【发布时间】：2015-03-24 15:10:19
【问题描述】：
我想开发一个桌面应用程序，它能够绘制给定函数的图形，但在具有自定义轴的坐标系中。 例如：用户可以在 X 轴和 Y 轴的情况下在线性、对数、指数等轴类型之间进行切换。
- 您认为Java AWT 适合此目的吗？ （我还不知道），
- 您知道可以/应该使用哪些其他技术吗？
- 在这种情况下时间是最重要的，所以我需要最简单的方法..
提前谢谢你， 马顿
【问题讨论】：
标签： java function graph awt axis
【发布时间】：2015-03-24 15:10:19
【问题描述】：
Swing 或 JavaFX 会比 AWT 更好。
这是我开发的一些代码，用于在 Swing 绘图区域上放置笛卡尔和/或极坐标系。您可以以此为起点来做您想做的事。
坐标系类
package com.ggl.game.utilities;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.geom.Point2D;
/**
* <p>
* This class creates a Cartesian and Polar coordinate system to overlay a Swing
* drawing area (usually a <code>JPanel</code>). The user of the class sets a
* limit as to how far the X axis or the Y axis extends in the negative and
* positive direction from (0, 0). Point (0, 0) will be placed in the center of
* the drawing area.
* </p>
* <p>
* Since the drawing area is usually not square, the limit applies to the
* shorter dimension. The actual limits can be retrieved from this class, and
* will change if the user of the application changes the drawing area size by
* maximizing or normalizing the application <code>JFrame</code> window.
* </p>
* <p>
* Using a Cartesian or Polar coordinate system frees the user of this class
* from having to worry about Swing pixel coordinates.
* </p>
*
* @author Gilbert G. Le Blanc
* @version 1.0 - 23 February 2015
*
* @see com.ggl.game.utilities.Polar2D
* @see java.awt.geom.Point2D
* @see javax.swing.JFrame
* @see javax.swing.JPanel
*/
public class CoordinateSystem {
private double conversionFactor;
private double xLimit;
private double yLimit;
private int height;
private int width;
/**
* <p>
* This creates a Cartesian and Polar coordinate system over a Swing drawing
* area (usually a <code>JPanel</code>). If the drawing area is square, the
* X axis extends from -limit to limit and the Y axis extends from -limit to
* limit.
* </p>
* <p>
* If the drawing area is not square, then the smaller dimension, either X
* or Y, extends from -limit to limit. The larger dimension extends beyond
* the limit in both directions.
* </p>
* <p>
* Since most displays are not square, the X and Y axis will usually have
* different limits.
* </p>
*
* @param limit
* - The limit of the X and Y axis in a Cartesian coordinate
* system.
* @param width
* - The width of the drawing area in pixels.
* @param height
* - The height of the drawing area in pixels.
*/
public CoordinateSystem(double limit, int width, int height) {
this.width = width;
this.height = height;
if (width > height) {
this.xLimit = limit * width / height;
this.yLimit = limit;
this.conversionFactor = (limit + limit) / (double) height;
} else if (width < height) {
this.xLimit = limit;
this.yLimit = limit * height / width;
this.conversionFactor = (limit + limit) / (double) width;
} else {
this.xLimit = limit;
this.yLimit = limit;
this.conversionFactor = (limit + limit) / (double) width;
}
}
/**
* This method changes the drawing area dimension, along with the X and Y
* axis limits.
*
* @param dimension
* - A <code>Dimension</code> with the new drawing area
* dimension.
*/
public void setDrawingSize(Dimension dimension) {
setDrawingSize(dimension.width, dimension.height);
}
/**
* This method changes the drawing area width and height, along with the X
* and Y axis limits.
*
* @param width
* - The width of the drawing area in pixels.
* @param height
* - The height of the drawing area in pixels.
*/
public void setDrawingSize(int width, int height) {
xLimit = xLimit / this.width * width;
yLimit = yLimit / this.height * height;
this.width = width;
this.height = height;
}
/**
* This method returns the Cartesian coordinate limit for the X axis.
*
* @return The Cartesian coordinate limit for the X axis.
*/
public double getxLimit() {
return xLimit;
}
/**
* This method returns the Cartesian coordinate limit for the Y axis.
*
* @return The Cartesian coordinate limit for the Y axis.
*/
public double getyLimit() {
return yLimit;
}
/**
* This method converts a Polar coordinate distance and theta angle in
* radians to a pixel location on a drawing area.
*
* @param distance
* - A Polar coordinate distance
* @param theta
* - A Polar coordinate theta angle in radians
* @return A pixel location on a drawing area.
*/
public Point convertPolarToPixels(double distance, double theta) {
return convertToPixels(new Polar2D.Double(distance, theta));
}
/**
* This method converts a Cartesian coordinate x and y to a pixel location
* on a drawing area.
*
* @param x
* - A Cartesian coordinate x.
* @param y
* - A Cartesian coordinate y.
* @return A pixel location on a drawing area.
*/
public Point convertPointToPixels(double x, double y) {
return convertToPixels(new Point2D.Double(x, y));
}
/**
* This method converts a Polar coordinate to a pixel location on a drawing
* area.
*
* @param polar
* - A Polar coordinate.
* @return A pixel location on a drawing area.
*/
public Point convertToPixels(Polar2D polar) {
double x = polar.getDistance() * Math.cos(polar.getTheta());
double y = polar.getDistance() * Math.sin(polar.getTheta());
return convertToPixels(new Point2D.Double(x, y));
}
/**
* This method converts a Cartesian coordinate to a pixel location on a
* drawing area.
*
* @param cartesian
* - A Cartesian coordinate.
* @return A pixel location on a drawing area.
*/
public Point convertToPixels(Point2D cartesian) {
int x = (int) Math
.round((cartesian.getX() + xLimit) / conversionFactor);
int y = (int) Math.round((-cartesian.getY() + yLimit)
/ conversionFactor);
return new Point(x, y);
}
/**
* This method converts a pixel location on a drawing area to a Cartesian
* coordinate.
*
* @param x
* - The x pixel location.
* @param y
* - The y pixel location.
* @return A Cartesian coordinate.
*/
public Point2D convertToCartesian(int x, int y) {
return convertToCartesian(new Point(x, y));
}
/**
* This method converts a pixel location on a drawing area to a Cartesian
* coordinate.
*
* @param point
* - The pixel location.
* @return A Cartesian coordinate.
*/
public Point2D convertToCartesian(Point point) {
double x = (double) point.x * conversionFactor - xLimit;
double y = (double) -point.y * conversionFactor + yLimit;
return new Point2D.Double(x, y);
}
/**
* This method converts a pixel location on a drawing area to a Polar
* coordinate.
*
* @param x
* - The x pixel location.
* @param y
* - The y pixel location.
* @return A Polar coordinate.
*/
public Polar2D convertToPolar(int x, int y) {
return convertToPolar(new Point(x, y));
}
/**
* This method converts a pixel location on a drawing area to a Polar
* coordinate.
*
* @param point
* - The pixel location.
* @return A Polar coordinate.
*/
public Polar2D convertToPolar(Point point) {
double x = (double) point.x * conversionFactor - xLimit;
double y = (double) -point.y * conversionFactor + yLimit;
double distance = Math.sqrt(x * x + y * y);
double theta = Math.atan2(y, x);
return new Polar2D.Double(distance, theta);
}
}
Polar2D 类
package com.ggl.game.utilities;
/**
* The <code>Polar2D</code> class defines a point representing a location in
* distance, theta angle coordinate space.
* <p>
* This class is only the abstract superclass for all objects that store a 2D
* coordinate. The actual storage representation of the coordinates is left to
* the subclass.
*
* @version 1.0 - 23 February 2015
* @author Jim Graham (author of Point2D), Gilbert Le Blanc
*/
public abstract class Polar2D implements Cloneable {
/**
* The <code>Float</code> class defines a point specified in float
* precision.
*/
public static class Float extends Polar2D {
/**
* The distance of this <code>Polar2D</code>.
*
* @since 1.7
*/
public float distance;
/**
* The theta angle of this <code>Polar2D</code>.
*
* @since 1.7
*/
public float theta;
/**
* Constructs and initializes a <code>Polar2D</code> with coordinates
* (0, 0).
*
* @since 1.7
*/
public Float() {
}
/**
* Constructs and initializes a <code>Polar2D</code> with the specified
* coordinates.
*
* @param distance
* The distance to which to set the newly constructed
* <code>Polar2D</code>
* @param theta
* The theta angle in radians to which to set the newly
* constructed <code>Polar2D</code>
* @since 1.7
*/
public Float(float distance, float theta) {
this.distance = distance;
this.theta = theta;
}
/**
* Returns the distance of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return the distance of this <code>Polar2D</code>.
* @since 1.7
*/
@Override
public double getDistance() {
return (double) distance;
}
/**
* Returns the theta angle in radians of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return the theta angle in radians of this <code>Polar2D</code>.
* @since 1.7
*/
@Override
public double getTheta() {
return (double) theta;
}
/**
* Returns the theta angle in degrees of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return the theta angle in degrees of this <code>Polar2D</code>.
* @since 1.7
*/
@Override
public double getThetaInDegrees() {
double degrees = 180D / Math.PI * theta;
return (degrees < 0D) ? degrees + 360D : degrees;
}
/**
* Sets the location of this <code>Polar2D</code> to the specified
* <code>double</code> distance and theta angle in radians.
*
* @param distance
* The distance to which to set this <code>Polar2D</code>
* @param theta
* The theta angle in radians to which to set this
* <code>Polar2D</code>
* @since 1.7
*/
@Override
public void setLocation(double distance, double theta) {
this.distance = (float) distance;
this.theta = (float) theta;
}
/**
* Sets the location of this <code>Polar2D</code> to the specified
* <code>float</code> coordinates.
*
* @param distance
* The distance to which to set this <code>Polar2D</code>
* @param theta
* The theta angle in radians to which to set this
* <code>Polar2D</code>
* @since 1.7
*/
public void setLocation(float distance, float theta) {
this.distance = distance;
this.theta = theta;
}
/**
* Returns a <code>String</code> that represents the value of this
* <code>Polar2D</code>.
*
* @return A <code>String</code> representation of this
* <code>Polar2D</code>.
* @since 1.7
*/
@Override
public String toString() {
return "Polar2D.Float[" + distance + ", " + theta + "]";
}
}
/**
* The <code>Double</code> class defines a point specified in
* <code>double</code> precision.
*/
public static class Double extends Polar2D {
/**
* The distance of this <code>Polar2D</code>.
*
* @since 1.7
*/
public double distance;
/**
* The theta angle in radians of this <code>Polar2D</code>.
*
* @since 1.7
*/
public double theta;
/**
* Constructs and initializes a <code>Polar2D</code> with (0, 0)
* distance and theta angle in radians.
*
* @since 1.7
*/
public Double() {
}
/**
* Constructs and initializes a <code>Polar2D</code> with the specified
* coordinates.
*
* @param distance
* The distance to which to set the newly constructed
* <code>Polar2D</code>
* @param theta
* The theta angle in radians to which to set the newly
* constructed <code>Polar2D</code>
* @since 1.7
*/
public Double(double distance, double theta) {
this.distance = distance;
this.theta = theta;
}
/**
* Returns the distance of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return The distance of this <code>Polar2D</code>.
* @since 1.7
*/
@Override
public double getDistance() {
return distance;
}
/**
* Returns the theta angle in radians of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return The theta angle in radians of this <code>Polar2D</code>.
* @since 1.7
*/
@Override
public double getTheta() {
return theta;
}
/**
* Returns the theta angle in degrees of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return The theta angle in degrees of this <code>Polar2D</code>.
* @since 1.7
*/
@Override
public double getThetaInDegrees() {
double degrees = 180D / Math.PI * theta;
return (degrees < 0D) ? degrees + 360D : degrees;
}
/**
* Sets the location of this <code>Polar2D</code> to the specified
* <code>double</code> coordinates.
*
* @param distance
* The distance to which to set this <code>Polar2D</code>
* @param theta
* The theta angle in radians to which to set this
* <code>Polar2D</code>
* @since 1.7
*/
@Override
public void setLocation(double distance, double theta) {
this.distance = distance;
this.theta = theta;
}
/**
* Returns a <code>String</code> that represents the value of this
* <code>Polar2D</code>.
*
* @return A <code>String</code> representation of this
* <code>Polar2D</code>.
* @since 1.7
*/
@Override
public String toString() {
return "Polar2D.Double[" + distance + ", " + theta + "]";
}
}
/**
* This is an abstract class that cannot be instantiated directly.
* Type-specific implementation subclasses are available for instantiation
* and provide a number of formats for storing the information necessary to
* satisfy the various accessor methods below.
*
* @see java.awt.geom.Polar2D.Float
* @see java.awt.geom.Polar2D.Double
* @see java.awt.Point
*/
protected Polar2D() {
}
/**
* Returns the distance of this <code>Polar2D</code> in <code>double</code>
* precision.
*
* @return The distance of this <code>Polar2D</code>.
* @since 1.7
*/
public abstract double getDistance();
/**
* Returns the theta angle in radians of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return The theta angle in radians of this <code>Polar2D</code>.
* @since 1.7
*/
public abstract double getTheta();
/**
* Returns the theta angle in degrees of this <code>Polar2D</code> in
* <code>double</code> precision.
*
* @return The theta angle in degrees of this <code>Polar2D</code>.
* @since 1.7
*/
public abstract double getThetaInDegrees();
/**
* Sets the location of this <code>Polar2D</code> to the specified
* <code>double</code> coordinates.
*
* @param distance
* The distance of this <code>Polar2D</code>
* @param theta
* The theta angle in radians of this <code>Polar2D</code>
* @since 1.7
*/
public abstract void setLocation(double distance, double theta);
/**
* Sets the location of this <code>Polar2D</code> to the same coordinates as
* the specified <code>Polar2D</code> object.
*
* @param p
* the specified <code>Polar2D</code> the which to set this
* <code>Polar2D</code>
* @since 1.7
*/
public void setLocation(Polar2D p) {
setLocation(p.getDistance(), p.getTheta());
}
/**
* Returns the square of the distance between two points.
*
* @param distance1
* The distance of the first point
* @Parm theta1 The theta angle in radians of the first point
* @param distance2
* The distance of the second point
* @param theta2
* The theta angle in radians of the second point
* @return The square of the distance between the two specified points.
*/
public static double distanceSq(double distance1, double theta1,
double distance2, double theta2) {
double x1 = distance1 * Math.cos(theta1);
double y1 = distance1 * Math.sin(theta1);
double x2 = distance2 * Math.cos(theta2);
double y2 = distance2 * Math.sin(theta2);
return (x1 * x2 + y1 * y2);
}
/**
* Returns the distance between two points.
*
* @param distance1
* The distance of the first point
* @param theta1
* The theta angle in radians of the first point
* @param distance2
* The distance of the second point
* @param theta2
* The theta angle in radians of the second point
* @return The distance between the two specified points.
*/
public static double distance(double distance1, double theta1,
double distance2, double theta2) {
double x1 = distance1 * Math.cos(theta1);
double y1 = distance1 * Math.sin(theta1);
double x2 = distance2 * Math.cos(theta2);
double y2 = distance2 * Math.sin(theta2);
return Math.sqrt(x1 * x2 + y1 * y2);
}
/**
* Returns the square of the distance from this <code>Polar2D</code> to a
* specified point.
*
* @param distance
* The distance of the specified point
* @param theta
* The theta angle in radians of the specified point
* @return The square of the distance between this <code>Polar2D</code> and
* the specified point.
*/
public double distanceSq(double distance, double theta) {
double x1 = distance * Math.cos(theta);
double y1 = distance * Math.sin(theta);
double x2 = getDistance() * Math.cos(getTheta());
double y2 = getDistance() * Math.sin(getTheta());
return (x1 * x2 + y1 * y2);
}
/**
* Returns the square of the distance from this <code>Polar2D</code> to a
* specified <code>Polar2D</code>.
*
* @param pt
* The specified <code>Polar2D</code>
* @return The square of the distance between this <code>Polar2D</code> to a
* specified <code>Polar2D</code>.
*/
public double distanceSq(Polar2D pt) {
double x1 = pt.getDistance() * Math.cos(pt.getTheta());
double y1 = pt.getDistance() * Math.sin(pt.getTheta());
double x2 = getDistance() * Math.cos(getTheta());
double y2 = getDistance() * Math.sin(getTheta());
return (x1 * x2 + y1 * y2);
}
/**
* Returns the distance from this <code>Polar2D</code> to a specified point.
*
* @param distance
* The distance of the specified point
* @param theta
* The theta angle in radians of the specified point
* @return The distance between this <code>Polar2D</code> and a specified
* point.
*/
public double distance(double distance, double theta) {
double x1 = distance * Math.cos(theta);
double y1 = distance * Math.sin(theta);
double x2 = getDistance() * Math.cos(getTheta());
double y2 = getDistance() * Math.sin(getTheta());
return Math.sqrt(x1 * x2 + y1 * y2);
}
/**
* Returns the distance from this <code>Polar2D</code> to a specified
* <code>Polar2D</code>.
*
* @param pt
* the specified <code>Polar2D</code>
* @return The distance between this <code>Polar2D</code> and the specified
* <code>Polar2D</code>.
*/
public double distance(Polar2D pt) {
double x1 = pt.getDistance() * Math.cos(pt.getTheta());
double y1 = pt.getDistance() * Math.sin(pt.getTheta());
double x2 = getDistance() * Math.cos(getTheta());
double y2 = getDistance() * Math.sin(getTheta());
return Math.sqrt(x1 * x2 + y1 * y2);
}
/**
* Creates a new object of the same class and with the same contents as this
* object.
*
* @return a clone of this instance.
* @exception OutOfMemoryError
* if there is not enough memory.
* @see java.lang.Cloneable
* @since 1.7
*/
@Override
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
/**
* Returns the hash code for this <code>Polar2D</code>.
*
* @return a hash code for this <code>Polar2D</code>.
*/
@Override
public int hashCode() {
long bits = java.lang.Double.doubleToLongBits(getDistance());
bits ^= java.lang.Double.doubleToLongBits(getTheta()) * 31;
return (((int) bits) ^ ((int) (bits >> 32)));
}
/**
* Determines whether or not two points are equal. Two instances of
* <code>Polar2D</code> are equal if the values of their <code>x</code> and
* <code>y</code> member fields, representing their position in the
* coordinate space, are the same.
*
* @param obj
* an object to be compared with this <code>Polar2D</code>
* @return <code>true</code> if the object to be compared is an instance of
* <code>Polar2D</code> and has the same values; <code>false</code>
* otherwise.
* @since 1.7
*/
@Override
public boolean equals(Object obj) {
if (obj instanceof Polar2D) {
Polar2D p2d = (Polar2D) obj;
return (getDistance() == p2d.getDistance())
&& (getTheta() == p2d.getTheta());
}
return super.equals(obj);
}
}
在另一个答案中继续。
【讨论】：
从答案的第一部分继续，因为答案有 30,000 个字符的限制。
这里有一些代码来测试答案第一部分中的两个类。
CoordinateSystemTester 类
package com.ggl.game.utilities.swing;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.font.FontRenderContext;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import com.ggl.game.utilities.CoordinateSystem;
import com.ggl.game.utilities.Polar2D;
public class CoordinateSystemTester implements Runnable {
private DrawingPanel drawingPanel;
private JFrame frame;
@Override
public void run() {
frame = new JFrame("Coordinate System Tester");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BorderLayout());
drawingPanel = new DrawingPanel(640, 480);
mainPanel.add(drawingPanel);
frame.add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new CoordinateSystemTester());
}
private class DrawingPanel extends JPanel {
private static final long serialVersionUID = 1519119839534910933L;
private CoordinateSystem coordinateSystem;
private Point pixelPoint;
private Point2D coordinatePoint;
private String coordinateString;
public DrawingPanel(int width, int height) {
this.coordinateSystem = new CoordinateSystem(25.0D, width, height);
this.coordinatePoint = new Point2D.Double();
this.pixelPoint = new Point();
this.coordinateString = "";
addComponentListener(new SizeListener());
addMouseListener(new CoordinateListener());
setPreferredSize(new Dimension(width, height));
}
public CoordinateSystem getCoordinateSystem() {
return coordinateSystem;
}
public Point2D getCoordinatePoint() {
return coordinatePoint;
}
public void setCoordinatePoint(Point2D coordinatePoint) {
this.coordinatePoint = coordinatePoint;
}
public Point getPixelPoint() {
return pixelPoint;
}
public void setPixelPoint(Point pixelPoint) {
this.pixelPoint = pixelPoint;
}
public void setCoordinateString(String coordinateString) {
this.coordinateString = coordinateString;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.WHITE);
g2d.fillRect(0, 0, getWidth(), getHeight());
g2d.setColor(Color.BLACK);
g2d.drawString(createLimitsString(), 10, 20);
drawXAxis(g2d, g);
drawYAxis(g2d, g);
drawCoordinate(g2d, g);
}
private String createLimitsString() {
String xs = String.format("%.2f", coordinateSystem.getxLimit());
String ys = String.format("%.2f", coordinateSystem.getyLimit());
StringBuilder builder = new StringBuilder();
builder.append("The actual limits are (");
builder.append(xs);
builder.append(", ");
builder.append(ys);
builder.append(")");
return builder.toString();
}
private void drawXAxis(Graphics2D g2d, Graphics g) {
g2d.setColor(Color.BLACK);
g2d.setStroke(new BasicStroke(5.0F));
Point p1 = coordinateSystem.convertPointToPixels(-20.0D, 0.0D);
Point p2 = coordinateSystem.convertPointToPixels(20.0D, 0.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
g2d.setStroke(new BasicStroke(3.0F));
p1 = coordinateSystem.convertPointToPixels(-20.0D, -1.0D);
p2 = coordinateSystem.convertPointToPixels(-20.0D, 1.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
Font font = getFont();
Point p3 = coordinateSystem.convertPointToPixels(-20.0D, -1.0D);
Rectangle r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "-20.0", font);
p1 = coordinateSystem.convertPointToPixels(-10.0D, -1.0D);
p2 = coordinateSystem.convertPointToPixels(-10.0D, 1.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
p3 = coordinateSystem.convertPointToPixels(-10.0D, -1.0D);
r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "-10.0", font);
p1 = coordinateSystem.convertPointToPixels(10.0D, -1.0D);
p2 = coordinateSystem.convertPointToPixels(10.0D, 1.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
p3 = coordinateSystem.convertPointToPixels(10.0D, -1.0D);
r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "10.0", font);
p1 = coordinateSystem.convertPointToPixels(20.0D, -1.0D);
p2 = coordinateSystem.convertPointToPixels(20.0D, 1.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
p3 = coordinateSystem.convertPointToPixels(20.0D, -1.0D);
r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "20.0", font);
}
private void drawYAxis(Graphics2D g2d, Graphics g) {
g2d.setColor(Color.BLACK);
g2d.setStroke(new BasicStroke(5.0F));
Point p1 = coordinateSystem.convertPointToPixels(0.0D, -20.0D);
Point p2 = coordinateSystem.convertPointToPixels(0.0D, 20.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
g2d.setStroke(new BasicStroke(3.0F));
p1 = coordinateSystem.convertPointToPixels(-1.0D, -20.0D);
p2 = coordinateSystem.convertPointToPixels(1.0D, -20.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
Font font = getFont();
Point p3 = coordinateSystem.convertPointToPixels(3.0D, -20.0D);
Rectangle r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "-20.0", font);
p1 = coordinateSystem.convertPointToPixels(-1.0D, -10.0D);
p2 = coordinateSystem.convertPointToPixels(1.0D, -10.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
p3 = coordinateSystem.convertPointToPixels(3.0D, -10.0D);
r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "-10.0", font);
p1 = coordinateSystem.convertPointToPixels(-1.0D, 10.0D);
p2 = coordinateSystem.convertPointToPixels(1.0D, 10.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
p3 = coordinateSystem.convertPointToPixels(3.0D, 10.0D);
r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "10.0", font);
p1 = coordinateSystem.convertPointToPixels(-1.0D, 20.0D);
p2 = coordinateSystem.convertPointToPixels(1.0D, 20.0D);
g2d.drawLine(p1.x, p1.y, p2.x, p2.y);
p3 = coordinateSystem.convertPointToPixels(3.0D, 20.0D);
r = new Rectangle(p3.x - 20, p3.y, 40, 20);
centerString(g, r, "20.0", font);
}
private void drawCoordinate(Graphics2D g2d, Graphics g) {
if (!coordinateString.equals("")) {
g2d.setColor(Color.BLUE);
g2d.fillOval(pixelPoint.x - 5, pixelPoint.y - 5, 10, 10);
Font font = getFont();
Rectangle r = new Rectangle(pixelPoint.x - 30, pixelPoint.y,
60, 20);
centerString(g, r, coordinateString, font);
}
}
/**
* This method centers a <code>String</code> in a bounding
* <code>Rectangle</code>.
*
* @param g
* - The <code>Graphics</code> instance.
* @param r
* - The bounding <code>Rectangle</code>.
* @param s
* - The <code>String</code> to center in the bounding
* rectangle.
* @param font
* - The display font of the <code>String</code>
*
* @see java.awt.Graphics
* @see java.awt.Rectangle
* @see java.lang.String
*/
private void centerString(Graphics g, Rectangle r, String s, Font font) {
FontRenderContext frc = new FontRenderContext(null, true, true);
Rectangle2D r2D = font.getStringBounds(s, frc);
int rWidth = (int) Math.round(r2D.getWidth());
int rHeight = (int) Math.round(r2D.getHeight());
int rX = (int) Math.round(r2D.getX());
int rY = (int) Math.round(r2D.getY());
int a = (r.width / 2) - (rWidth / 2) - rX;
int b = (r.height / 2) - (rHeight / 2) - rY;
g.setFont(font);
g.drawString(s, r.x + a, r.y + b);
}
}
private class CoordinateListener extends MouseAdapter {
@Override
public void mousePressed(MouseEvent event) {
drawingPanel.setPixelPoint(event.getPoint());
Point2D coordinatePoint = drawingPanel.getCoordinateSystem()
.convertToCartesian(event.getPoint());
drawingPanel.setCoordinatePoint(coordinatePoint);
StringBuilder builder = new StringBuilder();
if (event.getButton() == MouseEvent.BUTTON1) {
builder.append("(");
builder.append(String.format("%.2f", coordinatePoint.getX()));
builder.append(", ");
builder.append(String.format("%.2f", coordinatePoint.getY()));
builder.append(")");
} else if (event.getButton() == MouseEvent.BUTTON3) {
Polar2D polarPoint = drawingPanel.getCoordinateSystem()
.convertToPolar(event.getPoint());
builder.append("(");
builder.append(String.format("%.2f", polarPoint.getDistance()));
builder.append(", ");
builder.append(String.format("%.2f",
polarPoint.getThetaInDegrees()));
builder.append(")");
}
drawingPanel.setCoordinateString(builder.toString());
drawingPanel.repaint();
}
}
private class SizeListener extends ComponentAdapter {
@Override
public void componentResized(ComponentEvent event) {
Dimension d = drawingPanel.getSize();
drawingPanel.getCoordinateSystem().setDrawingSize(d);
if (!drawingPanel.getPixelPoint().equals(new Point())) {
Point2D p2d = drawingPanel.getCoordinatePoint();
Point p = drawingPanel.getCoordinateSystem().convertToPixels(
p2d);
drawingPanel.setPixelPoint(p);
}
drawingPanel.repaint();
}
}
}
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