Java tutorial
/* ======================================================================== * JCommon : a free general purpose class library for the Java(tm) platform * ======================================================================== * * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/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. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * -------------- * TextBlock.java * -------------- * (C) Copyright 2003, 2004, by Object Refinery Limited and Contributors. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * $Id: TextBlock.java,v 1.15 2007/11/02 17:50:35 taqua Exp $ * * Changes * ------- * 07-Nov-2003 : Version 1 (DG); * 22-Dec-2003 : Added workaround for Java bug 4245442 (DG); * 09-Jan-2004 : Added an extra draw() method for no rotation case (DG); * 25-Feb-2004 : Added getLines() method (DG); * 22-Mar-2004 : Added equals() method and implemented Serializable (DG); * 24-Mar-2004 : Added 'paint' argument to addLine() method (DG); * 01-Apr-2004 : Changed java.awt.geom.Dimension2D to org.jfree.ui.Size2D * because of JDK bug 4976448 which persists on JDK 1.3.1 (DG); * 04-Oct-2004 : Renamed ShapeUtils --> ShapeUtilities (DG); * */ package org.jfree.text; import java.awt.Font; import java.awt.Graphics2D; import java.awt.Paint; import java.awt.Shape; import java.awt.geom.Rectangle2D; import java.io.Serializable; import java.util.Collections; import java.util.Iterator; import java.util.List; import org.jfree.ui.HorizontalAlignment; import org.jfree.ui.Size2D; import org.jfree.ui.TextAnchor; import org.jfree.util.ShapeUtilities; /** * A list of {@link TextLine} objects that form a block of text. * * @see TextUtilities#createTextBlock(String, Font, Paint) * * @author David Gilbert */ public class TextBlock implements Serializable { /** For serialization. */ private static final long serialVersionUID = -4333175719424385526L; /** Storage for the lines of text. */ private List lines; /** The alignment of the lines. */ private HorizontalAlignment lineAlignment; /** * Creates a new empty text block. */ public TextBlock() { this.lines = new java.util.ArrayList(); this.lineAlignment = HorizontalAlignment.CENTER; } /** * Returns the alignment of the lines of text within the block. * * @return The alignment (never <code>null</code>). */ public HorizontalAlignment getLineAlignment() { return this.lineAlignment; } /** * Sets the alignment of the lines of text within the block. * * @param alignment the alignment (<code>null</code> not permitted). */ public void setLineAlignment(HorizontalAlignment alignment) { if (alignment == null) { throw new IllegalArgumentException("Null 'alignment' argument."); } this.lineAlignment = alignment; } /** * Adds a line of text that will be displayed using the specified font. * * @param text the text. * @param font the font. * @param paint the paint. */ public void addLine(final String text, final Font font, final Paint paint) { addLine(new TextLine(text, font, paint)); } /** * Adds a {@link TextLine} to the block. * * @param line the line. */ public void addLine(final TextLine line) { this.lines.add(line); } /** * Returns the last line in the block. * * @return The last line in the block. */ public TextLine getLastLine() { TextLine last = null; final int index = this.lines.size() - 1; if (index >= 0) { last = (TextLine) this.lines.get(index); } return last; } /** * Returns an unmodifiable list containing the lines for the text block. * * @return A list of {@link TextLine} objects. */ public List getLines() { return Collections.unmodifiableList(this.lines); } /** * Returns the width and height of the text block. * * @param g2 the graphics device. * * @return The width and height. */ public Size2D calculateDimensions(final Graphics2D g2) { double width = 0.0; double height = 0.0; final Iterator iterator = this.lines.iterator(); while (iterator.hasNext()) { final TextLine line = (TextLine) iterator.next(); final Size2D dimension = line.calculateDimensions(g2); width = Math.max(width, dimension.getWidth()); height = height + dimension.getHeight(); } return new Size2D(width, height); } /** * Returns the bounds of the text block. * * @param g2 the graphics device (<code>null</code> not permitted). * @param anchorX the x-coordinate for the anchor point. * @param anchorY the y-coordinate for the anchor point. * @param anchor the text block anchor (<code>null</code> not permitted). * @param rotateX the x-coordinate for the rotation point. * @param rotateY the y-coordinate for the rotation point. * @param angle the rotation angle. * * @return The bounds. */ public Shape calculateBounds(final Graphics2D g2, final float anchorX, final float anchorY, final TextBlockAnchor anchor, final float rotateX, final float rotateY, final double angle) { final Size2D d = calculateDimensions(g2); final float[] offsets = calculateOffsets(anchor, d.getWidth(), d.getHeight()); final Rectangle2D bounds = new Rectangle2D.Double(anchorX + offsets[0], anchorY + offsets[1], d.getWidth(), d.getHeight()); final Shape rotatedBounds = ShapeUtilities.rotateShape(bounds, angle, rotateX, rotateY); return rotatedBounds; } /** * Draws the text block at a specific location. * * @param g2 the graphics device. * @param x the x-coordinate for the anchor point. * @param y the y-coordinate for the anchor point. * @param anchor the anchor point. */ public void draw(final Graphics2D g2, final float x, final float y, final TextBlockAnchor anchor) { draw(g2, x, y, anchor, 0.0f, 0.0f, 0.0); } /** * Draws the text block, aligning it with the specified anchor point and * rotating it about the specified rotation point. * * @param g2 the graphics device. * @param anchorX the x-coordinate for the anchor point. * @param anchorY the y-coordinate for the anchor point. * @param anchor the point on the text block that is aligned to the * anchor point. * @param rotateX the x-coordinate for the rotation point. * @param rotateY the x-coordinate for the rotation point. * @param angle the rotation (in radians). */ public void draw(final Graphics2D g2, final float anchorX, final float anchorY, final TextBlockAnchor anchor, final float rotateX, final float rotateY, final double angle) { final Size2D d = calculateDimensions(g2); final float[] offsets = calculateOffsets(anchor, d.getWidth(), d.getHeight()); final Iterator iterator = this.lines.iterator(); float yCursor = 0.0f; while (iterator.hasNext()) { TextLine line = (TextLine) iterator.next(); Size2D dimension = line.calculateDimensions(g2); float lineOffset = 0.0f; if (this.lineAlignment == HorizontalAlignment.CENTER) { lineOffset = (float) (d.getWidth() - dimension.getWidth()) / 2.0f; } else if (this.lineAlignment == HorizontalAlignment.RIGHT) { lineOffset = (float) (d.getWidth() - dimension.getWidth()); } line.draw(g2, anchorX + offsets[0] + lineOffset, anchorY + offsets[1] + yCursor, TextAnchor.TOP_LEFT, rotateX, rotateY, angle); yCursor = yCursor + (float) dimension.getHeight(); } } /** * Calculates the x and y offsets required to align the text block with the * specified anchor point. This assumes that the top left of the text * block is at (0.0, 0.0). * * @param anchor the anchor position. * @param width the width of the text block. * @param height the height of the text block. * * @return The offsets (float[0] = x offset, float[1] = y offset). */ private float[] calculateOffsets(final TextBlockAnchor anchor, final double width, final double height) { final float[] result = new float[2]; float xAdj = 0.0f; float yAdj = 0.0f; if (anchor == TextBlockAnchor.TOP_CENTER || anchor == TextBlockAnchor.CENTER || anchor == TextBlockAnchor.BOTTOM_CENTER) { xAdj = (float) -width / 2.0f; } else if (anchor == TextBlockAnchor.TOP_RIGHT || anchor == TextBlockAnchor.CENTER_RIGHT || anchor == TextBlockAnchor.BOTTOM_RIGHT) { xAdj = (float) -width; } if (anchor == TextBlockAnchor.TOP_LEFT || anchor == TextBlockAnchor.TOP_CENTER || anchor == TextBlockAnchor.TOP_RIGHT) { yAdj = 0.0f; } else if (anchor == TextBlockAnchor.CENTER_LEFT || anchor == TextBlockAnchor.CENTER || anchor == TextBlockAnchor.CENTER_RIGHT) { yAdj = (float) -height / 2.0f; } else if (anchor == TextBlockAnchor.BOTTOM_LEFT || anchor == TextBlockAnchor.BOTTOM_CENTER || anchor == TextBlockAnchor.BOTTOM_RIGHT) { yAdj = (float) -height; } result[0] = xAdj; result[1] = yAdj; return result; } /** * Tests this object for equality with an arbitrary object. * * @param obj the object to test against (<code>null</code> permitted). * * @return A boolean. */ public boolean equals(final Object obj) { if (obj == this) { return true; } if (obj instanceof TextBlock) { final TextBlock block = (TextBlock) obj; return this.lines.equals(block.lines); } return false; } /** * Returns a hash code for this object. * * @return A hash code. */ public int hashCode() { return (this.lines != null ? this.lines.hashCode() : 0); } }