Null pointer exception during box edition when clicking back to graph window

[eric-laporte]

When you are editing a box in a graph, if you interrupt your edition to use a non-Unitex program and then click back on the graph, a null pointer exception is raised.

What steps will reproduce the problem?

1. Open or create a graph ; click on a box
2. Edit the content (or output) of the box, without validating your changes
3. Bring a non-Unitex window into the foreground by clicking on it
4. Click on the empty background of the graph

What is the expected output?

Your changes to the box are checked and (if correct) validated. The box is unselected

What do you see instead?

The changes are checked and validated and the box is unselected, BUT a null pointer exception is raised

More info

• Unitex/GramLab IDE version: 3.2.119-rc
• UnitexToolLogger version: 3.2.119-rc