/*******************************************************************************

 * Copyright (c) 2000, 2007 IBM Corporation and others.

 * Portion Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

 * 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

 *     Nokia Corporation - Qt implementation

 *******************************************************************************/

package org.eclipse.swt.graphics;

/**

 * Instances of this class provide measurement information

 * about fonts including ascent, descent, height, leading

 * space between rows, and average character width.

 * <code>FontMetrics</code> are obtained from <code>GC</code>s

 * using the <code>getFontMetrics()</code> method.

 *

 * @see GC#getFontMetrics

 */

public final class FontMetrics {

	int ascent, descent, averageCharWidth, leading, height;

FontMetrics() {

}

/**

 * Compares the argument to the receiver, and returns true

 * if they represent the <em>same</em> object using a class

 * specific comparison.

 *

 * @param object the object to compare with this object

 * @return <code>true</code> if the object is the same as this object and <code>false</code> otherwise

 *

 * @see #hashCode

 */

public boolean equals (Object object) {

	if (object == this) return true;

	if (!(object instanceof FontMetrics)) return false;

	FontMetrics metrics = (FontMetrics)object;

	return ascent == metrics.ascent && descent == metrics.descent &&

		averageCharWidth == metrics.averageCharWidth && leading == metrics.leading &&

		height == metrics.height;

}

/**

 * Returns the ascent of the font described by the receiver. A

 * font's <em>ascent</em> is the distance from the baseline to the 

 * top of actual characters, not including any of the leading area,

 * measured in pixels.

 *

 * @return the ascent of the font

 */

public int getAscent() {

	return ascent;

}

/**

 * Returns the average character width, measured in pixels,

 * of the font described by the receiver.

 *

 * @return the average character width of the font

 */

public int getAverageCharWidth() {

	return averageCharWidth;

}

/**

 * Returns the descent of the font described by the receiver. A

 * font's <em>descent</em> is the distance from the baseline to the

 * bottom of actual characters, not including any of the leading area,

 * measured in pixels.

 *

 * @return the descent of the font

 */

public int getDescent() {

	return descent;

}

/**

 * Returns the height of the font described by the receiver, 

 * measured in pixels. A font's <em>height</em> is the sum of

 * its ascent, descent and leading area.

 *

 * @return the height of the font

 *

 * @see #getAscent

 * @see #getDescent

 * @see #getLeading

 */

public int getHeight() {

	return height;

}

/**

 * Returns the leading area of the font described by the

 * receiver. A font's <em>leading area</em> is the space

 * above its ascent which may include accents or other marks.

 *

 * @return the leading space of the font

 */

public int getLeading() {

	return leading;

}

/**

 * Returns an integer hash code for the receiver. Any two 

 * objects that return <code>true</code> when passed to 

 * <code>equals</code> must return the same value for this

 * method.

 *

 * @return the receiver's hash

 *

 * @see #equals

 */

public int hashCode() {

	return ascent ^ descent ^ averageCharWidth ^ leading ^ height;

}

}