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Chapter 5 - Icon Utilities / Icon Utilities Reference

Icon Utilities Routines / Converting an Icon Mask to a Region

IconIDToRgn

You can use the IconIDToRgn function to convert, to a region, the icon mask in an icon family. You specify a rectangle as one of the parameters to this function. IconIDToRgn determines, from the size of the specified rectangle, which mask from the icon family to convert. Once it has determined which icon mask to convert, IconIDToRgn uses the specified rectangle as the bounding box of the region.

FUNCTION IconIDToRgn (theRgn: RgnHandle; iconRect: Rect; 
                      align: IconAlignmentType; 
                      iconID: Integer): OSErr;

theRgn

IconIDToRgn returns a handle to the requested region in this parameter. You must allocate memory for the region handle before calling IconIDToRgn.

iconRect

The rectangle in which to draw the icon, specified in local coordinates of the current graphics port. IconIDToRgn uses this rectangle as the bounding box of the region. IconIDToRgn determines, from the size of the rectangle specified in this parameter, which icon mask to use from the icon family specified by iconID.

align

A value that specifies how IconIDToRgn should align the mask within the rectangle. See the description of PlotIconID on page 5-20 for a list of constants you can use in this parameter.

iconID

The resource ID of the icon for which to create a region.

DESCRIPTION

The IconIDToRgn function modifies the region referred to by the handle in the theRgn parameter. The returned region corresponds to the icon's mask (the mask defined by either an 'ICN#' or 'ics#' resource in an icon family, according to the rectangle and alignment specified in the iconRect and align parameters).

RESULT CODES

noErr	0	No error
noMaskFoundErr	-1000	No mask found