Determines whether a sequence of mouse events constitutes a double click.

UInt32 GetDblTime ();

DISCUSSION

The GetDblTime function returns the suggested maximum elapsed time, in ticks, between a mouse-up event and a mouse-down event. The user can adjust this value using the Mouse control panel.

If your application distinguishes a double click of the mouse from a single click, your application should use the value returned by GetDblTime to make this distinction. If your application uses TextEdit, the TextEdit functions automatically recognize and handle double clicks of text within a TextEdit edit structure by appropriately highlighting or unhighlighting the selection.

The ratio of ticks to value in the DoubleTime global variable is 1:1. However, the Finder multiplies DoubleTime by 2 to determine double click time because it needs to account for user problems that typically occur during icon arrangement. Therefore, the Finder uses DoubleTime*2 whereas the rest of the system uses DoubleTime.

Incidentally, the Finder does not limit the DoubleTime to 64 ticks. In most places, it treats it like a byte although in some others it treats it like a longword. The best method would be to provide a one-second double-byte (two seconds in the Finder).

The value returned by GetDblTime is also accessible in the system global variable DoubleTime.

AVAILABILITY

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

© 2000 Apple Computer, Inc. — (Last Updated 5/8/2000)