WorkingSetFilter.java

/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.rubypeople.rdt.internal.ui.workingsets;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IStorage;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.ui.IWorkingSet;
import org.rubypeople.rdt.core.IRubyElement;
import org.rubypeople.rdt.core.IRubyProject;
import org.rubypeople.rdt.core.IRubyScript;
import org.rubypeople.rdt.core.ISourceFolderRoot;
import org.rubypeople.rdt.internal.ui.packageview.LoadPathContainer;

/**
 * Working set filter for Ruby viewers.
 */
public class WorkingSetFilter extends ViewerFilter {

	private IWorkingSet fWorkingSet = null;
	private IAdaptable[] fCachedWorkingSet = null;

	/**
	 * Returns the working set which is used by this filter.
	 * 
	 * @return the working set
	 */
	public IWorkingSet getWorkingSet() {
		return fWorkingSet;
	}

	/**
	 * Sets this filter's working set.
	 * 
	 * @param workingSet
	 *            the working set
	 */
	public void setWorkingSet(IWorkingSet workingSet) {
		fWorkingSet = workingSet;
	}

	/*
	 * Overrides method from ViewerFilter.
	 */
	public boolean select(Viewer viewer, Object parentElement, Object element) {
		if (fWorkingSet == null
				|| (fWorkingSet.isAggregateWorkingSet() && fWorkingSet
						.getElements().length == 0))
			return true;

		if (element instanceof IRubyElement)
			return isEnclosing((IRubyElement) element);

		if (element instanceof IResource)
			return isEnclosing(((IResource) element).getFullPath());

		if (element instanceof LoadPathContainer) {
			return isEnclosing((LoadPathContainer) element);
		}

		if (element instanceof IAdaptable) {
			IAdaptable adaptable = (IAdaptable) element;
			IRubyElement je = (IRubyElement) adaptable
					.getAdapter(IRubyElement.class);
			if (je != null)
				return isEnclosing(je);

			IResource resource = (IResource) adaptable
					.getAdapter(IResource.class);
			if (resource != null)
				return isEnclosing(resource.getFullPath());
		}

		return true;
	}

	private boolean isEnclosing(LoadPathContainer container) {
		// check whether the containing packagefragment root is enclosed
		Object[] roots = container.getSourceFolderRoots();
		if (roots.length > 0)
			return isEnclosing((ISourceFolderRoot) roots[0]);
		return false;
	}

	/*
	 * Overrides method from ViewerFilter
	 */
	public Object[] filter(Viewer viewer, Object parent, Object[] elements) {
		Object[] result = null;
		if (fWorkingSet != null)
			fCachedWorkingSet = fWorkingSet.getElements();
		try {
			result = super.filter(viewer, parent, elements);
		} finally {
			fCachedWorkingSet = null;
		}
		return result;
	}

	private boolean isEnclosing(IPath elementPath) {
		if (elementPath == null)
			return false;

		IAdaptable[] cachedWorkingSet = fCachedWorkingSet;
		if (cachedWorkingSet == null)
			cachedWorkingSet = fWorkingSet.getElements();

		int length = cachedWorkingSet.length;
		for (int i = 0; i < length; i++) {
			if (isEnclosing(cachedWorkingSet[i], elementPath))
				return true;
		}
		return false;
	}

	public boolean isEnclosing(IRubyElement element) {
		Assert.isNotNull(element);

		IAdaptable[] cachedWorkingSet = fCachedWorkingSet;
		if (cachedWorkingSet == null)
			cachedWorkingSet = fWorkingSet.getElements();

		boolean isElementPathComputed = false;
		IPath elementPath = null; // will be lazy computed if needed

		int length = cachedWorkingSet.length;
		for (int i = 0; i < length; i++) {
			IRubyElement scopeElement = (IRubyElement) cachedWorkingSet[i]
					.getAdapter(IRubyElement.class);
			if (scopeElement != null) {
				// compare Ruby elements
				IRubyElement searchedElement = element;
				while (searchedElement != null) {
					if (searchedElement.equals(scopeElement))
						return true;
					else {
						if (scopeElement.getElementType() == IRubyElement.RUBY_PROJECT
								&& searchedElement.getElementType() == IRubyElement.SOURCE_FOLDER_ROOT) {
							ISourceFolderRoot pkgRoot = (ISourceFolderRoot) searchedElement;
							if (pkgRoot.isExternal() && pkgRoot.isArchive()) {
								if (((IRubyProject) scopeElement)
										.isOnLoadpath(searchedElement))
									return true;
							}
						}
						if (searchedElement.getElementType() == IRubyElement.SOURCE_FOLDER
								&& scopeElement.getElementType() == IRubyElement.SOURCE_FOLDER) {
							IPath searchPath = searchedElement.getPath();
							IPath scopePath = scopeElement.getPath();
							ISourceFolderRoot root = (ISourceFolderRoot) searchedElement
									.getParent();
							IPath rootPath = root.getPath();
							IPath parentFolderPath = searchPath
									.removeFirstSegments(
											rootPath.segmentCount())
									.removeLastSegments(1);
							searchedElement = root
									.getSourceFolder(parentFolderPath
											.segments());
						} else {
							searchedElement = searchedElement.getParent();
						}
						if (searchedElement != null
								&& searchedElement.getElementType() == IRubyElement.SCRIPT) {
							IRubyScript unit = (IRubyScript) searchedElement;
							unit = unit.getPrimary();
						}
					}
				}
				while (scopeElement != null) {
					if (element.equals(scopeElement))
						return true;
					else
						scopeElement = scopeElement.getParent();
				}
			} else {
				// compare resource paths
				if (!isElementPathComputed) {
					IResource elementResource = (IResource) element
							.getAdapter(IResource.class);
					if (elementResource != null)
						elementPath = elementResource.getFullPath();
				}
				if (isEnclosing(cachedWorkingSet[i], elementPath))
					return true;
			}
		}
		return false;
	}

	private boolean isEnclosing(IAdaptable element, IPath path) {
		if (path == null)
			return false;

		IPath elementPath = null;

		IResource elementResource = (IResource) element
				.getAdapter(IResource.class);
		if (elementResource != null)
			elementPath = elementResource.getFullPath();

		if (elementPath == null) {
			IRubyElement javaElement = (IRubyElement) element
					.getAdapter(IRubyElement.class);
			if (javaElement != null)
				elementPath = javaElement.getPath();
		}

		if (elementPath == null && element instanceof IStorage)
			elementPath = ((IStorage) element).getFullPath();

		if (elementPath == null)
			return false;

		if (elementPath.isPrefixOf(path))
			return true;

		if (path.isPrefixOf(elementPath))
			return true;

		return false;
	}

}