RE: [XaraXtreme-dev] Current/default font

["Phil Martin" <Phil@xxxxxxxx>]

Further: The ability to save the Current attributes in documents is a
recent addition (<4 years ago). So the current attributes sections of
document are not guaranteed to be present and there will be many old
documents which do not carry /any/ Current attributes.

Further2: There are only two Current attribute sets saved in documents
at the moment but there could be more in the future.

To answer Neil's question (as Gerry already has): Default attributes are
not saved with documents.

To answer Alex's question: It looks as if text objects always carry at
least one pair of TAG_FONT_DEF_XXX and TAG_TEXT_FONT_TYPEFACE records in
XAR files controlling the font - even when that font is "Times Roman",
the value of the Default font face attribute. I can't say for sure
whether that's always been true, though.

Phil
 

> -----Original Message-----
> From: owner-dev@xxxxxxxxxxxxxxxx 
> [mailto:owner-dev@xxxxxxxxxxxxxxxx] On Behalf Of Gerry Iles
> Sent: 27 July 2006 13:16
> To: dev@xxxxxxxxxxxxxx
> Subject: RE: [XaraXtreme-dev] Current/default font
> 
> There is obviously much confusion about what is really meant 
> by the terms default and current when dealing with attributes.
> 
> The default attributes are the ones right at the top of the 
> document tree that ensure that all attributes get set to a 
> sensible initial value when the tree is rendered.  In the 
> case of text, this is always Times New Roman and always has 
> been.  The default attributes do not get saved in the Xar 
> format as every xar file would have to have a copy of them 
> and this would be a waste of space.  They must therefore never change.
> 
> A current attribute is the attribute applied when a new 
> object is created.  For text this is currently Arial.  The 
> current attributes are saved in the xar format.  In fact, two 
> sets of them are saved, one set that applies to new text 
> objects and another set that applies to everything else.

> 
> Attribute optimisation ensures that there are at most two 
> attributes of each type affecting each object.  One of these 
> is always the default attribute at the top of the tree and 
> the other is the actual attribute applied to the object 
> (though it can be either a child of the object or a 
> left-sibling or a left sibling of an ancestor due to optimisation).
> This attribute is only present if it is different to the default one.
> 
> The issue here seems to be that if the current font attribute 
> in a document is not installed, whether we can change it to 
> one that is installed.  There should be no danger whatsoever 
> in changing the current attributes to ones that make sense 
> for the user's machine.  The only issue I can really come up 
> with is if someone creates a template for a specific purpose 
> that has the current font set to something explicit, if the 
> current font is silently changed because you don't have the 
> correct one installed then text you create will not be in the 
> "correct" font.
> 
> Gerry
> 
> -----Original Message-----
> From: owner-dev@xxxxxxxxxxxxxxxx 
> [mailto:owner-dev@xxxxxxxxxxxxxxxx] On Behalf Of Alex Bligh
> Sent: 27 July 2006 12:49
> To: dev@xxxxxxxxxxxxxx
> Cc: Alex Bligh
> Subject: Re: [XaraXtreme-dev] Current/default font
> 
> Neil Howe wrote:
> 
> > Ok - specific question Phil. Is the default font saved in a document
> or
> > not? I'm surprised if it's not saved, but that's what Martin is
> saying. 
> > 
> > If the default font is saved, we can safely change both as 
> originally 
> > decided. If it isn't saved we should only change the current font.
> 
> No that's not the right question. The default attribute 
> doesn't need to be saved. What we need to be sure of is that 
> any text node saved always has AN attribute attached when 
> saved. If so, we don't care what the default attribute is, as 
> it won't influence rendering.
> 
> Alex
>