This interface provides access to a specific, XCanvas-dependent
font incarnation. This font is not universally usable, but belongs
to the XCanvas it was queried from.
Create a text layout interface for the given string, using
this font to generate the glyphs from.
Parameter aText
The text to layout.
Parameter nDirection
Main text direction for the string specified. The main text
direction is e.g. important for characters that are not
strong, i.e. that change affinity according to the current
writing direction. Make sure that across text portions and
lines, the direction is set consistently.
Parameter nRandomSeed
Optional random seed for OpenType glyph variations.
Query metric information about the font, that is generic to
all its glyphs.
Note that the metric values in the returned result are in the
font coordinate system, i.e. relative to the corresponding
size of this font. That is, when this font was created with a
cell size of 20 units, the metrics returned are calculated
relative to this size.
This method queries the list of available font sizes (in
device units) for this font. For scalable fonts that are not
restricted to discrete sizes, this list is empty,
meaning that every size is possible. Fonts that do
restrict the device size to certain discrete values, setting
an overall transformation that scales the
FontRequest::CellSize to something not
contained in the list returned by this method can lead to
visible disturbances.
