Java example text editor

Text Editor in Java with Source Code

Today, I am going to make a Text Editor program using our Java. Yeah, Like notepad. I want to add some basic functionalities like Opening a file, Saving a file and option to change the font size. It will only take less than 100 lines of code to do this (Excluding User Interface).

I started with the toolbar javax.swing.JToolBar and added 4 buttons. Button with simple label logo and text for open,save and font size changing. The display area is simply a JTextArea with monotype font.

Opening a Text File

It is pretty straightforward to use JFileChooser to select a file. When I started thinking about opening a file, I wanted a File Chooser that filter and display only text files.Thanks to FileNameExtensionFilter from javax.swing.filechooser.FileNameExtensionFilter. I am able to display only text files on the JFileChooser using the code

FileNameExtensionFilter filter = new FileNameExtensionFilter("TEXT FILES", "txt", "text"); fileOpener.setFileFilter(filter); 

When the user selects a file and click open, The Scanner from java.util.Scanner is used to read the file.

Scanner scn = new Scanner(file); String buffer = ""; while (scn.hasNext()) < buffer += scn.nextLine() + "\n"; >display.setText(buffer); 

The “file” is nothing but the file taken from the JFileChooser and the while loop will continue until the end of file. “display” is the name of JTextArea, our display.

Saving a Text File

A global file variable called “currentEditingFile” is maintained to know whether we are working on a new, unsaved data or on an opened file. If “currentEditingFile” is null we have a new uncreated file. So the saving method will look to “currentEditingFile” and if it is null a JFileChooser will be opened to select the location for the new file. After selecting the directory, file name is taken from JOptionPane input dialog.

Changing Font Size

A global variable with default font size as 14 is maintained and increased or decreased depending upon the button pressed.

display.setFont(new java.awt.Font("Monospaced", 0, ++fontSize)); //Increase font size display.setFont(new java.awt.Font("Monospaced", 0, --fontSize)); //Decrease font size 

Extra Works

It is not acceptable to exit the program without any notice when the user clicks on the Close button. In order to add a save confirmation, i made an override on the Window Closing operating and added a confirmation message. It is done from the constructor itself

this.addWindowListener(new WindowAdapter() < @Override public void windowClosing(WindowEvent e) < super.windowClosing(e); //To change body of generated methods, choose Tools | Templates. int ans = JOptionPane.showConfirmDialog(rootPane, "Save Changes ?", "Confirm", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE); if (ans == JOptionPane.YES_OPTION) < //Write Changes saveChanges(); >> >); 

So that’s it. Download the program / source code from below buttons. If this was helpful please like me on facebook and keep visiting for more cool programs and sources.

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Build a text editor using Java swing

Hi, we are learning how to build a text editor using Java or we can say a simple notepad. Java swing components are lightweight as compared to other GUI components of Java. It is also platform-independent.

So let’s discuss how to build this project using Java swing. First, let’s discuss the components required to build this project are Text area require to writing or reading the text, then we require some menu items like file, edit, and info file contains options like open, save, new and exit whereas edit contains cut, copy, paste, undo and redo and finally on info contains information about developer and text editor. Now we require a scroll bar that scrolls the page according to the requirement of the user. Now we need to add functionality to each menu item to cut, copy, and past we require only one line of code as given below respectively.

textArea.cut(); textArea.copy(); textArea.paste();

Where textArea is the object of the JTextArea which is used for the Text Area component. Now we require to add undo and redo functionality so we require to create an object of UndoManager class and then attach this object with textArea.

UndoManager undo = new UndoManager(); textArea.getDocument().addUndoableEditListener(undo);

Now use this object and add undo and redo functionality to the menu items by writing a single line of code for each one.

Next, we require to add functionality to new, open, save and exit menu items. Let’s being with new for it we just need to clear the text in the teaxtArea component so for that, we need to set the empty string in it.

Now it time to save and open both of them the code require to add functionality in them is similar. First, we will code for the functionality to save a file.

JFileChooser filechooser = new JFileChooser("f:"); int temp = filechooser.showSaveDialog(null); if (temp == JFileChooser.APPROVE_OPTION) < File file = new File(filechooser.getSelectedFile().getAbsolutePath()); try < FileWriter filewriter = new FileWriter(file, false); BufferedWriter bufferwr = new BufferedWriter(filewriter); bufferwr.write(textRegion.getText()); bufferwr.flush(); bufferwr.close(); >catch (Exception ex) < JOptionPane.showMessageDialog(frmTextEditor, ex.getMessage()); >>

Now we will code for opening a file in the text editor.

JFileChooser filechooser = new JFileChooser("f:"); int temp = filechooser.showOpenDialog(null); if (temp == JFileChooser.APPROVE_OPTION) < File file = new File(filechooser.getSelectedFile().getAbsolutePath()); try < String str="",str1=""; FileReader fileread = new FileReader(file); BufferedReader bufferrd = new BufferedReader(fileread); str1=bufferrd.readLine(); while((str=bufferrd.readLine())!=null) < str1=str1+"\n"+str; >textRegion.setText(str1); > catch(Exception ex) < JOptionPane.showMessageDialog(frmTextEditor, ex.getMessage()); >>

Now finally we will code for exiting from the text editor through the exit menu item.

frmTextEditor.dispatchEvent(new WindowEvent(frmTextEditor, WindowEvent.WINDOW_CLOSING));

finally, we discuss the major and some minor parts of the code of the project so to completely deploy or build this project we require complete code which is attached below just copy it and build your own text editor.

import java.awt.EventQueue; import javax.swing.JFrame; import javax.swing.JMenuBar; import javax.swing.JMenu; import javax.swing.JMenuItem; import javax.swing.JOptionPane; import javax.swing.JRadioButtonMenuItem; import javax.swing.JLabel; import javax.swing.JSeparator; import javax.swing.JEditorPane; import javax.swing.JFileChooser; import java.awt.CardLayout; import javax.swing.JTextArea; import javax.swing.SpringLayout; import javax.swing.undo.UndoManager; import java.awt.event.ActionListener; import java.awt.event.WindowEvent; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.awt.event.ActionEvent; import javax.swing.BoxLayout; import java.awt.BorderLayout; import javax.swing.JScrollBar; import javax.swing.JScrollPane; public class text_editor < private JFrame frmTextEditor; /** * Launch the application. */ public static void main(String[] args) < EventQueue.invokeLater(new Runnable() < public void run() < try < text_editor window = new text_editor(); window.frmTextEditor.setVisible(true); >catch (Exception e) < e.printStackTrace(); >> >); > /** * Create the application. */ public text_editor() < initialize(); >/** * Initialize the contents of the frame. */ private void initialize() < frmTextEditor = new JFrame(); frmTextEditor.setTitle("Text Editor"); frmTextEditor.setBounds(100, 100, 505, 490); frmTextEditor.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frmTextEditor.getContentPane().setLayout(new BorderLayout(0, 0)); JTextArea textRegion = new JTextArea(); frmTextEditor.getContentPane().add(textRegion, BorderLayout.CENTER); JMenuBar menuBar = new JMenuBar(); frmTextEditor.setJMenuBar(menuBar); UndoManager undo = new UndoManager(); textRegion.getDocument().addUndoableEditListener(undo); JMenu mnFile = new JMenu("File"); menuBar.add(mnFile); JMenuItem mntmNew = new JMenuItem("New"); mntmNew.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent arg0) < textRegion.setText(""); >>); mnFile.add(mntmNew); JMenuItem mntmSave = new JMenuItem("Save"); mntmSave.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < JFileChooser filechooser = new JFileChooser("f:"); int temp = filechooser.showSaveDialog(null); if (temp == JFileChooser.APPROVE_OPTION) < File file = new File(filechooser.getSelectedFile().getAbsolutePath()); try < FileWriter filewriter = new FileWriter(file, false); BufferedWriter bufferwr = new BufferedWriter(filewriter); bufferwr.write(textRegion.getText()); bufferwr.flush(); bufferwr.close(); >catch (Exception ex) < JOptionPane.showMessageDialog(frmTextEditor, ex.getMessage()); >> > >); mnFile.add(mntmSave); JMenuItem mntmOpen = new JMenuItem("Open"); mntmOpen.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < JFileChooser filechooser = new JFileChooser("f:"); int temp = filechooser.showOpenDialog(null); if (temp == JFileChooser.APPROVE_OPTION) < File file = new File(filechooser.getSelectedFile().getAbsolutePath()); try < String str="",str1=""; FileReader fileread = new FileReader(file); BufferedReader bufferrd = new BufferedReader(fileread); str1=bufferrd.readLine(); while((str=bufferrd.readLine())!=null) < str1=str1+"\n"+str; >textRegion.setText(str1); > catch(Exception ex) < JOptionPane.showMessageDialog(frmTextEditor, ex.getMessage()); >> > >); mnFile.add(mntmOpen); JMenuItem mntmExit = new JMenuItem("Exit"); mntmExit.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < frmTextEditor.dispatchEvent(new WindowEvent(frmTextEditor, WindowEvent.WINDOW_CLOSING)); >>); mnFile.add(mntmExit); JMenu mnEdit = new JMenu("Edit"); menuBar.add(mnEdit); JMenuItem mntmCut = new JMenuItem("Cut"); mntmCut.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < textRegion.cut(); >>); mnEdit.add(mntmCut); JMenuItem mntmCopy = new JMenuItem("Copy"); mntmCopy.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < textRegion.copy(); >>); mnEdit.add(mntmCopy); JMenuItem mntmExi = new JMenuItem("Paste"); mntmExi.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < textRegion.paste(); >>); mnEdit.add(mntmExi); JMenuItem mntmUndo = new JMenuItem("Undo"); mntmUndo.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < undo.undo(); >>); mnEdit.add(mntmUndo); JMenuItem mntmRedo = new JMenuItem("Redo"); mntmRedo.addActionListener(new ActionListener() < public void actionPerformed(ActionEvent e) < undo.redo(); >>); mnEdit.add(mntmRedo); JMenu mnInfo = new JMenu("Info"); menuBar.add(mnInfo); JLabel lblThisEditorIs = new JLabel("This Editor is designed in Java Swing"); mnInfo.add(lblThisEditorIs); JSeparator separator = new JSeparator(); mnInfo.add(separator); JLabel lblDevelopedByYashika = new JLabel("& Developed By Yashika Jain"); mnInfo.add(lblDevelopedByYashika); JScrollPane scrollabletextRegion = new JScrollPane(textRegion); scrollabletextRegion.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS); scrollabletextRegion.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS); frmTextEditor.getContentPane().add(scrollabletextRegion); > >

Thank you for reading this Blog.

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📝 PHNotepad is a simple Java text/code editor (notepad) written in Java. It has also nice features such as Search tool, Find/Replace text/code, Auto-completion, Nice Image Buttons for better UX, etc.

License

pH-7/Simple-Java-Text-Editor

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README.md

PH NotePad is a simple and light text editor (notepad) written in Java.

• Search tool (to search text/keywords easily in the code) + highlighting the code found.
• Find/Replace text/code.
• Auto completion for Java and C++ keywords (files need to be saved as .java/.cpp). It can be easily expanded to support pretty much any number of languages.
• Drag and Drop (drag files into the text area and they get loaded).
• Nice image buttons for better UX.

• Pierre-Henry Soria: hi [AT] ph7 [D0T] me
• Achintha Gunasekara: contact [AT] achinthagunasekara [D0T] com

Download the Jar file and double click to run

Or run java -jar SimpleJavaTextEditor.jar from the command line

You can also generate easily a new jar file with the following command when you are in src/ directory jar cmvf ../manifest.mf ../SimpleJavaTextEditor.jar simplejavatexteditor/*.class

Icons directory and its files must be present on the path when running the application (so you will have to move «icons/» into «src/» directory)

Apache License, Version 2.0 or later; See the license.txt file in the notepad folder.

About

📝 PHNotepad is a simple Java text/code editor (notepad) written in Java. It has also nice features such as Search tool, Find/Replace text/code, Auto-completion, Nice Image Buttons for better UX, etc.

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