/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
/**
* @author Ilya S. Okomin
* @version $Revision$
*/
package java.awt;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;
import java.text.CharacterIterator;
import org.apache.harmony.awt.internal.nls.Messages;
/**
* The FontMetrics class contains information about the rendering of a
* particular font on a particular screen.
* <p>
* Each character in the Font has three values that help define where to place
* it: an ascent, a descent, and an advance. The ascent is the distance the
* character extends above the baseline. The descent is the distance the
* character extends below the baseline. The advance width defines the position
* at which the next character should be placed.
* <p>
* An array of characters or a string has an ascent, a descent, and an advance
* width too. The ascent or descent of the array is specified by the maximum
* ascent or descent of the characters in the array. The advance width is the
* sum of the advance widths of each of the characters in the character array.
* </p>
*
* @since Android 1.0
*/
public abstract class FontMetrics implements Serializable {
/**
* The Constant serialVersionUID.
*/
private static final long serialVersionUID = 1681126225205050147L;
/**
* The font from which the FontMetrics is created.
*/
protected Font font;
/**
* Instantiates a new font metrics from the specified Font.
*
* @param fnt
* the Font.
*/
protected FontMetrics(Font fnt) {
this.font = fnt;
}
/**
* Returns the String representation of this FontMetrics.
*
* @return the string.
*/
@Override
public String toString() {
return this.getClass().getName() + "[font=" + this.getFont() + //$NON-NLS-1$
"ascent=" + this.getAscent() + //$NON-NLS-1$
", descent=" + this.getDescent() + //$NON-NLS-1$
", height=" + this.getHeight() + "]"; //$NON-NLS-1$ //$NON-NLS-2$
}
/**
* Gets the font associated with this FontMetrics.
*
* @return the font associated with this FontMetrics.
*/
public Font getFont() {
return font;
}
/**
* Gets the height of the text line in this Font.
*
* @return the height of the text line in this Font.
*/
public int getHeight() {
return this.getAscent() + this.getDescent() + this.getLeading();
}
/**
* Gets the font ascent of the Font associated with this FontMetrics. The
* font ascent is the distance from the font's baseline to the top of most
* alphanumeric characters.
*
* @return the ascent of the Font associated with this FontMetrics.
*/
public int getAscent() {
return 0;
}
/**
* Gets the font descent of the Font associated with this FontMetrics. The
* font descent is the distance from the font's baseline to the bottom of
* most alphanumeric characters with descenders.
*
* @return the descent of the Font associated with this FontMetrics.
*/
public int getDescent() {
return 0;
}
/**
* Gets the leading of the Font associated with this FontMetrics.
*
* @return the leading of the Font associated with this FontMetrics.
*/
public int getLeading() {
return 0;
}
/**
* Gets the LineMetrics object for the specified CharacterIterator in the
* specified Graphics.
*
* @param ci
* the CharacterIterator.
* @param beginIndex
* the offset.
* @param limit
* the number of characters to be used.
* @param context
* the Graphics.
* @return the LineMetrics object for the specified CharacterIterator in the
* specified Graphics.
*/
public LineMetrics getLineMetrics(CharacterIterator ci, int beginIndex, int limit,
Graphics context) {
return font.getLineMetrics(ci, beginIndex, limit, this.getFRCFromGraphics(context));
}
/**
* Gets the LineMetrics object for the specified String in the specified
* Graphics.
*
* @param str
* the String.
* @param context
* the Graphics.
* @return the LineMetrics object for the specified String in the specified
* Graphics.
*/
public LineMetrics getLineMetrics(String str, Graphics context) {
return font.getLineMetrics(str, this.getFRCFromGraphics(context));
}
/**
* Gets the LineMetrics object for the specified character array in the
* specified Graphics.
*
* @param chars
* the character array.
* @param beginIndex
* the offset of array.
* @param limit
* the number of characters to be used.
* @param context
* the Graphics.
* @return the LineMetrics object for the specified character array in the
* specified Graphics.
*/
public LineMetrics getLineMetrics(char[] chars, int beginIndex, int limit, Graphics context) {
return font.getLineMetrics(chars, beginIndex, limit, this.getFRCFromGraphics(context));
}
/**
* Gets the LineMetrics object for the specified String in the specified
* Graphics.
*
* @param str
* the String.
* @param beginIndex
* the offset.
* @param limit
* the number of characters to be used.
* @param context
* the Graphics.
* @return the LineMetrics object for the specified String in the specified
* Graphics.
*/
public LineMetrics getLineMetrics(String str, int beginIndex, int limit, Graphics context) {
return font.getLineMetrics(str, beginIndex, limit, this.getFRCFromGraphics(context));
}
/**
* Returns the character's maximum bounds in the specified Graphics context.
*
* @param context
* the Graphics context.
* @return the character's maximum bounds in the specified Graphics context.
*/
public Rectangle2D getMaxCharBounds(Graphics context) {
return this.font.getMaxCharBounds(this.getFRCFromGraphics(context));
}
/**
* Gets the bounds of the specified CharacterIterator in the specified
* Graphics context.
*
* @param ci
* the CharacterIterator.
* @param beginIndex
* the begin offset of the array.
* @param limit
* the number of characters.
* @param context
* the Graphics.
* @return the bounds of the specified CharacterIterator in the specified
* Graphics context.
*/
public Rectangle2D getStringBounds(CharacterIterator ci, int beginIndex, int limit,
Graphics context) {
return font.getStringBounds(ci, beginIndex, limit, this.getFRCFromGraphics(context));
}
/**
* Gets the bounds of the specified String in the specified Graphics
* context.
*
* @param str
* the String.
* @param beginIndex
* the begin offset of the array.
* @param limit
* the number of characters.
* @param context
* the Graphics.
* @return the bounds of the specified String in the specified Graphics
* context.
*/
public Rectangle2D getStringBounds(String str, int beginIndex, int limit, Graphics context) {
return font.getStringBounds(str, beginIndex, limit, this.getFRCFromGraphics(context));
}
/**
* Gets the bounds of the specified characters array in the specified
* Graphics context.
*
* @param chars
* the characters array.
* @param beginIndex
* the begin offset of the array.
* @param limit
* the number of characters.
* @param context
* the Graphics.
* @return the bounds of the specified characters array in the specified
* Graphics context.
*/
public Rectangle2D getStringBounds(char[] chars, int beginIndex, int limit, Graphics context) {
return font.getStringBounds(chars, beginIndex, limit, this.getFRCFromGraphics(context));
}
/**
* Gets the bounds of the specified String in the specified Graphics
* context.
*
* @param str
* the String.
* @param context
* the Graphics.
* @return the bounds of the specified String in the specified Graphics
* context.
*/
public Rectangle2D getStringBounds(String str, Graphics context) {
return font.getStringBounds(str, this.getFRCFromGraphics(context));
}
/**
* Checks if the Font has uniform line metrics or not. The Font can contain
* characters of other fonts for covering character set. In this case the
* Font isn't uniform.
*
* @return true, if the Font has uniform line metrics, false otherwise.
*/
public boolean hasUniformLineMetrics() {
return this.font.hasUniformLineMetrics();
}
/**
* Returns the distance from the leftmost point to the rightmost point on
* the string's baseline showing the specified array of bytes in this Font.
*
* @param data
* the array of bytes to be measured.
* @param off
* the start offset.
* @param len
* the number of bytes to be measured.
* @return the advance width of the array.
*/
public int bytesWidth(byte[] data, int off, int len) {
int width = 0;
if ((off >= data.length) || (off < 0)) {
// awt.13B=offset off is out of range
throw new IllegalArgumentException(Messages.getString("awt.13B")); //$NON-NLS-1$
}
if ((off + len > data.length)) {
// awt.13C=number of elemets len is out of range
throw new IllegalArgumentException(Messages.getString("awt.13C")); //$NON-NLS-1$
}
for (int i = off; i < off + len; i++) {
width += charWidth(data[i]);
}
return width;
}
/**
* Returns the distance from the leftmost point to the rightmost point on
* the string's baseline showing the specified array of characters in this
* Font.
*
* @param data
* the array of characters to be measured.
* @param off
* the start offset.
* @param len
* the number of bytes to be measured.
* @return the advance width of the array.
*/
public int charsWidth(char[] data, int off, int len) {
int width = 0;
if ((off >= data.length) || (off < 0)) {
// awt.13B=offset off is out of range
throw new IllegalArgumentException(Messages.getString("awt.13B")); //$NON-NLS-1$
}
if ((off + len > data.length)) {
// awt.13C=number of elemets len is out of range
throw new IllegalArgumentException(Messages.getString("awt.13C")); //$NON-NLS-1$
}
for (int i = off; i < off + len; i++) {
width += charWidth(data[i]);
}
return width;
}
/**
* Returns the distance from the leftmost point to the rightmost point of
* the specified character in this Font.
*
* @param ch
* the specified Unicode point code of character to be measured.
* @return the advance width of the character.
*/
public int charWidth(int ch) {
return 0;
}
/**
* Returns the distance from the leftmost point to the rightmost point of
* the specified character in this Font.
*
* @param ch
* the specified character to be measured.
* @return the advance width of the character.
*/
public int charWidth(char ch) {
return 0;
}
/**
* Gets the maximum advance width of character in this Font.
*
* @return the maximum advance width of character in this Font.
*/
public int getMaxAdvance() {
return 0;
}
/**
* Gets the maximum font ascent of the Font associated with this
* FontMetrics.
*
* @return the maximum font ascent of the Font associated with this
* FontMetrics.
*/
public int getMaxAscent() {
return 0;
}
/**
* Gets the maximum font descent of character in this Font.
*
* @return the maximum font descent of character in this Font.
* @deprecated Replaced by getMaxDescent() method.
*/
@Deprecated
public int getMaxDecent() {
return 0;
}
/**
* Gets the maximum font descent of character in this Font.
*
* @return the maximum font descent of character in this Font.
*/
public int getMaxDescent() {
return 0;
}
/**
* Gets the advance widths of the characters in the Font.
*
* @return the advance widths of the characters in the Font.
*/
public int[] getWidths() {
return null;
}
/**
* Returns the advance width for the specified String in this Font.
*
* @param str
* String to be measured.
* @return the the advance width for the specified String in this Font.
*/
public int stringWidth(String str) {
return 0;
}
/**
* Returns a FontRenderContext instance of the Graphics context specified.
*
* @param context
* the specified Graphics context.
* @return a FontRenderContext of the specified Graphics context.
*/
private FontRenderContext getFRCFromGraphics(Graphics context) {
FontRenderContext frc;
if (context instanceof Graphics2D) {
frc = ((Graphics2D)context).getFontRenderContext();
} else {
frc = new FontRenderContext(null, false, false);
}
return frc;
}
}