Inside Macintosh: QuickTime Components /

Chapter 5 - Sequence Grabber Components / Sequence Grabber Components Reference

Application-Defined Functions /

MyModalFilter

The SGSettingsDialog function causes the sequence grabber to present its settings dialog box to the user. This is a movable modal dialog box, so you must provide a filter function to handle update events in your window. You specify your filter function with the proc parameter.

A modal-dialog filter function whose address is passed to SGSettingsDialog should support the following interface:

pascal Boolean MyModalFilter (DialogPtr theDialog, 
                              EventRecord *theEvent, 
                              short *itemHit, long refCon);

theDialog

Points to the settings dialog box's dialog structure.

theEvent

Contains a pointer to an event structure. This event structure contains information identifying the nature of the event.

itemHit

Contains a pointer to a field that contains the item selected by the user. If you handle the event, you should update this field to reflect the item number of the selected item.

refCon

Contains a reference constant. You provide this reference constant to the sequence grabber in the procRefNum parameter of the SGSettingsDialog function, which is described on page 5-45.

DESCRIPTION

Your modal-dialog filter function returns a Boolean value that indicates whether you handled the event. Set this value to true if you handled the event; otherwise, set it to false. If you handle the event, be sure to update the value of the field referred to by the itemHit parameter.

SEE ALSO

See Inside Macintosh: Files for a sample modal-dialog filter function.