FileInfo.java :  » IDE-Eclipse » core » org » eclipse » core » filesystem » provider » Java Open Source

/*******************************************************************************
 * Copyright (c) 2005, 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
 *   Martin Oberhuber (Wind River) - [170317] add symbolic link support to API
 *******************************************************************************/
package org.eclipse.core.filesystem.provider;

import org.eclipse.core.filesystem.EFS;
import org.eclipse.core.filesystem.IFileInfo;

/**
 * This class should be used by file system providers in their implementation
 * of API methods that return {@link IFileInfo} objects.
 * 
 * @since org.eclipse.core.filesystem 1.0
 * @noextend This class is not intended to be subclassed by clients.
 */
public class FileInfo implements IFileInfo {
  /**
   * Internal attribute indicating if the file is a directory
   */
  private static final int ATTRIBUTE_DIRECTORY = 1 << 0;

  /**
   * Internal attribute indicating if the file exists.
   */
  private static final int ATTRIBUTE_EXISTS = 1 << 16;

  /**
   * Bit field of file attributes
   */
  private int attributes = 0;

  /**
   * The last modified time.
   */
  private long lastModified = EFS.NONE;

  /**
   * The file length.
   */
  private long length = EFS.NONE;

  /**
   * The file name.
   */
  private String name = ""; //$NON-NLS-1$

  /**
   * The target file name if this is a symbolic link
   */
  private String linkTarget = null;

  /**
   * Creates a new file information object with default values.
   */
  public FileInfo() {
    super();
  }

  /**
   * Creates a new file information object. All values except the file name
   * will have default values.
   * 
   * @param name The name of this file
   */
  public FileInfo(String name) {
    super();
    this.name = name;
  }

  /**
   * Convenience method to clear a masked region of the attributes bit field.
   * 
   * @param mask The mask to be cleared
   */
  private void clear(int mask) {
    attributes &= ~mask;
  }

  /*
   * (non-Javadoc)
   * @see java.lang.Object#clone()
   */
  public Object clone() {
    try {
      return super.clone();
    } catch (CloneNotSupportedException e) {
      //we know this object is cloneable
      return null;
    }
  }

  /*
   * (non-Javadoc)
   * @see java.lang.Comparable#compareTo(java.lang.Object)
   */
  public int compareTo(Object o) {
    return name.compareTo(((FileInfo) o).name);
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#exists()
   */
  public boolean exists() {
    return getAttribute(ATTRIBUTE_EXISTS);
  }

  public boolean getAttribute(int attribute) {
    return isSet(attribute);
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#getStringAttribute(int)
   */
  public String getStringAttribute(int attribute) {
    if (attribute == EFS.ATTRIBUTE_LINK_TARGET)
      return this.linkTarget;
    return null;
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#lastModified()
   */
  public long getLastModified() {
    return lastModified;
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#length()
   */
  public long getLength() {
    return length;
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#getName()
   */
  public String getName() {
    return name;
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#isDirectory()
   */
  public boolean isDirectory() {
    return isSet(ATTRIBUTE_DIRECTORY);
  }

  private boolean isSet(long mask) {
    return (attributes & mask) != 0;
  }

  private void set(int mask) {
    attributes |= mask;
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#setAttribute(int, boolean)
   */
  public void setAttribute(int attribute, boolean value) {
    if (value)
      set(attribute);
    else
      clear(attribute);
  }

  /**
   * Sets whether this is a file or directory.
   * 
   * @param value <code>true</code> if this is a directory, and <code>false</code>
   * if this is a file.
   */
  public void setDirectory(boolean value) {
    if (value)
      set(ATTRIBUTE_DIRECTORY);
    else
      clear(ATTRIBUTE_DIRECTORY);
  }

  /**
   * Sets whether this file or directory exists.
   * 
   * @param value <code>true</code> if this file exists, and <code>false</code>
   * otherwise.
   */
  public void setExists(boolean value) {
    if (value)
      set(ATTRIBUTE_EXISTS);
    else
      clear(ATTRIBUTE_EXISTS);
  }

  /* (non-Javadoc)
   * @see org.eclipse.core.filesystem.IFileInfo#setLastModified(long)
   */
  public void setLastModified(long value) {
    lastModified = value;
  }

  /**
   * Sets the length of this file. A value of {@link EFS#NONE}
   * indicates the file does not exist, is a directory, or the length could not be computed.
   * 
   * @param value the length of this file, or {@link EFS#NONE}
   */
  public void setLength(long value) {
    this.length = value;
  }

  /**
   * Sets the name of this file.
   * 
   * @param name The file name
   */
  public void setName(String name) {
    if (name == null)
      throw new IllegalArgumentException();
    this.name = name;
  }

  /**
   * Sets or clears a String attribute, e.g. symbolic link target.
   * 
   * @param attribute The kind of attribute to set. Currently only
   * {@link EFS#ATTRIBUTE_LINK_TARGET} is supported.
   * @param value The String attribute, or <code>null</code> to clear
   * the attribute
   * @since org.eclipse.core.filesystem 1.1
   */
  public void setStringAttribute(int attribute, String value) {
    if (attribute == EFS.ATTRIBUTE_LINK_TARGET)
      this.linkTarget = value;
  }

  /**
   * For debugging purposes only.
   */
  public String toString() {
    return name;
  }
}