/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-present, 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.]
 *
 * ---------------
 * ImageTitle.java
 * ---------------
 * (C) Copyright 2000-present, by David Berry and Contributors;
 *
 * Original Author:  David Berry;
 * Contributor(s):   David Gilbert;
 *                   Tracy Hiltbrand (equals/hashCode comply with EqualsVerifier);
 *
 */

package org.jfree.chart.title;

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.geom.Rectangle2D;
import java.util.Objects;

import org.jfree.chart.block.RectangleConstraint;
import org.jfree.chart.event.TitleChangeEvent;
import org.jfree.chart.ui.HorizontalAlignment;
import org.jfree.chart.ui.RectangleEdge;
import org.jfree.chart.ui.RectangleInsets;
import org.jfree.chart.ui.Size2D;
import org.jfree.chart.ui.VerticalAlignment;

/**
 * A chart title that displays an image.  This is useful, for example, if you
 * have an image of your corporate logo and want to use as a footnote or part
 * of a title in a chart you create.
 * <P>
 * ImageTitle needs an image passed to it in the constructor.  For ImageTitle
 * to work, you must have already loaded this image from its source (disk or
 * URL).  It is recommended you use something like
 * Toolkit.getDefaultToolkit().getImage() to get the image.  Then, use
 * MediaTracker or some other message to make sure the image is fully loaded
 * from disk.
 * <P>
 * SPECIAL NOTE:  this class fails to serialize, so if you are
 * relying on your charts to be serializable, please avoid using this class.
 */
public class ImageTitle extends Title {

    /** The title image. */
    private Image image;

    /**
     * Creates a new image title.
     *
     * @param image  the image ({@code null} not permitted).
     */
    public ImageTitle(Image image) {
        this(image, image.getHeight(null), image.getWidth(null),
                Title.DEFAULT_POSITION, Title.DEFAULT_HORIZONTAL_ALIGNMENT,
                Title.DEFAULT_VERTICAL_ALIGNMENT, Title.DEFAULT_PADDING);
    }

    /**
     * Creates a new image title.
     *
     * @param image  the image ({@code null} not permitted).
     * @param position  the title position.
     * @param horizontalAlignment  the horizontal alignment.
     * @param verticalAlignment  the vertical alignment.
     */
    public ImageTitle(Image image, RectangleEdge position,
                      HorizontalAlignment horizontalAlignment,
                      VerticalAlignment verticalAlignment) {

        this(image, image.getHeight(null), image.getWidth(null),
                position, horizontalAlignment, verticalAlignment,
                Title.DEFAULT_PADDING);
    }

    /**
     * Creates a new image title with the given image scaled to the given
     * width and height in the given location.
     *
     * @param image  the image ({@code null} not permitted).
     * @param height  the height used to draw the image.
     * @param width  the width used to draw the image.
     * @param position  the title position.
     * @param horizontalAlignment  the horizontal alignment.
     * @param verticalAlignment  the vertical alignment.
     * @param padding  the amount of space to leave around the outside of the
     *                 title.
     */
    public ImageTitle(Image image, int height, int width,
                      RectangleEdge position,
                      HorizontalAlignment horizontalAlignment,
                      VerticalAlignment verticalAlignment,
                      RectangleInsets padding) {

        super(position, horizontalAlignment, verticalAlignment, padding);
        if (image == null) {
            throw new NullPointerException("Null 'image' argument.");
        }
        this.image = image;
        setHeight(height);
        setWidth(width);
    }

    /**
     * Returns the image for the title.
     *
     * @return The image for the title (never {@code null}).
     */
    public Image getImage() {
        return this.image;
    }

    /**
     * Sets the image for the title and notifies registered listeners that the
     * title has been modified.
     *
     * @param image  the new image ({@code null} not permitted).
     */
    public void setImage(Image image) {
        if (image == null) {
            throw new NullPointerException("Null 'image' argument.");
        }
        this.image = image;
        notifyListeners(new TitleChangeEvent(this));
    }

    /**
     * Arranges the contents of the block, within the given constraints, and
     * returns the block size.
     *
     * @param g2  the graphics device.
     * @param constraint  the constraint ({@code null} not permitted).
     *
     * @return The block size (in Java2D units, never {@code null}).
     */
    @Override
    public Size2D arrange(Graphics2D g2, RectangleConstraint constraint) {
        Size2D s = new Size2D(this.image.getWidth(null),
                this.image.getHeight(null));
        return new Size2D(calculateTotalWidth(s.getWidth()),
                calculateTotalHeight(s.getHeight()));
    }

    /**
     * Draws the title on a Java 2D graphics device (such as the screen or a
     * printer).
     *
     * @param g2  the graphics device.
     * @param area  the area allocated for the title.
     */
    @Override
    public void draw(Graphics2D g2, Rectangle2D area) {
        RectangleEdge position = getPosition();
        if (position == RectangleEdge.TOP || position == RectangleEdge.BOTTOM) {
            drawHorizontal(g2, area);
        }
        else if (position == RectangleEdge.LEFT
                     || position == RectangleEdge.RIGHT) {
            drawVertical(g2, area);
        }
        else {
            throw new RuntimeException("Invalid title position.");
        }
    }

    /**
     * Draws the title on a Java 2D graphics device (such as the screen or a
     * printer).
     *
     * @param g2  the graphics device.
     * @param chartArea  the area within which the title (and plot) should be
     *                   drawn.
     *
     * @return The size of the area used by the title.
     */
    protected Size2D drawHorizontal(Graphics2D g2, Rectangle2D chartArea) {
        double startY;
        double topSpace;
        double bottomSpace;
        double leftSpace;
        double rightSpace;

        double w = getWidth();
        double h = getHeight();
        RectangleInsets padding = getPadding();
        topSpace = padding.calculateTopOutset(h);
        bottomSpace = padding.calculateBottomOutset(h);
        leftSpace = padding.calculateLeftOutset(w);
        rightSpace = padding.calculateRightOutset(w);

        if (getPosition() == RectangleEdge.TOP) {
            startY = chartArea.getY() + topSpace;
        }
        else {
            startY = chartArea.getY() + chartArea.getHeight() - bottomSpace - h;
        }

        // what is our alignment?
        HorizontalAlignment horizontalAlignment = getHorizontalAlignment();
        double startX = 0.0;
        if (horizontalAlignment == HorizontalAlignment.CENTER) {
            startX = chartArea.getX() + leftSpace + chartArea.getWidth() / 2.0
                     - w / 2.0;
        }
        else if (horizontalAlignment == HorizontalAlignment.LEFT) {
            startX = chartArea.getX() + leftSpace;
        }
        else if (horizontalAlignment == HorizontalAlignment.RIGHT) {
            startX = chartArea.getX() + chartArea.getWidth() - rightSpace - w;
        }
        g2.drawImage(this.image, (int) startX, (int) startY, (int) w, (int) h,
                null);

        return new Size2D(chartArea.getWidth() + leftSpace + rightSpace,
            h + topSpace + bottomSpace);

    }

    /**
     * Draws the title on a Java 2D graphics device (such as the screen or a
     * printer).
     *
     * @param g2  the graphics device.
     * @param chartArea  the area within which the title (and plot) should be
     *                   drawn.
     *
     * @return The size of the area used by the title.
     */
    protected Size2D drawVertical(Graphics2D g2, Rectangle2D chartArea) {

        double startX;
        double topSpace = 0.0;
        double bottomSpace = 0.0;
        double leftSpace = 0.0;
        double rightSpace = 0.0;

        double w = getWidth();
        double h = getHeight();

        RectangleInsets padding = getPadding();
        if (padding != null) {
            topSpace = padding.calculateTopOutset(h);
            bottomSpace = padding.calculateBottomOutset(h);
            leftSpace = padding.calculateLeftOutset(w);
            rightSpace = padding.calculateRightOutset(w);
        }

        if (getPosition() == RectangleEdge.LEFT) {
            startX = chartArea.getX() + leftSpace;
        }
        else {
            startX = chartArea.getMaxX() - rightSpace - w;
        }

        // what is our alignment?
        VerticalAlignment alignment = getVerticalAlignment();
        double startY = 0.0;
        if (alignment == VerticalAlignment.CENTER) {
            startY = chartArea.getMinY() + topSpace
                     + chartArea.getHeight() / 2.0 - h / 2.0;
        }
        else if (alignment == VerticalAlignment.TOP) {
            startY = chartArea.getMinY() + topSpace;
        }
        else if (alignment == VerticalAlignment.BOTTOM) {
            startY = chartArea.getMaxY() - bottomSpace - h;
        }

        g2.drawImage(this.image, (int) startX, (int) startY, (int) w, (int) h,
                null);

        return new Size2D(chartArea.getWidth() + leftSpace + rightSpace,
            h + topSpace + bottomSpace);

    }

    /**
     * Draws the block within the specified area.
     *
     * @param g2  the graphics device.
     * @param area  the area.
     * @param params  ignored ({@code null} permitted).
     *
     * @return Always {@code null}.
     */
    @Override
    public Object draw(Graphics2D g2, Rectangle2D area, Object params) {
        draw(g2, area);
        return null;
    }

    /**
     * Tests this {@code ImageTitle} for equality with an arbitrary
     * object.  Returns {@code true} if:
     * <ul>
     * <li>{@code obj} is an instance of {@code ImageTitle};
     * <li>{@code obj} references the same image as this
     *     {@code ImageTitle};
     * <li>{@code super.equals(obj)} returns {@code true};
     * </ul>
     *
     * @param obj  the object ({@code null} permitted).
     *
     * @return A boolean.
     */
    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof ImageTitle)) {
            return false;
        }
        ImageTitle that = (ImageTitle) obj;
        if (!Objects.equals(this.image, that.image)) {
            return false;
        }
        if (!that.canEqual(this)) {
            return false;
        }
        return super.equals(obj);
    }

    /**
     * Ensures symmetry between super/subclass implementations of equals. For
     * more detail, see http://jqno.nl/equalsverifier/manual/inheritance.
     *
     * @param other Object
     * 
     * @return true ONLY if the parameter is THIS class type
     */
    @Override
    public boolean canEqual(Object other) {
        // fix the "equals not symmetric" problem
        return (other instanceof ImageTitle);
    }

    @Override
    public int hashCode() {
        int hash = super.hashCode(); // equals calls superclass, hashCode must also
        hash = 17 * hash + Objects.hashCode(this.image);
        return hash;
    }
}