Team, Chapter 4.2.2 Common Traits defines four traits (top-position, bottom-position, left-position, right-position) which describes the placement of areas within the nearest ancestor reference-area (or the page-viewport-area). We don't use these trait but recreate the placement of individual areas in the renderer (actually and effectively in each (!) renderer). I wondered a few times during the last month if we should have the layout manager handle the calculation of the coordinates. This has a few advantages: - All layout is really in the layout managers. - Each renderer really only paints the areas in the place it is told to.
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The obvious disadvantage is the effort needed to write the code that generates these traits in all layout managers. The reason I'm bringing this up now is my attempt to implement table row backgrounds where I don't manage to place the background areas in the right places due to placement logic in the renderer(s). Of course, there are work-arounds and I only have to fix AbstractRenderer in this case but it doesn't feel right. There's already enough placement logic in the PDFRenderer which needs to be duplicated in all other renderers. I can also remember the synchronization effort when I wrote the original PSRenderer. I think it would also simplify the renderers itself, making it easier to develop a new one, if we started using left-position and top-position traits. The other two may be necessary as soon as there's more effort towards implementing writing-modes. Keiron responded to a similar question in 2002: http://nagoya.apache.org/eyebrowse/[EMAIL PROTECTED]&by=thread&from=214823 I don't share his opinion on point 3 because whenever we have a change in reference-orientation we also have a new reference-area which establishes a new coordinate system. So I don't think it will be complicated to calculate the right coordinates. But I may be wrong. Opinions? Jeremias Maerki
