[Manuel]
As a consequence of the recent discussion on the correct bpd for inline
areas I was looking at actually implementing it. Part of that is
correct vertical positioning, i.e. baseline alignments, of those areas.
Am I correct in saying that the vertical-align property which is a
shorthand for a combination of baseline related properties is not
currently implemented as shorthand, that is the property system doesn't
do the mapping to the corresponding properties (alignment-baseline,
alignment-adjust, baseline-shift and dominant-baseline)?
Correct.
Also those 4 properties, while set on the various fo's, don't seem to
have getters so are not available to the layout system.
So, the first step in moving away from vertical-align and to the four
corresponding properties is to fix the property subsystem and the fo
definitions.
Correct.
Finn, the property system already has a notion of corresponding
properties, etc.. I haven't looked into it in any detail but can that
be used for the mapping of vertical-align or do we need some custom
mechanism in this case?
There is also explicit support shorthands. For the 4 properties the
vertical-align must be specified as a shorthand:
m.addShorthand(s_generics[PR_VERTICAL_ALIGN]);
and a new custom ShorthandParser must be written and added to the
vertical-align maker
m.setDatatypeParser(new VerticalAlignShorthandParser());
which consist of code to implement the rule in [7.29.22]:
if (property.getEnum() == EN_BASELINE)
switch (propId) {
case PR_ALIGNMENT_BASELINE:
return new EnumProperty(EN_BASELINE)
case PR_ALIGNMAENT_ADJUST:
return new EnumProperty(EN_AUTO)
case PR_BASELINE_SHIFT:
return new EnumProperty(EN_BASELINE)
case PR_DOMINENT_BASELINE:
return new EnumProperty(EN_AUTO)
}
} else property.getEnum() == EN_TOP) {
switch (propId) {
case PR_ALIGNMENT_BASELINE:
return new EnumProperty(EN_BEFORE_EDGE)
case PR_ALIGNMAENT_ADJUST:
return new EnumProperty(EN_AUTO)
case PR_BASELINE_SHIFT:
return new EnumProperty(EN_BASELINE)
case PR_DOMINENT_BASELINE:
return new EnumProperty(EN_AUTO)
}
....
As an aside, the FOP implementation deviates from the spec since
shorthands should set values for other properties, but our system pulls
the values out of the shorthand property with the help of a ShorthandParser.
regards,
finn
