www.pudn.com > jfreechart-0.9.12.zip > AbstractTitle.java
/* ====================================== * JFreeChart : a free Java chart library * ====================================== * * Project Info: http://www.jfree.org/jfreechart/index.html * Project Lead: David Gilbert (david.gilbert@object-refinery.com); * * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors. * * 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., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. * * ------------------ * AbstractTitle.java * ------------------ * (C) Copyright 2000-2003, by David Berry and Contributors. * * Original Author: David Berry; * Contributor(s): David Gilbert (for Object Refinery Limited); * * $Id: AbstractTitle.java,v 1.5 2003/08/20 11:31:13 mungady Exp $ * * Changes (from 21-Aug-2001) * -------------------------- * 21-Aug-2001 : Added standard header (DG); * 18-Sep-2001 : Updated header (DG); * 14-Nov-2001 : Package com.jrefinery.common.ui.* changed to com.jrefinery.ui.* (DG); * 07-Feb-2002 : Changed blank space around title from Insets --> Spacer, to allow for relative * or absolute spacing (DG); * 25-Jun-2002 : Removed unnecessary imports (DG); * 01-Oct-2002 : Fixed errors reported by Checkstyle (DG); * 14-Oct-2002 : Changed the event listener storage structure (DG); * */ package org.jfree.chart; import java.awt.Graphics2D; import java.awt.geom.Rectangle2D; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import javax.swing.event.EventListenerList; import org.jfree.chart.event.TitleChangeEvent; import org.jfree.chart.event.TitleChangeListener; import org.jfree.util.ObjectUtils; /** * The base class for all chart titles. ** A chart can have multiple titles, appearing at the top, bottom, left or * right of the chart (defined by the constants TOP, BOTTOM, LEFT and RIGHT --- * we also use the constants NORTH, SOUTH, EAST and WEST to remain consistent * with java.awt.BorderLayout, as most developers will be familiar with that * class). *
* Concrete implementations of this class will render text, images, and hence * do the actual work of drawing titles. * * @author David Berry */ public abstract class AbstractTitle extends Object implements Cloneable, Serializable { /** Useful constant for the title position (also used for vertical alignment). */ public static final int TOP = 0; /** Useful constant for the title position (also used for vertical alignment). */ public static final int BOTTOM = 1; /** Useful constant for the title position (also used for horizontal alignment). */ public static final int RIGHT = 2; /** Useful constant for the title position (also used for horizontal alignment). */ public static final int LEFT = 3; /** Useful constant for the title position. */ public static final int NORTH = 0; /** Useful constant for the title position. */ public static final int SOUTH = 1; /** Useful constant for the title position. */ public static final int EAST = 2; /** Useful constant for the title position. */ public static final int WEST = 3; /** Useful constant for the title alignment (horizontal or vertical). */ public static final int CENTER = 4; /** Useful constant for the title alignment (horizontal or vertical). */ public static final int MIDDLE = 4; /** The default title position. */ public static final int DEFAULT_POSITION = AbstractTitle.TOP; /** The default horizontal alignment. */ public static final int DEFAULT_HORIZONTAL_ALIGNMENT = AbstractTitle.CENTER; /** The default vertical alignment. */ public static final int DEFAULT_VERTICAL_ALIGNMENT = AbstractTitle.MIDDLE; /** Default title spacer. */ public static final Spacer DEFAULT_SPACER = new Spacer(Spacer.RELATIVE, 0.01, 0.30, 0.01, 0.15); /** * The position of the title (use the constants NORTH, SOUTH, EAST and * WEST, or if you prefer you can also use TOP, BOTTOM, LEFT and RIGHT). */ private int position; /** The horizontal alignment of the title. */ private int horizontalAlignment; /** The vertical alignment of the title. */ private int verticalAlignment; /** The amount of blank space to leave around the title. */ private Spacer spacer; /** Storage for registered change listeners. */ private transient EventListenerList listenerList; /** A flag that can be used to temporarily disable the listener mechanism. */ private boolean notify; /** * Creates a new title, using default attributes where necessary. */ protected AbstractTitle() { this(AbstractTitle.DEFAULT_POSITION, AbstractTitle.DEFAULT_HORIZONTAL_ALIGNMENT, AbstractTitle.DEFAULT_VERTICAL_ALIGNMENT, AbstractTitle.DEFAULT_SPACER); } /** * Creates a new title, using default attributes where necessary. * * @param position the relative position of the title (TOP, BOTTOM, RIGHT and LEFT). * @param horizontalAlignment the horizontal alignment of the title (LEFT, CENTER or RIGHT). * @param verticalAlignment the vertical alignment of the title (TOP, MIDDLE or BOTTOM). */ protected AbstractTitle(int position, int horizontalAlignment, int verticalAlignment) { this(position, horizontalAlignment, verticalAlignment, AbstractTitle.DEFAULT_SPACER); } /** * Constructs a new AbstractTitle. *
* This class defines constants for the valid position and alignment values * --- an IllegalArgumentException will be thrown if invalid values are * passed to this constructor. * * @param position the relative position of the title (TOP, BOTTOM, RIGHT and LEFT). * @param horizontalAlignment the horizontal alignment of the title (LEFT, CENTER or RIGHT). * @param verticalAlignment the vertical alignment of the title (TOP, MIDDLE or BOTTOM). * @param spacer the amount of space to leave around the outside of the title. */ protected AbstractTitle(int position, int horizontalAlignment, int verticalAlignment, Spacer spacer) { // check arguments... if (!isValidPosition(position)) { throw new IllegalArgumentException("AbstractTitle(): invalid position."); } if (!AbstractTitle.isValidHorizontalAlignment(horizontalAlignment)) { throw new IllegalArgumentException("AbstractTitle(): invalid horizontal alignment."); } if (!AbstractTitle.isValidVerticalAlignment(verticalAlignment)) { throw new IllegalArgumentException("AbstractTitle(): invalid vertical alignment."); } // initialise... this.position = position; this.horizontalAlignment = horizontalAlignment; this.verticalAlignment = verticalAlignment; this.spacer = spacer; this.listenerList = new EventListenerList(); this.notify = true; } /** * Returns the relative position of the title---represented by one of four * integer constants defined in this class: TOP, BOTTOM, RIGHT or LEFT (or * the equivalent NORTH, SOUTH, EAST and WEST). * * @return The title position. */ public int getPosition() { return this.position; } /** * Sets the position for the title. * * @param position the relative position of the title (use one of the constants TOP, BOTTOM, * RIGHT and LEFT, or the equivalent NORTH, SOUTH, EAST and WEST). */ public void setPosition(int position) { if (this.position != position) { // check that the position is valid this.position = position; notifyListeners(new TitleChangeEvent(this)); } } /** * Returns the horizontal alignment of the title. The constants LEFT, * CENTER and RIGHT (defined in this class) are used. * * @return the horizontal alignment of the title (LEFT, CENTER or RIGHT). */ public int getHorizontalAlignment() { return this.horizontalAlignment; } /** * Sets the horizontal alignment for the title, and notifies any registered * listeners of the change. The constants LEFT, CENTER and RIGHT (defined * in this class) can be used to specify the alignment. * * @param alignment the new horizontal alignment (LEFT, CENTER or RIGHT). */ public void setHorizontalAlignment(int alignment) { if (this.horizontalAlignment != alignment) { this.horizontalAlignment = alignment; notifyListeners(new TitleChangeEvent(this)); } } /** * Returns the vertical alignment of the title. The constants TOP, MIDDLE * and BOTTOM (defined in this class) are used. * * @return the vertical alignment of the title (TOP, MIDDLE or BOTTOM). */ public int getVerticalAlignment() { return this.verticalAlignment; } /** * Sets the vertical alignment for the title, and notifies any registered * listeners of the change. * The constants TOP, MIDDLE and BOTTOM (defined in this class) can be used * to specify the alignment. * * @param alignment the new vertical alignment (TOP, MIDDLE or BOTTOM). */ public void setVerticalAlignment(int alignment) { if (this.verticalAlignment != alignment) { this.verticalAlignment = alignment; notifyListeners(new TitleChangeEvent(this)); } } /** * Returns the spacer (determines the blank space around the edges) for * this title. * * @return the spacer for this title. */ public Spacer getSpacer() { return this.spacer; } /** * Sets the spacer for the title, and notifies registered listeners of the * change. * * @param spacer the new spacer. */ public void setSpacer(Spacer spacer) { if (!this.spacer.equals(spacer)) { this.spacer = spacer; notifyListeners(new TitleChangeEvent(this)); } } /** * Returns the flag that indicates whether or not the notification mechanism is enabled. * * @return the flag. */ public boolean getNotify() { return this.notify; } /** * Sets the flag that indicates whether or not the notification mechanism * is enabled. There are certain situations (such as cloning) where you * want to turn notification off temporarily. * * @param flag the new value of the flag. */ public void setNotify(boolean flag) { this.notify = flag; } /** * Returns true if the title can assume the specified location, and false otherwise. * * @param position the position. * * @return
trueif the title can assume the specified position. */ public abstract boolean isValidPosition(int position); /** * Returns the preferred width of the title. When a title is displayed at * the left or right of a chart, the chart will attempt to give the title * enough space for it's preferred width. * * @param g2 the graphics device. * * @return the preferred width of the title. */ public abstract double getPreferredWidth(Graphics2D g2); /** * Returns the preferred height of the title. When a title is displayed at * the top or bottom of a chart, the chart will attempt to give the title * enough space for it's preferred height. * * @param g2 the graphics device. * * @return the preferred height of the title. */ public abstract double getPreferredHeight(Graphics2D g2); /** * Draws the title on a Java 2D graphics device (such as the screen or a printer). * * @param g2 the graphics device. * @param titleArea the area for drawing the title. */ public abstract void draw(Graphics2D g2, Rectangle2D titleArea); /** * Returns a clone of the title. ** One situation when this is useful is when editing the title properties - * you can edit a clone, and then it is easier to cancel the changes if * necessary. * * @return a clone of the title. * */ public Object clone() { AbstractTitle duplicate = null; try { duplicate = (AbstractTitle) super.clone(); } catch (CloneNotSupportedException e) { // this should never happen because Cloneable is implemented throw new RuntimeException("AbstractTitle.clone()"); } return duplicate; } /** * Registers an object for notification of changes to the title. * * @param listener the object that is being registered. */ public void addChangeListener(TitleChangeListener listener) { this.listenerList.add(TitleChangeListener.class, listener); } /** * Unregisters an object for notification of changes to the chart title. * * @param listener the object that is being unregistered. */ public void removeChangeListener(TitleChangeListener listener) { this.listenerList.remove(TitleChangeListener.class, listener); } /** * Notifies all registered listeners that the chart title has changed in some way. * * @param event an object that contains information about the change to the title. */ protected void notifyListeners(TitleChangeEvent event) { if (this.notify) { Object[] listeners = this.listenerList.getListenerList(); for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == TitleChangeListener.class) { ((TitleChangeListener) listeners[i + 1]).titleChanged(event); } } } } /** * Utility method for checking a horizontal alignment code. * * @param code the alignment code. * * @return
trueif alignment isLEFT|MIDDLE|RIGHT. */ protected static boolean isValidHorizontalAlignment(int code) { switch(code) { case AbstractTitle.LEFT: return true; case AbstractTitle.MIDDLE: return true; case AbstractTitle.RIGHT: return true; default: return false; } } /** * Utility method for checking a vertical alignment code. * * @param code the alignment code. * * @returntrue, if alignment isTOP|MIDDLE|BOTTOM. */ protected static boolean isValidVerticalAlignment(int code) { switch(code) { case AbstractTitle.TOP: return true; case AbstractTitle.MIDDLE: return true; case AbstractTitle.BOTTOM: return true; default: return false; } } /** * Tests an object for equality with this title. * * @param obj the object. * * @returntrueorfalse. */ public boolean equals(Object obj) { if (obj == null) { return false; } if (obj == this) { return true; } if (obj instanceof AbstractTitle) { AbstractTitle t = (AbstractTitle) obj; // if (super.equals(obj)) { boolean b0 = (this.position == t.position); boolean b1 = (this.horizontalAlignment == t.horizontalAlignment); boolean b2 = (this.verticalAlignment == t.verticalAlignment); boolean b3 = ObjectUtils.equal(this.spacer, t.spacer); boolean b4 = (this.notify == t.notify); return b0 && b1 && b2 && b3 && b4; // } } return false; } /** * Provides serialization support. * * @param stream the output stream. * * @throws IOException if there is an I/O error. */ private void writeObject(ObjectOutputStream stream) throws IOException { stream.defaultWriteObject(); } /** * Provides serialization support. * * @param stream the input stream. * * @throws IOException if there is an I/O error. * @throws ClassNotFoundException if there is a classpath problem. */ private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException { stream.defaultReadObject(); this.listenerList = new EventListenerList(); } }