RE: [DiaCanvas] handle, connect & constraint stuff

[<aur...@wa...>]

Le ven 04/04/2003 à 21:19, Arjan J. Molenaar a écrit :

> There are some things wrt handle placement that are maybe harder to
> understand.

It's not the individual pieces that are harder to
grasp, but there are many of them, and they are strongly coupled. I had
to go back and forth to see the picture.

> Event driven: putting the right piece of code in the right function...

hmmm...

> There is some documentation about what every callback does in
> dia-canvas.h, in the struct DiaCanvasItemClass.

I've read it off course, and also probably all the associated code.
An event-driven app has no main function from which all subsequent
function calls recursively branch, calls seem to appear out of nowhere.
That makes understanding the control flow harder.

> 
> > A ripoff' of Element with very slight modifications matches exactly our
> > needs. The only question so far : how shall we name it ? 
> 
> How about "Node"?

Ok.


-About object rendering : it seems that the later an object is added to
the canvas, the later it will be rendered.

It may be nice to provide the renderer with some hints about the
rendering order. For instance, Nodes should always follow Edges, thus
Nodes would happily cover the Edge extremities without complicated code
to make Edges masking themselves or things like that.

Thanks,

Aurélien.