Enable auto-layout

[aalmiray]

Related to #33. Would be great if the canvas had an auto-layout feature. Perhaps http://jung.sourceforge.net/ and https://github.com/prefuse/Prefuse can serve as inspiration; even better, their layouting algorithms could be reused "as is".

[miho]

One of our students is already working on it...

[TCMBoby]

Prototype layouting functionality added to branch "layouting".
Still work in progress.

[miho]

The current implementation uses the VisualizationViewer component to compute the JUNG layout. It is probably better to work with VisualizationModel instead.

Example:

VisualizationModel visModel= new DefaultVisualizationModel(myLayout, new Dimension(800, 600));

This will also solve potential multithreading problems with the Swing EDT and JavaFX.

[aalmiray]

Great news! Very much looking forward to testing the new codebase 😄

[TCMBoby]

Fixed the bug with multiplying edges and switched from using VisualizationViewer to DefaultVisualizationModel.
VisualizationViewer is only instantiated once "testvis()" is run.

[miho]

Great news! Just tried the new implementation. Worked well!

Some ideas for improving the current layout generators:

• use simple grid-alignment after layout to prevent "almost-aligned" nodes:

• naive layout could be highly improved if max-width was chosen per row instead of globally:

[TCMBoby]

Newest implementation adresses both problems.
node-alignment is done pairwise for all nodepairs with a distance smaller than a certain threshold. This threshold is given by the size of the concerned nodes and the scaling parameter.

[miho]

Looks much better now. Thanks!

[miho]

Current implementation will be published in next maven release. Since it is still an incubating feature, LayoutGenerator* classes will be moved to the incubating package.

[miho]

@TCMBoby are we ready for maven/bintray publication?

[TCMBoby]

Yes.