Inside Macintosh: QuickTime Components

Component Capability Flags for Clocks

The Component Manager allows you to specify information about your component's capabilities in the componentFlags field of the component description structure. Apple has defined two component flags for clock components. These flags specify information about the capabilities of the clock component. You set these flags in the componentFlags field of your component's component description structure. You can use the following constants to manipulate these flags. You should set them appropriately for your clock. For more on the component description structure, see the chapter "Component Manager" in Inside Macintosh: More Macintosh Toolbox .



 
enum {

                                         kClockRateIsLinear = 1,/* clock keeps constant 

                                         rate */

                                         kClockImplementsCallBacks = 2/* clock supports callback

                                         events */

                     };

kClockRateIsLinear: Indicates that your clock maintains a constant rate. Most clocks that you deal with in the everyday world fall into this category. An example of a clock with an irregular rate is a clock that is dependent on the position of the Macintosh computer's mouse--the clock's rate might change depending upon where the user moves the mouse. Set this flag to 1 if your clock has a constant rate.
kClockImplementsCallBacks: Indicates that your clock supports callback events. Set this flag to 1 if your clock supports callback events.

You should set the componentFlags field appropriately in the component description structure that is associated with your clock component.

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