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Add element to JFrame from other class

I have two classes in one JFrame creation:
public class Window extends JFrame {
public void createWindow() throws IOException {
setTitle(GeneralValues.PROGRAM_NAME);
setSize(1100, 600);
setResizable(false);
setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
setLayout(null);
setVisible(true);
}
}
And in the second I have a JLabel:
public class InitialConfiguration {
Window w = new Window();
public void main() {
JLabel blauncherIcon = new JLabel();
blauncherIcon.setBounds(100, 100, 100, 100);
blauncherIcon.setOpaque(true);
blauncherIcon.setText("Text");
w.add(blauncherIcon);
}
}
My main method:
public class Main {
Window w = new Window();
InitialConfiguration ic = new InitialConfiguration();
public static void main(String[] args) {
w.createWindow();
ic.main();
}
}
I wanted to add a label from the InitialConfiguration class to the frame from the Window class but unfortunately this code creates a frame but does not add the label from the InitialConfiguration class. Can it be done at all?

Your issue is, that you went wrong with the instances of your Window. Your InitialConfiguration has a member variable of Window, to which the label is being added. But this is not the same instance of the Window that you have in your Main class.
So all in all, you create and show the window, but never show the second window you actually added your label to.
So altogether, if you really want to keep your structure this way (I would advise against that but you may have your reasons), passing the correct Window instance as a method parameter should fix it.
public class InitialConfiguration {
// Removed second Window here
public void main(Window w) { // rename this method please
JLabel blauncherIcon = new JLabel();
blauncherIcon.setBounds(100, 100, 100, 100); // use layout managers
blauncherIcon.setOpaque(true);
blauncherIcon.setText("Text");
w.add(blauncherIcon);
}
}
And your "Main":
public class Main {
Window w = new Window(); // rename the class Window please
InitialConfiguration ic = new InitialConfiguration();
public static void main(String[] args) {
w.createWindow();
ic.main(w);
}
}

You didn't start the Jframe at window class and I don't know your main class so I made it for your understanding. Check this codes;
(Edited)
Main: Example code:
public class MainMenu{
public static void main(String[] args) {
Windows w = new Windows();
InitialConfiguration ini = new InitialConfiguration(w);
w.createWindow();
ini.main();
}
}
ICONFIG class example code:
public class InitialConfiguration {
Window w;
public InitialConfiguration(Windows w){
this.w = w;
}
public void main() {
JLabel blauncherIcon = new JLabel();
blauncherIcon.setBounds(100, 100, 100, 100);
blauncherIcon.setOpaque(true);
blauncherIcon.setText("Text");
w.add(blauncherIcon);
w.repaint();
}
}
Window class example code:
public class Window extends JFrame {
public void createWindow(){
setTitle("Your title");
setSize(1100, 600);
setResizable(false);
setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
setLayout(null);
setVisible(true);
}
}

OK button and String not showing up on JPanel

I am trying to make a panel showing a printed statement "Hello World!" and an OK button. Neither will show up on the panel and I have no idea why. I started with a block of code that was supposed to create just a blank popup. The blank popup worked great. I can't add the string or button and see them. I have tried calling paintComponent. I have tried adding the content to the panel. Does anyone know what I am missing?
Here is my code
package painting;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SwingPaintDemo1 {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
private static class SwingPaintDemo extends JPanel{
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawString("Hello World!", 20,30);
}
}
private static void createAndShowGUI() {
System.out.println("Created GUI on EDT? "+
SwingUtilities.isEventDispatchThread());
JFrame f = new JFrame("Swing Paint Demo");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(250,250);
f.setVisible(true);
JButton okbutton = new JButton("OK");
ButtonHandler listener = new ButtonHandler();
okbutton.addActionListener(listener);
SwingPaintDemo displayPanel = new SwingPaintDemo();
JPanel content = new JPanel();
content.setLayout(new BorderLayout());
content.add(displayPanel, BorderLayout.CENTER);
content.add(okbutton, BorderLayout.SOUTH);
}
private static class ButtonHandler implements ActionListener{
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
}

You forgot to add the JPanel to the JFrame. Just add the following line at the bottom of your createAndShowGUI() method:
f.add(content);
I would also recommend moving your f.setVisible(true); line to the bottom of the method just to be safe. When you make the frame visible, the component tree is set up to take into account all the components added to the JFrame. If you add more components after that, you will need to do either manually revalidate the tree or do something that triggers an automatic revalidation. I'm assuming you're not revalidating your tree anywhere, so you should move f.setVisible(true); to after all the components are added.

Issue with adding JLabel to JPanel

I'm looking to display an image on a JPanel, but when I run the code, the panel is blank. The method I'm attempting is a slightly modified version of this tutorial.
I've confirmed that all methods in the code are actually called using println. My frame and panel are visible, and I'm fairly certain I've added both the icon to the label, and the label to the panel. What am I missing?
The relevant parts of my code:
public class SYSTEM
public static void start() {
GameFrame GF = new GameFrame();
GamePanel GP = new GamePanel();
GF.add(GP);
GP.loadSprite("Player", new Dimension(0,0));
}
}
public class GameFrame extends JFrame {
public GameFrame() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(SYSTEM.windowSize);
setVisible(true);
}
}
public class GamePanel extends JPanel {
ArrayList<Sprite> sprites = new ArrayList<Sprite>();
GamePanel() {
setVisible(true);
setSize(SYSTEM.windowSize);
setLayout(null);
}
public void loadSprite(String spriteName, Dimension pos) {
sprites.add(new Player());
add(sprites.get(0).getIcon());
}
public class Sprite {
protected JLabel icon;
protected BufferedImage image;
protected String filePath;
protected Dimension pos;
public JLabel getIcon() {
return icon;
}
}
public class Player extends Sprite {
public Player() {
filePath = "FILEPATH_OMITTED";
pos = new Dimension(0,0);
try {
image = ImageIO.read(new File(filePath));
} catch (IOException e) {
System.out.println(e);
}
icon = new JLabel(new ImageIcon(image));
}
}

Don't use components for games, you've thrown out the layout manager which is responsible for determining the size and location of the components, but you've failed to compensate for it. I'd recommend that you use a custom painting approach instead, see Painting in AWT and Swing and Performing Custom Painting for starters.
Just so I'm clear, you problem is directly related to setLayout(null); which is bad regardless of what you're doing

Displaying an image, Java

I'm new to Java GUI, and am having issues displaying an image. My intention is to display a large image and allow the user to click on regions of the image to indicate where certain features are located. Anyway, I'm getting a rough start because I can't even get the image to appear, despite reading Oracle's explanation and other solutions.
I've created a JFrame and used its setContentPane() method to add a JPanel and JLabel. I use the setIcon() method of the JLabel to add an image to it, or at least that's my intention...
Any advice is appreciated, especially if there's a better way of doing this. I'll be using OpenCV to process images, and plan to convert them to Java image (or BufferedImage) before displaying them.
Here is the code. I left out the libraries to save space.
public class Pathology {
public static void main(String[] args) {
PrimaryFrame primaryFrame = new PrimaryFrame();
primaryFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE);
primaryFrame.setSize(1500, 900);
primaryFrame.setVisible( true );
primaryFrame.setContentPane(primaryFrame.getGui());
try {
primaryFrame.setImage(ImageIO.read(new File("C:\\Users\\Benjamin\\Pictures\\Pathology\\C\\001.png")));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
GUI Class:
public class PrimaryFrame extends JFrame{
//private JTextField textField1;
JPanel gui;
JLabel imageCanvas;
public PrimaryFrame() {
super( "Pathology-1" );
//setLayout(new FlowLayout());
//textField1 = new JTextField("Chup!", 50);
//add(textField1);
}
public void setImage(Image image) {
imageCanvas.setIcon(new ImageIcon(image));
}
public void initComponents() {
if (gui==null) {
gui = new JPanel(new BorderLayout());
gui.setBorder(new EmptyBorder(5,5,5,5));
imageCanvas = new JLabel();
JPanel imageCenter = new JPanel(new GridBagLayout());
imageCenter.add(imageCanvas);
JScrollPane imageScroll = new JScrollPane(imageCenter);
imageScroll.setPreferredSize(new Dimension(300,100));
gui.add(imageScroll, BorderLayout.CENTER);
}
}
public Container getGui() {
initComponents();
return gui;
}
}

Would you laugh at me if I'd tell you that you just have to put the primaryFrame.setVisible( true ); to the end of the main method? :)
For furture understanding, you don't have to call frame.setVisible(true) every time you want to add/update something in the frame (in an ActionListener, for example). Instead you can call frame.revalidate() and frame.repaint(). (Where frame can be replaced with the particular panel)

You need to setVisible(true) after the call to setImage():
primaryFrame.setImage(ImageIO.read(new
File("C:\\Users\\Benjamin\\Pictures\\Pathology\\C\\001.png")));
because any update to the GUI after setVisible() will not be shown.
That's it and the code should be like this:
public class Pathology {
public static void main(String[] args) {
PrimaryFrame primaryFrame = new PrimaryFrame();
primaryFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE);
primaryFrame.setSize(1500, 900);
primaryFrame.setContentPane(primaryFrame.getGui());
try {
primaryFrame.setImage(ImageIO.read(new File(
"C:\\Users\\Benjamin\\Pictures\\Pathology\\C\\001.png")));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
primaryFrame.setVisible( true );
}
}

One JFrame opening another

I have a JFrame and JPanel full of Jsomethings with an actionlistener. When the user clicks an object I want to open another JFrame. Here is what I did:
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == rejectionbutton){
RejectApp ra = new RejectApp();
ra.main(null);
}
}
(RejectApp calls a new JFrame.) So another JFrame opens on the screen with more options. It works OK (so far), but I want to know is this standard? I mean calling the main method like this?
Another question is, without using a cardlayout (which I don't want to use), is the best way to handle multiple panels, by doing this sort of thing?

I would change a few things. First off, usually an application has one JFrame and then if it needs to show another window does so as a modal or non-modal dialog such as can be obtained with a JDialog or JOptionPane. Having said that, it's even more common to have one JFrame and swap "views" in the JFrame -- swap contentPanes or other large panels via a CardLayout as this would mimic the behavior of many gui programs we all currently use.
Personally, I also try to gear my GUI creation towards creating a JPanel or JComponent rather than towards creating a top-level window. This way if I want to display the GUI as a stand alone app, a dialog, or an applet I can pop it into the contentPane of a JFrame or JDialog or JApplet respectively, or if as an inner panel of a more complex GUI, then insert it there, or in an application with a swapping view, then as a card in a CardLayout as noted above. The bottom line is I feel that this structure gives you the developer a lot more options in how you can use this GUI.
Also, I would avoid calling another class's main as you're doing (assuming this is the public static void main method) as you lose all benefits of OOPs. You also seem to be trying to call a static method in a non-static way (assuming I understand your program structure correctly).
For your second question, it begs a question of my own: why do you not want to use CardLayout?
edit: an example of what I meant is as follows:
import java.awt.Dimension;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class SwingEg {
private static void createAndShowUI() {
JFrame frame = new JFrame("Main JFrame");
frame.getContentPane().add(new MainGUI().getMainPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class MainGUI {
private static final Dimension MAIN_PANEL_SIZE = new Dimension(450, 300);
private JPanel mainPanel = new JPanel();
private JDialog modalDialog;
private JDialog nonModalDialog;
public MainGUI() {
JButton openModalDialogBtn = new JButton("Open Modal Dialog Window");
openModalDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openModalDialogBtnActionPerformed(e);
}
});
JButton openNonModalDialogBtn = new JButton("Open Non-Modal Dialog Window");
openNonModalDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openNonModalDialogBtnActionPerformed(e);
}
});
mainPanel.setPreferredSize(MAIN_PANEL_SIZE);
mainPanel.add(openModalDialogBtn);
mainPanel.add(openNonModalDialogBtn);
}
private void openModalDialogBtnActionPerformed(ActionEvent e) {
if (modalDialog == null) {
Window topWindow = SwingUtilities.getWindowAncestor(mainPanel);
modalDialog = new JDialog(topWindow, "Modal Dialog", ModalityType.APPLICATION_MODAL);
modalDialog.getContentPane().add(new DialogPanel().getMainPanel());
modalDialog.pack();
modalDialog.setLocationRelativeTo(topWindow);
modalDialog.setVisible(true);
} else {
modalDialog.setVisible(true);
}
}
private void openNonModalDialogBtnActionPerformed(ActionEvent e) {
if (nonModalDialog == null) {
Window topWindow = SwingUtilities.getWindowAncestor(mainPanel);
nonModalDialog = new JDialog(topWindow, "Non-Modal Dialog", ModalityType.MODELESS);
nonModalDialog.getContentPane().add(new DialogPanel().getMainPanel());
nonModalDialog.pack();
nonModalDialog.setLocationRelativeTo(topWindow);
nonModalDialog.setVisible(true);
} else {
nonModalDialog.setVisible(true);
}
}
public JPanel getMainPanel() {
return mainPanel;
}
}
class DialogPanel {
private static final Dimension DIALOG_SIZE = new Dimension(300, 200);
private JPanel dialogPanel = new JPanel();
public DialogPanel() {
dialogPanel.add(new JLabel("Hello from a dialog", SwingConstants.CENTER));
dialogPanel.setPreferredSize(DIALOG_SIZE);
}
public JPanel getMainPanel() {
return dialogPanel;
}
}

I would rather make a new instance of JFrame or a subclass, or call a new method who makes a new JFrame:
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == rejectionbutton){
JFrame frame = new JFrame("New Frame");
//or
makeNewFrame();
}
}
Another simple Layout-Manager is the BorderLayout, it´s the default Layout-Manager of the JFrame class.

new YourJFrameNameHere().setVisible(true);
Replace YourJFrameNameHere with the JFrame name.
Simple, no?