ATSJustPriorityWidthDeltaOverrides

The ATSJustPriorityWidthDeltaOverrides type is an array of four width delta override structures of type ATSJustWidthDeltaEntryOverride, one for each of the four justification priorities. Each structure contains, for both the grow and shrink cases, limits to the amount of space that can be added or removed from both the right and left sides of each of the glyphs of a given justification priority.

The ATSJustPriorityWidthDeltaOverrides type can be used to set and get justification behavior and priority override weighting; see Style Run Attribute Tag Constants.

struct ATSJustWidthDeltaEntryOverride {
    Fixed               beforeGrowLimit; 
    Fixed               beforeShrinkLimit; 
    Fixed               afterGrowLimit;     
    Fixed               afterShrinkLimit; 
    JustificationFlags  growFlags;       
    JustificationFlags  shrinkFlags;     
};
typedef struct ATSJustWidthDeltaEntryOverride 
ATSJustWidthDeltaEntryOverride;
typedef ATSJustWidthDeltaEntryOverride
ATSJustPriorityWidthDeltaOverrides[4];

Field descriptions

beforeGrowLimit
The number of points by which a 1-point glyph can expand on the left side (top side for vertical text). For example, a value of 0.2 means that a 24-point glyph can have by no more than 4.8 points of extra space added on the left side (top side for vertical text).

beforeShrinkLimit
The number of points by which a 1-point glyph can shrink on the left side (top side for vertical text). If specified, this value should be negative.

afterGrowLimit
The number of points by which a 1-point glyph can expand on the right side (bottom side for vertical text).

afterShrinkLimit
The number of points by which a 1-point glyph can shrink on the right side (bottom side for vertical text). If specified, this value should be negative.

growFlags
Mask constants that indicate whether ATSUI should apply the limits defined in the beforeGrowLimit and afterGrowLimit fields. See Justification Override Mask Constants for a description of possible values. These mask constants also control whether unlimited gap absorption should be applied to the priority of glyphs specified in the given width delta override structure. You can use these mask constants to selectively override the grow case only, while retaining default behavior for other cases.

shrinkFlags
Mask constants that indicate whether ATSUI should apply the limits defined in the beforeShrinkLimit and afterShrinkLimit fields. See Justification Override Mask Constants for a description of possible values. These mask constants also control whether unlimited gap absorption should be applied to the priority of glyphs specified in the given width delta override structure. You can use these mask constants to selectively override the grow case only, while retaining default behavior for other cases.
VERSION NOTES
Available beginning with ATSUI 1.0

© 2000 Apple Computer, Inc. – (Last Updated 25 Jan 00)