[scribus-dev] Tables GSoC - Weekly Report #6

[Elvis Stansvik]

2011/7/11 Elvis Stansvik <elvstone at gmail.com>:
> 2011/7/11 Elvis Stansvik <elvstone at gmail.com>:
>> 2011/7/11 Elvis Stansvik <elvstone at gmail.com>:
>>> ...
>>> ===Question 2===
>>> I've now finally hit some problems relating to painting outside of the
>>> table frame (before I didn't have any artifacts because of this, but
>>> now they've started to appear sometimes when changing the border
>>> through UI).
>>
>> I should note that this happens when the border reaches a certain
>> width, probably when it goes outside the area around the frame that is
>> actually repainted. So I really do think the table should never paint
>> outside its frame. Is it OK if I try to implement the offset thing
>> (and also at the same time finally get around to setting the cliprect
>> properly, I think I did try early on with using the PoLine but it
>> wasn't working, I'll try again).
>>
>> If it is OK, then my old question from the mid-week mini report is
>> still valid; How can I be notified of style changes? Since the table
>> needs to have this offset correctly set at all times, it needs to be
>> notified of the following style changes, whether they came as a result
>> of a change in a parent style or as a change in the locally stored
>> style used for direct formatting:
>>
>> 1) Table top border changes.
>> 2) Table left border changes.
>> 3) Cell top border changes (on cells in row 0)
>> 4) Cell left border changes (on cells in col 0)
>
> After some more investigation I realize that it's not possible to
> listen to individual style changes, but that it's possible to listen
> to changes in the StyleContext. That means I should be able to listen
> to the StyleContexts I have for table and cell styles in ScribusDoc
> (docTableStyles and docCellStyles) to get notified of possible changes
> in relevant parent styles. And for direct formatting I can just ensure
> that the offset is also recalculated when setters are called on
> PageItem_Table. Does that sound sane?
>
> Listening to the style context like that will notify me of all style
> changes, which is a bit liberal, but it's OK I think since it's not
> time critical and besided the recalculation of the offsets should be
> quite quick.

Many questions at once now. Sorry about that ;) Here's another one; I
noticed that it's not using regular Qt signals/slots but that
StyleContext implements Observable<StyleContext>. What requirement are
there on a class that wants to be an observer in the observer pattern
implementation in Scribus? Does it need to be a QObject? Or implement
some Observer interface?

Elvis