Re: [Inkscape-devel] RDF nodes

-- Christoffer Holmstedt 2013/7/31 Markus Engel <p637777@...1081...> > I don't seem to get what you mean by "values" and "building blocks"? Is it > necessary to create a class just holding a key and a value? Wouldn't a > std::map suffice? > > 1) > The SPObject class exposes a method "connectModified" which you can use to > register a sigc::slot with the modification signal. This should work I > hope. > Or look at "src/ui/dialog/document-metadata.cpp". Inside this file there's > a > method called "on_repr_attr_changed": > /** > * Called when XML node attribute changed; updates dialog widgets. > */ > I don't know why this does not work currently. > > 2) > Sorry? When the xml tree is modified, the corresponding SPObject is > automatically informed, I don't think you have to do anything there > yourself. When you want to update the xml node after you made a change to > an > SPObject, just call the modified SPObject's updateRepr method. > > 3) > Yes, I think so. The SPObject will stay, not as a struct but as a real > class > ;) . For the moment you'll have to get into creating a derived GObject > "class". There is an example in sp-skeleton.cpp. I'm just waiting for the > 0.49 release to propose for merging, as I made some big changes to the code > base with probably some nasty bugs. > > > > > > ------------------------------ > > Message: 7 > Date: Wed, 31 Jul 2013 14:58:48 +0200 > From: Christoffer Holmstedt <christoffer.holmstedt@...400...> > Subject: Re: [Inkscape-devel] RDF nodes > To: inkscape-devel@lists.sourceforge.net > Message-ID: > <CAG9Fz+tsLNe019Y=qu5Miu4-YtmsQA5Ya9xKNuD= > PP+cm9O+xw@...401...> > Content-Type: text/plain; charset="utf-8" > > I've looked into this a little bit more now when the GUI is more or less > complete (Gtkmm 2 for now). In the Document Properties I've added the > "Metadata and License" tab. Name can be discussed and I have also left the > "Metadata" and "License" tab as is for now during development, they will be > removed later on. Code can be found at > lp:~christoffer-holmstedt/inkscape/improved-copy-paste-with-metadata > > ### The RDF refactoring > So after thinking about RDF within Inkscape for a while I like your idea > Markus. This is my proposal... > > RDFNode : SPObject; > - Class that can be instantiated as rdf:RDF, rdf:Bag, rdf:Seq or similiar > nodes. > > RDFTriple : SPObject; > - One object for each triple (value). > > The difference between RDFNodes and RDFTriples would be that RDFTriples > include values and RDFNodes contain building blocks to build the rdf > structure. Any comments about this are appreciated. > > ### Questions > 1) If I make changes directly in the XML editor some values affect the > image > as soon as I set the value. Though if I change any Metadata value in > current > trunk it will not change the GUI. How do properly make this work in this > new > version? Should the GUI somehow "listen" for updates to the object tree or > xml tree? > > 2) I should try to work with the typed object tree as much as possible and > not directly to the xml tree, should changes to the xml tree then go > through > each object in the typed object tree? > > 3) Should I keep the "sp" prefix for now as long as we keep using the > SPObject, so it should rather be SPRdfNode and SPRdfTriple? > > -- > Christoffer Holmstedt > > > 2013/7/29 Christoffer Holmstedt <christoffer.holmstedt@...400...> > > > Thank you very much. I will look into this during the upcoming week. > > > > -- > > Christoffer Holmstedt > > > > > > 2013/7/27 Markus Engel <p637777@...1081...> > > > >> Hi,**** > >> > >> I generated the documentation for the object tree and picked out the > relevant parts for you:**** > >> > >> https://dl.dropboxusercontent.com/u/37427492/sp-object.pdf**** > >> > >> https://dl.dropboxusercontent.com/u/37427492/sp-metadata1.pdf**** > >> > >> https://dl.dropboxusercontent.com/u/37427492/sp-metadata2.pdf**** > >> > >> ** ** > >> > >> Note that this is not how it is currently implemented in trunk, but in > my > own branch instead. This shouldn?t matter for understanding, though, I just > converted the tree to ?real? c++ classes.**** > >> > >> SPObject is the base class for all tree nodes. As you can see in the > first pdf, every svg element has got one counterpart of the right class in > the object tree. Whenever a change is made to an xml node, it informs the > tree node belonging to him by calling for example onUpdate(). The tree node > then updates its internal state. Whenever possible, one should work on the > tree nodes and leave the xml nodes alone.**** > >> > >> You?ll find lots of information on this in the inkscape wiki, e. g. > ?Changes in the XML tree are automatically propagated to the object tree > via > observers, but *not* the other way around?a function called updateRepr() > must be explicitly called.?**** > >> > >> ** ** > >> > >> As the rdf information is not a drawable object (-> SPItem subclasses), > it should probably derive directly from SPObject. Maybe you could then add > it as a member to SPMetadata. I?m not quite sure how to handle that best > either. We should wait for some more opinions? or just try it out :) .**** > >> > >> ** ** > >> > >> Regards,**** > >> > >> Markus**** > >> > >> ** ** > >> > >> > Hi Markus**** > >> > >> > I started work on Inkscape earlier this year (April/May). During the > summer**** > >> > >> > I work with Commons Machinery [1] to improve metadata handling and the > GUI**** > >> > >> > for metadata and license information. In this prototype I'm working > with**** > >> > >> > the idea that multiple metadata tags are allowed and therefore > multiple > rdf**** > >> > >> > tags (though only one per metadata tag). With my limited experience > with**** > >> > >> > Inkscape codebase and the object tree I'm not sure how to best > refactor > RDF**** > >> > >> > to fit in.**** > >> > >> >** ** > >> > >> > In an earlier discussion with Peter Liljenberg [2] he said that a > refactor**** > >> > >> > of RDF should be done to be more general and easy to work with. I'm > not**** > >> > >> > sure about the specifics about this but I will look into it later on > in**** > >> > >> > August hopefully.**** > >> > >> >** ** > >> > >> > You seem to have a lot more experience with the Inkscape codebase than > I**** > >> > >> > have so it would been fun to discuss any changes that is done here in > this**** > >> > >> > area with you. The goal now for me is to complete the prototype with > as**** > >> > >> > simple code as possible and then during the summer/fall (when time > permits)**** > >> > >> > refactor so it can be merged into Inkscape trunk.**** > >> > >> >** ** > >> > >> > Concerning GSOC merge before 0.49, I don't know.**** > >> > >> >** ** > >> > >> > [1] http://commonsmachinery.se/**** > >> > >> > [2] https://launchpad.net/~peter-liljenberg**** > >> > >> >** ** > >> > >> > -- **** > >> > >> > Christoffer Holmstedt**** > >> > >> >** ** >