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I have a JApplet which has to display 3 Components. (2 JPanels and 1 Paint Method)

Matthewborg
P: 2
I have an assignment in which I have to allow a user to plot a graph using a quadratic equation.

I managed to draw the skeleton of the graph, and now I am trying to display the "control panel" for the user to input the values.

I have 4 files:

graph.java
panel.java
panelB.java
panelC.java
My problem is when I run the code it is displaying only the panel.java even in the container where it should display the other two panels.

Code

graph.java

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import javax.swing.*;

public class graph extends JApplet{

public void init(){

Container conn = getContentPane();
conn.setLayout(new BorderLayout());

panel p = new panel();//graph
p.setPreferredSize(new Dimension(460,560));
conn.add(p,BorderLayout.CENTER);
p.setVisible(true);

panel a = new panel();//vertical
a.setPreferredSize(new Dimension(10,50));
conn.add(a,BorderLayout.NORTH);
a.setVisible(true);

panel b = new panel();//horizontal
b.setPreferredSize(new Dimension(201,50));
conn.add(b,BorderLayout.SOUTH);
b.setVisible(true);
}
}
panel.java

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.*;
import java.awt.geom.*;
import javax.swing.JPanel;


public class panel extends JPanel {

public panel(){
this.setBackground(Color.yellow);
}

public void paint(Graphics p) {

super.paintComponent(p);

Graphics2D graph = (Graphics2D)p;

Dimension appletSize = this.getSize();
int appletHeight = (int)(appletSize.height);
int appletWidth = appletSize.width;

this.setBackground(Color.yellow);//set background color.

int x,y,y1,x1,a,b,p1x,p1y,p2x,p2y;

//line co-ordinates
//the numbers represent the number of boxes on the graph
int xstart = 7;
int ystart = 1;

int xfinish = 3;
int yfinish = 9;

//other variables
int i = 0;
int i2 = 0;
int m = 0;
int n = 0;
int m2 = 0;
int n2 = 0;
int f2 = 0;
int g2 = 1;

//ranges
int f = 5;
int g = -5;

//change -ve num to +ve
int g3 = Math.abs(g);

int a1 = g3 + f;
int b1 = a1;

y1 = (appletHeight);
x1 = (appletWidth);
y = (appletHeight / 2);
x = (appletWidth / 2);
a = (appletWidth / a1);
b = (appletHeight / b1);

int d = (appletWidth / a1);
int e = (appletHeight / b1);

/**
to determine the
ammount of pixles there
is in each box of the
graph, both y-axis and
x-axis
*/
int xbox = x1 / 10;
int ybox = y1 / 10;

//line variables
//the xstart, ystart, etc represent the number of boxes

//top point of the line on the graph
p1x = xbox * xstart;//start x
p1y = ybox * ystart;//start y

//lowwer point of the line on the graph
p2x = xbox * xfinish;//finish x
p2y = ybox * yfinish;//finish y

//draw y-axis numbers
//(+ve)
while(f != 0){
String s = String.valueOf(f);
p.drawString(s,(x + 5),m + 13);
m = m + b;
f = f - 1;
}
//(-ve)
m2 = y;
while(f2 != g-1){
String u = String.valueOf(f2);
p.drawString(u,(x + 5),m2 - 3);
m2 = m2 + b;
f2 = f2 - 1;
}
//draw x-axis numbers.
//(-ve)
while(g != 0){
String t = String.valueOf(g);
p.drawString(t,n,y - 5);
n = n + a;
g = g + 1;
}
//(+ve)
n2 = x + a;
while(g2 != g3+1){
String vw = String.valueOf(g2);
p.drawString(vw,n2 -10,y - 5);
n2 = n2 + a;
g2 = g2 + 1;
}

BasicStroke aLine2 = new BasicStroke(1.0F,
BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
graph.setStroke(aLine2);

//notch on numbers and grid lines
//left to right, top to bottom notches
int v2 = -5;
int v5 = 0;
while(i <= a1-1){
p.setColor(Color.lightGray);//lightgray line
p.drawLine(a,0,a,y1);//vertical lightgray
p.drawLine(0,b,x1,b);//horizontal lightgray
a = a + d;
b = b + e;
i = i + 1;
}
//notches
while(i2 <= a1){
p.setColor(Color.blue);//notch color
p.drawString("x",v2+2,y+3);//xaxis
p.drawString("x",x-4,v5+4);//yaxis
v5 = v5 + e;
v2 = v2 + d;
i2 = i2 + 1;
}

//draws the border of the graph
p.setColor(Color.black);
Rectangle2D.Float rect = new Rectangle2D.Float(0,0,x1,y1);
BasicStroke aLine = new BasicStroke(2.5F,
BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
graph.setStroke(aLine);
graph.draw(rect);

//draw cross
BasicStroke aLine3 = new BasicStroke(2.5F,
BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
graph.setStroke(aLine3);
p.drawLine(x,0,x,y1); //vertical line
p.drawLine(0,y,x1,y); //horizontal line

//display the value of graph width and graph height
String aw = String.valueOf(x1);
p.drawString("Graph Width = ", 50,90);
p.drawString(aw,150,90);
p.drawString("Graph Height = ", 50,110);
String ah = String.valueOf(y1);
p.drawString(ah,156,110);

//draw line on graph

BasicStroke aLine4 = new BasicStroke(1.5F,
BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
graph.setStroke(aLine4);
p.setColor(Color.red);

if(p1x <= x1 && p2x <= x1 && p1y <= y1 && p2y <= y1){
p.drawLine(p1x,p1y,p2x,p2y);
Color c = new Color(0,0,0);
p.setColor(c);
p.drawString("X", p1x-4,p1y+4);
p.drawString("X", p2x-4,p2y+4);
}
else{
p.setColor(Color.black);
p.drawRect(48,34,223,35);
p.setColor(Color.white);
p.fillRect(49,35,222,34);
p.setColor(Color.red);
p.drawString("Wrong co-ordinates!!!", 50,50);
p.drawString("Values exceede applet dimensions.", 50,65);
}
}
}

// 6 variables the user has to input
// A,B,C,D - CO-EFFICIENTS
// RANGE (EX: -5 - 5)
panelB.java

import javax.swing.*;
import java.awt.*;
import javax.swing.JPanel;


public class panelB extends JPanel{

public panelB (Box a) {

a = Box.createVerticalBox();
a.add(new JLabel("Please enter the values below:"));
a.add(new JLabel("a"));
JTextField g1 = new JTextField("0.0");
g1.setMaximumSize(new Dimension(100,30));
a.add(g1);
a.add(new JLabel("b"));
JTextField g2 = new JTextField("0.0");
g2.setMaximumSize(new Dimension(100,30));
a.add(g2);
a.add(new JLabel("c"));
JTextField g3 = new JTextField("0.0");
g3.setMaximumSize(new Dimension(100,30));
a.add(g3);
a.add(new JLabel("d"));
JTextField g4 = new JTextField("0.0");
g4.setMaximumSize(new Dimension(100,30));
a.add(g4);
a.add(new JButton("Plot"));
a.add(new JButton("Refine"));
}
}
panelC.java

import javax.swing.*;
import javax.swing.JPanel;
import java.awt.Dimension;

public class panelC extends JPanel{

public void init (Box b) {

b = Box.createHorizontalBox();
b.add(new JLabel("a"));
JTextField f1 = new JTextField("0.0");
f1.setMaximumSize(new Dimension(100,30));
b.add(f1);
b.add(new JLabel("b"));
JTextField f2 = new JTextField("0.0");
f2.setMaximumSize(new Dimension(100,30));
b.add(f2);
b.add(new JLabel("c"));
JTextField f3 = new JTextField("0.0");
f3.setMaximumSize(new Dimension(100,30));
b.add(f3);
b.add(new JLabel("d"));
JTextField f4 = new JTextField("0.0");
f4.setMaximumSize(new Dimension(100,30));
b.add(f4);
b.add(new JButton("Plot"));
b.add(new JButton("Refine"));

}
}
Jun 16 '12 #1
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