How do I add an item to for every folder in the system?
There is a folder in the System Filesystem called Loaders. It is where various things are registered that apply to specific DataObject types. For example, there is a folder Loaders/text/x-java
that contains things that pertain to Java files (notice that the path is a MIME type). It has an Actions
subfolder where you can add actions to the popup menu for Java files.
You may not think of a folder as being a file type, but to NetBeans it is. There is a subfolder Loaders/folder/any/Actions
which contains actions that should appear in the popup menu for folders. Just add your action in your layer file to that folder, i.e.
<filesystem>
<folder name="Loaders">
<folder name="folder">
<folder name="any">
<folder name="Actions">
<file name="com-foo-module-MyAction.instance"/>
</folder>
</folder>
</folder>
</folder>
</filesystem>