TextUtils.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2022, by David Gilbert and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
*/
package org.jfree.chart.text;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.font.TextLayout;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.text.AttributedString;
import java.text.BreakIterator;
import org.jfree.chart.internal.Args;
/**
* Some utility methods for working with text in Java2D.
*/
public class TextUtils {
/**
* When this flag is set to {@code true}, strings will be drawn
* as attributed strings with the attributes taken from the current font.
* This allows for underlining, strike-out etc, but it means that
* TextLayout will be used to render the text:
*
* http://www.jfree.org/phpBB2/viewtopic.php?p=45459&highlight=#45459
*/
private static boolean drawStringsWithFontAttributes = false;
/**
* A flag that controls whether or not the rotated string workaround is
* used.
*/
private static boolean useDrawRotatedStringWorkaround = false;
/**
* A flag that controls whether the FontMetrics.getStringBounds() method
* is used or a workaround is applied.
*/
private static boolean useFontMetricsGetStringBounds = false;
/**
* Private constructor prevents object creation.
*/
private TextUtils() {
// prevent instantiation
}
/**
* Creates a {@link TextBlock} from a {@code String}. Line breaks
* are added where the {@code String} contains '\n' characters.
*
* @param text the text ({@code null} not permitted).
* @param font the font.
* @param paint the paint.
*
* @return A text block.
*/
public static TextBlock createTextBlock(String text, Font font, Paint paint) {
Args.nullNotPermitted(text, "text");
TextBlock result = new TextBlock();
String input = text;
boolean moreInputToProcess = (text.length() > 0);
int start = 0;
while (moreInputToProcess) {
int index = input.indexOf("\n");
if (index > start) {
String line = input.substring(start, index);
if (index < input.length() - 1) {
result.addLine(line, font, paint);
input = input.substring(index + 1);
} else {
moreInputToProcess = false;
}
} else if (index == start) {
if (index < input.length() - 1) {
input = input.substring(index + 1);
}
else {
moreInputToProcess = false;
}
} else {
result.addLine(input, font, paint);
moreInputToProcess = false;
}
}
return result;
}
/**
* Creates a new text block from the given string, breaking the
* text into lines so that the {@code maxWidth} value is respected.
*
* @param text the text.
* @param font the font.
* @param paint the paint.
* @param maxWidth the maximum width for each line.
* @param measurer the text measurer.
*
* @return A text block.
*/
public static TextBlock createTextBlock(String text, Font font,
Paint paint, float maxWidth, TextMeasurer measurer) {
return createTextBlock(text, font, paint, maxWidth, Integer.MAX_VALUE,
measurer);
}
/**
* Creates a new text block from the given string, breaking the
* text into lines so that the {@code maxWidth} value is
* respected.
*
* @param text the text.
* @param font the font.
* @param paint the paint.
* @param maxWidth the maximum width for each line.
* @param maxLines the maximum number of lines.
* @param measurer the text measurer.
*
* @return A text block.
*/
public static TextBlock createTextBlock(String text, Font font,
Paint paint, float maxWidth, int maxLines, TextMeasurer measurer) {
TextBlock result = new TextBlock();
BreakIterator iterator = BreakIterator.getLineInstance();
iterator.setText(text);
int current = 0;
int lines = 0;
int length = text.length();
while (current < length && lines < maxLines) {
int next = nextLineBreak(text, current, maxWidth, iterator,
measurer);
if (next == BreakIterator.DONE) {
result.addLine(text.substring(current), font, paint);
return result;
} else if (next == current) {
next++; // we must take one more character or we'll loop forever
}
result.addLine(text.substring(current, next), font, paint);
lines++;
current = next;
while (current < text.length()&& text.charAt(current) == '\n') {
current++;
}
}
if (current < length) {
TextLine lastLine = result.getLastLine();
TextFragment lastFragment = lastLine.getLastTextFragment();
String oldStr = lastFragment.getText();
String newStr = "...";
if (oldStr.length() > 3) {
newStr = oldStr.substring(0, oldStr.length() - 3) + "...";
}
lastLine.removeFragment(lastFragment);
TextFragment newFragment = new TextFragment(newStr,
lastFragment.getFont(), lastFragment.getPaint());
lastLine.addFragment(newFragment);
}
return result;
}
/**
* Returns the character index of the next line break. If the next
* character is wider than {@code width]} this method will return
* {@code start} - the caller should check for this case.
*
* @param text the text ({@code null} not permitted).
* @param start the start index.
* @param width the target display width.
* @param iterator the word break iterator.
* @param measurer the text measurer.
*
* @return The index of the next line break.
*/
private static int nextLineBreak(String text, int start, float width,
BreakIterator iterator, TextMeasurer measurer) {
// this method is (loosely) based on code in JFreeReport's
// TextParagraph class
int current = start;
int end;
float x = 0.0f;
boolean firstWord = true;
int newline = text.indexOf('\n', start);
if (newline < 0) {
newline = Integer.MAX_VALUE;
}
while (((end = iterator.following(current)) != BreakIterator.DONE)) {
x += measurer.getStringWidth(text, current, end);
if (x > width) {
if (firstWord) {
while (measurer.getStringWidth(text, start, end) > width) {
end--;
if (end <= start) {
return end;
}
}
return end;
} else {
end = iterator.previous();
return end;
}
} else {
if (end > newline) {
return newline;
}
}
// we found at least one word that fits ...
firstWord = false;
current = end;
}
return BreakIterator.DONE;
}
/**
* Returns the bounds for the specified text.
*
* @param text the text ({@code null} permitted).
* @param g2 the graphics context (not {@code null}).
* @param fm the font metrics (not {@code null}).
*
* @return The text bounds ({@code null} if the {@code text}
* argument is {@code null}).
*/
public static Rectangle2D getTextBounds(String text, Graphics2D g2,
FontMetrics fm) {
Rectangle2D bounds;
if (TextUtils.useFontMetricsGetStringBounds) {
bounds = fm.getStringBounds(text, g2);
// getStringBounds() can return incorrect height for some Unicode
// characters...see bug parade 6183356, let's replace it with
// something correct
LineMetrics lm = fm.getFont().getLineMetrics(text,
g2.getFontRenderContext());
bounds.setRect(bounds.getX(), bounds.getY(), bounds.getWidth(),
lm.getHeight());
} else {
double width = fm.stringWidth(text);
double height = fm.getHeight();
bounds = new Rectangle2D.Double(0.0, -fm.getAscent(), width,
height);
}
return bounds;
}
/**
* Returns the bounds of an aligned string.
*
* @param text the string ({@code null} not permitted).
* @param g2 the graphics target ({@code null} not permitted).
* @param x the x-coordinate.
* @param y the y-coordinate.
* @param anchor the anchor point that will be aligned to
* {@code (x, y)} ({@code null} not permitted).
*
* @return The text bounds (never {@code null}).
*/
public static Rectangle2D calcAlignedStringBounds(String text,
Graphics2D g2, float x, float y, TextAnchor anchor) {
Rectangle2D textBounds = new Rectangle2D.Double();
float[] adjust = deriveTextBoundsAnchorOffsets(g2, text, anchor,
textBounds);
// adjust text bounds to match string position
textBounds.setRect(x + adjust[0], y + adjust[1] + adjust[2],
textBounds.getWidth(), textBounds.getHeight());
return textBounds;
}
/**
* Draws a string such that the specified anchor point is aligned to the
* given (x, y) location.
*
* @param text the text.
* @param g2 the graphics device.
* @param x the x coordinate (Java 2D).
* @param y the y coordinate (Java 2D).
* @param anchor the anchor location.
*
* @return The text bounds (adjusted for the text position).
*/
public static Rectangle2D drawAlignedString(String text, Graphics2D g2,
float x, float y, TextAnchor anchor) {
Rectangle2D textBounds = new Rectangle2D.Double();
float[] adjust = deriveTextBoundsAnchorOffsets(g2, text, anchor,
textBounds);
// adjust text bounds to match string position
textBounds.setRect(x + adjust[0], y + adjust[1] + adjust[2],
textBounds.getWidth(), textBounds.getHeight());
if (!drawStringsWithFontAttributes) {
g2.drawString(text, x + adjust[0], y + adjust[1]);
} else {
AttributedString as = new AttributedString(text,
g2.getFont().getAttributes());
g2.drawString(as.getIterator(), x + adjust[0], y + adjust[1]);
}
return textBounds;
}
/**
* A utility method that calculates the anchor offsets for a string.
* Normally, the (x, y) coordinate for drawing text is a point on the
* baseline at the left of the text string. If you add these offsets to
* (x, y) and draw the string, then the anchor point should coincide with
* the (x, y) point.
*
* @param g2 the graphics device (not {@code null}).
* @param text the text.
* @param anchor the anchor point.
* @param textBounds the text bounds (if not {@code null}, this
* object will be updated by this method to match the
* string bounds).
*
* @return The offsets.
*/
private static float[] deriveTextBoundsAnchorOffsets(Graphics2D g2,
String text, TextAnchor anchor, Rectangle2D textBounds) {
float[] result = new float[3];
FontRenderContext frc = g2.getFontRenderContext();
Font f = g2.getFont();
FontMetrics fm = g2.getFontMetrics(f);
Rectangle2D bounds = TextUtils.getTextBounds(text, g2, fm);
LineMetrics metrics = f.getLineMetrics(text, frc);
float ascent = metrics.getAscent();
result[2] = -ascent;
float halfAscent = ascent / 2.0f;
float descent = metrics.getDescent();
float leading = metrics.getLeading();
float xAdj = 0.0f;
float yAdj = 0.0f;
if (anchor.isHorizontalCenter()) {
xAdj = (float) -bounds.getWidth() / 2.0f;
} else if (anchor.isRight()) {
xAdj = (float) -bounds.getWidth();
}
if (anchor.isTop()) {
yAdj = -descent - leading + (float) bounds.getHeight();
} else if (anchor.isHalfAscent()) {
yAdj = halfAscent;
} else if (anchor.isVerticalCenter()) {
yAdj = -descent - leading + (float) (bounds.getHeight() / 2.0);
} else if (anchor.isBaseline()) {
yAdj = 0.0f;
} else if (anchor.isBottom()) {
yAdj = -metrics.getDescent() - metrics.getLeading();
}
if (textBounds != null) {
textBounds.setRect(bounds);
}
result[0] = xAdj;
result[1] = yAdj;
return result;
}
/**
* A utility method for drawing rotated text.
* <P>
* A common rotation is -Math.PI/2 which draws text 'vertically' (with the
* top of the characters on the left).
*
* @param text the text.
* @param g2 the graphics device.
* @param angle the angle of the (clockwise) rotation (in radians).
* @param x the x-coordinate.
* @param y the y-coordinate.
*/
public static void drawRotatedString(String text, Graphics2D g2,
double angle, float x, float y) {
drawRotatedString(text, g2, x, y, angle, x, y);
}
/**
* A utility method for drawing rotated text.
* <P>
* A common rotation is -Math.PI/2 which draws text 'vertically' (with the
* top of the characters on the left).
*
* @param text the text.
* @param g2 the graphics device.
* @param textX the x-coordinate for the text (before rotation).
* @param textY the y-coordinate for the text (before rotation).
* @param angle the angle of the (clockwise) rotation (in radians).
* @param rotateX the point about which the text is rotated.
* @param rotateY the point about which the text is rotated.
*/
public static void drawRotatedString(String text, Graphics2D g2,
float textX, float textY,
double angle, float rotateX, float rotateY) {
if ((text == null) || (text.equals(""))) {
return;
}
if (angle == 0.0) {
drawAlignedString(text, g2, textX, textY, TextAnchor.BASELINE_LEFT);
return;
}
AffineTransform saved = g2.getTransform();
AffineTransform rotate = AffineTransform.getRotateInstance(
angle, rotateX, rotateY);
g2.transform(rotate);
if (useDrawRotatedStringWorkaround) {
// workaround for JDC bug ID 4312117 and others...
TextLayout tl = new TextLayout(text, g2.getFont(),
g2.getFontRenderContext());
tl.draw(g2, textX, textY);
} else {
if (!drawStringsWithFontAttributes) {
g2.drawString(text, textX, textY);
} else {
AttributedString as = new AttributedString(text,
g2.getFont().getAttributes());
g2.drawString(as.getIterator(), textX, textY);
}
}
g2.setTransform(saved);
}
/**
* Draws a string that is aligned by one anchor point and rotated about
* another anchor point.
*
* @param text the text.
* @param g2 the graphics device.
* @param x the x-coordinate for positioning the text.
* @param y the y-coordinate for positioning the text.
* @param textAnchor the text anchor.
* @param angle the rotation angle.
* @param rotationX the x-coordinate for the rotation anchor point.
* @param rotationY the y-coordinate for the rotation anchor point.
*/
public static void drawRotatedString(String text, Graphics2D g2,
float x, float y, TextAnchor textAnchor,
double angle, float rotationX, float rotationY) {
if (text == null || text.equals("")) {
return;
}
if (angle == 0.0) {
drawAlignedString(text, g2, x, y, textAnchor);
} else {
float[] textAdj = deriveTextBoundsAnchorOffsets(g2, text,
textAnchor);
drawRotatedString(text, g2, x + textAdj[0], y + textAdj[1], angle,
rotationX, rotationY);
}
}
/**
* Draws a string that is aligned by one anchor point and rotated about
* another anchor point.
*
* @param text the text.
* @param g2 the graphics device.
* @param x the x-coordinate for positioning the text.
* @param y the y-coordinate for positioning the text.
* @param textAnchor the text anchor.
* @param angle the rotation angle (in radians).
* @param rotationAnchor the rotation anchor.
*/
public static void drawRotatedString(String text, Graphics2D g2,
float x, float y, TextAnchor textAnchor,
double angle, TextAnchor rotationAnchor) {
if (text == null || text.equals("")) {
return;
}
if (angle == 0.0) {
drawAlignedString(text, g2, x, y, textAnchor);
} else {
float[] textAdj = deriveTextBoundsAnchorOffsets(g2, text,
textAnchor);
float[] rotateAdj = deriveRotationAnchorOffsets(g2, text,
rotationAnchor);
drawRotatedString(text, g2, x + textAdj[0], y + textAdj[1],
angle, x + textAdj[0] + rotateAdj[0],
y + textAdj[1] + rotateAdj[1]);
}
}
/**
* Returns a shape that represents the bounds of the string after the
* specified rotation has been applied.
*
* @param text the text ({@code null} permitted).
* @param g2 the graphics device.
* @param x the x coordinate for the anchor point.
* @param y the y coordinate for the anchor point.
* @param textAnchor the text anchor.
* @param angle the angle.
* @param rotationAnchor the rotation anchor.
*
* @return The bounds (possibly {@code null}).
*/
public static Shape calculateRotatedStringBounds(String text, Graphics2D g2,
float x, float y, TextAnchor textAnchor,
double angle, TextAnchor rotationAnchor) {
if (text == null || text.equals("")) {
return null;
}
float[] textAdj = deriveTextBoundsAnchorOffsets(g2, text, textAnchor);
float[] rotateAdj = deriveRotationAnchorOffsets(g2, text,
rotationAnchor);
Shape result = calculateRotatedStringBounds(text, g2,
x + textAdj[0], y + textAdj[1], angle,
x + textAdj[0] + rotateAdj[0], y + textAdj[1] + rotateAdj[1]);
return result;
}
/**
* A utility method that calculates the anchor offsets for a string.
* Normally, the (x, y) coordinate for drawing text is a point on the
* baseline at the left of the text string. If you add these offsets to
* (x, y) and draw the string, then the anchor point should coincide with
* the (x, y) point.
*
* @param g2 the graphics device (not {@code null}).
* @param text the text.
* @param anchor the anchor point.
*
* @return The offsets.
*/
private static float[] deriveTextBoundsAnchorOffsets(Graphics2D g2,
String text, TextAnchor anchor) {
float[] result = new float[2];
FontRenderContext frc = g2.getFontRenderContext();
Font f = g2.getFont();
FontMetrics fm = g2.getFontMetrics(f);
Rectangle2D bounds = getTextBounds(text, g2, fm);
LineMetrics metrics = f.getLineMetrics(text, frc);
float ascent = metrics.getAscent();
float halfAscent = ascent / 2.0f;
float descent = metrics.getDescent();
float leading = metrics.getLeading();
float xAdj = 0.0f;
float yAdj = 0.0f;
if (anchor.isHorizontalCenter()) {
xAdj = (float) -bounds.getWidth() / 2.0f;
} else if (anchor.isRight()) {
xAdj = (float) -bounds.getWidth();
}
if (anchor.isTop()) {
yAdj = -descent - leading + (float) bounds.getHeight();
} else if (anchor.isHalfAscent()) {
yAdj = halfAscent;
} else if (anchor.isVerticalCenter()) {
yAdj = -descent - leading + (float) (bounds.getHeight() / 2.0);
} else if (anchor.isBaseline()) {
yAdj = 0.0f;
} else if (anchor.isBottom()) {
yAdj = -metrics.getDescent() - metrics.getLeading();
}
result[0] = xAdj;
result[1] = yAdj;
return result;
}
/**
* A utility method that calculates the rotation anchor offsets for a
* string. These offsets are relative to the text starting coordinate
* ({@code BASELINE_LEFT}).
*
* @param g2 the graphics device.
* @param text the text.
* @param anchor the anchor point.
*
* @return The offsets.
*/
private static float[] deriveRotationAnchorOffsets(Graphics2D g2,
String text, TextAnchor anchor) {
float[] result = new float[2];
FontRenderContext frc = g2.getFontRenderContext();
LineMetrics metrics = g2.getFont().getLineMetrics(text, frc);
FontMetrics fm = g2.getFontMetrics();
Rectangle2D bounds = TextUtils.getTextBounds(text, g2, fm);
float ascent = metrics.getAscent();
float halfAscent = ascent / 2.0f;
float descent = metrics.getDescent();
float leading = metrics.getLeading();
float xAdj = 0.0f;
float yAdj = 0.0f;
if (anchor.isLeft()) {
xAdj = 0.0f;
} else if (anchor.isHorizontalCenter()) {
xAdj = (float) bounds.getWidth() / 2.0f;
} else if (anchor.isRight()) {
xAdj = (float) bounds.getWidth();
}
if (anchor.isTop()) {
yAdj = descent + leading - (float) bounds.getHeight();
} else if (anchor.isVerticalCenter()) {
yAdj = descent + leading - (float) (bounds.getHeight() / 2.0);
} else if (anchor.isHalfAscent()) {
yAdj = -halfAscent;
} else if (anchor.isBaseline()) {
yAdj = 0.0f;
} else if (anchor.isBottom()) {
yAdj = metrics.getDescent() + metrics.getLeading();
}
result[0] = xAdj;
result[1] = yAdj;
return result;
}
/**
* Returns a shape that represents the bounds of the string after the
* specified rotation has been applied.
*
* @param text the text ({@code null} permitted).
* @param g2 the graphics device.
* @param textX the x coordinate for the text.
* @param textY the y coordinate for the text.
* @param angle the angle.
* @param rotateX the x coordinate for the rotation point.
* @param rotateY the y coordinate for the rotation point.
*
* @return The bounds ({@code null} if {@code text} is
* {@code null} or has zero length).
*/
public static Shape calculateRotatedStringBounds(String text, Graphics2D g2,
float textX, float textY, double angle, float rotateX,
float rotateY) {
if ((text == null) || (text.equals(""))) {
return null;
}
FontMetrics fm = g2.getFontMetrics();
Rectangle2D bounds = TextUtils.getTextBounds(text, g2, fm);
AffineTransform translate = AffineTransform.getTranslateInstance(
textX, textY);
Shape translatedBounds = translate.createTransformedShape(bounds);
AffineTransform rotate = AffineTransform.getRotateInstance(
angle, rotateX, rotateY);
Shape result = rotate.createTransformedShape(translatedBounds);
return result;
}
/**
* Returns the flag that controls whether the FontMetrics.getStringBounds()
* method is used or not. If you are having trouble with label alignment
* or positioning, try changing the value of this flag.
*
* @return A boolean.
*/
public static boolean getUseFontMetricsGetStringBounds() {
return useFontMetricsGetStringBounds;
}
/**
* Sets the flag that controls whether the FontMetrics.getStringBounds()
* method is used or not. If you are having trouble with label alignment
* or positioning, try changing the value of this flag.
*
* @param use the flag.
*/
public static void setUseFontMetricsGetStringBounds(boolean use) {
useFontMetricsGetStringBounds = use;
}
/**
* Returns the flag that controls whether or not a workaround is used for
* drawing rotated strings.
*
* @return A boolean.
*/
public static boolean isUseDrawRotatedStringWorkaround() {
return useDrawRotatedStringWorkaround;
}
/**
* Sets the flag that controls whether or not a workaround is used for
* drawing rotated strings. The related bug is on Sun's bug parade
* (id 4312117) and the workaround involves using a {@code TextLayout}
* instance to draw the text instead of calling the
* {@code drawString()} method in the {@code Graphics2D} class.
*
* @param use the new flag value.
*/
public static void setUseDrawRotatedStringWorkaround(boolean use) {
TextUtils.useDrawRotatedStringWorkaround = use;
}
/**
* Returns the flag that controls whether or not strings are drawn using
* the current font attributes (such as underlining, strikethrough etc).
* The default value is {@code false}.
*
* @return A boolean.
*/
public static boolean getDrawStringsWithFontAttributes() {
return TextUtils.drawStringsWithFontAttributes;
}
/**
* Sets the flag that controls whether or not strings are drawn using the
* current font attributes. This is a hack to allow underlining of titles
* without big changes to the API. See:
* http://www.jfree.org/phpBB2/viewtopic.php?p=45459&highlight=#45459
*
* @param b the new flag value.
*/
public static void setDrawStringsWithFontAttributes(boolean b) {
TextUtils.drawStringsWithFontAttributes = b;
}
}