Eclipse: how to hide custom files in Project Explorer

I have a custom builder in CDT, which adds alot of files into project directory. I want those files to be filtered out from Project Explorer, but cannot figure out how (the file mask is *.ooj).

Is it possible to add a custom filter by file mask into Customize View? Or maybe there is anther way to hide files in Project Explorer?

Here's how to do it on Eclipse Indigo/Luna/Neon (as of 2018-05-22):

• Open the "project properties"
  • pull down menu --> Project --> Properties
  • A new dialog window named "Properties" will appear
• Create a "Resource Filter"
  • Select Resource --> Resource Filters -> Add Filter...
  • A new dialog window named "Add Resource Filter for project" will appear
  • In the new dialog select the following
    • Filter Type: Exclude All
    • Applies to: Files
    • Make sure to click the checkbox for "All children (recusive)"
    • File and Folder Attributes
      • select: Name
      • select: Matches
      • fill in: *.ooj
    • Click OK
    • Dialog closes
• Apply the new filter
  • Click Apply
  • You should see a change in your "Navigator" View
• Close the "Project Properties"
  • Click OK
• Done

You can define a filter for that. Open the view menu in the Package Explorer and then choose "Filters..." Here you can define a pattern to hide files.

How to add global user defined resource filters to the Eclipse Project Explorer view:

Modifying and switching filters on a project level needs a lot of clicks and can be tedious if you have many projects in your workspace. If you need to apply or switch the same filter settings on all projects again and again you might prefer a quicker and global solution for all projects and all workspaces.

• Modify the files plugin.xml and plugin.properties in plugins/org.eclipse.ui.navigator.resources_{version}.jar (extract, modify and re-add the modified files).

• For example, add a file only filter in plugin.xml to the element /plugin/extension @point="org.eclipse.ui.navigator.navigatorContent":

    <commonFilter id="org.eclipse.ui.navigator.resources.filters.{unique-id-a}" name="%filters.{unique-id-a}.name" description="%filters.{unique-id-a}.description" activeByDefault="true|false">
       <filterExpression>
          <and>
             <instanceof value="org.eclipse.core.resources.IFile"/>
             <test property="org.eclipse.core.resources.name" value="{file-wildcard-pattern-a}"/>
          </and>
       </filterExpression>
    </commonFilter>
  

• As another example, add a file and directory filter in plugin.xml to the same element:

    <commonFilter id="org.eclipse.ui.navigator.resources.filters.{unique-id-b}" name="%filters.{unique-id-b}.name" description="%filters.{unique-id-b}.description" activeByDefault="true|false">
       <filterExpression>
          <and>
             <adapt type="org.eclipse.core.resources.IResource">
                <test property="org.eclipse.core.resources.name" value="{file-wildcard-pattern-b}"/>
             </adapt>
          </and>
       </filterExpression>
    </commonFilter>
  

• Provide filter names and descriptions for all added filters in plugin.properties. Filter display order in Project Explorer view is by this filter name regardless of filter type:

    filters.{unique-id-a}.name={file-wildcard-pattern-a} files
    filters.{unique-id-a}.description=Hides files that match "{file-wildcard-pattern-a}"
  
    filters.{unique-id-b}.name={file-wildcard-pattern-b} files and folders
    filters.{unique-id-b}.description=Hides files and folders that match "{file-wildcard-pattern-b}"
  

• Restart Eclipse and reset its caches: eclipse.exe -clean

Firstly thanks to @emmzett Just wanna explain in a verbose mode of emmzett's answer because I didn't know anything editing plugin files and I spent 2 hours on this. Maybe I can save your time with this clarified expression.

1. Firstly go in eclipse file then plugins->org.eclipse.ui.navigator.resources_(your eclipse version).jar
2. Right click to .jar file and open with winrar
3. Find the plugin.xml open with an editor(notepad,Notepad++ etc) the plugin.xml file
4. Find the point="org.eclipse.ui.navigator.navigatorContent" and paste code below

   <commonFilter id="org.eclipse.ui.navigator.resources.filters.SpecifyAnIdForYourFileType"
   name="%filters.SpecifyAnIdForYourFileType.name"
   description="%filters.SpecifyAnIdForYourFileType.description"
   activeByDefault="true">
   <filterExpression>
   <and>
   <instanceof value="org.eclipse.core.resources.IFile"/>
   <test property="org.eclipse.core.resources.name" value="your specific file"/>
   </and>
   </filterExpression>
   </commonFilter>

5. Change SpecifyAnIdForYourFileType with a unique name for id Change "your specific file" with your specific file suffix like *.pdf or desktop.ini etc.
6. Save the plugin.xml and exit
7. Find the plugin.properties open with an editor same as 3.step Paste this code

   filters.SpecifyAnIdForYourFileType.name=your specific file files
   filters.SpecifyAnIdForYourFileType.description=Hides files that match your specific file

8. Save plugin.properties and exit
9. Restart the eclipse and clear cache than go to Project Explorer at the left side
10. Click the View Menu icon at the top right corner
11. Click the Filters and Customization...
12. Tick your new filter in the Filters menu.

That's all I want to thanks again to emmzett.

Regards.