GUI

Introduction

Main.java

import javax.swing.JFrame;
import javax.swing.JLabel;

public class Main {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setTitle("My Title");
        frame.setResizable(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JLabel label = new JLabel("Hello, World!");
        frame.add(label);
        frame.pack();
        frame.setVisible(true);
    }
}

Corrected Java Swing Example

The following Java program creates a simple graphical application using Swing. This application displays a window with the title "My Title" and includes a label saying "Hello, World!".

Main.java

import javax.swing.JFrame;
import javax.swing.JLabel;

public class Main {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setTitle("My Title");
        frame.setSize(500, 500);
        frame.setResizable(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JLabel label = new JLabel("Hello, World!");
        frame.add(label);
        frame.setVisible(true);
    }
}

Key Components:

• JFrame: The main window.

• JLabel: Displays text within the window.

• setTitle(): Sets the window title.

• setSize(): Defines the window dimensions.

• setResizable(): Allows the window to be resized by the user.

• setDefaultCloseOperation(): Determines the close operation of the frame

To set a window's icon in a Java application, first create an ImageIcon object with the desired image file and then use the setIconImage method:

ImageIcon myLogo = new ImageIcon("filename");
this.setIconImage(myLogo.getImage());

Replace "filename" with the path to your image file.

Java GUI Example

This example demonstrates a basic Java GUI application using a custom frame called MyFrame which extends JFrame.

Main.java

public class Main {
    public static void main(String[] args) {
        MyFrame new_frame = new MyFrame();
    }
}

MyFrame.java

import javax.swing.JFrame;
import javax.swing.JLabel;

public class MyFrame extends JFrame {
    
    MyFrame() {
        this.setTitle("My Title");
        this.setSize(500, 500);
        this.setResizable(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JLabel label = new JLabel("Hello, World!");
        this.add(label);
        this.setVisible(true);
    }
}

Key Components:

• Title: Sets the window title to "My Title".

• Size: Window dimensions set to 500x500 pixels.

• Resizable: Allows users to resize the window.

• Close Operation: Exits the application on closing the window.

• Label: Displays "Hello, World!" in the window.

Note:

Ensure javax.swing is imported for JFrame and

The following code snippets demonstrate how to change the background color of a GUI component using Java:

1. Set the background to red:

   this.getContentPane().setBackground(Color.RED);

2. Set the background to green using RGB values:

   this.getContentPane().setBackground(new Color(0, 255, 0));

3. Set the background to white using a hexadecimal value:

   this.getContentPane().setBackground(new Color(0xFFFFFF));

// Creating a label with text
JLabel label = new JLabel("Hello, World!");

// Setting an image icon
ImageIcon img = new ImageIcon("filepath");
label.setIcon(img);

// Configuring text position
label.setHorizontalTextPosition(JLabel.CENTER);
label.setVerticalTextPosition(JLabel.TOP);

// Changing text color
label.setForeground(Color.RED);

// Setting font style and size
label.setFont(new Font("MV Boli", Font.PLAIN, 30));

// Adjusting icon-text gap
label.setIconTextGap(100);

// Aligning label vertically and horizontally
label.setVerticalAlignment(JLabel.CENTER);
label.setHorizontalAlignment(JLabel.CENTER);

// Customizing background and border
label.setBackground(Color.BLUE);
label.setOpaque(true);
Border border = BorderFactory.createLineBorder(Color.GREEN);
label.setBorder(border);

In the example code, a component on a frame has its layout set to null, allowing for absolute positioning. The setBounds method is missing a component identifier. To correct the code, include the component's name before setBounds. For example, if the component is a button, the corrected line would be:

button.setBounds(0, 0, 100, 100);

Ensure to replace button with the actual component variable name you are using.