/*******************************************************************************
* Copyright (c) 2010 EclipseSource 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:
* EclipseSource - initial API and implementation
******************************************************************************/
package org.eclipse.swt.graphics;
import org.eclipse.rwt.graphics.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
* @since 1.3
*/
public final class FontMetrics {
private Font font;
/**
* Prevents instances from being created outside the package.
*/
FontMetrics( final Font font ) {
this.font = font;
}
/**
* 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 ( int )Graphics.getAvgCharWidth( font );
}
/**
* 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 Graphics.getCharHeight( font );
}
/**
* 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( final Object object ) {
boolean result = false;
if( object == this ) {
result = true;
} else if( object instanceof FontMetrics ) {
FontMetrics other = ( FontMetrics )object;
result = font.equals( other.font );
}
return result;
}
/**
* 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 font.hashCode();
}
}