Obtains the relative position of a track’s indicator, given an offset from its prior position.

OSStatus GetThemeTrackThumbPositionFromOffset (
    const ThemeTrackDrawInfo *drawInfo, 
    Point thumbOffset, 
    SInt32 *relativePosition
);

drawInfo

A pointer to a structure of type ThemeTrackDrawInfo. Before calling GetThemeTrackThumbPositionFromOffset, set the structure to contain the current visual characteristics of the track.

thumbOffset

A structure of type Point. Pass the point (in coordinates local to the control’s window) that specifies the vertical and horizontal offset, in pixels, by which the indicator has moved from its current position. Typically, this is the offset between the locations where the cursor was when the user pressed and released the mouse button while dragging the indicator.

relativePosition

A pointer to a signed 32-bit value. On return, this value contains the new distance, in pixels, between the minimum end of the track and the near side of the indicator.

function result

A result code.

DISCUSSION

Your application can use the GetThemeTrackThumbPositionFromOffset function to respond to the posCntl control definition message.

VERSION NOTES

This function is available with Appearance Manager 1.1 and later.

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)