Locator.java

// Copyright 2008 Google Inc. All Rights Reserved.
package org.waveprotocol.wave.model.document.indexed;

import org.waveprotocol.wave.model.document.ReadableWDocument;
import org.waveprotocol.wave.model.document.util.Point;

/**
 * A utility class for obtaining locations in an indexed DOM structure.
 *
 * @author danilatos@google.com (Daniel Danilatos)
*
 */
public class Locator {

  /**
   * Gets the location before a given node.
   *
   * @param <N> The type of DOM nodes.
   * @param doc The indexed document.
   * @param node A node.
   * @return The location before the given node.
   */
  public static <N> int before(ReadableWDocument<N, ?, ?> doc, N node) {
    return doc.getLocation(node);
  }

  /**
   * Gets the location after a given node.
   *
   * @param <N> The type of DOM nodes.
   * @param doc The indexed document.
   * @param node A node.
   * @return The location after the given node.
   */
  public static <N> int after(ReadableWDocument<N, ?, ?> doc, N node) {
    return doc.getLocation(Point.after(doc, node));
  }

  /**
   * Gets the location of the start of a given element.
   *
   * @param <E> The type of DOM Element nodes.
   * @param doc The indexed document.
   * @param element An element.
   * @return The location of the start of the given element.
   */
  public static <N, E extends N> int start(ReadableWDocument<N, E, ?> doc, E element) {
    return doc.getLocation(Point.start(doc, element));
  }

  /**
   * Gets the location of the end of a given element.
   *
   * @param <N> The type of DOM nodes.
   * @param <E> The type of DOM Element nodes.
   * @param doc The indexed document.
   * @param element An element.
   * @return The location of the end of the given element.
   */
  public static <N, E extends N> int end(ReadableWDocument<N, E, ?> doc, E element) {
    return doc.getLocation(Point.<N>end(element));
  }

}