ResourceNode.java :  » IDE-Eclipse » All-Other-packages » org » eclipse » compare » Java Open Source

/*******************************************************************************
 * Copyright (c) 2000, 2008 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.eclipse.compare;

import java.io.*;
import java.util.ArrayList;

import org.eclipse.compare.internal.Utilities;
import org.eclipse.compare.structuremergeviewer.IStructureComparator;
import org.eclipse.core.resources.*;
import org.eclipse.core.runtime.*;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Shell;

/**
 * A <code>ResourceNode</code> wraps an <code>IResources</code> so that it can be used
 * as input for the differencing engine (interfaces <code>IStructureComparator</code> and <code>ITypedElement</code>)
 * and the <code>ReplaceWithEditionDialog</code> (interfaces <code>ITypedElement</code> and <code>IModificationDate</code>).
 * <p>
 * Clients may instantiate this class; it is not intended to be subclassed.
 * </p>
 * @noextend This class is not intended to be subclassed by clients.
 */
public class ResourceNode extends BufferedContent
      implements IEncodedStreamContentAccessor, IStructureComparator, ITypedElement,
              IEditableContent, IModificationDate, IResourceProvider, IEditableContentExtension {
      
  private IResource fResource;
  private ArrayList fChildren;
    
  
  /**
   * Creates a <code>ResourceNode</code> for the given resource.
   *
   * @param resource the resource
   */
  public ResourceNode(IResource resource) {
    fResource= resource;
    Assert.isNotNull(resource);
  }
    
  /**
   * Returns the corresponding resource for this object.
   *
   * @return the corresponding resource
   */
  public IResource getResource() {
    return fResource;
  }
  
  /* (non Javadoc)
   * see IStreamContentAccessor.getContents
   */
  public InputStream getContents() throws CoreException {
    if (fResource instanceof IStorage)
      return super.getContents();
    return null;
  }
  
  /* (non Javadoc)
   * see IModificationDate.getModificationDate
   */
  public long getModificationDate() {
    return fResource.getLocalTimeStamp();
  }
  
  /* (non Javadoc)
   * see ITypedElement.getName
   */
  public String getName() {
    if (fResource != null)
      return fResource.getName();
    return null;
  }
    
  /* (non Javadoc)
   * see ITypedElement.getType
   */
  public String getType() {
    if (fResource instanceof IContainer)
      return ITypedElement.FOLDER_TYPE;
    if (fResource != null) {
      String s= fResource.getFileExtension();
      if (s != null)
        return s;
    }
    return ITypedElement.UNKNOWN_TYPE;
  }
  
  /* (non Javadoc)
   * see ITypedElement.getImage
   */
  public Image getImage() {
    return CompareUI.getImage(fResource);
  }

  /*
   * Returns <code>true</code> if the other object is of type <code>ITypedElement</code>
   * and their names are identical. The content is not considered.
   */
  public boolean equals(Object other) {
    if (other instanceof ITypedElement) {
      String otherName= ((ITypedElement)other).getName();
      return getName().equals(otherName);
    }
    return super.equals(other);
  }
  
  /**
   * Returns the hash code of the name.
     * @return a hash code value for this object.
   */
  public int hashCode() {
    return getName().hashCode();
  }
  
  /* (non Javadoc)
   * see IStructureComparator.getChildren
   */
  public Object[] getChildren() {
    if (fChildren == null) {
      fChildren= new ArrayList();
      if (fResource instanceof IContainer) {
        try {
          IResource members[]= ((IContainer)fResource).members();
          for (int i= 0; i < members.length; i++) {
            IStructureComparator child= createChild(members[i]);
            if (child != null)
              fChildren.add(child);
          }
        } catch (CoreException ex) {
          // NeedWork
        }
      }
    }
    return fChildren.toArray();
  }
  
  /**
   * This hook method is called from <code>getChildren</code> once for every
   * member of a container resource. This implementation
   * creates a new <code>ResourceNode</code> for the given child resource.
   * Clients may override this method to create a different type of
   * <code>IStructureComparator</code> or to filter children by returning <code>null</code>.
   *
   * @param child the child resource for which a <code>IStructureComparator</code> must be returned
   * @return a <code>ResourceNode</code> for the given child or <code>null</code>
   */
  protected IStructureComparator createChild(IResource child) {
    return new ResourceNode(child);
  }
    
  /**
   * Returns an open stream if the corresponding resource implements the
   * <code>IStorage</code> interface. Otherwise the value <code>null</code> is returned.
   *
   * @return a buffered input stream containing the contents of this storage
   * @exception CoreException if the contents of this storage could not be accessed
   */
  protected InputStream createStream() throws CoreException {
    if (fResource instanceof IStorage) {
      InputStream is= null;
      IStorage storage= (IStorage) fResource;
      try {
        is= storage.getContents();
      } catch (CoreException e) {
        if (e.getStatus().getCode() == IResourceStatus.OUT_OF_SYNC_LOCAL) {
          fResource.refreshLocal(IResource.DEPTH_INFINITE, null);
          is= storage.getContents();
        } else
          throw e;
      }
      if (is != null)
        return new BufferedInputStream(is);
    }
    return null;
  }
      
  /* (non Javadoc)
   * see IEditableContent.isEditable
   */
  public boolean isEditable() {
    return true;
  }
  
  /* (non Javadoc)
   * see IEditableContent.replace
   */
  public ITypedElement replace(ITypedElement child, ITypedElement other) {
    return child;
  }

  /* (non-Javadoc)
   * @see org.eclipse.compare.IEncodedStreamContentAccessor#getCharset()
   */
  public String getCharset() {
    return Utilities.getCharset(fResource);
  }

  /* (non-Javadoc)
   * @see org.eclipse.compare.IEditableContentExtension#isReadOnly()
   */
  public boolean isReadOnly() {
    if (fResource.getType() == IResource.FILE) {
      ResourceAttributes attrs = fResource.getResourceAttributes();
      if (attrs != null) {
        return attrs.isReadOnly();
      }
    }
    return false;
  }

  /* (non-Javadoc)
   * @see org.eclipse.compare.IEditableContentExtension#validateEdit(org.eclipse.swt.widgets.Shell)
   */
  public IStatus validateEdit(Shell shell) {
    if (isReadOnly())
      return ResourcesPlugin.getWorkspace().validateEdit(new IFile[] { (IFile)fResource}, shell);
    return Status.OK_STATUS;
  }
}