mirror of git://gcc.gnu.org/git/gcc.git
449 lines
13 KiB
Java
449 lines
13 KiB
Java
/* FontMetrics.java -- Information about about a fonts display characteristics
|
|
Copyright (C) 1999, 2002, 2005 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
02110-1301 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
|
|
package java.awt;
|
|
|
|
import java.awt.font.FontRenderContext;
|
|
import java.awt.font.LineMetrics;
|
|
import java.awt.geom.Rectangle2D;
|
|
import java.text.CharacterIterator;
|
|
|
|
// FIXME: I leave many methods basically unimplemented. This
|
|
// should be reviewed.
|
|
|
|
/**
|
|
* This class returns information about the display characteristics of
|
|
* a font. It is abstract, and concrete subclasses should implement at
|
|
* least the following methods:
|
|
*
|
|
* <ul>
|
|
* <li>getAscent()</li>
|
|
* <li>getDescent()</li>
|
|
* <li>getLeading()</li>
|
|
* <li>getMaxAdvance()</li>
|
|
* <li>charWidth(char)</li>
|
|
* <li>charsWidth(char[], int, int)</li>
|
|
* </ul>
|
|
*
|
|
* @author Aaron M. Renn (arenn@urbanophile.com)
|
|
*/
|
|
public abstract class FontMetrics implements java.io.Serializable
|
|
{
|
|
// Serialization constant.
|
|
private static final long serialVersionUID = 1681126225205050147L;
|
|
|
|
/**
|
|
* This is the font for which metrics will be returned.
|
|
*/
|
|
protected Font font;
|
|
|
|
/**
|
|
* Initializes a new instance of <code>FontMetrics</code> for the
|
|
* specified font.
|
|
*
|
|
* @param font The font to return metric information for.
|
|
*/
|
|
protected FontMetrics(Font font)
|
|
{
|
|
this.font = font;
|
|
}
|
|
|
|
/**
|
|
* Returns the font that this object is creating metric information fo.
|
|
*
|
|
* @return The font for this object.
|
|
*/
|
|
public Font getFont()
|
|
{
|
|
return font;
|
|
}
|
|
|
|
/**
|
|
* Returns the leading, or spacing between lines, for this font.
|
|
*
|
|
* @return The font leading.
|
|
*/
|
|
public int getLeading()
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Returns the ascent of the font, which is the distance from the base
|
|
* to the top of the majority of characters in the set. Some characters
|
|
* can exceed this value however.
|
|
*
|
|
* @return The font ascent.
|
|
*/
|
|
public int getAscent()
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Returns the descent of the font, which is the distance from the base
|
|
* to the bottom of the majority of characters in the set. Some characters
|
|
* can exceed this value however.
|
|
*
|
|
* @return The font descent.
|
|
*/
|
|
public int getDescent()
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Returns the height of a line in this font. This will be the sum
|
|
* of the leading, the ascent, and the descent.
|
|
*
|
|
* @return The height of the font.
|
|
*/
|
|
public int getHeight()
|
|
{
|
|
return getAscent() + getDescent() + getLeading();
|
|
}
|
|
|
|
/**
|
|
* Returns the maximum ascent value. This is the maximum distance any
|
|
* character in the font rised above the baseline.
|
|
*
|
|
* @return The maximum ascent for this font.
|
|
*/
|
|
public int getMaxAscent()
|
|
{
|
|
return getAscent();
|
|
}
|
|
|
|
/**
|
|
* Returns the maximum descent value. This is the maximum distance any
|
|
* character in the font extends below the baseline.
|
|
*
|
|
* @return The maximum descent for this font.
|
|
*/
|
|
public int getMaxDescent()
|
|
{
|
|
return getMaxDecent();
|
|
}
|
|
|
|
/**
|
|
* Returns the maximum descent value. This is the maximum distance any
|
|
* character in the font extends below the baseline.
|
|
*
|
|
* @return The maximum descent for this font.
|
|
*
|
|
* @deprecated This method is deprecated in favor of
|
|
* <code>getMaxDescent()</code>.
|
|
*/
|
|
public int getMaxDecent()
|
|
{
|
|
return getDescent();
|
|
}
|
|
|
|
/**
|
|
* Returns the width of the widest character in the font.
|
|
*
|
|
* @return The width of the widest character in the font.
|
|
*/
|
|
public int getMaxAdvance()
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Returns the width of the specified character.
|
|
*
|
|
* @param ch The character to return the width of.
|
|
*
|
|
* @return The width of the specified character.
|
|
*/
|
|
public int charWidth(int ch)
|
|
{
|
|
char[] chars = Character.toChars(ch);
|
|
return charsWidth(chars, 0, chars.length);
|
|
}
|
|
|
|
/**
|
|
* Returns the width of the specified character.
|
|
*
|
|
* @param ch The character to return the width of.
|
|
*
|
|
* @return The width of the specified character.
|
|
*/
|
|
public int charWidth(char ch)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Returns the total width of the specified string
|
|
*
|
|
* @param str The string to return the width of.
|
|
*
|
|
* @return The width of the string.
|
|
*/
|
|
public int stringWidth(String str)
|
|
{
|
|
char[] buf = new char[str.length()];
|
|
str.getChars(0, str.length(), buf, 0);
|
|
|
|
return charsWidth(buf, 0, buf.length);
|
|
}
|
|
|
|
/**
|
|
* Returns the total width of the specified character array.
|
|
*
|
|
* @param buf The character array containing the data.
|
|
* @param offset The offset into the array to start calculating from.
|
|
* @param len The total number of bytes to process.
|
|
*
|
|
* @return The width of the requested characters.
|
|
*/
|
|
public int charsWidth(char[] buf, int offset, int len)
|
|
{
|
|
int total_width = 0;
|
|
int endOffset = offset + len;
|
|
for (int i = offset; i < endOffset; i++)
|
|
total_width += charWidth(buf[i]);
|
|
return total_width;
|
|
}
|
|
|
|
/**
|
|
* Returns the total width of the specified byte array.
|
|
*
|
|
* @param buf The byte array containing the data.
|
|
* @param offset The offset into the array to start calculating from.
|
|
* @param len The total number of bytes to process.
|
|
*
|
|
* @return The width of the requested characters.
|
|
*/
|
|
public int bytesWidth(byte[] buf, int offset, int len)
|
|
{
|
|
int total_width = 0;
|
|
for (int i = offset; i < len; i++)
|
|
total_width = charWidth((char) buf[i]);
|
|
|
|
return total_width;
|
|
}
|
|
|
|
/**
|
|
* Returns the widths of the first 256 characters in the font.
|
|
*
|
|
* @return The widths of the first 256 characters in the font.
|
|
*/
|
|
public int[] getWidths()
|
|
{
|
|
int[] result = new int[256];
|
|
for (char i = 0; i < 256; i++)
|
|
result[i] = charWidth(i);
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* Returns a string representation of this object.
|
|
*
|
|
* @return A string representation of this object.
|
|
*/
|
|
public String toString()
|
|
{
|
|
return (this.getClass() + "[font=" + font + ",ascent=" + getAscent()
|
|
+ ",descent=" + getDescent() + ",height=" + getHeight() + "]");
|
|
}
|
|
|
|
// Generic FontRenderContext used when getLineMetrics is called with a
|
|
// plain Graphics object.
|
|
private static final FontRenderContext gRC = new FontRenderContext(null,
|
|
false,
|
|
false);
|
|
|
|
/**
|
|
* Returns a {@link LineMetrics} object constructed with the
|
|
* specified text and the {@link FontRenderContext} of the Graphics
|
|
* object when it is an instance of Graphics2D or a generic
|
|
* FontRenderContext with a null transform, not anti-aliased and not
|
|
* using fractional metrics.
|
|
*
|
|
* @param text The string to calculate metrics from.
|
|
* @param g The Graphics object that will be used.
|
|
*
|
|
* @return A new {@link LineMetrics} object.
|
|
*/
|
|
public LineMetrics getLineMetrics(String text, Graphics g)
|
|
{
|
|
return getLineMetrics(text, 0, text.length(), g);
|
|
}
|
|
|
|
/**
|
|
* Returns a {@link LineMetrics} object constructed with the
|
|
* specified text and the {@link FontRenderContext} of the Graphics
|
|
* object when it is an instance of Graphics2D or a generic
|
|
* FontRenderContext with a null transform, not anti-aliased and not
|
|
* using fractional metrics.
|
|
*
|
|
* @param text The string to calculate metrics from.
|
|
* @param begin Index of first character in <code>text</code> to measure.
|
|
* @param limit Index of last character in <code>text</code> to measure.
|
|
* @param g The Graphics object that will be used.
|
|
*
|
|
* @return A new {@link LineMetrics} object.
|
|
*
|
|
* @throws IndexOutOfBoundsException if the range [begin, limit] is
|
|
* invalid in <code>text</code>.
|
|
*/
|
|
public LineMetrics getLineMetrics(String text, int begin, int limit,
|
|
Graphics g)
|
|
{
|
|
FontRenderContext rc;
|
|
if (g instanceof Graphics2D)
|
|
rc = ((Graphics2D) g).getFontRenderContext();
|
|
else
|
|
rc = gRC;
|
|
return font.getLineMetrics(text, begin, limit, rc);
|
|
}
|
|
|
|
/**
|
|
* Returns a {@link LineMetrics} object constructed with the
|
|
* specified text and the {@link FontRenderContext} of the Graphics
|
|
* object when it is an instance of Graphics2D or a generic
|
|
* FontRenderContext with a null transform, not anti-aliased and not
|
|
* using fractional metrics.
|
|
*
|
|
* @param chars The string to calculate metrics from.
|
|
* @param begin Index of first character in <code>text</code> to measure.
|
|
* @param limit Index of last character in <code>text</code> to measure.
|
|
* @param g The Graphics object that will be used.
|
|
*
|
|
* @return A new {@link LineMetrics} object.
|
|
*
|
|
* @throws IndexOutOfBoundsException if the range [begin, limit] is
|
|
* invalid in <code>text</code>.
|
|
*/
|
|
public LineMetrics getLineMetrics(char[] chars, int begin, int limit,
|
|
Graphics g)
|
|
{
|
|
FontRenderContext rc;
|
|
if (g instanceof Graphics2D)
|
|
rc = ((Graphics2D) g).getFontRenderContext();
|
|
else
|
|
rc = gRC;
|
|
return font.getLineMetrics(chars, begin, limit, rc);
|
|
}
|
|
|
|
/**
|
|
* Returns the bounds of the largest character in a Graphics context.
|
|
* @param context the Graphics context object.
|
|
* @return a <code>Rectangle2D</code> representing the bounds
|
|
*/
|
|
public Rectangle2D getMaxCharBounds(Graphics context)
|
|
{
|
|
if( context instanceof Graphics2D )
|
|
return font.getMaxCharBounds(((Graphics2D)context).getFontRenderContext());
|
|
return font.getMaxCharBounds( gRC );
|
|
}
|
|
|
|
/**
|
|
* Returns a {@link LineMetrics} object constructed with the
|
|
* specified text and the {@link FontRenderContext} of the Graphics
|
|
* object when it is an instance of Graphics2D or a generic
|
|
* FontRenderContext with a null transform, not anti-aliased and not
|
|
* using fractional metrics.
|
|
*
|
|
* @param ci An iterator over the string to calculate metrics from.
|
|
* @param begin Index of first character in <code>text</code> to measure.
|
|
* @param limit Index of last character in <code>text</code> to measure.
|
|
* @param g The Graphics object that will be used.
|
|
*
|
|
* @return A new {@link LineMetrics} object.
|
|
*
|
|
* @throws IndexOutOfBoundsException if the range [begin, limit] is
|
|
* invalid in <code>text</code>.
|
|
*/
|
|
public LineMetrics getLineMetrics(CharacterIterator ci, int begin,
|
|
int limit, Graphics g)
|
|
{
|
|
FontRenderContext rc;
|
|
if (g instanceof Graphics2D)
|
|
rc = ((Graphics2D) g).getFontRenderContext();
|
|
else
|
|
rc = gRC;
|
|
return font.getLineMetrics(ci, begin, limit, rc);
|
|
}
|
|
|
|
public Rectangle2D getStringBounds(String str, Graphics context)
|
|
{
|
|
return font.getStringBounds(str, getFontRenderContext(context));
|
|
}
|
|
|
|
public Rectangle2D getStringBounds(String str, int beginIndex, int limit,
|
|
Graphics context)
|
|
{
|
|
return font.getStringBounds(str, beginIndex, limit,
|
|
getFontRenderContext(context));
|
|
}
|
|
|
|
public Rectangle2D getStringBounds(char[] chars, int beginIndex, int limit,
|
|
Graphics context)
|
|
{
|
|
return font.getStringBounds(chars, beginIndex, limit,
|
|
getFontRenderContext(context));
|
|
}
|
|
|
|
public Rectangle2D getStringBounds(CharacterIterator ci, int beginIndex,
|
|
int limit, Graphics context)
|
|
{
|
|
return font.getStringBounds(ci, beginIndex, limit,
|
|
getFontRenderContext(context));
|
|
}
|
|
|
|
private FontRenderContext getFontRenderContext(Graphics context)
|
|
{
|
|
if (context instanceof Graphics2D)
|
|
return ((Graphics2D) context).getFontRenderContext();
|
|
|
|
return gRC;
|
|
}
|
|
|
|
/**
|
|
* Returns if the font has uniform line metrics.
|
|
* @see Font#hasUniformLineMetrics()
|
|
*/
|
|
public boolean hasUniformLineMetrics()
|
|
{
|
|
return font.hasUniformLineMetrics();
|
|
}
|
|
}
|