[reportlab-users] Release notes on the website

[Robin Becker]

Marius Gedminas wrote:
.........

> 

> So, is the bug

> 

>  (1) in the font metrics,

> 

>  (2) in Table layout code,

> 

> or

> 

>  (3) in Paragraph drawing code, i.e. the change made in r3192?

> 

> Marius Gedminas


It's impossible to say. Because we introduced images in paragraphs  and needed 
to allow for height adjustments I needed to be more exact about the height above 
(and below) baseline. Originally we used Andy's approximation which was
leading = 1.2*fontSize; where leading is the total distance between consecutive 
lines(not the size of the lead spacer as in traditional print speak). There was 
an implicit assumption that leading=ascent+descent and that ascent=fontSize. 
Clearly the 10pt Times New Roman doesn't come close to that. In the paragraph 
case we used to work out the height (in lines*leading) and then start the first 
baseline at top-ascent (ie top - fontSize). If we change our notion of ascent 
then the first baseline will move. Unfortunately nothing prevents people from 
separately specifying the leading as 12pt so paragraphs appear to shift upwards.

On the other hand our table formatting code assumes either flowables(about which 
it knows nothing) or simple strings which I believe it assumes obey the original 
leading rule. If the leading rule is wrong then it's wrong in tables as well so 
probably we ought to fix it there. That still won't satisfy people who think 
vertical centred cells should have equal space above and below the text (unless 
ascent==descent).
-- 
Robin Becker