how to collapse a class

IntelliJ IDEA only adds folding points at the class level if the file contains more than one class (and each class has some content). For example, here is a file with two classes. Notice it has folding regions for the classes.

In the long run, this makes sense since a collapsed class (when there is only one class in the file) does not make much sense. In fact it is a small pet peeve of mine that in XML files the root tag is collapsed when you do a collapse all. To me that makes little sense since when would I want to look at just <root ...> in the editor? I care about the nested elements.

If you want, you can manually add the folding to a class either via

1. the "Fold Selection/Region" action (Ctrl+Period or Code > Folding > Fold Selection) after selecting the class section (use Ctrl+W and Ctrl+Shift+W to make that easier). The folding will be defined for that editor session; or
   
2. Use in code comments to define the region. See http://www.jetbrains.com/idea/webhelp/folding-custom-regions-with-line-comments.html