NetBeans Code Folding

Tired of lose the fight against NetBeans MDR stuff, I decided to check out Code Folding. Pretty easy, indeed. I haven't done a full code fold example, but I was able to use NB 'editor-fold' pseudo-tag. Considering that you have the syntax support (see NBP Tutorials), the steps are:

1. On your SettingsInitializer, you need to add this line:
   

   settingsMap.put(SettingsNames.CODE_FOLDING_ENABLE, Boolean.TRUE);

   This is not obvious, but it is the most important step. Without it, you will never activate folding (this was hard to find out - like any other "non-layer.xml" stuff).
   


2. On your EditorKit, you need to implement the SyntaxUpdateTokens class and put it as a document property. Like this:
   

   public class MyEditorKit extends NbEditorKit {
       [ ... ]        
   
       protected void initDocument(BaseDocument doc) {
           doc.putProperty(SyntaxUpdateTokens.class, new SUT());
       }
       
       public class SUT extends SyntaxUpdateTokens {
   
           private List list;
           
           public void syntaxUpdateStart() {
               list = new ArrayList();
           }
   
           public List syntaxUpdateEnd() {
               return list;
           }
   
           public void syntaxUpdateToken(TokenID tid, TokenContextPath tcp,
                   int offset, int len) {
               if (tokenID == MyTokenContext.LINE_COMMENT) {
                   list.add(new TokenInfo(tid, tcp, offset, len));
               }
           }
       }
   }

   This will tell CustomFold which tokens it must use to find the pseudo-tag.
   


3. You need to create a three-line class to add the sidebar to the editor:
   

   public class MyFoldingSideBarFactory implements SideBarFactory {
       public JComponent createSideBar(JTextComponent jTextComponent) {
           return new CodeFoldingSideBar(jTextComponent);
       }
   }

   This is a weird step. I don't know why there's no ready-to-go class to do this job.
   


4. Now, glue everything in your layer.xml, under "Editor/MIME" folder:
   

   <folder name="SideBar">
       <file name="mypkg-MyFoldingSideBarFactory.instance"/>
       <attr name="org-netbeans-editor-GlyphGutter.instance
           /mypkg-MyFoldingSideBarFactory.instance"
           boolvalue="true"/>
   </folder>
   <folder name="FoldManager">
       <file name="org-netbeans-editor-CustomFoldManager$Factory.instance"/>
   </folder>

   FoldManager can be chained, just like the SideBar. Making it easy to add a "real" code fold based on tokens.