I have a main.java file which I like to use to call the GUI made in JPanel.
It's my first NetBeans experience though, so be gentle :-) ...
It fails to compile; the error i get is :Erroneous sym type: main.GUI.GUI (which makes sense as it is interpreted).
But now: HOW DO I FIX IT??
I've tried GUI.GUI(); as well, but without positive results..
(I'm used to programming C++, but since import is not a true option in java (or is it?).
My main.java:
package main;
public class Main {
public static void main(String[] args) {
GUI obj = new GUI();
obj.GUI();
}
}
My GUI.java file:
package main;
public class GUI extends javax.swing.JPanel {
public GUI() {
initComponents();
}
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);
}
}
If I understand your question correctly you want to display the GUI from your Main class. One thing to keep in mind is that a JPanel itself cannot be displayed. It must be added to a JFrame before it shows. Try something like:
package main;
public class Main {
public static void main(String[] args) {
GUI obj = new GUI(); // creates your panel
JFrame frame = new JFrame("some title"); // creates the frame
frame.add(obj);
frame.setSize(200,300);
frame.setVisible(true);
}
}
GUI obj = new GUI();
it created new object of GUI. So, the constructor is operated already. The constructor method is special method, that plays when new object is created from the class.
Related
My problem is quite weird: even if I create a JFrame with literally nothing in it, so it should just display a white window, but it crashes after doing anything with it. For example, when I resize the window, the new, resized area will be black in most cases (or sometimes be the right color I really don't know why) and it will either just close or display "Not responding" and then close after a few seconds.
GUI class:
public class GUI extends JFrame {
private static JFrame frame;
public GUI() {
frame = new JFrame();
frame.setTitle("test");
frame.getContentPane().setLayout(new FlowLayout());
frame.pack();
frame.setVisible(true);
}
}
Main class:
public class Main {
public static void main(String[] args) {
GUI gui = new GUI();
}
}
And here's an image exactly showing the behavior:
Why does it behave like this? It's most definitely not because of the code, I think. It must be something else. I tried reinstalling Java, didn't help out. Switched from SDK 13 to 1.8.0_171, nothing. Older programs using Swing also suddenly don't work anymore and behave the same. Any ideas?
Always start your GUI from the event dispatching thread to avoid unwanted behavior.
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
GUI gui = new GUI();
}
});
}
See the javadoc: invokeLater
Try this (width 400, height 300):
public class GUI extends JFrame {
private static JFrame frame;
public GUI() {
frame = new JFrame();
frame.setTitle("test");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);
frame.pack();
frame.setVisible(true);
}
}
Hello I'm facing this problem:
I created a button in class Luncher, when I click it I want to call a function in another class (Main) but I dont have a result.
However when i define (Main) class in run mode I get the intended result. What is the problem ?
This work for me :
When i set Main.class in run mode
And this not work :/ :
When i click in button to show Main.class
This is the code for the runable class (Luncher):
public class Luncher extends javax.swing.JFrame {
public Luncher() {
setSize(600,400);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
JButton jButton1 = new javax.swing.JButton();
jButton1.setText("CLIC ON ME !");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
Main example = new Main();
example.doThis();
}
});
GroupLayout layout = new GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(147, 147, 147)
.addComponent(jButton1)
.addContainerGap(180, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(108, 108, 108)
.addComponent(jButton1)
.addContainerGap(169, Short.MAX_VALUE))
);
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Luncher().setVisible(true);
}
});
} }
And the second class is Main:
public class Main extends javax.swing.JFrame {
private static GUI gameGui = new GUI(); //GUI its a JFrame class
private static CardLayout card = new CardLayout();
private static JPanel content = new JPanel();
public Main(){
doThis();
}
public static void doThis (){
content.setLayout(card);
gameGui.setVisible(true);
gameGui.add(content);
gameGui.repaint();
gameGui.revalidate();
card.show(content);
}
public static void main (String [] args) {
} }
You have a few basic solutions available to you.
You could...
Pass a reference of Main to Luncher. This way, when you want to, you can just call the functionality of Main you need to.
This is not the best solution, as it couples Launcher to Main, making it difficult to re-use the code and possibly exposing functionality (of Main) to Launcher, which Launcher should have access to.
You could...
You could use a delegate or observer pattern...
Define an interface (or contract) which Launcher requires delegates to implement in order to perform the functionality it requires.
public interface LauncherDelegate {
//...
}
You would then have Main implement this interface
public class Main extends javax.swing.JFrame implements LauncherDelegate {
//...
and pass a reference of itself to Launcher
public class Luncher extends javax.swing.JFrame {
private LauncherDelegate delegate;
public Luncher(LauncherDelegate delegate) {
this.delegate = delegate
//...
This way, Launcher can only call the functionality described in the contract, it decouples the code, as any implementation of LauncherDelegate can be used and Launcher won't care, making the code more re-usable and configurable.
I'm newbie in java GUI , so i'm facing a problem right now ...
i've created a GUI using Netbeans GUI Builder ..
i've Created a file called MainUI.java and gdUI.Java
the MainUI.java contains the frame and buttons in which if a button is clicked the Jpanel Hides and opens the Panel from gdUI.java
here's the code i've done so far :
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
jPanel1.setVisible(false);
}
and gdUI code is :
package GUI;
public class gdUI extends javax.swing.JPanel {
/**
* Creates new form gdUI
*/
public gdUI() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
setBackground(new java.awt.Color(255, 153, 51));
setMaximumSize(new java.awt.Dimension(600, 500));
setMinimumSize(new java.awt.Dimension(600, 500));
setPreferredSize(new java.awt.Dimension(600, 500));
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 600, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 500, Short.MAX_VALUE)
);
}// </editor-fold>
// Variables declaration - do not modify
// End of variables declaration
}
when i click the button , i successfully hided the current JPanel , how can i add the other files new one ?
Thanks In Advance
The way you want to accomplish this task is using a CardLayout as pointed out by trashgod. This will allow you to switch between views, with simple Cardayout commands like next(), previous() and show(), the last allowing to show any particular component/view by name.
You can see the Oracle tutorial on How to Use CardLayout
You can see How to Use CardLayout with Netbeans GUI Builder
You can see how to drag and drop other panel forms here
I created a JFrame form using Java Swing in NetBeans. It contains some text fields, some combo boxes and a button to navigate to the next form. Everything works fine until I close and re-open NetBeans. Now when I run the form only the text fields become unresponsive. The combo boxes and the button work correctly. I tried using setEditable(), setFocusable() and requestFocusinWindow() with the text fields but the output hasn't changed. Please help me.
package Hora.GUI;
import java.awt.Color;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class InputJFrame3 extends javax.swing.JFrame
{
public InputJFrame3()
{
initComponents();
numberJTextField.addMouseListener(new MouseAdapter()
{
public void mouseClicked(MouseEvent e)
{
numberJTextField.setForeground(Color.black);
}
});
}
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {
numberJLabel = new javax.swing.JLabel();
numberJTextField = new javax.swing.JTextField();
nextJButton = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("HORA");
setFocusableWindowState(false);
numberJLabel.setText("Number");
nextJButton.setText("next >");
nextJButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
nextJButtonActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(nextJButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(layout.createSequentialGroup()
.addComponent(numberJLabel)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(numberJTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 50, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 0, Short.MAX_VALUE)))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(numberJLabel)
.addComponent(numberJTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(nextJButton)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
pack();
}// </editor-fold>//GEN-END:initComponents
private void nextJButtonActionPerformed(java.awt.event.ActionEvent evt)
{
//GEN-FIRST:event_nextJButtonActionPerformed
number=Integer.parseInt(numberJTextField.getText());
Boolean mistake=false;
if(number<1 || number>249)
{
mistake=true;
numberJTextField.setForeground(Color.red);
}
if(!mistake)
setVisible(false);
}//GEN-LAST:event_nextJButtonActionPerformed
public int getNumber()
{
return number;
}
private int number;
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton nextJButton;
private javax.swing.JLabel numberJLabel;
private javax.swing.JTextField numberJTextField;
// End of variables declaration//GEN-END:variables
}
package Hora.GUI;
public class Run
{
public static void main(String[] args)
{
java.awt.EventQueue.invokeLater(new Runnable()
{
public void run()
{
InputJFrame3 frame = new InputJFrame3();
frame.setVisible(true);
}
});
}
}
Your problem is here:
setFocusableWindowState(false);
Doing this prevents the JTextField from getting focus and being usable. I suggest that you not do this.
Also, I agree with camickr, that you should not use an IDE to create your sscce. Just add your components to a simple JPanel which uses FlowLayout by default, something like:
nextJButton.setText("next >");
nextJButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
nextJButtonActionPerformed(evt);
}
});
JPanel panel = new JPanel();
panel.add(numberJLabel);
panel.add(numberJTextField);
panel.add(otherJTextField);
panel.add(nextJButton);
getContentPane().add(panel);
pack();
}// </editor-fold>//GEN-END:initComponents
Also and again, your program looks as if it's swapping JFrames which generally considered a weak design. Instead gear your code to create JPanel "views" and have your GUI swap views with a CardLayout. If you must show a detail window, then use a JDialog.
Edit 2
In a comment you state:
But that part is in the generated code. I opened the java file in Wordpad and modified it. It works now. Is there any other way to do it using the IDE? Thanks a lot Mr. Hovercraft and Mr. Camickr for helping me out. I'm doing this a hobby project for my grandpa who wants to automate his astrology calculations.
I think it is fair to say that most of the main Swing advisers on this site (at least the ones that that I am familiar with) create their Swing code by hand. Don't get me wrong, we use IDE's, but we don't use an IDE's drag-and-drop tool in creating our Swing code. The Swing Tutorials will help you learn how to do this. In particular, please have a look at Lesson: Laying Out Components Within a Container the section.
Note that even if you do end up using a Swing code generator such as NetBeans's Matisse tool, it won't hurt you to learn how to do some hand coding since the knowledge gained will be directly applicable in your work with the code-generating tool.
ContainerPanel is a custom JPanel class using a BorderLayout. The SOUTH contains a JPanel with a button. I want the CENTER to be an instance of another custom JPanel, say AbstractPanel, which provides an abstract method which will be called when the button is clicked. I also want to set this JPanel programmatically (at run-time). So far, I can do all of this as you can see in the following code (some of which is generated by the NetBeans GUI Builder):
package jpaneldemo;
import java.awt.BorderLayout;
public class ContainerPanel extends javax.swing.JPanel {
public ContainerPanel() {
initComponents();
}
public ContainerPanel(AbstractPanel abPanel) {
initComponents();
this.abPanel = abPanel;
this.add(this.abPanel, BorderLayout.SOUTH);
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
private void initComponents() {
buttonPanel = new javax.swing.JPanel();
okButton = new javax.swing.JButton();
setLayout(new java.awt.BorderLayout());
okButton.setText("OK");
okButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
okButtonActionPerformed(evt);
}
});
buttonPanel.add(okButton);
add(buttonPanel, java.awt.BorderLayout.PAGE_END);
}
private void okButtonActionPerformed(java.awt.event.ActionEvent evt) {
this.abPanel.abstractMethod();
}
// Variables declaration - do not modify
private javax.swing.JPanel buttonPanel;
private javax.swing.JButton okButton;
// End of variables declaration
private AbstractPanel abPanel = null;
}
I also created the AbstractPanel class:
package jpaneldemo;
public abstract class AbstractPanel extends javax.swing.JPanel {
public AbstractPanel() {
initComponents();
}
protected abstract void abstractMethod();
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
private void initComponents() {
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);
}
// Variables declaration - do not modify
// End of variables declaration
}
Now I want to create subclasses of this AbstractPanel class which I can edit in the NetBeans GUI. Typically, I right-click on a package name in the Projects window and then navigate to "New -> JPanel..." to create a custom JPanel. How do I get AbstractPanel to appear in the "New" menu so that I can edit the new class with the NetBeansGUI Builder? Or is there another way to accomplish the same thing?
If your intention is to provide a "template" component that can then be added to the palette and included in other containers, then yes you can.
Have a read through FaqFormCustomContainerBean
The basic idea (apart from creating a BeanDescriptor is you will need to provide a "content" panel of some kind, where additional content can be added at design time.
Now, if you're interested in providing a custom template, that's something I've not done before.
You could try reading through http://netbeans.org/competition/win-with-netbeans/customize-java-template.html. It may be a little out of date, but might help you in the right direction