/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */
package org.eclipse.compare.structuremergeviewer;

import org.eclipse.swt.graphics.Image;
import org.eclipse.compare.ITypedElement;
import org.eclipse.jface.util.Assert;

/**
 * An abstract base implementation of the <code>IDiffElement</code> interface.
 * <p>
 * Subclasses may add behavior and state, and may override <code>getImage</code>
 * and <code>getType</code> to suit.
 * </p>
 */
public abstract class DiffElement implements IDiffElement {

	private int fKind;
	private IDiffContainer fParent;

	/**
	 * Creates a new <code>DiffElement</code> as a child of the given parent.
	 * If parent is not <code>null</code> the new element is added to the parent.
	 *
	 * @param parent the parent of this child; if not <code>null</code> this element is automatically added as a child
	 * @param kind the kind of change
	 */
	public DiffElement(IDiffContainer parent, int kind) {
		fParent= parent;
		fKind= kind;
		if (parent != null)
			parent.add(this);
	}

	/**
	 * The <code>DiffElement</code> implementation of this <code>ITypedInput</code>
	 * method returns <code>null</code>. Subclasses may re-implement to provide
	 * an image for this element.
	 */
	public Image getImage() {
		return null;
	}

	/**
	 * The <code>DiffElement</code> implementation of this <code>ITypedElement</code>
	 * method returns <code>ITypedElement.UNKNOWN_TYPE</code>. Subclasses may
	 * re-implement to provide a type for this element.
	 */
	public String getType() {
		return ITypedElement.UNKNOWN_TYPE;
	}

	/**
	 * Sets the kind of difference for this element.
	 *
	 * @param kind set the kind of difference this element represents
	 * @see Differencer
	 */
	public void setKind(int kind) {
		fKind= kind;
	}

	/* (non Javadoc)
	 * see IDiffElement.getKind
	 */
	public int getKind() {
		return fKind;
	}

	/* (non Javadoc)
	 * see IDiffElement.getParent
	 */
	public IDiffContainer getParent() {
		return fParent;
	}

	/* (non Javadoc)
	 * see IDiffElement.setParent
	 */
	public void setParent(IDiffContainer parent) {
		fParent= parent;
	}
}