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Display image using Swing in Java

I searched Oracle and Stack Overflow, trying to find a solution to my problem, but I could not find what I was looking for.

Below I have two classes, and all that needs to be done at the moment in the program is to allow the user to open the image file with JFileChooserand display it in the graphical interface (so that it will be possible to do some manipulations with the images to it)

I tested the code execution to such an extent that I know that the variable imgin the class is ImageGUIinitialized with the image that I want on line 99. My problem is that the image is displayed in the GUI before I did pack();it.

What am I missing?

 public class ImageEditLaunch {

public static void main(String[] args) {
    ImageEditEngine program = new ImageEditEngine();

}

}

import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;

public class ImageEditEngine {

    private static int[][][] originalImage;
    private static BufferedImage originalImageBuffer;

    public ImageEditEngine() {
        originalImage = new int[0][0][0];
        ImageGUI gui = new ImageGUI();
        gui.setVisible(true);
    }

    public static ImageIcon openImage(String filepath){
        try{

        File f = new File(filepath);
        BufferedImage image = ImageIO.read(f);
        originalImageBuffer = image;
        ImageIcon icon = new ImageIcon(image);
        return icon;

        }
        catch(Exception e){
            e.printStackTrace();
            return new ImageIcon();
        }

    }
}

import java.awt.Dimension;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import javax.swing.ImageIcon;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.UIManager;

public class ImageGUI extends JFrame implements ActionListener{

    private JFrame window;

    private JMenuItem mOpenFile;
    private JMenuItem mSaveFile;
    private JMenuItem mExitCommand;

    private JMenuBar parentBar;
    private JMenu fileMenu;
    private JMenu commandMenu;

    private JPanel mainPanel;

    public ImageIcon img;

    private JLabel mLabel;

    public ImageGUI(){
        super();
        try{
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        }
        catch(Exception e){
            e.printStackTrace();
        }
        //setup CommandMenu
        commandMenu = makeMenu("Command", 'C');

        //setup FileMenu
        fileMenu  = makeMenu("File", 'F');
        mOpenFile     = makeMenuItem(fileMenu, "Open...", 'O');
        mSaveFile     = makeMenuItem(fileMenu, "Save...", 'S');
        mExitCommand  = makeMenuItem(fileMenu, "Exit", 'X');

        //setup parentBar
        parentBar = new JMenuBar();
        parentBar.add(fileMenu);
        parentBar.add(commandMenu);

        //main panel
        mainPanel = new JPanel(new BorderLayout());
        mLabel = new JLabel();
        mainPanel.add(mLabel, BorderLayout.CENTER);
        setJMenuBar(parentBar);
        setSize(new Dimension(400, 300));

    }

    protected JMenuItem makeMenuItem(JMenu menu, String name, char mnemonic){
        JMenuItem m = new JMenuItem(name, (int) mnemonic);
        m.addActionListener(this);
        menu.add(m);
        return m;
    }

    protected JMenu makeMenu(String name, char mnemonic){
        JMenu menu = new JMenu(name);
        menu.setMnemonic(mnemonic);
        return menu;
    }


    @Override
    public void actionPerformed(ActionEvent arg0) {
        if(arg0.getSource()==mOpenFile){
            String path = null;

            JFileChooser jfc = new JFileChooser();
            jfc.setCurrentDirectory(new File("."));

            int result = jfc.showOpenDialog(this);

            if (result == JFileChooser.APPROVE_OPTION) {
                File file = jfc.getSelectedFile();
                path = file.getAbsolutePath();
            }

            img=ImageEditEngine.openImage(path);
            mLabel= new JLabel(img);
            mLabel.setVisible(true);
            this.repaint();
            pack();

        }

    }
}

The value of toString () on mLabel immediately after:

mLabel = new JLabel(img);

as follows

javax.swing.JLabel[,0,0,0x0,invalid,alignmentX=0.0,alignmentY=0.0,
border=,flags=8388608,maximumSize=,minimumSize=,preferredSize=,
defaultIcon=javax.swing.ImageIcon@2bd58ce,disabledIcon=,
horizontalAlignment=CENTER,horizontalTextPosition=TRAILING,
iconTextGap=4,labelFor=,text=,verticalAlignment=CENTER,
verticalTextPosition=CENTER]
+4
2

, . , ( ), , . , ( , ).

, . . , MCVE, , .

import java.awt.image.*;
import java.awt.*;
import javax.swing.*;
import javax.imageio.*;
import java.net.URL;

public class ImageEditEngine {

    private static int[][][] originalImage;
    private static BufferedImage originalImageBuffer;

    public ImageEditEngine() {
        originalImage = new int[0][0][0];
        ImageGUI gui = new ImageGUI();
        gui.setVisible(true);
    }

    public static ImageIcon openImage(){
        try{
            URL url = new URL("https://i.stack.imgur.com/OVOg3.jpg");

            BufferedImage image = ImageIO.read(url);
            originalImageBuffer = image;
            ImageIcon icon = new ImageIcon(image);
            return icon;

        }
        catch(Exception e){
            e.printStackTrace();
            return new ImageIcon();
        }
    }

    public static void main(String[] args) {
        new ImageEditEngine();
    }
}


class ImageGUI extends JFrame {

    private JPanel mainPanel;

    public ImageIcon img;

    private JLabel mLabel;

    public ImageGUI(){
        super();
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        try{
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        }
        catch(Exception e){
            e.printStackTrace();
        }
        //main panel
        mainPanel = new JPanel(new BorderLayout());
        mLabel = new JLabel();
        mainPanel.add(mLabel, BorderLayout.CENTER);

        add(mainPanel);

        setSize(new Dimension(400, 300));

        img=ImageEditEngine.openImage();
        mLabel.setIcon(img);
        mLabel.setVisible(true);
        this.repaint();
        pack();
    }
}
+2

, JLabel. .

BufferedImage img = ImageIO.read(new File(IMG_PATH));
ImageIcon icon = new ImageIcon(img);
JLabel label = new JLabel(icon);

Java Swing

!

-1

Source: https://habr.com/ru/post/1665944/

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