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applet with 2 panels with cardLayout, need to pass parameter from p1 to p2

2 replies on 1 page. Most recent reply: Oct 10, 2004 8:25 AM by Tienshan

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Tienshan

Posts: 7
Nickname: tienshan
Registered: Oct, 2004

applet with 2 panels with cardLayout, need to pass parameter from p1 to p2

Posted: Oct 9, 2004 12:29 PM

Hi All!


I have an applet with two panels, A110 and A150, set up with card layout. A110 and A150 are instantiated (from separate classes) and added in that order in the applet. I need to pass some parameters from A110 to A150 and do certain things (like make a textField editable, etc.) with the received parameter.


For example, A110 has 2 buttons, btnUpdate and btnDisplay. When I call the applet A110Main, the first child (A110) is displayed. With a click on any button, I can switch to the second child(A150).


I want to make the textField of A150 editable when I click btnUpdate.


I don't know how to do it because panel A150 has already been created (just not shown )with initial paramers from the applet(A110Main). How do I gain access to the second child's components from the first child? How do I repaint the component, to make it editable? Do I have a design flaw from the very beginning? At the very least, I do need to have two panels and control one panel from the other.


Does anyone have some suggestion?


Thanks.


Here is my code

<pre>
import java.applet.Applet;
import java.awt.*;

public class A110Main extends Applet {

Container cont = null;
CardLayout clayout = null;
Panel cpanel = null;

A110 p110 = null;
A150 p150 = null;

String dispString = "I am non-editable";

public void init() {

clayout = new CardLayout();
cpanel = new Panel();
cpanel.setLayout(clayout);

p110 = new A110();
Panel jp1 = (Panel)p110.showPage( cpanel);

p150 = new A150(dispString);
Panel jp2 = (Panel)p150.showPage( cpanel );

cpanel.add("1",jp1);
cpanel.add("2",jp2);

add(cpanel);

this.setBackground(Color.lightGray);

}

}

import java.awt.*;
import java.awt.event.*;

public class A110 {

public A110 () {}

Button btnUpdate;
Button btnDisplay;
Panel cPanel;

public Component showPage(Panel _cPanel) {

this.cPanel = _cPanel;

Panel p110 = new Panel();
p110.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
p110.setBackground(Color.lightGray);

btnUpdate = new Button("Update");
c.gridx = 0;
c.gridy = 0;
c.gridwidth = 2;
p110.add(btnUpdate, c);

btnUpdate.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e){

((CardLayout)cPanel.getLayout()).next(cPanel);

}
});

Button btnDisplay = new Button("Display Only");
c.gridx = 2;
c.gridy = 0;
p110.add(btnDisplay, c);

btnDisplay.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e){
((CardLayout)cPanel.getLayout()).next(cPanel);
}
});

return p110;

}

}

import java.awt.*;
import java.awt.event.*;

public class A150 {

String displayString = "";

public A150 (String _displayString) {
this.displayString = _displayString;

}

public Component showPage(Panel _cPanel) {

Panel p150 = new Panel();
p150.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
p150.setBackground(Color.lightGray);

final Panel cPanel = _cPanel;

Button btnBack = new Button("Back");
c.gridx = 0;
c.gridy = 0;
p150.add(btnBack, c);

btnBack.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e){
((CardLayout)cPanel.getLayout()).next(cPanel);
}
});

Label lblDummy = new Label();
c.gridx = 1;
c.gridy = 0;
c.gridwidth = GridBagConstraints.REMAINDER;
p150.add(lblDummy, c);

TextField txtDisp = new TextField(40);
c.gridx = 0;
c.gridy = 2;
p150.add(txtDisp, c);

txtDisp.setText(displayString);
txtDisp.setEditable(false);

return p150;

}

}

</pre>

Tienshan

Posts: 7
Nickname: tienshan
Registered: Oct, 2004

Re: applet with 2 panels with cardLayout, need to pass parameter from p1 to p2

Posted: Oct 9, 2004 12:37 PM

I messed the formatting and I am sorry. It did look alright when I previewed it. Believe me! In fact, when I put [pre][(slash pre], the square brackets, it didn't look alright, everything was like flowlayout!! A firm believer in WYSWYG, I am embarassed!

Tienshan

Posts: 7
Nickname: tienshan
Registered: Oct, 2004

Re: applet with 2 panels with cardLayout, need to pass parameter from p1 to p2

Posted: Oct 10, 2004 8:25 AM


Hello All!

Two answers have been proposed by paulcw, 74philip and Michael_Dunn and both work fine.


First proposal:
(1)pass a reference to class A150 instance, so A110 instance can access fields in class A150.
A110 p110 = new A110(p150);

(2) inside my actioListner of btnAdd
a150.txtDisp.setEditable(true);

Second proposal:

(1) inside my actioListner of btnAdd
((A110Main)cPanel.getParent()).p150.txtDisp.setEditable(true);

Thank you paulcw, 74philip and Michael_Dunn and all for reading my post.

Best of Octobers,
tienshan.

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