Percentages

[Finn Bock]

Hi,

I just uploaded a patch which add support for percentages and 
calculations on percentages to bugzilla.

I don't think that the patch is quite right in its attempt to find the 
correct base length to combine with the percentage. Some of my confusion 
comes from the fact that I can't tell the different boxes/areas/blocks 
apart.

How f.ex. are these specifications different:
- ipd of closest area generated by a block-level fo
- width of containing block
- ipd of closest ancestor block-area.
Perhaps somebody who understand the spec better then me can describe 
what boxes and sizes that are to used.

I went through the spec and came up with these descriptions of the bases 
for the properties that support percentage:

top, bottom, height, max-height:
    height of containing block if explicit. Auto otherwise.
left, right, padding-*, margin-[left,right],
max-width, min-width, width, text-indent:
    width of containing block
background-position-horizontal, background-position-vertical:
    Size of padding-rectangle. Relative values.
font-size:
    inherited font-size.
margin-[top,bottom]:
    width of containing block, except for page context where it
    is page box height.
[start,end]-indent:
    ipd of containing reference-area.
space-[end,start], line-line-end-indent:
    ipd of closest ancestor block-area.
alignment-adjust:
    'height' if fo:external-graphics or fo:instream-foreign-object,
    'font-size' if fo:character and 'line-height' otherwise.
baseline-shift:
    'line-height' of the parent-area.
block-progression-dimension:
    corresponding dimension of closest area generated by a
    block-level fo.
    Auto if not specified explicit.
content-[height,width]
    intrinsic height and width
inline-progression-dimension:
    corresponding dimension of closest area generated by a
    block-level fo.
    Auto if not specified explicit.
min-height:
    height of containing.
line-height:
    'font-size'
leader-pattern-width, leader-length:
    ipd of content-rect of parent area.
column-gap:
    width of region being divided into columns.
extent:
    corresponding height or width of the page.
column-width:
    width of table.
text-altitude, text-depth:
    fonts em-height.
provisional-label-seperation, provisional-distance-between-starts:
    ipd of closest block-area that is not a line-area
vertical-align:
    'line-height'
regards,
finn