java - 使用仿射变换在条形图上绘制曲线箭头

Question

我正在尝试在堆积条形图上绘制曲线箭头。我已经能够绘制曲线和箭头。但是我无法将箭头连接到曲线的末端。我正在使用仿射变换来绘制曲线。下面的链接描述了我已经能够绘制的曲线和箭头http://i58.tinypic.com/2m422hy.png.Can有人指导我如何将箭头连接到曲线的末端。

这是代码

包堆栈；

/* * 要更改此模板，请选择“工具”|“模板 * 并在编辑器中打开模板。 */

/** * * @作者 OSPL-B4 // * 要更改此模板，请选择“工具”|“模板 * 并在编辑器中打开模板。 */

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Polygon;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.font.TextLayout;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.QuadCurve2D;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import org.jfree.chart.annotations.CategoryAnnotation;

import org.jfree.chart.axis.CategoryAnchor;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.event.AnnotationChangeListener;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.CategoryDataset;
import org.jfree.io.SerialUtilities;
import org.jfree.ui.RectangleEdge;
import org.jfree.util.ObjectUtilities;
import org.jfree.util.PaintUtilities;

//导入java.awt.Font;

/**
* A line annotation that can be placed on a
* {@link org.jfree.chart.plot.CategoryPlot}.
*/
public class CategoryLineAnnotation_demo1 implements CategoryAnnotation,
                                               Cloneable, Serializable {

    /** The category for the start of the line. */
    private Comparable category1;

    /** The value for the start of the line. */
    private double value1;

    /** The category for the end of the line. */
    private Comparable category2;

    /** The value for the end of the line. */
    private double value2;
     private final int ARR_SIZE = 4;
    /** The line color. */
    private transient Paint paint = Color.black;

    /** The line stroke. */
    private transient Stroke stroke = new BasicStroke(1.0f);

    /**
     * Creates a new annotation that draws a line between (category1, value1)
     * and (category2, value2).
     *
     * @param category1  the category (<code>null</code> not permitted).
     * @param value1  the value.
     * @param category2  the category (<code>null</code> not permitted).
     * @param value2  the value.
     */
    public CategoryLineAnnotation_demo1(Comparable category1, double value1,
                                  Comparable category2, double value2,
                                  Paint paint, Stroke stroke) {
        if (category1 == null) {
            throw new IllegalArgumentException("Null 'category1' argument.");   
        }
        if (category2 == null) {
            throw new IllegalArgumentException("Null 'category2' argument.");   
        }
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument.");   
        }
        if (stroke == null) {
            throw new IllegalArgumentException("Null 'stroke' argument.");   
        }
        this.category1 = category1;

        System.out.println("First Category value is "+category1);
        this.value1 = value1;
        this.category2 = category2;

         System.out.println("Second Category value is "+category2);
        this.value2 = value2;
        this.paint = paint;
        this.stroke = stroke;
    }


    /**
     * Returns the category for the start of the line.
     *
     * @return The category for the start of the line (never <code>null</code>).
     */
    public Comparable getCategory1() {
        return this.category1;
    }

    /**
     * Sets the category for the start of the line.
     *
     * @param category  the category (<code>null</code> not permitted).
     */
    public void setCategory1(Comparable category) {
        if (category == null) {
            throw new IllegalArgumentException("Null 'category' argument.");   
        }
        this.category1 = category;
    }

    /**
     * Returns the y-value for the start of the line.
     *
     * @return The y-value for the start of the line.
     */
    public double getValue1() {
        return this.value1;
    }

    /**
     * Sets the y-value for the start of the line.
     *
     * @param value  the value.
     */
    public void setValue1(double value) {
        this.value1 = value;   
    }

    /**
     * Returns the category for the end of the line.
     *
     * @return The category for the end of the line (never <code>null</code>).
     */
    public Comparable getCategory2() {
        return this.category2;
    }

    /**
     * Sets the category for the end of the line.
     *
     * @param category  the category (<code>null</code> not permitted).
     */
    public void setCategory2(Comparable category) {
        if (category == null) {
            throw new IllegalArgumentException("Null 'category' argument.");   
        }
        this.category2 = category;
    }

    /**
     * Returns the y-value for the end of the line.
     *
     * @return The y-value for the end of the line.
     */
    public double getValue2() {
        return this.value2;
    }

    /**
     * Sets the y-value for the end of the line.
     *
     * @param value  the value.
     */
    public void setValue2(double value) {
        this.value2 = value;   
    }

    /**
     * Returns the paint used to draw the connecting line.
     *
     * @return The paint (never <code>null</code>).
     */
    public Paint getPaint() {
        return this.paint;
    }

    /**
     * Sets the paint used to draw the connecting line.
     *
     * @param paint  the paint (<code>null</code> not permitted).
     */
    public void setPaint(Paint paint) {
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument.");
        }
        this.paint = paint;
    }

    /**
     * Returns the stroke used to draw the connecting line.
     *
     * @return The stroke (never <code>null</code>).
     */
    public Stroke getStroke() {

       // System.out.println("In Stacked bar Stroke is "+getStroke());
        return this.stroke;
    }

    /**
     * Sets the stroke used to draw the connecting line.
     *
     * @param stroke  the stroke (<code>null</code> not permitted).
     */
    public void setStroke(Stroke stroke) {
        if (stroke == null) {
            throw new IllegalArgumentException("Null 'stroke' argument.");
        }
        this.stroke = stroke;
    }

    /**
     * Draws the annotation.
     *
     * @param g2  the graphics device.
     * @param plot  the plot.
     * @param dataArea  the data area.
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     */
    public void draw(Graphics2D g2, CategoryPlot plot, Rectangle2D dataArea,
                     CategoryAxis domainAxis, ValueAxis rangeAxis) {

        CategoryDataset dataset = plot.getDataset();
        int catIndex1 = dataset.getColumnIndex(this.category1);
        int catIndex2 = dataset.getColumnIndex(this.category2);

        int catCount = dataset.getColumnCount();

        double lineX1 = 0.0f;
        double lineY1 = 0.0f;
        double lineX2 = 0.0f;
        double lineY2 = 0.0f;
        PlotOrientation orientation = plot.getOrientation();
        RectangleEdge domainEdge = Plot.resolveDomainAxisLocation(
            plot.getDomainAxisLocation(), orientation);
        RectangleEdge rangeEdge = Plot.resolveRangeAxisLocation(
            plot.getRangeAxisLocation(), orientation);

        if (orientation == PlotOrientation.HORIZONTAL) {
            lineY1 = domainAxis.getCategoryJava2DCoordinate(
                CategoryAnchor.MIDDLE, catIndex1, catCount, dataArea,
                domainEdge);
            lineX1 = rangeAxis.valueToJava2D(this.value1, dataArea, rangeEdge);
            lineY2 = domainAxis.getCategoryJava2DCoordinate(
                CategoryAnchor.MIDDLE, catIndex2, catCount, dataArea,
                domainEdge);
            lineX2 = rangeAxis.valueToJava2D(this.value2, dataArea, rangeEdge);
        }
        else if (orientation == PlotOrientation.VERTICAL) {
            lineX1 = domainAxis.getCategoryJava2DCoordinate(
                CategoryAnchor.MIDDLE, catIndex1, catCount, dataArea,
                domainEdge);
            lineY1 = rangeAxis.valueToJava2D(this.value1, dataArea, rangeEdge);
            lineX2 = domainAxis.getCategoryJava2DCoordinate(
                CategoryAnchor.MIDDLE, catIndex2, catCount, dataArea,
                domainEdge);
            lineY2 = rangeAxis.valueToJava2D(this.value2, dataArea, rangeEdge);
        }
        g2.setPaint(this.paint);
        g2.setStroke(this.stroke);

        drawArrow(g2,(int) lineX1, (int) lineY1, (int) lineX2, (int) lineY2);
    }

     void drawArrow(Graphics g1, int x1, int y1, int x2, int y2) {
            Graphics2D g = (Graphics2D) g1.create();


            double dx = x2 - x1, dy = y2 - y1;

            System.out.println("Value of DX "+dx);
            System.out.println("Value of DY "+dy);
            double angle = Math.atan2(dy, dx);

            System.out.println("Getting angle "+angle);
            int len = (int) Math.sqrt(dx*dx + dy*dy);
            AffineTransform at = AffineTransform.getTranslateInstance(x1, y1);
            at.concatenate(AffineTransform.getRotateInstance(angle));
            g.transform(at);

            System.out.println("Affine transform X co-ordinate value is "+at.getScaleX());

           System.out.println("Affine transform Y co-ordinate value is "+at.getScaleY());
         float center1=(x1+x2)/2-40;
         float center2= (y1+y2)/2-40;     
         QuadCurve2D q=new QuadCurve2D.Float(0,0,center1,center2,x2,y2);


         g.draw(q);

         g.setColor(Color.RED);

         System.out.println("Length of arrow is "+len); 

         System.out.println("Get Start point 2D "+q.getP1());
         System.out.println("Get End  point 2D "+q.getP2());

          g.fillPolygon(new int[] {len, len-ARR_SIZE, len-ARR_SIZE-10, len-60},
                      new int[] {0, -ARR_SIZE, ARR_SIZE-20, 5}, 4);


        }

        public void paintComponent(Graphics g) {
            for (int x = 15; x < 200; x += 16)
                drawArrow(g, x, x, x, 150);
            drawArrow(g, 30, 300, 300, 190);
        }



    /**
     * Tests this object for equality with another.
     *
     * @param obj  the object (<code>null</code> permitted).
     *
     * @return <code>true</code> or <code>false</code>.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof CategoryLineAnnotation_demo1)) {
            return false;
        }
        CategoryLineAnnotation_demo1 that = (CategoryLineAnnotation_demo1) obj;
        if (!this.category1.equals(that.getCategory1())) {
            return false;
        }
        if (this.value1 != that.getValue1()) {
            return false;   
        }
        if (!this.category2.equals(that.getCategory2())) {
            return false;
        }
        if (this.value2 != that.getValue2()) {
            return false;   
        }
        if (!PaintUtilities.equal(this.paint, that.paint)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.stroke, that.stroke)) {
            return false;
        }
        return true;
    }

    /**
     * Returns a hash code for this instance.
     *
     * @return A hash code.
     */
    public int hashCode() {
        // TODO: this needs work
        return this.category1.hashCode() + this.category2.hashCode();
    }

    /**
     * Returns a clone of the annotation.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException  this class will not throw this
     *         exception, but subclasses (if any) might.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();   
    }

    /**
     * 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();
        SerialUtilities.writePaint(this.paint, stream);
        SerialUtilities.writeStroke(this.stroke, stream);
    }

    /**
     * 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.paint = SerialUtilities.readPaint(stream);
        this.stroke = SerialUtilities.readStroke(stream);
    }

@Override
public void addChangeListener(AnnotationChangeListener al) {

}

@Override
public void removeChangeListener(AnnotationChangeListener al) {


}

}

Answer 1

您可以根据最后一条线段(可能已使用 AffineTransform 进行转换)创建箭头

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.geom.Line2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class ArrowPainter
{
    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                createAndShowGUI();
            }
        });
    }

    private static void createAndShowGUI()
    {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new ArrowPaintPanel();
        f.getContentPane().add(panel);
        f.setSize(500,500);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}

class ArrowPaintPanel extends JPanel implements MouseMotionListener
{
    private Point2D startPoint = null;
    private Point2D endPoint = null;

    ArrowPaintPanel()
    {
        addMouseMotionListener(this);
    }

    @Override
    protected void paintComponent(Graphics gr)
    {
        super.paintComponent(gr);
        Graphics2D g = (Graphics2D)gr;

        if (startPoint == null)
        {
            startPoint = new Point(getWidth()/2, getHeight()/2);
        }
        if (endPoint == null)
        {
            return;
        }

        Line2D line = new Line2D.Double(startPoint, endPoint);
        Shape arrowHead = createArrowHead(line, 30, 20);
        g.draw(line);
        g.fill(arrowHead);
    }

    @Override
    public void mouseDragged(MouseEvent e)
    {
        endPoint = e.getPoint();
        repaint();
    }

    @Override
    public void mouseMoved(MouseEvent e)
    {
        endPoint = e.getPoint();
        repaint();
    }

    private static Shape createArrowHead(Line2D line, double length, double width)
    {
        Point2D p0 = line.getP1();
        Point2D p1 = line.getP2();
        double x0 = p0.getX();
        double y0 = p0.getY();
        double x1 = p1.getX();
        double y1 = p1.getY();
        double dx = x1 - x0;
        double dy = y1 - y0;
        double invLength = 1.0 / Math.sqrt(dx*dx+dy*dy);
        double dirX = dx * invLength;
        double dirY = dy * invLength;
        double ax = x1 - length * dirX;
        double ay = y1 - length * dirY;
        double offsetX = width * -dirY * 0.5;
        double offsetY = width * dirX * 0.5;
        double c0x = ax + offsetX;
        double c0y = ay + offsetY;
        double c1x = ax - offsetX;
        double c1y = ay - offsetY;
        Path2D arrowHead = new Path2D.Double();
        arrowHead.moveTo(x1, y1);
        arrowHead.lineTo(c0x, c0y);
        arrowHead.lineTo(c1x, c1y);
        arrowHead.closePath();
        return arrowHead;
    }


}

编辑:更新上述编辑和注释:这是很多代码，但仍然没有可以轻松测试的内容。更换线路后会发生什么

drawArrow(g2,(int) lineX1, (int) lineY1, (int) lineX2, (int) lineY2);

与

g.fill(createArrowHead(new Line2D.Double(lineX1, lineY1, lineX2, lineY2), 30, 20));

？