[reportlab-users] From intra-paragraph images to drawings?

[Robin Becker]

On 08/05/2013 17:05, Andy Robinson wrote:

> I am going a bit off topic, but in the (infinitely regressing)

> ReportLab 3.0, we probably want two ways to produce a paragraph:  (1)

> a string with markup, and (2) a list of Fragment objects, which is

> pretty much what we parse (1) into anyway.  In the latter

> representation you could have inline graphical elements initialised

> how you want in your python code.  They need to be able to report

> their size.

>

> Robin, maybe you could see if it's possible for a user to construct a

> paragraph from fragments, and post an example if it is?

>

.........
all of my recent experiments have been about getting rid of fragments :( they 
were introduced when I/we first started using markup because I/we didn't know 
any better and they were fairly fast. In practice it would be better to just 
mark the transitions from one style to another with action objects. That way we 
could eliminate all the fragment style comparisons and a lot of code where we 
check to see if the incoming frag changes font, font size, or some other attribute.

In the box glue model we would then have boxes with text or other content, glue 
and actions. There are various well known schemes for joining these all together.

You are supposed to be able to make a paragraph out of frags and the parser is 
not called when they are given. Currently there are only text fragments and 
cbDefns (callbacks originally). The cbDefns have a kind which can be img to get 
image handling or anchor for an anchor (as in the original a tag). All other 
cbDefns are assumed to be proper callbacks with a function name etc etc. Only 
the 'img' kind has a size and gets special treatment. Presumably we could add 
another kind which has size that could as Andy suggests be created directly with 
special behaviours. Personally I don't find the idea of generating paragraphs 
directly from fragments all that attractive. Having just slogged through the 
code to split fragment words that are over long I'm not sure fragments are an 
easy way to do things.
-- 
Robin Becker