All fo elements are required to
extract all the
properties that they need and to store the values as
instance fields in
the fo element.

I love the performance boost you're recording but have
a philosophical issue of an "fo object needing a
property"--it is really an issue of the
*FOEventHandler subclass* that needs the
properties--and some handlers need/implement more
properties than others.

Does any event handler need more or different properties than what is defined in the spec under each fo element? Because that is the set of properties that I store in the fo objects.

If further properties are needed by any property consumer, it can just be added to the fo element. An example could be "text-decoration" on fo:block.

So if we did this at the FO level, in effect, we'd
have to (1) store an instance variable of every valid
property for each FO, given that we wouldn't know
whether the FOEventHandler's needs it beforehand, and

Yes. Which is massively more efficient than storing the exact same properties in a PropertyList.

(2) instead of the programmatic convenience of
getPropString(PR_OFFICIAL_PROPERTY_NAME), we'd have to
remember what each of the properties are named in the
FO's (We can probably standardize these though.)

I've consistly picked getOfficielPropertyName() as the name of the getter method.

Another clarification needed: when would the property
list's memory get released--at the PageSequence level,
or as soon as the FO is finished?

At the endElement() event.

Because the values
of some FO's properties further downstream depend on
an earlier FO's properties, we may not be able to
release the memory when the earlier FO is finished.

If a property value is needed by a following sibling, then it can be found as an instance field on the fo object that defined the property.

Or, (to support inheritance) we may need to store
instance variables for what may be a very unlikely
event of a child needing that value.

I don't understand what you mean. All property inheritence is resolved at the time of the child startElement() event. The resolution is done using the parent propertylist while it still exists.

Also, are there any other options for releasing this
memory that you know of? Is there someway this .bind()
or other releasing of memory can be done within the
FOEventHandler subclasses, or at least within
LayoutManager (forgetting about RTF) instead?

I don't see any benefit at all, from such approaches.

PS. The description of releasing property list only apply to normal elements. All element under fo:marker are treated differently.


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