/* * Copyright 1999-2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* $Id$ */ package org.apache.fop.render.java2d; // Java import java.awt.Font; import java.awt.Graphics2D; import java.awt.geom.Rectangle2D; import java.awt.FontMetrics; import java.awt.font.TextLayout; /** * This is a FontMetrics to be used for AWT rendering. * It instanciates a font, depening on family and style * values. The java.awt.FontMetrics for this font is then * created to be used for the actual measurement. * Since layout is word by word and since it is expected that * two subsequent words often share the same style, the * Font and FontMetrics is buffered and only changed if needed. *

* Since FontState and FontInfo multiply all factors by * size, we assume a "standard" font of FONT_SIZE. */ public class Java2DFontMetrics { /** * Font size standard used for metric measurements */ public static final int FONT_SIZE = 1; /** * This factor multiplies the calculated values to scale * to FOP internal measurements */ public static final int FONT_FACTOR = (1000 * 1000) / FONT_SIZE; /** * The width of all 256 character, if requested */ private int width[] = null; /** * The typical height of a small cap latter */ private int xHeight = 0; /** * Buffered font. * f1 is bufferd for metric measurements during layout. * fSized is buffered for display purposes */ private Font f1 = null; // , fSized = null; /** * The family type of the font last used */ private String family = ""; /** * The style of the font last used */ private int style = 0; /** * The size of the font last used */ private float size = 0; /** * The FontMetrics object used to calculate character width etc. */ private FontMetrics fmt = null; /** * Temp graphics object needed to get the font metrics */ private Graphics2D graphics; /** * Constructs a new Font-metrics. * @param graphics a temp graphics object - this is needed so * that we can get an instance of java.awt.FontMetrics */ public Java2DFontMetrics(Graphics2D graphics) { this.graphics = graphics; } /** * Determines the font ascent of the Font described by this * FontMetrics object * @param family font family (java name) to use * @param style font style (java def.) to use * @param size font size * @return ascent in milliponts */ public int getAscender(String family, int style, int size) { setFont(family, style, size); // return (int)(FONT_FACTOR * fmt.getAscent()); // workaround for sun bug on FontMetrics.getAscent() // http://developer.java.sun.com/developer/bugParade/bugs/4399887.html /* * Bug 4399887 has status Closed, not a bug. The comments on the bug * are: * The submitter is incorrectly assuming that the string he has used * is displaying characters which represent those with the maximum * ascent in the font. If (for example) the unicode character * \u00c1 which is the A-acute character used in many European * languages is placed in the bodu of the "Wrong" string it can be * seen that the JDK is exactly correct in its determination of the * ascent of the font. * If the bounds of a particular string are interesting then the * Rectangle FontMetrics.getStringBounds(..) method can be called. * The y value of the rectangle is the offset from the origin * (baseline) apparently needed by the sample test program * * xxxxx@xxxxx 2001-05-15 */ int realAscent = fmt.getAscent() - (fmt.getDescent() + fmt.getLeading()); return FONT_FACTOR * realAscent; } /** * The size of a capital letter measured from the font's baseline * @param family font family * @param style font style * @param size font size * @return capital height in millipoints */ public int getCapHeight(String family, int style, int size) { // currently just gets Ascent value but maybe should use // getMaxAcent() at some stage return getAscender(family, style, size); } /** * Determines the font descent of the Font described by this * FontMetrics object * @param family font family (jave name) to use * @param style font style (jave def.) to use * @param size font size * @return descent in milliponts */ public int getDescender(String family, int style, int size) { setFont(family, style, size); return (-1 * FONT_FACTOR * fmt.getDescent()); } /** * Determines the typical font height of a small cap letter * FontMetrics object * @param family font family (jave name) to use * @param style font style (jave def.) to use * @param size font size * @return font height in milliponts */ public int getXHeight(String family, int style, int size) { setFont(family, style, size); return (int)(FONT_FACTOR * xHeight); } /** * Returns width (in 1/1000ths of point size) of character at * code point i * @param i the character for which to get the width * @param family font family (jave name) to use * @param style font style (jave def.) to use * @param size font size * @return character width in millipoints */ public int width(int i, String family, int style, int size) { int w; setFont(family, style, size); // the output seems to look a little better if the // space is rendered larger than given by // the FontMetrics object if (i <= 32) { w = (int)(1.4 * fmt.charWidth(i) * FONT_FACTOR); } else { w = (int)(fmt.charWidth(i) * FONT_FACTOR); } return w; } /** * Return widths (in 1/1000ths of point size) of all * characters * @param family font family (jave name) to use * @param style font style (jave def.) to use * @param size font size * @return array of character widths in millipoints */ public int[] getWidths(String family, int style, int size) { int i; if (width == null) { width = new int[256]; } setFont(family, style, size); for (i = 0; i < 256; i++) { width[i] = FONT_FACTOR * fmt.charWidth(i); } return width; } /** * Checks whether the font for which values are * requested is the one used immediately before or * whether it is a new one * @param family font family (jave name) to use * @param style font style (jave def.) to use * @param size font size * @return true if the font was changed, false otherwise */ private boolean setFont(String family, int style, int size) { boolean changed = false; Rectangle2D rect; TextLayout layout; int s = (int)(size / 1000f); if (f1 == null) { f1 = new Font(family, style, s); fmt = graphics.getFontMetrics(f1); changed = true; } else { if ((this.style != style) || !this.family.equals(family) || this.size != s) { if (family.equals(this.family)) { f1 = f1.deriveFont(style, (float)s); } else { f1 = new Font(family, style, s); } fmt = graphics.getFontMetrics(f1); changed = true; } // else the font is unchanged from last time } if (changed) { layout = new TextLayout("m", f1, graphics.getFontRenderContext()); rect = layout.getBounds(); xHeight = (int)rect.getHeight(); } // save the family and style for later comparison this.family = family; this.style = style; this.size = s; return changed; } /** * Returns a java.awt.Font instance for the desired * family, style and size type. * This is here, so that the font-mapping * of FOP-defined fonts to java-fonts can be done * in one place and does not need to occur in * AWTFontRenderer. * @param family font family (jave name) to use * @param style font style (jave def.) to use * @param size font size * @return font with the desired characeristics. */ public java.awt.Font getFont(String family, int style, int size) { setFont(family, style, size); return f1; /* * if( setFont(family,style, size) ) fSized = null; * if( fSized == null || this.size != size ) { * fSized = f1.deriveFont( size / 1000f ); * } * this.size = size; * return fSized; */ } }