QDDone

QDDone
Header:	QDOffscreen.h		Carbon status:	Supported

Determines whether QuickDraw has completed drawing in a given graphics port.

Boolean QDDone (
    GrafPtr port
);

Parameter descriptions

port: The GrafPort structure for a graphics port in which your application has begun drawing; if you pass NULL, QDDone tests all open graphics ports.

function result: TRUE if all drawing operations have finished in the graphics port specified in the port parameter, FALSE if any remain to be executed. If you pass NULL in the port parameter, then QDDone returns TRUE only if drawing operations have completed in all ports.

DISCUSSION

The QDDone function may be useful if a graphics accelerator is present and operating asynchronously. You can use it to ensure that all drawing is done before issuing new drawing commands, and to avoid the possibility that the new drawing operations might be overlaid by previously issued but unexecuted operations.

SPECIAL CONSIDERATIONS

If a graphics port draws a clock or some other continuously operating drawing process, QDDone may never return TRUE.

To determine whether all drawing in a color graphics port has completed, you must coerce its CGrafPort structure to a GrafPort structure, which you pass in the port parameter.

AVAILABILITY

Supported in Carbon. Available in Carbon 1.0.2 and later when running Mac OS 8.1 or later.