Returns a handle for the first video device in the device list.

GDHandle DMGetFirstScreenDevice (
    Boolean activeOnly
);

Parameter descriptions

activeOnly

If true, the DMGetFirstScreenDevice function returns a handle to the first of all active video devices. If false, the function returns a handle to the first of all video devices, active or not. You may use the Active Device Constants in this parameter. See “Active Device Only Values”.

function result

If activeOnly is true, a handle to the GDevice structure for the first active video device. If activeOnly is false, a handle to the GDevice structure for the first video device.

DISCUSSION

The DMGetFirstScreenDevice function is useful if you want to find out more about the current mode.

You can use the function DMGetNextScreenDevice to loop through all of the video devices in the device list.

The DMGetFirstScreenDevice function is similar to the QuickDraw function GetDeviceList, except that when returning GDevice structures, GetDeviceList does not distinguish between inactive and active video devices or between the GDevice structures for video devices and the GDevice structures associated with no video devices.

SPECIAL CONSIDERATIONS

Because this function may move or purge memory blocks or access handles, you cannot call it at interrupt time.

AVAILABILITY

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

© 2000 Apple Computer, Inc. (Last Updated 6/30/2000)