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Parabola.java
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Parabola.java
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/*
* Parabola.java
*
* Created on August 3, 2004, 3:55 PM
* Revised on October 11, 2004
* @author Guy Lemire
*/
package Parabola;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import javax.swing.Timer;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.*;
import java.awt.geom.AffineTransform;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import java.text.DecimalFormat;
import java.awt.event.ActionListener;
/** @noinspection ALL*/
class Parabola extends JFrame {
Timer timer;
private ActionEvent evt;
private ActionEvent actionEvent;
/**
* Creates new form Parabola
*/
public Parabola() {
JPanel infoPanel = new JPanel();
JButton jResetButton = new JButton();
JButton jProofButton = new JButton();
startStopButton = new JButton();
JLabel jReflectLabel = new JLabel();
JLabel jTurnLabel = new JLabel();
jPFvalue = new JLabel();
jPHvalue = new JLabel();
jPFlabel = new JLabel();
jPHlabel = new JLabel();
jTangentButton = new JButton();
jTangentLabel = new JLabel();
jSlopeValue = new JLabel();
jSlopeLabel = new JLabel();
JButton jApplications = new JButton();
ViewPanel viewPanel = new ViewPanel();
setVisible(true);
infoPanel.setLayout(null);
infoPanel.setBorder(new javax.swing.border.TitledBorder(" PARABOLA"));
infoPanel.setMaximumSize(new Dimension(140, 500));
infoPanel.setPreferredSize(new Dimension(140, 500));
jResetButton.setText("RESET");
jResetButton.setHorizontalTextPosition(SwingConstants.CENTER);
jResetButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jResetButtonActionPerformed();
}
});
infoPanel.add(jResetButton);
jResetButton.setBounds(10, 390, 110, 26);
jProofButton.setText("PROOF");
jProofButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jProofButtonActionPerformed(evt);
}
});
infoPanel.add(jProofButton);
jProofButton.setBounds(10, 60, 110, 26);
startStopButton.setText("ON");
startStopButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
startStopButtonActionPerformed(evt);
}
});
Component add = infoPanel.add(startStopButton);
startStopButton.setBounds(10, 310, 110, 26);
jReflectLabel.setHorizontalAlignment(SwingConstants.CENTER);
jReflectLabel.setText("REFLECTOR");
infoPanel.add(jReflectLabel);
jReflectLabel.setBounds(10, 290, 110, 20);
jTurnLabel.setText("TURN");
infoPanel.add(jTurnLabel);
jTurnLabel.setBounds(50, 280, 41, 16);
jPFvalue.setMaximumSize(new Dimension(23, 16));
jPFvalue.setPreferredSize(new Dimension(23, 16));
infoPanel.add(jPFvalue);
jPFvalue.setBounds(70, 90, 30, 16);
jPHvalue.setMaximumSize(new Dimension(23, 16));
jPHvalue.setPreferredSize(new Dimension(23, 16));
infoPanel.add(jPHvalue);
jPHvalue.setBounds(70, 110, 30, 16);
jPFlabel.setText(" ");
infoPanel.add(jPFlabel);
jPFlabel.setBounds(20, 90, 60, 16);
jPHlabel.setText(" ");
infoPanel.add(jPHlabel);
jPHlabel.setBounds(20, 110, 60, 16);
jTangentButton.setBorder(new javax.swing.border.CompoundBorder(null, new javax.swing.border.EtchedBorder()));
jTangentButton.setHorizontalTextPosition(SwingConstants.CENTER);
jTangentButton.setPreferredSize(new Dimension(74, 26));
jTangentButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jTangentButtonActionPerformed(evt);
}
});
infoPanel.add(jTangentButton);
jTangentButton.setBounds(40, 190, 50, 26);
jTangentLabel.setHorizontalAlignment(SwingConstants.CENTER);
jTangentLabel.setPreferredSize(new Dimension(74, 26));
jTangentLabel.setHorizontalTextPosition(SwingConstants.CENTER);
infoPanel.add(jTangentLabel);
jTangentLabel.setBounds(10, 150, 110, 26);
jSlopeValue.setPreferredSize(new Dimension(30, 16));
infoPanel.add(jSlopeValue);
jSlopeValue.setBounds(86, 220, 50, 16);
jSlopeLabel.setText(" ");
infoPanel.add(jSlopeLabel);
jSlopeLabel.setBounds(10, 220, 90, 16);
jApplications.setFont(new Font("Arial", Font.BOLD, 10));
jApplications.setText("APPLICATIONS");
jApplications.setHorizontalTextPosition(SwingConstants.CENTER);
jApplications.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jApplicationsActionPerformed(evt);
}
});
infoPanel.add(jApplications);
jApplications.setBounds(10, 460, 115, 23);
getContentPane().add(infoPanel, BorderLayout.WEST);
viewPanel.setBackground(new Color(204, 204, 204));
//ViewPanel viewPanel = new ViewPanel();
viewPanel.setBounds(10, 460, 500, 23);
viewPanel.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent evt) {
viewPanelMousePressed(evt);
}
public void mouseReleased(MouseEvent evt) {
viewPanelMouseReleased(evt);
}
public void mouseClicked(MouseEvent evt) {
viewPanelMouseClicked(evt);
}
public void mouseExited(MouseEvent evt) {
viewPanelMouseExited(evt);
}
public void mouseEntered(MouseEvent evt) {
viewPanelMouseEntered();
}
});
viewPanel.addMouseMotionListener(new MouseMotionAdapter() {
public void mouseMoved(MouseEvent evt) {
viewPanelMouseMoved(evt);
}
public void mouseDragged(MouseEvent evt) {
viewPanelMouseDragged(evt);
}
});
getContentPane().add(viewPanel, BorderLayout.CENTER);
y = 0;
} //GEN-END:Parabola()
private void jApplicationsActionPerformed(ActionEvent evt) {//GEN-FIRST:event_jApplicationsActionPerformed
applications = true;
proof = false;
tangent = false;
animation = false;
definition = false;
}//GEN-LAST:event_jApplicationsActionPerformed
private void jTangentButtonActionPerformed(ActionEvent evt) {//GEN-FIRST:event_jTangentButtonActionPerformed
if ("ON".equals(jTangentButton.getText())) {
proof = true;
tangent = true;
jTangentButton.setText("OFF");
} else if ("OFF" == jTangentButton.getText()) {
proof = false;
jTangentButton.setText("ON");
}
definition = false;
repaint();
}//GEN-LAST:event_jTangentButtonActionPerformed
private void viewPanelMouseMoved(MouseEvent evt) {//GEN-FIRST:event_viewPanelMouseMoved
}//GEN-LAST:event_viewPanelMouseMoved
private void viewPanelMouseEntered() {//GEN-FIRST:event_viewPanelMouseEntered
}//GEN-LAST:event_viewPanelMouseEntered
private void viewPanelMouseExited(MouseEvent evt) {//GEN-FIRST:event_viewPanelMouseExited
}//GEN-LAST:event_viewPanelMouseExited
private void viewPanelMouseClicked(MouseEvent evt) {//GEN-FIRjPHvalueST:event_viewPanelMouseClicked
}//GEN-LAST:event_viewPanelMouseClicked
private void startStopButtonActionPerformed(ActionEvent evt) {
this.evt = evt;//GEN-FIRST:event_startStopButtonActionPerformed
definition = false;
// Animate reflector
t = 400;
if ("ON" == startStopButton.getText()) {
k = 1;
b = -100;
px = false;
applications = false;
//timer.restart();
animation = true;
startStopButton.setText("OFF");
} else {
animation = false;
startStopButton.setText("ON");
}
jTangentButton.setText("ON");
proof = false;
tangent = false;
applications = false;
repaint();
}//GEN-LAST:event_startStopButtonActionPerformed
private void jProofButtonActionPerformed() {
jProofButtonActionPerformed();
}//GEN-LAST:event_jProofButtonActionPerformed
private void jProofButtonActionPerformed(ActionEvent evt) {//GEN-FIRST:event_jProofButtonActionPerformed
// Proof
proof = true;
b = 30;
px = true;
definition = false;
animation = false;
tangent = false;
applications = false;
isDraggingDot = false;
startStopButton.setText("ON");
jTangentButton.setText("ON");
jTangentLabel.setText("Tangent Line");
repaint();
}//GEN-LAST:event_jProofButtonActionPerformed
private void jResetButtonActionPerformed() {//GEN-FIRST:event_jResetButtonActionPerformed
// Plot Curve y^2=4px
b = 30;
px = true;
definition = true;
proof = false;
tangent = false;
animation = false;
applications = false;
startStopButton.setText("ON");
jTangentButton.setText("ON");
startStopButton.setText("ON");
repaint();
}//GEN-LAST:event_jResetButtonActionPerformed
private void viewPanelMouseDragged(MouseEvent evt) {//GEN-FIRST:event_viewPanelMouseDragged
new_x = evt.getX();
new_y = evt.getY();
if (!isDraggingDot) {
x2 = -evt.getX() + width / 2;
y2 = height / 2 + evt.getY();
b = 30;
}
// with Mouse change values of Focus x & y
if (isDraggingDot) {
{
if (new_y < height / 2 - 5 || new_y > height / 2 + 5) {
px = true;// Focus on y-axis
b = height / 2 - new_y;
} else {
px = false;//Focus on x-axis
b = (width / 2 - new_x);
}
}
}
// Lock focus on x-axis
if (animation) {
px = false;
b = width / 2 - new_x;
}
repaint();
evt.consume();
}//GEN-LAST:event_viewPanelMouseDragged
private void viewPanelMouseReleased(MouseEvent evt) {//GEN-FIRST:event_viewPanelMouseReleased
isDraggingDot = false;
repaint();
evt.consume();
}//GEN-LAST:event_viewPanelMouseReleased
private void viewPanelMousePressed(MouseEvent evt) {//GEN-FIRST:event_viewPanelMousePressed
definition = false;
if (!proof) {
// Get Mouse pointer's new x & y values
new_x = evt.getX();
new_y = evt.getY();
isDraggingDot = true;
} else {
isDraggingDot = false;
}
repaint();
evt.consume();
}//GEN-LAST:event_viewPanelMousePressed
private int y;
private int new_x;
private int new_y;
private int p;
private int b = 30;
private int k = 1;
private int t;
private int l;
private int width, height, i, y2, x2 = 100;
private boolean isDraggingDot = false, px = true, proof = false, animation = false;
private boolean tangent = false, applications = false, definition = true;
public class ViewPanel extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
// Get panel size in unit pixels
Rectangle r = getBounds();
height = r.height;
width = r.width;
// Move Cartesian X, Y coordinates to centre of panel
float centreX = r.width / 2;
float centreY = r.height / 2;
// Paint canvas
g.setColor(new Color(255, 255, 240));// Get new colour
g.fillRect(0, 0, r.width, r.height); // Canvas background colour
// Draw grid
int hlines = height / 10;
int vlines = width / 10;
Graphics2D g2d = (Graphics2D) g;
AffineTransform old = g2d.getTransform();
g2d.translate(centreX, centreY);
g.setColor(Color.lightGray);
for (int i = -hlines / 2; i <= hlines / 2; i++) {
g.drawLine(-width / 2, i * 10, width / 2, i * 10);
}
for (int i = -vlines; i <= vlines / 2; i++) {
g.drawLine(i * 10, height / 2, i * 10, -height / 2);
}
// Draw Y, X axis
g.setColor(Color.magenta);
g.drawLine(-width / 2, 0, width / 2, 0); // X axis
g.drawLine(0, height / 2, 0, -height / 2); // Y axis
// Instruction
g.setColor(Color.white);
g.setFont(new Font("Serif", Font.BOLD, 16));
g.fillRect(-250, -height / 2 + 15, 430, 20);
g.setColor(Color.red);
g.drawString("NOTE: ", -240, -height / 2 + 30);
g.drawString("Red Dots", 87, -height / 2 + 30);
g.setColor(Color.black);
g.drawString("Use Mouse Pointer to move", -175, -height / 2 + 30);
g.drawRect(-250, -height / 2 + 15, 430, 20);
if (definition) {
g.setColor(Color.white);
g.fillRect(-360, height / 2 - 175, 700, 140);
g.setColor(Color.black);
g.drawRect(-360, height / 2 - 175, 700, 140);
g.drawString("A locus of points is a collection of points that satisfies a given equation.", -355, height / 2 - 160);
g.drawString("A parabola is a collection of points (a locus) such that the moving locus", -355, height / 2 - 130);
g.drawString("point P(x,y) is always equidistant from the focus and the directrix.", -355, height / 2 - 115);
g.drawString("A focus is the point used to determine the parabola's openness and", -355, height / 2 - 85);
g.drawString("distance from the directrix.", -355, height / 2 - 70);
g.drawString("A directrix is a fixed line that serves as a guide in creating our parabola.", -355, height / 2 - 40);
g.fillOval(-x2 - 4, (int) -f(x2) - 4, 8, 8);
g.drawString(" P(x,y)", -x2 - 7, (int) -f(x2) - 5);
g.setColor(Color.blue);
g.drawString("Directrix", 155, b);
g.setColor(Color.red);
g.drawString("Focus", 4, -b - 4);
}
// ****** If mouse pressed, change colour on Focus dot?
if (isDraggingDot)
g.setColor(Color.orange);
else
g.setColor(Color.red);
int x1 = 0;
if (px) {
g.fillOval(x1 - 4, y - b - 4, 8, 8);// red dot Focus on y axis*
// Directrix
g.setColor(Color.blue);
g.drawLine(-150, b, 150, b);
}
g.setColor(Color.black);
g.setFont(new Font("Serif", Font.BOLD, 18));
for (int x = -200; x < 200; x++) {
if (px) {
g.drawLine(x, -(int) f(x), x + 1, -(int) f(x + 1));// Draw curve
if (b > 0) {// Focus above the X axis.....x^2=4py
g.setColor(Color.white);
g.fillRect(-30, -height / 2 + 75, 85, 20);
g.setColor(Color.red);
g.drawString("x\u00b2= 4py", -25, -height / 2 + 90);//x^2=4py
g.setColor(Color.black);
g.drawRect(-30, -height / 2 + 75, 85, 20);
} else {// Focus below the X axis.... x^2= -4py
g.setColor(Color.white);
g.fillRect(-30, height / 2 - 85, 88, 20);
g.setColor(Color.red);
g.drawString("x\u00b2= -4py", -25, height / 2 - 70);// x^2= -4py
g.setColor(Color.black);
g.drawRect(-30, height / 2 - 85, 88, 20);
}
} else {// px== false, draw y^2=-4px
g.setColor(Color.red);
g.fillOval(-b - 4, -4, 8, 8);// red dot (p) on x axis
// Directrix
g.setColor(Color.blue);
g.drawLine(b, -150, b, 150);
g.setColor(Color.black);
g.drawLine(-(int) f(x), x, -(int) f(x + 1), x + 1);// Draw curve
if (b < 0) {// Focus on left side of X origin
g.setColor(Color.white);
g.fillRect(width / 2 - 145, -25, 85, 20);
g.setColor(Color.red);
g.drawString("y\u00b2= 4px", width / 2 - 140, -10);// y^2=4px
g.setColor(Color.black);
g.drawRect(width / 2 - 145, -25, 85, 20);
} else {// Focus on right side of X origin
g.setColor(Color.white);
g.fillRect(-width / 2 + 55, -25, 85, 20);
g.setColor(Color.red);
g.drawString("y\u00b2= -4px", -width / 2 + 60, -10);// y^2=-4px
g.setColor(Color.black);
g.drawRect(-width / 2 + 55, -25, 85, 20);
}
}
}
g.setColor(Color.black);
g.setFont(new Font("Serif", Font.BOLD, 14));
g.drawString("Y", -12, -height / 2 + 50);
g.drawString("X", width / 2 - 20, -2);
//**************** PROOF **********************
if (proof && px) {
// The Focus(x,y) is locked but P(x,y) can be moved
g.setColor(Color.black);
// Draw line from P(x,y)to half distance from H to Ft, tangent to P(x,y)
g.drawLine(-x2, (int) -f(x2), -x2 / 2, 0);
DecimalFormat form1 = new DecimalFormat("0.0");
// Values of P (x,y)
g.drawString("P(" + form1.format((float) -x2 / 10) + "," + (form1.format(f(x2) / 10)) + ")", -x2 - 5, (int) -f(x2) - 5);
g.setColor(Color.red);
g.drawLine(-x2, (int) -f(x2), -x2, b - 4);// Draw line from directrix H(x,-b)
g.drawLine(0, -b, -x2, (int) -f(x2));// Draw line from Focus to Point(x,y)
g.fillOval(-x2 - 4, (int) -f(x2) - 4, 8, 8);// Draw oval at P(x,y)
g.setColor(Color.magenta);
g.fillOval(y - 4, x1 - b - 4, 8, 8);// Draw oval at Focus
g.fillOval(-x2 - 3, b - 4, 8, 8);// Draw oval at H(x,-b)
// *********Display proof************************************
g.setColor(Color.black);
double k = Point2D.distance(-x2, (int) -f(x2), -x2, b);// Distance from Directrix to P
double k2 = Point2D.distance(0, -b, -x2, (int) -f(x2));// Distance from Focus to P
//double k3 = Point2D.distance(0, -b - 4, -x2, b + 4);// Distance from Focus to H
// double h = Math.sqrt(k2 * k2 - k3 * k3 / 4);
double slope = (k - b) / (x2 / 2);
jPFlabel.setText("P\u2192 F= ");// P (unicode symbol right arrow) F=
jPFvalue.setText(String.valueOf((int) k / 10));// Display distance value
jPHlabel.setText("P\u2192 H= ");// P (unicode symbol right arrow) H=
jPHvalue.setText(String.valueOf((int) k2 / 10));
// Describe the Parabola
if (!tangent) {
g.setColor(Color.white);
g.fillRect(-250, 80, 500, 160);
g.setColor(Color.lightGray);
g.drawLine(-x2, b, 0, -b);
g.setColor(Color.black);
g.drawRect(-250, 80, 500, 160);
g.drawString("Focus(a,p)", 4, -b - 4);
g.drawString("H(x,-p)", -x2, b + 10);
g.drawString("Directrix", 130, b - 8);
g.setColor(Color.red);
g.drawString("PARABOLA", -245, 100);
g.setColor(Color.black);
g.drawString("The properties: ", -150, 100);
g.drawString("The distances from a point P on the parabola to the focus F", -245, 115);
g.drawString("or to a point H on the directrix are the same \u2234 P\u2192F=P\u2192H.", -245, 130);
g.drawString("Let the coordinates of F, P and H be (a,p), (x,y) and (x,-p).", -245, 145);
g.drawString("Since P \u2192 F=P \u2192 H \u2234 (x-a)\u00B2 + (y-p)\u00B2 = (y+p)\u00B2", -245, 175);
g.drawString("In this case the vertex is at the origin (0,0) therefore a=0", -245, 190);
g.drawString(" and p is equal to the distance of F from the origin.", -245, 205);
g.drawString("The equation of parabola is:y=x\u00B2/4p or x\u00b2=4py", -245, 225);
}
// ********Draw moving tangent. Calculate coordinates********
else {
//if(tangent is true, draw tangent line
double theta = Math.atan2(k - b, x2 / 2);// Calculate angle in radian of tangent line
g.setColor(new Color(0, 130, 130));
int temp = 180 - (int) Math.toDegrees(theta);// Slope
g.fillArc(-x2 / 2 - 13, -13, 26, 26, 0, temp);
g.drawString("\u03b8", -x2 / 2, -15);
g.setFont(new Font("Serif", Font.BOLD, 16));
g.setColor(Color.black);
g.drawString("Angle \u03b8 (" + temp + "\u00b0) = the slope of the tangent line in degrees", -150, b + 20);
double x4 = -x2 + (100 * Math.cos(Math.PI - theta));// Tangent extension line above P(x,y)
double y4 = -(int) f(x2) - (100 * Math.sin(Math.PI - theta));
g.drawLine(-x2, -(int) f(x2), (int) x4, (int) y4);//
g.setFont(new Font("Serif", Font.BOLD, 14));
double x5 = -x2 + (1000 * Math.cos(2 * Math.PI - theta));// Tangent extension below P(x,y)
double y5 = -(int) f(x2) - (1000 * Math.sin(2 * Math.PI - theta));
g.drawLine(-x2, -(int) f(x2), (int) x5, (int) y5);
jSlopeLabel.setText("Slope m = ");
DecimalFormat form2 = new DecimalFormat("0.000");
jSlopeValue.setText(String.valueOf(form2.format(-slope)));
g.setColor(Color.red);
g.fillRect(-90, b + 22, 30, 4);
g.setColor(Color.white);
g.fillRect(-250, 180, 450, 60);
g.setColor(Color.black);
g.drawString("TANGENT - The line with slope m at P(x,y):", -240, 200);
g.drawString("The equation for the tangent line is y=mx+b", -240, 215);
g.drawString("where b=p/m, p= distance from origin to the Focus", -240, 230);
g.drawRect(-250, 180, 450, 60);
}
}
// if(!proof) clear values
else {
jPFvalue.setText("");
jPFlabel.setText(" ");
jPHvalue.setText("");
jPHlabel.setText(" ");
jSlopeValue.setText("");
jSlopeLabel.setText(" ");
jTangentButton.setText("");
jTangentLabel.setText("");
}
repaint();
// ***************************************
t = 100; // Timer interval
if (animation) { // Used in reflector....
if (b <= 0) {
g.setColor(Color.black);
// draw reflector lines
for (i = -200; i <= 200; i += 40) {
g2d.draw(new Line2D.Double(centreX, i, -(int) f(i), i));
g2d.drawLine(-b, 0, -(int) f(i), i);
g2d.setStroke(new BasicStroke(3.0f));
g2d.draw(new Line2D.Double(centreX - 700 - (int) f(i), i, centreX - 690 - (int) f(i), i + 6));// Arrows
g2d.draw(new Line2D.Double(centreX - 700 - (int) f(i), i, centreX - 690 - (int) f(i), i - 6));
g2d.setStroke(new BasicStroke(2.0f));
repaint();
}
}
else // b> 0
{
centreX = -centreX;
for (i = -200; i <= 200; i += 40) {
g2d.draw(new Line2D.Double(centreX, i, -(int) f(i), i));
g2d.drawLine(-b, 0, -(int) f(i), i);
g2d.setStroke(new BasicStroke(3.0f));
g2d.draw(new Line2D.Double(centreX + 700 - (int) f(i), i, centreX + 690 - (int) f(i), i + 6));
g2d.draw(new Line2D.Double(centreX + 700 - (int) f(i), i, centreX + 690 - (int) f(i), i - 6));
g2d.setStroke(new BasicStroke(2.0f));
}
}
g.setColor(Color.red);
g.fillOval(-b - 4, -4, 8, 8);// Focus red dot
}
// Enter list of applications using the parabolic shapes
if (applications) {
g2d.setTransform(old);
g.setColor(new Color(255, 255, 240));// Get new colour
g.fillRect(0, 0, width, height);
g.setColor(Color.black);
g.drawString("APPLICATIONS", 210, 30);
g.drawString("Parabolic dishes to receive satellite signals for radio and television.", 40, 60);
g.drawString("Parabolic reflectors in car headlights.", 40, 80);
g.drawString("Parabolic structures in bridges.", 40, 100);
g.drawString("Parabolic dome in large buildings such as arenas.", 40, 120);
g.drawString("Parabolic mirrors in telescopes.", 40, 140);
g.drawString("Parabolic curve of flight.", 40, 160);
}
}
}
// Responds to Timer's event
private final ActionListener timerListener = new ActionListener() {
public ActionEvent getActionEvent() {
return actionEvent;
}
private ActionEvent actionEvent;
public void actionPerformed(ActionEvent actionEvent) {
this.actionEvent = actionEvent;
k++;
if (k > (int) 24) {
timer.stop();
}
}
};
public void actionPerformed(ActionEvent actionEvent) {
this.actionEvent = actionEvent;
// Start time for reflector
if (animation) {
if (timer == null) {
start();
} else
timer.stop();
}
}
private void start(){
if(timer==null){
timer=new Timer(t,timerListener);
timer.start();
}
else timer.restart();
}
public void stopAnimation(){
if(timer!=null){
timer = null;
}
}
private double f(double x) {// Function x and y calculation
return -(x*x/(-4*b));
}
public static void main(String[] args) {
JFrame frame;
frame = new Parabola (); //"Parabola by Guy Lemire, 2004, rev. 2018"
frame.setSize ( 2000,1000 );
frame.setVisible(true); // usual step to make frame visible
}
// Variables declaration - do not modify//GEN-BEGIN:variables
private JLabel jSlopeValue;
private JLabel jPHvalue;
private JButton jTangentButton;
private JButton startStopButton;
private JLabel jPFlabel;
private JLabel jPFvalue;
private JLabel jSlopeLabel;
private JLabel jPHlabel;
private JLabel jTangentLabel;
// End of variables declaration//GEN-END:variables
}