Re: from-page-master-region()

Peter B. West wrote:
...
> In some previous communications from the WG, layout-based formatting has
> been mentioned as a possible future development.  Inheriting from the
> simple-page-masters could be a step in this direction.  If a switching
> mechanism, as mentioned above, in the earlier message, were implemented
> as a means of preserving backward compatiblity, static-content and flow
> would inherit directly from the controlling simple-page-master.  Only
> simple-page-masters would be in the inheritance ancestry.
> Simple-page-master property resolution is "stand-alone"; it proceeds
> independently of any use to which particular simple-page-masters are
> put.  Note that I am thinking here of switching inheritance in toto from
> page-sequence to simple-page-master.

Such a switch (in retrospect) wouldn't work.  Although I have no 
specific solutions to offer, it seems to me possible to introduce a 
conceptual change which recognizes that the areas to the level of 
region-reference-areas have, in effect, already been generated when the 
layout-master-set has been processed.  When a page master-reference is 
encountered, it invokes a "pre-compiled" page. Although new 
span-reference-areas and normal-flow-reference-areas are generated in 
response to the contents of flows, they are children of the page-level 
areas and they spring into being to accomodate patterns in the flow, but 
  are nonetheless ancestors of those flow elements.

Properties defined on the page-sequences can then be inherited by the 
the elements of the flows.  Reference areas defined in those flows are 
free to change the writing-mode and reference-orientation, but this 
occurs at the level of block-container, table, etc.

I realise that major conceptual changes would be involved here.  To go 
this way would also involve either special-casing reference-orientation 
and writing-mode (as they are in from-page-master-region()) or having 
page-sequence dynamically inherit across the board from the page-level 
areas into which it is currently rendering.  In order to implement 
from-page-master-region() one has to travel a long way down the path of 
dynamic inheritance anyway.

My apologies for the repetition and backtracking in these posts.

Yours faithfully,
-- 
Peter B. West <http://cv.pbw.id.au/>
Project Folio <http://defoe.sourceforge.net/folio/>