We are happy to announce GT Mondrian, a graph visualization engine built on top of Bloc.
It is similar to the original Mondrian and the Mondrian from Roassal, but it is different
in that it is built directly out of Bloc elements. This is interesting because it allows
us to combine typical widgets with visualizations. The other interesting thing about it is
that it validates the design of Bloc: right now, the implementation has 509 lines of code
(excluding graph-specific layouts). The goal is to make visualization a first class
citizen and an integral part of the IDE.
The key ingredient that made this happen is that Bloc can now treat graph layouts, such as
tree or force based, behave under the same rules as typical widget layouts, such as grid
or flow. The challenge comes from the fact that a graph layout depends on the notion of
edges between elements, and we did not want to have elements know about edges in the core
The solution was to split the typical edge implementation in graph visualization libraries
into two distinct concepts:
• Line is an element that draws the connections.
• Edge defines constraints imposed by connections between elements.
Thus, edges form constraints, and constraints are what layouts deal with. That is one
reason why elements in bloc have the ability of defining layout-specific constraints.
Using this, we can nicely define edges between elements as a plugin to Bloc, but still be
able to connect arbitrary elements. What's more, it turns out that we need constraints
for other layouts as well. For example, an element in a grid layout might specify the
The API of GT Mondrian is similar to the one from Roassal, but there are a few differences
as well. These are described in the Pillar documentation available in the GitHub repo.
The best way to experience GT Mondrian and its documentation is to load the GToolkit as
If you download the GT code through Iceberg, the documentation can be experienced live by
The feenk team
"Quality cannot be an afterthought."