NestedProjectFilter.java

package com.codeaffine.extras.ide.internal.resourcefilter;

import static java.util.Arrays.asList;
import static org.eclipse.core.resources.IResource.PROJECT;

import java.net.URI;
import java.util.Collection;
import java.util.Collections;

import org.eclipse.core.filesystem.IFileInfo;
import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.filtermatchers.AbstractFileInfoMatcher;
import org.eclipse.core.runtime.Path;


public class NestedProjectFilter extends AbstractFileInfoMatcher {

  public static final String ID
    = "com.codeaffine.extras.ide.internal.resourcefilter.NestedProjectFilter";

  private static RecursionGuard recursionGuard = new RecursionGuard();

  private IProject project;

  @Override
  public void initialize( IProject project, Object arguments ) {
    this.project = project;
  }

  @Override
  public boolean matches( IContainer parent, IFileInfo fileInfo ) {
    if( !fileInfo.isDirectory() || recursionGuard.isInUse( project )) {
      return false;
    }
    recursionGuard.enter( project );
    try {
      return findContainer( parent, fileInfo.getName() )
        .stream()
        .anyMatch( container -> container.getType() == PROJECT && !container.equals( project ) );
    } finally {
      recursionGuard.leave( project );
    }
  }

  private Collection<IContainer> findContainer( IContainer parent, String folderName ) {
    URI locationURI = parent.getFolder( new Path( folderName ) ).getLocationURI();
    return locationURI == null ? Collections.emptyList() : findContainers( locationURI );
  }

  private Collection<IContainer> findContainers( URI locationURI ) {
    return asList( project.getWorkspace().getRoot().findContainersForLocationURI( locationURI ) );
  }

}