculates the coordinates that the Help Manager uses for a particular balloon, permitting you to specify the help message for a help balloon and then obtaining the size (but not the position) of the rectangle used for the balloon. Note that the HMBalloonRect function does not display the help balloon.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the HMBalloonRect function are

Trap macro	Selector
_Pack14	$040E

RESULT CODES

noErr	0	No error
paramErr	-50	Error in parameter list
memFullErr	-108	Not enough room in heap zone

SEE ALSO

The aHelpMsg parameter is of data type HMMessageRecord, which is described in "Providing Help Balloons for Dynamic Windows" beginning on page 3-69.