Develop Reference

Access difficulty with ArrayList of panels with buttons

my question is: how do I get the object of my CustomPanel, so that I am able to access its fields (because in my real programm I have some more fields in there) and also am able to delete it from my ArrayList?
I don't know how I have to implement an ActionListener in the Class Window, to somehow get the Object in my Arraylist, which containes the button that got pressed.
Also I am wondering if I am somehow able to implement an ActionListener in the Class CustomPanel which can influence the behaviour of the Object which is an instance of my Class Window.
I have kind of the following code:
public class Window extends JFrame{
ArrayList<CustomPanel> aLCustomPanel = new ArrayList();
JPanel jp = new JPanel();
public Window() {
for(int i=0;i<5;i++){
aLCustomPanel.add(new CustomPanel());
//here I could put the code from the 1 edit - see below
jp.add(aLCustomPanel.get(i));
}
this.add(jp);
}
public static void main(String args[]){
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Window().setVisible(true);
}
});
}
}
class CustomPanel extends JPanel {
private JButton button;
public CustomPanel(){
button = new JButton("button");
this.add(button);
}
public JButton getButton(){
return this.button;
}
}
my Code is much longer and weirder, so I tried to extract the (for this question) importing things.
Thanks for any help in advance!
edit:
for example: I would like to delete the object from the ArrayList, of which the button got pressed.
//imagine this comment in above code
aLCustomPanel.get(aLCustomPanel.size()-1).getButton().addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button_IwantToDeleteYou(e); //here I want to remove the panel, containing the button that got pressed from the above ArrayList, which is located in Class Window
}
});
edit2:
added a missing bracket and fixed some mistakes, code should be ok now.

Your code contained a few "gaps", i.e. missing code, which I filled in, as follows:
Added calls to [JFrame] methods setDefaultCloseOperation() and pack() and setLocationByPlatform(). I suggest you refer to the javadoc for those methods in order to understand what they do.
I set a layout manager for jp class member variable in your Window class.
Yes, you need to register an ActionListener with the JButton in class CustomPanel and that listener should reside in your Window class - the one that extends JFrame.
Here is my rewrite of your code. Note that I changed the name of class Window to CusPanel so as to distinguish between your class and java.awt.Window class. Not that it makes a difference, I just prefer not to use names of classes from the JDK.
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
public class CusPanel extends JFrame implements ActionListener {
private static final int COUNT = 5;
private ArrayList<CustomPanel> aLCustomPanel = new ArrayList<>();
private JPanel jp = new JPanel(new GridLayout(0, COUNT));
public CusPanel() {
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
for (int i = 0; i < COUNT; i++) {
aLCustomPanel.add(new CustomPanel(this));
// here I could put the code from the 1 edit - see below
jp.add(aLCustomPanel.get(i));
}
this.add(jp);
pack();
setLocationByPlatform(true);
}
public void actionPerformed(ActionEvent actionEvent) {
Object source = actionEvent.getSource();
if (source instanceof JButton) {
JButton button = (JButton) source;
Container parent = button.getParent();
jp.remove(parent);
jp.invalidate();
jp.repaint();
pack();
// aLCustomPanel.remove(parent); <- optional
}
}
public static void main(String args[]) {
EventQueue.invokeLater(new Runnable() {
public void run() {
new CusPanel().setVisible(true);
}
});
}
}
class CustomPanel extends JPanel {
private JButton button;
public CustomPanel(ActionListener parent) {
button = new JButton("button");
button.addActionListener(parent);
this.add(button);
}
public JButton getButton() {
return this.button;
}
}
Note that after removing a CustomPanel, the GUI components need to be laid out again and the JFrame should also be resized accordingly. Hence in the actionPerformed() method, I call invalidate(), then repaint() and then pack(). I also think that if you remove a CustomPanel from the GUI, you should also remove it from the ArrayList, but hey, I still don't understand why you want to do this although I obviously don't know the whole story behind you wanting to do this in the first place.
Of-course, since each button (and each CustomPanel) looks exactly the same, you can't really know which button was removed. Again, I assume you see the big picture whereas I don't.

How to call a panel from a button with ActionListener

So I'm making a simple program that jumps from panel to panel and am using an actionlistener Button to make the jump. What kind of method or operation do I use to jump from panel to panel?
I tried to use setVisible(true); under the action listener, but I get just a blanks screen. Tried using setContentPane(differentPanel); but that doesn't work.
ackage Com.conebind.Characters;
import Com.conebind.Tech.TechA16;
import Com.conebind.Overviews.OverviewA16;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Char_A16 extends JFrame {
private JButton combosButton16;
private JButton techButton16;
private JButton overviewButton16;
private JLabel Image16;
private JPanel panel16;
private JPanel panelOverviewA16;
public Char_A16() {
overviewButton16.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
OverviewA16 overview16 = new OverviewA16();
overview16.setVisible(true);
overview16.pack();
overview16.setContentPane(new Char_A16().panelOverviewA16);
}
});
techButton16.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
//Todo
}
});
}
private void createUIComponents(){
Image16 = new JLabel(new ImageIcon("Android 16.png"));
}
public static void main (String[] args){
JFrame frame = new JFrame("Android 16");
frame.setContentPane(new Char_A16().panel16);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);}
}
The setContentPane(OverviewA16) doesn't work because there's not an object that defines the panel.

Please check this demo project showing how to use CardLayout with IntelliJ IDEA GUI Designer.
The main form has a method that switches between 2 forms displayed inside it:
public void showPanel(String id) {
final CardLayout cl = (CardLayout) cardPanel.getLayout();
cl.show(cardPanel, id);
}
Both forms are added to the card layout during the main form initialization:
FormOne one = new FormOne();
one.setParentForm(this);
cardPanel.add(one.getPanel(), FORM_ONE);
FormTwo two = new FormTwo();
two.setParentForm(this);
cardPanel.add(two.getPanel(), FORM_TWO);
final CardLayout cl = (CardLayout) cardPanel.getLayout();
cl.show(cardPanel, FORM_ONE);
A reference to the main parent form is passed to these 2 forms using setParentForm() method so that FormOne and FormTwo classes can access the showPanel() method of the MainForm.
In a more basic case you may have a button or some other control that switches the forms
located directly on the MainForm, then you may not need passing the main form reference to the subforms, but it can be still useful depending on your app logic.

java swing it doesn't without system.out.println

Hello so i started learning java a week back and i basically started making a gui just to see how things work and i found a weird "bug" or i don't exactly understand how things work and it's not even a bug
i have a class called startPanel that makes a panel that is visible from the start
and it asks you as to what you wish to log in admin,user or a guest
this is startPanel:
package library;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
/*
* this panel is responsible for the first opening panel and redirects you to your panel
*
*
*/
import javax.swing.*;
public class startPanel extends JFrame {
boolean adminState=false;
boolean userState=false;
boolean guestState=false;
JButton adminBut,userBut,guestBut ;
//start of constructor
public startPanel(){
//frame size,close when pressing x,title,and spawn at middle of the screen
this.setSize(500,500);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("Welcome guest");
this.setLocationRelativeTo(null);
//making the panel
JPanel panel1 = new JPanel();
//making a label to fill things up it doesn't really do anything
JLabel startLabel = new JLabel("you wan't to log in as...");
//3 buttons for the user to click 1 only and the according frame will show up
adminBut = new JButton("Admin");
userBut = new JButton("User");
guestBut = new JButton("Guest");
//making an event handler for admin only so far just for test purposes
ListenForButton lForButton = new ListenForButton();
adminBut.addActionListener(lForButton);
//adding comps to the panel
panel1.add(startLabel);
panel1.add(adminBut);
panel1.add(userBut);
panel1.add(guestBut);
//adding the panel to the frame
this.add(panel1);
} // end of startPanel constructor
private class ListenForButton implements ActionListener {
#Override
public void actionPerformed(ActionEvent event) {
/*probably not the correct way to do what i want to but just figured this might work
*it only works for admin button if the user presses the adminBut
*it will change the states and with a getter we can change each state
*from main accordingly
*/
if (event.getSource() == adminBut ){
adminState=true;
guestState=false;
userState= false;
}
}
} // end of Listen for button
//all getters for the states
public boolean getAdminState(){
return adminState;
}
public boolean getUserState(){
return guestState;
}
public boolean getGuestState(){
return userState;
}
}
this is main :
package library;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class mainLibrary {
public static void main(String[] args) {
adminPanel adminP = new adminPanel();
userPanel userP = new userPanel();
startPanel gui = new startPanel();
gui.setVisible(true);
while(true){
System.out.println(gui.getAdminState());
if (gui.getAdminState() == true) {
gui.setVisible(false);
userP.setVisible(true);
}
}
the problem now is that if i remove System.out.println(gui.getAdminState());
this does not work it doesn't even get in the if at all if it's false at start
if i don't remove it works correctly :/
so what is going on
this is adminPanel for the adminPanel if it matters
package library;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class adminPanel extends JFrame {
//start of adminPanel constructor
public adminPanel(){
//frame size,close when pressing x,title,and spawn at middle of the screen
this.setSize(500,500);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("Admin panel area");
this.setLocationRelativeTo(null);
JPanel panel1 = new JPanel();
this.add(panel1);
} //end of admin constructor
}

This is not a good GUI design. Never use such active loop.
Remarks: use standard naming convention (uppercase/lowercase), and never call a frame a panel (this is too confusing).
A better design would be to have references to Panels to be activated in the startPanel and setting appropriate property reacting to button actions. Something like:
class StartFrame extends JFrame implements ActionListener {
private JFrame adminFrame;
private JFrame userFrame;
...
// add construtor to initialize adminFrame and userFrame appropriately
...
public void actionPerformed(ActionEvent e) {
if (e.getSource() == adminBut) {
this.setVisible(false);
adminFrame.setVisible(true);
}
if (e.getSource() == userBut) {
this.setVisible(false);
userFrame.setVisible(true);
}
}
}

Change attribute in other jframe when a button is clicked in another JFrame

I have 2 jframes, 1 is kinda like the main menu, i want an attribute to change in the level jframe when a button is pressed so i tried:
SpeelVeld frame = new SpeelVeld();
frame.level = 1;
System.out.println(frame.level);
I used the sout to see what really happens because it wasnt working, but i see that the level goes from 0 to 1 back to 0 and goes on and on, does someone know why and how to fix?
SpeelVeld frame = new SpeelVeld();
frame.setBounds(0,0,519,591);
frame.setLocationRelativeTo(null);
frame.getContentPane().setBackground(Color.WHITE);
frame.setTitle("RWINA");
frame.setVisible(true);
frame.setLevel(1);
this is in the main method of my original GameProject file.
How can i make a jdialog

I have 2 jframes, 1 is kinda like the main menu,
You shouldn't use 2 JFrames for this. The dependent sub-window, likely your main menu window, should in fact be a JDialog, probably a non-modal dialog from the looks of it.
I want an attribute to change in the level jframe when a button is pressed so i tried:
SpeelVeld frame = new SpeelVeld();
frame.level = 1;
System.out.println(frame.level);
and here's a big problem. Understand that in this code, you're creating a new SpeelVeld object, the stress being on the word new. Changing the state of this object will have no effect on the other SeelVeld object that is currently being displayed. Do do that, your second window will need a valid reference to the displayed SeelVeld object. How to do this will depend all on code not yet shown, but often it can be done simply by passing in the displayed SpeelVeld object into the main menu object by use of a constructor parameter or setter method.
For example:
import java.awt.Dialog.ModalityType;
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
// JPanel for our main GUI
public class SpeelVeldFoo {
private static void createAndShowGui() {
// JPanel used by the main JFrame
SpeelVeldPanel speelVeldPanel = new SpeelVeldPanel();
// JPanel used by the main menu JDialog. Pass the above into it
MainMenuPanel mainMenuPanel = new MainMenuPanel(speelVeldPanel);
// create your JFrame
JFrame frame = new JFrame("Speel Veld");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(speelVeldPanel); // add the JPanel
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
// create your non-modal JDialog
JDialog menuDialog = new JDialog(frame, "Main Menu", ModalityType.MODELESS);
menuDialog.add(mainMenuPanel); // add the JPanel that holds its "guts"
menuDialog.pack();
menuDialog.setLocationByPlatform(true);
menuDialog.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
createAndShowGui();
});
}
}
#SuppressWarnings("serial")
class SpeelVeldPanel extends JPanel {
private int level = 1; // simple example just has a level int
private JLabel levelLabel = new JLabel("1"); // and displays it in a JLabel
public SpeelVeldPanel() {
add(new JLabel("Level:"));
add(levelLabel);
int ebGap = 50;
setBorder(BorderFactory.createEmptyBorder(ebGap, 2 * ebGap, ebGap, 2 * ebGap));
}
public int getLevel() {
return level;
}
public void setLevel(int level) {
// whenever level is changed, update the display
this.level = level;
levelLabel.setText(String.valueOf(level));
}
}
// class for the JPanel held by the JDialog
#SuppressWarnings("serial")
class MainMenuPanel extends JPanel {
private JSpinner levelSpinner = new JSpinner(new SpinnerNumberModel(1, 1, 5, 1));
private SpeelVeldPanel speelVeldPanel = null; // reference to the main GUI
// note the parameter.... you pass in the displayed main GUI so you can
// change it
public MainMenuPanel(final SpeelVeldPanel speelVeldPanel) {
this.speelVeldPanel = speelVeldPanel; // set the field
// respond when the spinner's data changes
levelSpinner.addChangeListener(new LevelListener());
add(new JLabel("Set the Speel Veld's level:"));
add(levelSpinner);
int ebGap = 10;
setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap, ebGap, ebGap));
}
private class LevelListener implements ChangeListener {
#Override
public void stateChanged(ChangeEvent e) {
// when the spinner's data changes
int level = (int) levelSpinner.getValue(); // get the data
speelVeldPanel.setLevel(level); // and send it to the main GUI
}
}
}
You'll note that I don't like extending JFrame or JDialog if I can avoid it. My feeling is that one can paint oneself into a corner by having your class extend JFrame, forcing you to create and display JFrames, when often more flexibility is called for. More commonly your GUI classes will be geared towards creating JPanels, which can then be placed into JFrames or JDialogs, or JTabbedPanes, or swapped via CardLayouts, wherever needed. This will greatly increase the flexibility of your GUI coding.

You probably want the JFrame to be the top-level container, then have a JPanel that holds your menu. The menu could be whatever you want, I'm using a JTextArea. Then, you need a JButton for the JPanel or JFrame that when pressed, changes the text in the JTextArea. Here is an implementation that you could work from. I'm using the ActionEvent as the trigger for when to mess with the JTextArea:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
public class SimpleSwing {
public static void main(String[] args) {
JFrame mainFrame = new JFrame();
JPanel mainMenuPanel = new JPanel();
JTextArea textAttribute = new JTextArea("Original Text");
JButton changeAttributeButton = new JButton("Change Attribute");
changeAttributeButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
textAttribute.setText("Whatever new text you want");
}
});
mainMenuPanel.add(textAttribute);
mainMenuPanel.add(changeAttributeButton);
mainFrame.add(mainMenuPanel);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.setSize(500, 500);
mainFrame.setVisible(true);
}
}

Where have I messed up regarding creating a Game Menu?

I am trying to create a basic game menu for a game right now. I am just testing out the menu for now, and most of the options I wrote are just to test out whether the menu actually works or not. So I have a Menu class and a OptionPanel class as well.
Here is the Menu Class:
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
public class Main extends JFrame {
JPanel cardPanel;
public Main(String title) {
super(title);
setBounds(100, 100, 800, 600);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
cardPanel = new JPanel();
CardLayout cl = new CardLayout();
cardPanel.setLayout(cl);
OptionPanel panel1 = new OptionPanel(this);
Board panel2 = new Board();
Rules panel3 = new Rules();
cardPanel.add(panel1,"1");
cardPanel.add(panel2,"2");
cardPanel.add(panel3,"3");
add(cardPanel);
setVisible(true);
}
public static void main(String[] args)
{
Main w = new Main("AP Animation Demo");
}
public void changePanel() {
((CardLayout)cardPanel.getLayout()).next(cardPanel);
requestFocus();
}
}
And here is my Option Panel class:
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class OptionPanel extends JPanel implements ActionListener {
Main w;
public OptionPanel(Main w) {
this.w = w;
JButton button = new JButton("Press me!");
button.addActionListener(this);
add(button);
JButton button2 = new JButton("Game rules");
button2.addActionListener(this);
add(button2);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
setBackground(Color.BLACK);
}// Call JPanel's paintComponent method to paint the background
public void actionPerformed(ActionEvent e) {
w.changePanel();
}
}
How do I make it so when the menu pops up, I can click on one button that leads to the game, and when clicking on another button, get linked to another screen. I think it has something to do with the actionPerformed thing, so I tried adding if (e.getSource == button) and stuff like that, but it could not find any button variable. Any advice/feedback?

If you want the actionPerformed() method to be able to access a button variable, then the variable has to have an instance scope (or static, less preferable almost always). Referring to it in the method as you have it written won't work because the button variable is local to the constructor.
The suggestion in the comments is to make a separate ActionListener for each button; you only need to use the if (e.getSource() == button) if the one actionPerformed() method is getting called for multiple buttons. The difference between these is a little much for a SO answer; you can get a tutorial on action listeners in the Java tutorials at Oracle.
The way you have started above suggests you are going to use the OptionPanel as a single action listener for all buttons, and therefore it needs to test which button invoked it. If instead you have a separate action listener for each button, then it knows which button invoked it and doesn't need to test.
Try looking up "anonymous inner classes" as they relate to action listeners in Java.