I come across Graphviz. Open source and available on near enough all platforms–Mac, Linux and Windows. Using a very simple syntax, you create dot files and then using the dot tool, you can generate PNG images of your diagrams.

Here is an example dot script:

digraph my_fsm {
    label = "ab*(cd)+|b";
    rankdir = LR;
    node [shape = doublecircle]; 3 4;
    node [shape = circle];
    0 -> 1 [label = "a"];
    1 -> 1 [label = "b"];
    1 -> 2 [label = "c"];
    2 -> 3 [label = "d"];
    3 -> 2 [label = "c"];
    0 -> 4 [label = "b"];
}

Following is an explanation of the above script:

1. I’m declaring the graph as a directed graph with digraph.
2. my_fsm is just the name I’ve given the graph. This can be anything.
3. I add a label to the graph which holds the regular expression that I’m drawing. This isn’t required, but just helps by giving it a title.
4. rankdir specifies the direction of the diagram. I’m specifying ‘left to right’ with LR.
5. So that I can differentiate between accepting states and normal states, I’m declaring that nodes 3 and 4 will have a double circle around them.
6. For all other nodes, I just want to use the normal circle shape.
7. Lastly, I declare the nodes and their edges. Also, I add a label to each edge.

Once you save the file, you can run it through the dot program using the following command:

dot my_file.dot -Tpng -o my_fsm.png

You’ll need to check where dot was installed. With the Mac installer package it is installed to /usr/local/graphviz-2.12/bin/dot, so you’ll need to modify the above command to reflect the correct location.

The outputted file, my_fsm.png in this example, should result in something that looks like the one below.

A very handy tool indeed. There is a PDF guide on all the commands available. Of which, I’m next going to look for how to space the graph out a bit more as it’s a little squashed at the moment.

Hope this helps.

Brightside is the Ubuntu app to do the job.

sudo apt-get install brightside

Once installed, go to System, Preferences, Screen Actions. I then checked the “Bottom right corner” and then chose “Start screensaver”. Works a charm.

Be sure that in your Screensaver settings to check the “Lock screen when screensaver is active” option.

It helped build the designs for this blog and countless others, as well as my James Bond site, CommanderBond.net.

It really speeds up development for me compared to writing the CSS rules out.

Congratulations to Jan for a great release!