plugins/org.eclipse.jst.j2ee.ui/j2ee_ui/org/eclipse/jst/j2ee/internal/dialogs/TypedFileViewerFilter.java

package org.eclipse.jst.j2ee.internal.dialogs;

import java.util.Hashtable;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.jface.viewers.Viewer;

public class TypedFileViewerFilter extends org.eclipse.jface.viewers.ViewerFilter {
	private String[] fAcceptedExtensions;
	private Hashtable visitedElements;
	public TypedFileViewerFilter(String[] acceptedExtensions) {
		fAcceptedExtensions = acceptedExtensions;
		visitedElements = new Hashtable();
	}
	public boolean isFilterProperty(Object element, Object property) {
		return false;
	}
	public boolean isValid(Object element) {
		if (IFile.class.isInstance(element))
			return isValidFile((IFile) element);
		if (IContainer.class.isInstance(element))
			return isValidContainer((IContainer) element);
		return false;
	}
	/*
	 * A valid container is one that contains at least one valid member.
	 */
	public boolean isValidContainer(IContainer container) {
		IResource[] members;
		Object valid = visitedElements.get(container);
		if (valid != null)
			return ((Boolean) valid).booleanValue();
		try {
			members = container.members();
			for (int i = 0; i < members.length; i++) {
				if (isValid(members[i])) {
					visitedElements.put(container, Boolean.TRUE);
					return true;
				}
			}
		} catch (CoreException e) {
			// Do nothing
		}
		visitedElements.put(container, Boolean.FALSE);
		return false;
	}
	public boolean isValidFile(IFile file) {
		String ext = file.getFileExtension();
		for (int i = 0; i < fAcceptedExtensions.length; i++) {
			if (fAcceptedExtensions[i].equalsIgnoreCase(ext)) {
				return true;
			}
		}
		return false;
	}
	public boolean select(Viewer viewer, Object parentElement, Object element) {
		return isValid(element);
	}
}