Bug 357895

Comment 1 Miles Parker 2011-09-15 21:12:27 EDT

Created attachment 203463 [details]
Demonstrates potential solution

OK, I experimented with one approach to handling this. This might also help with the package issue. But I'm a little hesitant about it — because the background is gradiated and the lables are not full width, I think it looks kind of cheesy.. thoughts?

Comment 2 Miles Parker 2011-09-15 21:59:11 EDT

Created attachment 203464 [details]
Mask with Diagram Background

Comment 3 Miles Parker 2011-09-15 21:59:39 EDT

Created attachment 203465 [details]
Mask with figure Background

Comment 4 Miles Parker 2011-09-15 22:01:48 EDT

OK, I think I've found two approaches that work pretty well and that are probably worth doing. Of the two last ones, does anyone have a preference?

Comment 5 Steffen Pingel 2011-09-16 05:27:55 EDT

I like the last screenshot best.

Comment 6 Miles Parker 2011-09-16 13:39:18 EDT

Yeah, so did I -- but after asking this I spent some more time playing with it and the second one works much better in terms of interface and transition. The gradiant fill that is being used by the GMF nodes makes things look pretty odd otherwise. you might try it on the ecore model and let me know what you think.

Comment 7 Miles Parker 2011-09-16 13:41:02 EDT

Created attachment 203507 [details]
Ecore example diagram

Comment 8 Miles Parker 2011-09-16 13:41:42 EDT

Created attachment 203508 [details]
Ecore sample diagram file

Comment 9 Miles Parker 2011-09-16 13:42:19 EDT

I've attached the ecore files (actually mangled, but that shouldn't matter) for better usage testing.

Comment 10 Steffen Pingel 2011-09-16 16:58:40 EDT

Created attachment 203533 [details]
overlapping edges

Comment 11 Steffen Pingel 2011-09-16 17:01:40 EDT

Looks pretty cool! I just noticed an oddity when edges overlap.

I would suggest removing the decoration when the mouse leaves the diagram editor. I find that the half faded elements looks a bit odd when I navigate to the toolbar or other elements in the workbench.

Comment 12 Miles Parker 2011-09-16 17:30:28 EDT

(In reply to comment #11)
> Looks pretty cool! I just noticed an oddity when edges overlap.

Thanks. Yeah, that's an oddity that I'm hoping that not too many people notice, because there isn't much we can do about it without even more fiddling -- and there was a lot of fiddling to get to this point. :) Without getting into all the details :) and after much experimentation, this is the workable strategy I found.

First some background..

1. GEF consumes mouse events, which means that we need to get an SWT mouse listener into the picture. This is an "engineer-around" approach that I discovered a while back.
2. To do this we can't use the built-in GEF figure mouse detect anymore.
3. We still ned to attach these to figures on the diagram, so we create dummy figures that can then be referred to from the mouse to determine distance from the line.
4. Because of the way GMF handles points for connections -- they're sort of faked -- and the way decorations work, we can't attach those figures to the points, we have to use just the end-points. But this ended up being better anyway because it means that stray lines that happen by items aren't shown, instead we end up basing distance on the minimum distance to the endpoints/anchors. It also looks cool because you get that kind of ray effect under movement. 
5. We can't change Z-order for components including the connections without monster GEF/GMF hacking.

All that ends up causing the whited out edges under the following scenario:

1. Orthogonal edge layout so that edges are either vertical or horizontal.
2. Edges that connect distinct nodes overlap.
3. The edge farthest away happens to be the top-most.

Then the top-most edge is furthest away and (in the case of a white background) is thus lightest, obscuring the darker edge below.

> I would suggest removing the decoration when the mouse leaves the diagram
> editor. I find that the half faded elements looks a bit odd when I navigate to
> the toolbar or other elements in the workbench.

Yes, agreed. We'll go to all masked when we leave the editor.

Comment 13 Miles Parker 2011-09-20 13:07:10 EDT

(In reply to comment #11)

> I would suggest removing the decoration when the mouse leaves the diagram
> editor. I find that the half faded elements looks a bit odd when I navigate to
> the toolbar or other elements in the workbench.

See bug 358276

Comment 14 Miles Parker 2011-09-20 13:33:46 EDT

Closing. Don't know if it worth opening another bug to track the fact that we can't / won't fix the edge overlap issue at least for now.