To create a simple text editor in Java Swing we will use a JTextArea, a JMenuBar and add JMenu to it and we will add JMenuItems. All the menu items will have actionListener to detect any action.
There will be a menu bar and it will contain two menus and a button:
- File menu
- open: this menuitem is used to open a file
- save: this menuitem is used to save a file
- print : this menuitem is used to print the components of the text area
- new : this menuitem is used to create a new blank file
- Edit menu
- cut: this menuitem is to cut the selected area and copy it to clipboard
- copy: this menuitem is to copy the selected area to the clipboard
- paste : this menuitem is to paste the text from the clipboard to the text area
- Close : this button closes the frame
We have used file reader and file writer for more information on file reading and writing in Java. Please follow the below links:
Methods used:
| method | explanation |
|---|---|
| cut() | removes the selected area from the text area and store it in clipboard |
| copy() | copies the selected area from the text area and store it in clipboard |
| paste() | removes the selected area from the text area and store it in clipboard |
| print() | prints the components of the text area |
For more methods on JSwing components refer:
- Java Swing | JPanel
- Java Swing | JMenuBar
- Creating Frames using Swings in Java
- Java Swing | JTextArea
Program to create a simple text editor:
To create a simple text editor:
- First, we will create a frame f titled “editor” and apply a metal look and feel and set an ocean theme in it.
- We will add a text area and a menubar with three menu File, Edit, and Close.
- The “File” option has 4 menu items new, open, save and print.
- “Edit” has 3 menu items cut, copy and paste. We will add an action listener to all the menu items(using addActionListener() function) to detect any action.
- We will add the menu items to the menu and menu to the menubar using add() function and we would add the menubar to the frame using addJMenuBar() function.
- We will add the text area to the frame using add function set the size of the frame to 500,500 using setSize(500,500) function and then display the frame using show function.
Here is how the functions of the menu will be invoked:
- On selecting the cut, copy, paste and print menu item the inbuilt functions of text area cut(), copy(), paste() and print() will be invoked.
- On selecting “save” menu item, a file chooser will get opened which will show the save dialog after selecting a file the filewriter(buffered writer) would write the contents of the text area to the file and close the file writer and buffered writer.
- On selecting “open” menu item, a file chooser will get opened which will show the open dialog after selecting a file a file reader and a buffered reader would read the file and set the text of the text area to the contents of the file.
- If the “new” menu item is selected the text of the text area will be set to blank. If “close” menu item is selected the frame is closed by using the function isVisible(false).
Program:
Java
// Java Program to create a text editor using javaimport java.awt.*;import javax.swing.*;import java.io.*;import java.awt.event.*;import javax.swing.plaf.metal.*;import javax.swing.text.*;class editor extends JFrame implements ActionListener { // Text component JTextArea t; // Frame JFrame f; // Constructor editor() { // Create a frame f = new JFrame("editor"); try { // Set metal look and feel UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel"); // Set theme to ocean MetalLookAndFeel.setCurrentTheme(new OceanTheme()); } catch (Exception e) { } // Text component t = new JTextArea(); // Create a menubar JMenuBar mb = new JMenuBar(); // Create amenu for menu JMenu m1 = new JMenu("File"); // Create menu items JMenuItem mi1 = new JMenuItem("New"); JMenuItem mi2 = new JMenuItem("Open"); JMenuItem mi3 = new JMenuItem("Save"); JMenuItem mi9 = new JMenuItem("Print"); // Add action listener mi1.addActionListener(this); mi2.addActionListener(this); mi3.addActionListener(this); mi9.addActionListener(this); m1.add(mi1); m1.add(mi2); m1.add(mi3); m1.add(mi9); // Create amenu for menu JMenu m2 = new JMenu("Edit"); // Create menu items JMenuItem mi4 = new JMenuItem("cut"); JMenuItem mi5 = new JMenuItem("copy"); JMenuItem mi6 = new JMenuItem("paste"); // Add action listener mi4.addActionListener(this); mi5.addActionListener(this); mi6.addActionListener(this); m2.add(mi4); m2.add(mi5); m2.add(mi6); JMenuItem mc = new JMenuItem("close"); mc.addActionListener(this); mb.add(m1); mb.add(m2); mb.add(mc); f.setJMenuBar(mb); f.add(t); f.setSize(500, 500); f.show(); } // If a button is pressed public void actionPerformed(ActionEvent e) { String s = e.getActionCommand(); if (s.equals("cut")) { t.cut(); } else if (s.equals("copy")) { t.copy(); } else if (s.equals("paste")) { t.paste(); } else if (s.equals("Save")) { // Create an object of JFileChooser class JFileChooser j = new JFileChooser("f:"); // Invoke the showsSaveDialog function to show the save dialog int r = j.showSaveDialog(null); if (r == JFileChooser.APPROVE_OPTION) { // Set the label to the path of the selected directory File fi = new File(j.getSelectedFile().getAbsolutePath()); try { // Create a file writer FileWriter wr = new FileWriter(fi, false); // Create buffered writer to write BufferedWriter w = new BufferedWriter(wr); // Write w.write(t.getText()); w.flush(); w.close(); } catch (Exception evt) { JOptionPane.showMessageDialog(f, evt.getMessage()); } } // If the user cancelled the operation else JOptionPane.showMessageDialog(f, "the user cancelled the operation"); } else if (s.equals("Print")) { try { // print the file t.print(); } catch (Exception evt) { JOptionPane.showMessageDialog(f, evt.getMessage()); } } else if (s.equals("Open")) { // Create an object of JFileChooser class JFileChooser j = new JFileChooser("f:"); // Invoke the showsOpenDialog function to show the save dialog int r = j.showOpenDialog(null); // If the user selects a file if (r == JFileChooser.APPROVE_OPTION) { // Set the label to the path of the selected directory File fi = new File(j.getSelectedFile().getAbsolutePath()); try { // String String s1 = "", sl = ""; // File reader FileReader fr = new FileReader(fi); // Buffered reader BufferedReader br = new BufferedReader(fr); // Initialize sl sl = br.readLine(); // Take the input from the file while ((s1 = br.readLine()) != null) { sl = sl + "\n" + s1; } // Set the text t.setText(sl); } catch (Exception evt) { JOptionPane.showMessageDialog(f, evt.getMessage()); } } // If the user cancelled the operation else JOptionPane.showMessageDialog(f, "the user cancelled the operation"); } else if (s.equals("New")) { t.setText(""); } else if (s.equals("close")) { f.setVisible(false); } } // Main class public static void main(String args[]) { editor e = new editor(); }} |
Output:
Note: The above programs might not run in an online IDE please use an offline compiler.
