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Is it possible to create a panel with a class on the left and right side?

I have been practicing my code with Java Swing and have gotten decent on controlling where to place some items, such as labels and or buttons, but I was wondering if you can do the same with classes? I have just a simple class with enough code to put a button in it and that's it, that I am trying to create an instance of the class and then control for to put on the left and right side but when I do, all it does is create two separate windows with the button in the middle and that's it. Am I doing something wrong, or can you not do classes the same way?
The code:
import java.awt.Color;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class Fun extends JFrame
{
private final int WIDTH = 500;
private final int HEIGHT = 400;
public Fun()
{
setTitle("Fun Management");
setSize(WIDTH, HEIGHT);
BuildPanel west = new BuildPanel(); /// BuildPanel is the name of the class that has just a button in it.
BuildPanel east = new BuildPanel(); ///
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
add(west, BorderLayout.WEST); /// I am doing the same thing with the instances as I would with buttons or labesl
add(east, BorderLayout.EAST);
setVisible(true);
}
public static void main(String[] args)
{
new Fun();
}
}

I took your code and created the following GUI.
Oracle has a rad tutorial, Creating a GUI With Swing, that will show you how to create Swing GUIs. Skip the Netbeans section.
Always start your Swing application with a call to the SwingUtilities invokeLater method. This method ensures that your Swing components are created and executed on the Event Dispatch Thread.
Use Swing components. Don't extend a Swing component unless you want to override one or more of the component methods.
The JFrame methods must be called in a specific order. This is the order I recommend for most Swing applications. Use the JFrame pack method and let the components size the JFrame.
I created a BuildPanel class to build a JPanel. There are good reasons to do this, but be careful. You have to manage each instance of the class you create. As an example, what if you want the text of the two buttons to be different? What if you want to assign two different ActionListener classes, one to each button?
Here's the complete runnable code. I made the BuildPanel class an inner class so I can post the code as one block.
import java.awt.BorderLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TwoPanelExample implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new TwoPanelExample());
}
#Override
public void run() {
JFrame frame = new JFrame("Fun Management");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
BuildPanel west = new BuildPanel();
BuildPanel east = new BuildPanel();
frame.add(west.getPanel(), BorderLayout.WEST);
frame.add(east.getPanel(), BorderLayout.EAST);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public class BuildPanel {
private final JPanel panel;
public BuildPanel() {
this.panel = createMainPanel();
}
private JPanel createMainPanel() {
JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createEmptyBorder(5, 30, 5, 30));
JButton button = new JButton("Click Me");
panel.add(button);
return panel;
}
public JPanel getPanel() {
return panel;
}
}
}

Attempting to set the layout to BoxLayout

I can't seem to find a solution online for why I'm getting this error on attempted run
I'm working on making a simple test system for a different program when are button press will yield value in a text box. I would like them to be on different lines to make it cleaner, so I looked into layouts. I decided a Box Layout would fit me best. I looked at different examples before attempting this and my code ended up looking like this, (apologies for the messy code)
Update
Got the box layout error to disappear but the code will not center them on the panel/frame. The label and button align left while the textfield becomes very large. I don't need it todo that
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import static javax.swing.BoxLayout.Y_AXIS;
import static javax.swing.SwingConstants.CENTER;
public class button extends JFrame {
static JFrame f;
static JButton b;
static JLabel l;
// main class
public static void main(String[] args)
{
// create a new frame to stor text field and button
f = new JFrame("panel");
BoxLayout layout = new BoxLayout(f, BoxLayout.Y_AXIS);
f.setLayout(layout);
// create a label to display text
l = new JLabel("panel label");
b = new JButton("button1");
JTextField textArea = new JTextField(5);
textArea.setEditable(false);
//textArea.append("Hello World");
// create a panel to add buttons
JPanel p = new JPanel();
// add buttons and textfield to panel
f.add(p);
f.setSize(300, 300);
p.add(l);
p.add(b);
p.setBackground(Color.white);
p.add(textArea);
f.show();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
Random r = new Random();
textArea.setText(String.valueOf(r));
}
});
}
}
Error
Exception in thread "main" java.awt.AWTError: BoxLayout can't be shared
at java.desktop/javax.swing.BoxLayout.checkContainer(BoxLayout.java:461)
at java.desktop/javax.swing.BoxLayout.invalidateLayout(BoxLayout.java:245)
at java.desktop/javax.swing.BoxLayout.addLayoutComponent(BoxLayout.java:278)
at java.desktop/java.awt.Container.addImpl(Container.java:1152)
at java.desktop/java.awt.Container.add(Container.java:1029)
at java.desktop/javax.swing.JFrame.addImpl(JFrame.java:553)
at java.desktop/java.awt.Container.add(Container.java:436)
at button.main(button.java:36)
I would like the three items to all to be stacked one on top of another with a space between them. The order doesn't matter right now.

Swing was first added to the JDK in 1998 and has undergone a lot of changes since. Unfortunately, when you read Web pages about Swing, it is not obvious when that page was last updated. Consequently you may be learning outdated techniques for writing Swing code.
First of all, according to the code you posted, class button does not need to extend class JFrame since you use a static variable as your application's JFrame. Also, JFrame is a top-level container which makes it a special kind of container and not the same kind of continer as a JPanel. You need to set the layout manager for your JPanel and then add the JLabel, JTextField and JButton to that JPanel. And then add the JPanel to the JFrame.
Calling method pack() of class JFrame will automatically set the preferred sizes for the components inside the JFrame. It appears in the code below.
Please also look at Java coding conventions which allows others to more easily read and understand your code. And note that, according to these conventions, I renamed your class from button to Buttons and also because there are already several class in the JDK named Button.
Here is my rewrite of your code...
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.WindowConstants;
public class Buttons implements Runnable {
public void run() {
createAndShowGui();
}
private void createAndShowGui() {
JFrame f = new JFrame("Box");
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JPanel p = new JPanel();
BoxLayout layout = new BoxLayout(p, BoxLayout.Y_AXIS);
p.setLayout(layout);
JLabel l = new JLabel("panel label");
JTextField textField = new JTextField(5);
JButton b = new JButton("button1");
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
Random r = new Random();
textField.setText(String.valueOf(r.nextBoolean()));
}
});
p.add(l);
p.add(textField);
p.add(b);
f.add(p);
f.pack();
f.setLocationByPlatform(true);
f.setVisible(true);
}
public static void main(String[] args) {
Buttons instance = new Buttons();
EventQueue.invokeLater(instance);
}
}

Java : using graphics component within an action listener

I've made a JFrame with Diferent JButtons and i'd like to get an image from another class. Any ideas? Or how draw on the same class but on the action performed?
Because it doesnt let me to do any drawings...my complier always gives me error messages
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import javax.swing.*;
public class red extends JFrame {
public JButton b;
public JButton b1;
public JButton b2;
public JButton b3;
public JButton b4;
public static Image p;
public static Graphics g;
public red() throws IOException {
gui1 x = new gui1();
setTitle(" ");
setSize(1200,700);
setLayout(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
b= new JButton("click");
b1= new JButton();
b.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e0){
b1.setBounds(0, 0, 200, 200);
b.show(false);
add(x);
}
});
b.setBounds(0, 0, 100, 100);
add(b1);
add(b);
setVisible(true);
}
public static void main(String[] args) throws IOException {
red k = new red();
}
}
import java.awt.*;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;
public class gui1 extends Canvas {
public static Image p;
public void paint(Graphics g){
g.drawImage(p, 700, 200, 100, 100, this);
}
{
try {
p= ImageIO.read(new File("Lighthouse.jpg"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

Phew! I see A LOT of errors in your code (even after I corrected the compilation errors):
You're not following the Java naming conventions:
Class names should be nouns, in mixed case with the first letter of each internal word capitalized
while red is a noun it should be more descriptive and be capitalized. The same goes for gui1
You're extending JFrame which in plain english would say: red is a JFrame, you should really avoid this and create your GUI based on JPanels instead... see Java Swing using extends JFrame vs callint it inside of class
You're setting size (a REAAAAAAALLY big one window for the JButton sizes you're using), instead use pack()
You're using null-layout, while pixel-perfect GUIs might seem like the easiest way to create complex GUIs for Swing newbies, the more you use them the more problems related to this you'll find in the future, they are hard to maintain and cause random problems, they don't resize, etc. Please read Null layout is evil and Why is it frowned upon to use a null layout in Swing? for more information about why you should avoid its use and why you should change your GUI to work with Layout Managers along with Empty Borders for extra spacing between components.
You're making use of a deprecated method JFrame#show() you should be using JFrame#setVisible(...) instead.
Related to point #4, you shouldn't be calling setBounds(...) method, but let that calculations to the layout managers.
You're not placing your program on the Event Dispatch Thread (EDT), Swing is not thread safe, you can fix this by changing your main() method as follows:
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
//Your constructor here
}
});
}
You're mixing AWT and Swing components, instead of using AWT's Canvas use Swing's JPanel which has more functionality and support.
Images will become embedded resources once they're packaged in a JAR file, so it's wise to start treating them as if they already were, not as external files as shown in the embedded-resource tag.
Once you change from Canvas to JPanel you should override its paintComponent(...) method and not paint(...) and call it's super.paintComponent(g) method as the first line, also don't forget to add the #Overrides annotation. See the tutorial on Swing custom painting.
You're abusing the use of static keyword, see how does the static keyword works?
After seeing all the above errors I recommend you to go back and Learn the basics of the language before starting with a graphical environment which will only add more difficulty to your learning.
From what I understand you want to draw an image on a button click, if that's the case then you can wrap your image in a JLabel and add that JLabel to a JPanel which then is added to a parent JPanel which is later added to the JFrame:
As you can see in the GIF above, the icon is displayed after user presses the button.
Obviously this can be improved for the GUI to be more "attractive" with combinations of layout managers and empty borders as stated before.
This was done with the following code:
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ImageDrawingFromOneClassToAnother {
private JFrame frame;
private JPanel pane;
private JPanel leftPane;
private JPanel rightPane;
private ImageIcon icon;
private JButton button;
private JLabel label;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new ImageDrawingFromOneClassToAnother().createAndShowGui();
}
});
}
public void createAndShowGui() {
frame = new JFrame(getClass().getSimpleName());
icon = new ImageIcon(this.getClass().getResource("king.png")); //Read images as if they were already embedded resources
button = new JButton("Draw image");
label = new JLabel(""); //Create an empty label
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
label.setIcon(icon); //On button click, we set the icon for the empty label
}
});
pane = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 200); //Set a size for the main panel
}
};
pane.setLayout(new GridLayout(1, 2)); //The main panel
leftPane = new JPanel(); //The button panel
leftPane.setLayout(new BoxLayout(leftPane, BoxLayout.PAGE_AXIS));
leftPane.add(button);
rightPane = new JPanel(); //The panel where the image will be drawn
rightPane.add(label);
//We add both (button and image) panels to the main panel
pane.add(leftPane);
pane.add(rightPane);
frame.add(pane); //Add the main panel to the frame
frame.pack(); //Calculate its preferred size
frame.setVisible(true); //Set it to be visible
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

Basic GUI Swing - components not showing

Here is my code snippet containing child JButton and JPanel objects but it's not working. And it's not showing any compilation errors in Eclipse.
import java.awt.FlowLayout;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
class gui extends JFrame implements ActionListener {
private JButton b;
private TextField c;
private JLabel l;
private String sn;
// Constructor for making framework
public gui() { setLayout(new FlowLayout());
JFrame f=new JFrame("Hello!");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
f.setSize(200,200);
f.setTitle("GUI");
b=new JButton("Click");
l=new JLabel("Enter Name");
c=new TextField("Enter..",10);
c.setEditable(true);
l.setBounds(20,20,20,20);
f.setBounds(10, 10, 10, 10);
b.addActionListener(this);
add(b);
add(f);
add(l);
add(c);
}
public static void main(String[] args) {
gui g=new gui();
g.setVisible(true);
} //main method
#Override
public void actionPerformed(ActionEvent e)
{
System.out.println("Working");
}
}

Your class "is a" GUI and then you also create a new JFrame, so you really have two frames in your code.
However the frame you make visible does not have any components added to it so all you see is the frame.
You then attempt to add components to your class the is a frame. However, you then have two problems:
you never make this frame visible and
Swing uses layout managers (you don't need to use setBounds(...)). By default it is using the BorderLayout. When you add components to the frame without specifying a constraint the components get added to the "CENTER". However, only one component can be displayed in the "CENTER" so only the last one added will ever be visible.
You also have other problems because you don't create the GUI on the Event Dispatch Thread. So there are really too many problems to correct.
I suggest you read the section from the Swing tutorial on How to Use BorderLayout for a working example of how to create a simple GUI. Then modify that code.

Your JFrame f=new JFrame("Hello!"); is not needed.
You need to use this which is already your JFrame like:
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.setSize(200,200);
this.setTitle("GUI");
Also remove: add(f); and f.setBounds(10, 10, 10, 10);

Because you already extend JFrame, you don't have to create a new JFrame.
Because now your class is a JFrame itself. That means that you can replace every usage of your f-JFrame by using this instead:
That way, also your other Components will be added correctly. Because at the moment you add b, f, i and c to the right JFrame.
So use this:
this.setVisible(true);
this.setSize(200,200);
this.setTitle("GUI");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
or even more simple:
setVisible(true);
setSize(200,200);
setTitle("GUI");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Java Swing: problems with width

I have problems with understanding the behavior of my application. I want to create a simple window (1000x700px), divided into two parts (250px and 750px width respectively). I tried the following code:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Example extends JFrame
{
private static final long serialVersionUID = 1L;
public Example()
{
this.setSize(1000, 700);
this.setTitle("Example");
this.setResizable(false);
this.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));
JPanel navigation_panel_wrap = new JPanel();
JPanel content_panel_wrap = new JPanel();
navigation_panel_wrap.setPreferredSize(new Dimension(250, 700));
content_panel_wrap.setPreferredSize(new Dimension(750, 700));
content_panel_wrap.setBackground(Color.green);
navigation_panel_wrap.setBackground(Color.red);
this.getContentPane().add(navigation_panel_wrap);
this.getContentPane().add(content_panel_wrap);
}
public static void main(String[] args)
{
Example example = new Example();
example.setVisible(true);
}
}
As you can see I manually set layout manager for JFrame (FlowLayout instead of BorderLayout with zero horizontal and vertical gaps). Of course, I can just use BorderLayout and than use add() method with BorderLayout.EAST and BorderLayout.WEST parameters, but I want to understand what's wrong with FlowLayout.
When I run my application, I get the following (no green JPanel):
If I decrease width of, for example, content_panel_wrap and make it 744px instead of 750px, everything works correctly.
So the question is - what are these strange 6 pixels? I'm not sure this value is constant for all operating systems, so I want to understand its origin.

There's nothing wrong with FlowLayout but you will need to call pack() for all components to be sized.

As for your codes problem (+1 to #Reimeus) calling pack() is the solution.
as per docs:
Causes this Window to be sized to fit the preferred size and layouts
of its subcomponents. If the window and/or its owner are not yet
displayable, both are made displayable before calculating the
preferred size. The Window will be validated after the preferredSize
is calculated.
Tips:
Dont extend JFrame unnecessarily.
Use Event Dispatch Thread when creating and changing UI components:
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
// create UI components etc here
}
});
Dont call setPreferredSize() rather override getPrefferedSize() of component.
Dont call setSize(...) on JFrame rather call JFrame#pack() before setting it visible.
Dont forget to call JFrame#defaultCloseOperation(..) or your initial/EDT thread will not be terminated when JFrame is closed.
Here is an example combining my advice and your code:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Example {
private final JFrame frame;
public Example() {
frame = new JFrame();
frame.setTitle("Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//app exited when frame closes
frame.setResizable(false);
frame.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));
JPanel navigation_panel_wrap = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(250, 700);
}
};
JPanel content_panel_wrap = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(750, 700);
}
};
content_panel_wrap.setBackground(Color.green);
navigation_panel_wrap.setBackground(Color.red);
frame.add(navigation_panel_wrap);
frame.add(content_panel_wrap);
//pack frame (size components to preferred size)
frame.pack();
frame.setVisible(true);//make frame visible
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Example();
}
});
}
}