Re: [pyGEF-develop] Some python tech: zope.interface andenthoughTraits

[<pyg...@li...>]

On 6/13/07, Bill Baxter <wb...@gm...> wrote:
> > [[RETIEF:]] There are a couple of options. In pyGEF I create the new
> Control (Document element), but don't add it to the document. All controls
> have a createfigure and createdragfigure method. When a element is added to
> the design the createfigure method is used to create the figure that is
> added to the document. The createdragfigure is used to create the figure
> that is dragged. This figure is held by the Tool, which adds and removes it
> from the canvas. All dragfigures should be placed on the drag layer. Then
> only this layer needs to be  redrawn as the figure is moved. The other
> layers can be drawn as a background  bitmap. The CreateCommand, that adds
> the element to the document, is then only called one the element is placed.
> This make undo easy. It also makes the escape easy as the add figure to
> canvas is not implemented as a command. You generally can't undo the escape
> from a specific tool, although this could be an interesting feature.

That sounds more or less like how I was doing it.  Tool holds onto the
new object till creation parameters are fixed, and then the
"AddObject" command is issued.  But for a more general drawing app you
might want the interactive placement step to draw the object in the
correct layer while dragging, so it won't necessarily be on top.

> > [[RETIEF:]] I can see that I must change the names of some of my classes
> to make things more clear.
> >
> > Here are some suggestions (please comment):
> >
> >               Editor -> Document

Document is often used to mean "DataModel" in things like the wx
DocView framework.  I'm not sure that's the role Editor is serving.

> >               Canvas -> View or DocumentView

Similarly it seems Editor has-a Canvas whereas in the typical Doc/View
paradigm one "Document" can have many "Views".

> >
> >               Control  -> Element or
> DocumentElement/Component/DocumentControl

I like Element, yep.

> >
> >               DataModel -> ElementData or
> ElementDataModel/DocumentDataModel/ElementModel

I like ElementData too, yep.

> >               Figure -> ElementView/ Graphic ? or
> GraphicObject/DrawObject/DocumentGraphic

I lean towards Graphic or GraphicObject.

--bb