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JFreeChart is a class library, written in Java, for generating charts.
Utilising the Java2D API, it supports a wide range of chart types including
bar charts, pie charts, line charts, XY-plots, time series plots, Sankey charts
and more.
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2014, by Object Refinery Limited 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.]
*
* --------------
* TextUtils.java
* --------------
* (C) Copyright 2014, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes
* -------
* 30-Jun-2014 : Version 1 (DG);
*
*/
package org.jfree.chart.util;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.geom.Rectangle2D;
import org.jfree.ui.TextAnchor;
/**
* Text utility functions.
*
* @since 1.0.18
*/
public class TextUtils {
/**
* Draws a string such that the specified anchor point is aligned to the
* given (x, y) location, and returns a bounding rectangle
* for the text.
*
* @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());
g2.drawString(text, x + adjust[0], y + adjust[1]);
return textBounds;
}
/**
* Returns the bounds of an aligned string.
*
* @param text the string (null not permitted).
* @param g2 the graphics target (null not permitted).
* @param x the x-coordinate.
* @param y the y-coordinate.
* @param anchor the anchor point that will be aligned to
* (x, y) (null not permitted).
*
* @return The text bounds (never null).
*
* @since 1.3
*/
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;
}
/**
* 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 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, 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 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 null).
* @param text the text.
* @param anchor the anchor point.
* @param textBounds the text bounds (if not 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 = getTextBounds(text, 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.isHorizontalCenter()) {
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;
}
/**
* Returns the bounds for the specified text. The supplied text is
* assumed to be on a single line (no carriage return or newline
* characters).
*
* @param text the text (null not permitted).
* @param fm the font metrics (null not permitted).
*
* @return The text bounds.
*/
public static Rectangle2D getTextBounds(String text, FontMetrics fm) {
return getTextBounds(text, 0.0, 0.0, fm);
}
/**
* Returns the bounds for the specified text when it is drawn with the
* left-baseline aligned to the point (x, y).
*
* @param text the text (null not permitted).
* @param x the x-coordinate.
* @param y the y-coordinate.
* @param fm the font metrics (null not permitted).
*
* @return The bounding rectangle (never null).
*/
public static Rectangle2D getTextBounds(String text, double x, double y,
FontMetrics fm) {
ParamChecks.nullNotPermitted(text, "text");
ParamChecks.nullNotPermitted(fm, "fm");
double width = fm.stringWidth(text);
double height = fm.getHeight();
return new Rectangle2D.Double(x, y - fm.getAscent(), width, height);
}
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