class represents information about the justification properties of a glyph. A glyph is the visual representation of one or more characters. Many different glyphs can be used to represent a single character or combination of characters. The four justification properties represented by
are weight, priority, absorb and limit.
Weight is the overall 'weight' of the glyph in the line. Generally it is proportional to the size of the font. Glyphs with larger weight are allocated a correspondingly larger amount of the change in space.
Priority determines the justification phase in which this glyph is used. All glyphs of the same priority are examined before glyphs of the next priority. If all the change in space can be allocated to these glyphs without exceeding their limits, then glyphs of the next priority are not examined. There are four priorities, kashida, whitespace, interchar, and none. KASHIDA is the first priority examined. NONE is the last priority examined.
Absorb determines whether a glyph absorbs all change in space. Within a given priority, some glyphs may absorb all the change in space. If any of these glyphs are present, no glyphs of later priority are examined.
Limit determines the maximum or minimum amount by which the glyph can change. Left and right sides of the glyph can have different limits.
GlyphJustificationInfo represents two sets of metrics, which are growing and shrinking. Growing metrics are used when the glyphs on a line are to be spread apart to fit a larger width. Shrinking metrics are used when the glyphs are to be moved together to fit a smaller width.