Inside Macintosh: QuickTime Components /

Chapter 6 - Sequence Grabber Channel Components / Sequence Grabber Channel Components Reference

Functions / Controlling Sequence Grabber Channel Components

SGUpdate

The SGUpdate function allows you to learn about update events. This gives you an opportunity to update your display.

pascal ComponentResult SGUpdate (SeqGrabComponent s, 
                                    RgnHandle updateRgn);

s

Identifies the sequence grabber component that has connected to your channel component.

updateRgn

Indicates the part of the window that has been changed. This parameter specifies a portion of the window that has been changed. Applications can obtain this information by examining the appropriate window record. For example, they may call the sequence grabber in this manner:

         SGUpdate (theSG, ((WindowPeek)updateWindow)->updateRgn);

If this parameter is set to nil, use the window's current visible region.

DESCRIPTION

Applications call the sequence grabber's SGUpdate function whenever they receive an update event for a window that contains a sequence grabber display. The sequence grabber then calls each affected channel. Applications should call this function before calling the Window Manager's BeginUpdate function.

RESULT CODE

deviceCantMeetRequest

-9408

Device cannot support grabber

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