axis.java

大家打开看看啊, 很有用的东西

/* ======================================
 * JFreeChart : a free Java chart library
 * ======================================
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 * Project Lead:  David Gilbert ([e-mail]);
 *
 * (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.
 *
 * ---------
 * Axis.java
 * ---------
 * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Bill Kelemen;
 *
 * $Id: Axis.java,v 1.14 2003/07/24 10:49:14 mungady Exp $
 *
 * Changes (from 21-Aug-2001)
 * --------------------------
 * 21-Aug-2001 : Added standard header, fixed DOS encoding problem (DG);
 * 18-Sep-2001 : Updated header (DG);
 * 07-Nov-2001 : Allow null axis labels (DG);
 *             : Added default font values (DG);
 * 13-Nov-2001 : Modified the setPlot(...) method to check compatibility between the axis and the
 *               plot (DG);
 * 30-Nov-2001 : Changed default font from "Arial" --> "SansSerif" (DG);
 * 06-Dec-2001 : Allow null in setPlot(...) method (BK);
 * 06-Mar-2002 : Added AxisConstants interface (DG);
 * 23-Apr-2002 : Added a visible property.  Moved drawVerticalString to RefineryUtilities.  Added
 *               fixedDimension property for use in combined plots (DG);
 * 25-Jun-2002 : Removed unnecessary imports (DG);
 * 05-Sep-2002 : Added attribute for tick mark paint (DG);
 * 18-Sep-2002 : Fixed errors reported by Checkstyle (DG);
 * 07-Nov-2002 : Added attributes to control the inside and outside length of the tick marks (DG);
 * 08-Nov-2002 : Moved to new package com.jrefinery.chart.axis (DG);
 * 18-Nov-2002 : Added axis location to refreshTicks(...) parameters (DG);
 * 15-Jan-2003 : Removed monolithic constructor (DG);
 * 17-Jan-2003 : Moved plot classes to separate package (DG);
 * 26-Mar-2003 : Implemented Serializable (DG);
 * 03-Jul-2003 : Modified reserveSpace method (DG);
 *
 */

package org.jfree.chart.axis;

import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Iterator;
import java.util.List;

import javax.swing.event.EventListenerList;

import org.jfree.chart.event.AxisChangeEvent;
import org.jfree.chart.event.AxisChangeListener;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.PlotNotCompatibleException;
import org.jfree.io.SerialUtilities;
import org.jfree.ui.RectangleEdge;
import org.jfree.ui.RefineryUtilities;
import org.jfree.ui.TextAnchor;
import org.jfree.util.ObjectUtils;

/**
 * The base class for all axes in JFreeChart.  Subclasses are divided into those that display
 * values ({@link ValueAxis}) and those that display categories ({@link CategoryAxis}).
 *
 * @author David Gilbert
 */
public abstract class Axis implements AxisConstants, Serializable {

    /** A flag indicating whether or not the axis is visible. */
    private boolean visible;

    /** The label for the axis. */
    private String label;

    /** The font for displaying the axis label. */
    private Font labelFont;

    /** The paint for drawing the axis label. */
    private transient Paint labelPaint;

    /** The insets for the axis label. */
    private Insets labelInsets;

    /** The label angle. */
    private double labelAngle;

    /** A flag that indicates whether or not tick labels are visible for the axis. */
    private boolean tickLabelsVisible;

    /** The font used to display the tick labels. */
    private Font tickLabelFont;

    /** The color used to display the tick labels. */
    private transient Paint tickLabelPaint;

    /** The blank space around each tick label. */
    private Insets tickLabelInsets;

    /** A flag that indicates whether or not tick marks are visible for the axis. */
    private boolean tickMarksVisible;

    /** The length of the tick mark inside the data area (zero permitted). */
    private float tickMarkInsideLength;

    /** The length of the tick mark outside the data area (zero permitted). */
    private float tickMarkOutsideLength;

    /** The stroke used to draw tick marks. */
    private transient Stroke tickMarkStroke;

    /** The paint used to draw tick marks. */
    private transient Paint tickMarkPaint;

    /** A working list of ticks - this list is refreshed as required. */
    private transient List ticks;

    /** A reference back to the plot that the axis is assigned to (can be <code>null</code>). */
    private transient Plot plot;

    /** The fixed (horizontal or vertical) dimension for the axis. */
    private double fixedDimension;

    /** Storage for registered listeners. */
    private transient EventListenerList listenerList;

    /**
     * Constructs an axis, using default values where necessary.
     *
     * @param label  the axis label (<code>null</code> permitted).
     */
    protected Axis(String label) {

        this.label = label;
        this.visible = DEFAULT_AXIS_VISIBLE;
        this.labelFont = DEFAULT_AXIS_LABEL_FONT;
        this.labelPaint = DEFAULT_AXIS_LABEL_PAINT;
        this.labelInsets = DEFAULT_AXIS_LABEL_INSETS;
        this.labelAngle = 0.0;
        this.tickLabelsVisible = DEFAULT_TICK_LABELS_VISIBLE;
        this.tickLabelFont = DEFAULT_TICK_LABEL_FONT;
        this.tickLabelPaint = DEFAULT_TICK_LABEL_PAINT;
        this.tickLabelInsets = DEFAULT_TICK_LABEL_INSETS;
        this.tickMarksVisible = DEFAULT_TICK_MARKS_VISIBLE;
        this.tickMarkStroke = DEFAULT_TICK_MARK_STROKE;
        this.tickMarkPaint = DEFAULT_TICK_MARK_PAINT;
        this.tickMarkInsideLength = DEFAULT_TICK_MARK_INSIDE_LENGTH;
        this.tickMarkOutsideLength = DEFAULT_TICK_MARK_OUTSIDE_LENGTH;

        this.plot = null;

        this.ticks = new java.util.ArrayList();
        this.listenerList = new EventListenerList();

    }

    /**
     * Returns true if the axis is visible, and false otherwise.
     *
     * @return a flag indicating whether or not the axis is visible.
     */
    public boolean isVisible() {
        return this.visible;
    }

    /**
     * Sets a flag that controls whether or not the axis is drawn on the chart.  An
     * {@link AxisChangeEvent} is sent to all registered listeners.
     *
     * @param flag  the flag.
     */
    public void setVisible(boolean flag) {

        if (flag != this.visible) {
            this.visible = flag;
            notifyListeners(new AxisChangeEvent(this));
        }

    }

    /**
     * Returns the label for the axis.
     *
     * @return the label for the axis (<code>null</code> possible).
     */
    public String getLabel() {
        return label;
    }

    /**
     * Sets the label for the axis (<code>null</code> permitted).  An {@link AxisChangeEvent} is
     * sent to all registered listeners.
     *
     * @param label  the new label.
     */
    public void setLabel(String label) {

        String existing = this.label;
        if (existing != null) {
            if (!existing.equals(label)) {
                this.label = label;
                notifyListeners(new AxisChangeEvent(this));
            }
        }
        else {
            if (label != null) {
                this.label = label;
                notifyListeners(new AxisChangeEvent(this));
            }
        }

    }

    /**
     * Returns the font for the axis label.
     *
     * @return the font.
     */
    public Font getLabelFont() {
        return labelFont;
    }

    /**
     * Sets the font for the axis label.
     * <P>
     * Registered listeners are notified of a general change to the axis.
     *
     * @param font  the new label font.
     */
    public void setLabelFont(Font font) {

        // check arguments...
        if (font == null) {
            throw new IllegalArgumentException("Axis.setLabelFont(...): null not permitted.");
        }

        // make the change (if necessary)...
        if (!this.labelFont.equals(font)) {
            this.labelFont = font;
            notifyListeners(new AxisChangeEvent(this));
        }

    }

    /**
     * Returns the color/shade used to draw the axis label.
     *
     * @return the color/shade used to draw the axis label.
     */
    public Paint getLabelPaint() {
        return this.labelPaint;
    }

    /**
     * Sets the color/shade used to draw the axis label.
     * <P>
     * Registered listeners are notified of a general change to the axis.
     *
     * @param paint  the new color/shade for the axis label.
     */
    public void setLabelPaint(Paint paint) {

        // check arguments...
        if (paint == null) {
            throw new IllegalArgumentException("Axis.setLabelPaint(...): null not permitted.");
        }

        // make the change (if necessary)...
        if (!this.labelPaint.equals(paint)) {
            this.labelPaint = paint;
            notifyListeners(new AxisChangeEvent(this));
        }
    }

    /**
     * Returns the insets for the label (that is, the amount of blank space
     * that should be left around the label).
     *
     * @return the label insets.
     */
    public Insets getLabelInsets() {
        return this.labelInsets;
    }

    /**
     * Sets the insets for the axis label, and notifies registered listeners
     * that the axis has been modified.
     *
     * @param insets  the new label insets.
     */
    public void setLabelInsets(Insets insets) {
        if (!insets.equals(this.labelInsets)) {
            this.labelInsets = insets;
            notifyListeners(new AxisChangeEvent(this));
        }
    }

    /**
     * Returns the angle of the axis label.
     *
     * @return The angle.
     */
    public double getLabelAngle() {
        return this.labelAngle;