Pavans-NotepadPlus

A lightweight multi-tab code editor built with Java Swing.

The application provides code-editing tools, language templates, syntax highlighting, a project explorer, themes, file management, and Windows packaging through jpackage and Inno Setup.

This is an independent educational project and is not affiliated with the official Notepad++ project.

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Features

Editor

• Multi-tab text and code editing
• Create, open, save, and save-as operations
• Unsaved-change indicator in tabs and the window title
• Confirmation before closing modified files
• Middle-click tab closing
• Drag-and-drop file opening
• Duplicate-file tab prevention from the project explorer
• UTF-8 file support
• Automatic indentation
• Current-line highlighting
• Line numbers
• Horizontal and vertical scrolling
• Configurable editor font and font size
• Zoom in, zoom out, and reset zoom
• Cut, copy, paste, select all, undo, and redo
• Comment or uncomment selected lines
• Context menu for common editing actions
• Reveal active file in explorer from editor context menu

Find and Replace

• Find next
• Replace selected match
• Replace all occurrences
• Keyboard shortcut support

Language Templates

Built-in templates are available for:

• Java
• HTML
• C
• C++
• Python
• JavaScript

Template files are stored in the res directory.

Automatic File Extensions

When a language template is selected, the correct extension is added automatically during save:

Language	Default extension
Java	.java
HTML	.html
C	.c
C++	.cpp
Python	.py
JavaScript	.js

Examples:

Java template + Main       -> Main.java
Python template + script   -> script.py
JavaScript template + app  -> app.js

When the user enters an extension explicitly, the editor preserves it:

Main.java -> Main.java
Main.txt  -> Main.txt
app.js    -> app.js

Syntax Highlighting

Java-oriented syntax highlighting includes:

• Reserved and contextual keywords
• Primitive types
• Literals
• Common Java classes
• Strings
• Character literals
• Numbers
• Comments
• Annotations

Highlighting is debounced to reduce typing lag and is limited for very large documents.

Project Explorer

• Left-side file and project explorer with advanced features
• Open a project folder
• Refresh the folder tree
• Search / filter bar with debounced filtering to quickly find files
• Collapse All / Expand All header buttons for quick tree navigation
• File type icons for 65+ extensions (java, python, html, json, zip, images, etc.)
• Rich tooltips showing file size and last modified date on hover
• Right-click context menu with file operations:
  • New File and New Folder (inside directories)
  • Rename (F2)
  • Delete (Del) with confirmation
  • Copy Full Path / Copy Relative Path to clipboard
  • Open in Windows Explorer
  • Open in Terminal (for directories)
  • Show Properties dialog
  • Refresh
• Keyboard shortcuts — F2 to rename, Delete to delete selected nodes
• Single-click toggle — single click expands/collapses directories; double click opens files
• Multi-selection support — Ctrl+Click and Shift+Click for selecting multiple files
• Auto-reveal active file — the currently open file is highlighted in the tree when switching tabs
• Smart ignore list — 25+ build/dependency directories excluded (.git, node_modules, target, build, bin, obj, .idea, .vscode, pycache, etc.)
• Directories displayed before files
• Prevent duplicate tabs for the same file
• Toolbar button to hide or show the explorer
• Remember the explorer width when toggled
• Toggle Project Explorer in the View menu
• Clone-based filtering that preserves original tree data
• "(No matches)" placeholder when filter yields no results

Themes

Available themes:

• Dracula
• One Dark
• Nord
• Light
• High Contrast

Theme colors are applied to:

• Editor
• Tabs
• Toolbar
• Menus
• Status bar
• Console area
• Project explorer (including filter bar, context menus, and icons)
• Line numbers
• Current-line highlight

Status Bar

The status bar displays:

• Current filename
• Unsaved-change state
• Line number
• Column number
• File encoding
• Active theme
• Auto-save notifications

Recent Files

• Maintains a recent-files list
• Reopens recent files from the File menu
• Removes missing files from the list
• Provides a Clear Recent Files action
• Saves the list in recent_files.dat

Auto-Save

• Runs every 30 seconds
• Saves modified files that already have a valid path
• Displays an auto-save confirmation in the status bar

Compile and Run

• Compile Java code with error output
• Run Java, Python, and JavaScript files
• Interactive console with input support
• Stop running processes
• Open CMD in the current file's directory

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Keyboard Shortcuts

Action	Shortcut
New file	Ctrl + N
New window	Ctrl + Shift + N
Open file	Ctrl + O
Open folder	Ctrl + Shift + O
Save	Ctrl + S
Save as	Ctrl + Shift + S
Find / Replace	Ctrl + F
Undo	Ctrl + Z
Redo	Ctrl + Y
Cut	Ctrl + X
Copy	Ctrl + C
Paste	Ctrl + V
Select all	Ctrl + A
Comment / Uncomment	Ctrl + /
Zoom in	Ctrl + +
Zoom out	Ctrl + -
Reset zoom	Ctrl + 0
Compile	Ctrl + Shift + B
Run	F5
Stop	Shift + F5
Rename (Explorer)	F2
Delete (Explorer)	Delete
Reveal in Explorer	Ctrl + Shift + R
Toggle Explorer	Toolbar button or View menu

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Windows Distribution Mode

The distributed Windows application is intended to operate as a self-contained editor.

The installed user does not need to install Java separately. The application image generated by jpackage includes a private Java runtime used internally by the editor launcher.

The final installer contains:

• Pavans-NotepadPlus.exe
• Application JAR and configuration
• Private Java runtime
• Language templates
• Editor resources
• Application icon
• Uninstaller
• Start Menu shortcut
• Optional desktop shortcut

Editor-Only Distribution

The packaged editor does not bundle or depend on:

• javac
• System java
• Python
• py
• Node.js
• node

Therefore, the distributed editor focuses on editing files rather than executing source code.

Compile and Run controls should be removed or disabled in the editor-only release.

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Project Structure

The project can remain in the current directory layout:

Notepad/
├── icons/
│   └── pavans-notepadplus.ico
├── src/
│   └── nn/
│       ├── Notepad.java
│       ├── build.bat
│       ├── installer.iss
│       └── res/
│           ├── JavaFormat.txt
│           ├── HTMLFormat.txt
│           ├── CFormat.txt
│           ├── CPPFormat.txt
│           ├── PythonFormat.txt
│           └── JavaScriptFormat.txt
└── bin/
    └── nn/
        └── Notepad.class

Generated files:

src/
└── nn/
    └── build/
        ├── classes/
        ├── input/
        └── package/
            └── Pavans-NotepadPlus/
                ├── Pavans-NotepadPlus.exe
                ├── app/
                ├── runtime/
                └── res/

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Requirements for Building

These tools are required only on the developer computer:

• Windows 10 or later
• JDK containing:
  • javac
  • jar
  • jpackage
• Inno Setup
• A valid Windows .ico file

The end user does not need the JDK or Java installed.

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Build the Self-Contained Application

Open Command Prompt in the directory containing build.bat:

cd /d "D:\programining\coding with pavan\Qspiders\java\Notpad\src\nn"

Run:

build.bat

Expected application output:

build\package\Pavans-NotepadPlus\Pavans-NotepadPlus.exe

Test the generated EXE before creating the installer.

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Create the Windows Installer

Open installer.iss with Inno Setup.

Select:

Build -> Compile

Expected installer output:

installer-output\Pavans-NotepadPlus-Setup-1.0.0.exe

Only the generated setup EXE needs to be distributed.

During installation, Inno Setup extracts the application launcher, private runtime, resources, and other required files into the installation directory.

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Resource Paths

The editor uses relative resource paths, including:

./res/
./recent_files.dat
./icons/pavans-notepadplus.ico

Windows shortcuts must use the application installation directory as their working directory:

WorkingDir={app}

This allows templates and recent-file data to be found correctly after installation.

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Application Data

The current implementation may create:

recent_files.dat

inside the application working directory.

For a future improvement, user-generated settings and recent-file data can be moved to:

%APPDATA%\Pavans-NotepadPlus

or:

%LOCALAPPDATA%\Pavans-NotepadPlus

This avoids writing user data into the installation directory.

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Known Limitations

• Word wrap is not supported by the current JTextPane implementation.
• Syntax highlighting is primarily designed for Java.
• Very large files may skip syntax highlighting for performance.
• The editor-only Windows release does not compile or execute source files.
• Fonts such as JetBrains Mono or Fira Code fall back to an available system font when not installed.
• The project explorer should avoid following symbolic links recursively.
• The application name Notepad++ may be confused with the existing Notepad++ product; using Pavans-NotepadPlus as the package name helps distinguish this project.

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Possible Future Improvements

• Language-specific syntax highlighting for HTML, C, C++, Python, JavaScript
• Configurable keyboard shortcuts
• Search across files
• Session restoration
• Settings persistence
• File encoding selection
• Word-wrap support
• Minimap
• Split editor views
• Markdown preview
• HTML preview
• Plugin system
• Update checker
• Store user data under %APPDATA%
• Code signing for the Windows installer and executable
• File watcher for auto-refresh on external changes
• Git integration (status indicators in explorer)

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Author

Pavan Wakade

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For an open-source educational project, the MIT License is a common option.