QObject Class Generator

A powerful code generator for Qt C++ classes that creates boilerplate code from simple declarative files.

Overview

QObject Class Generator simplifies Qt development by generating C++ header and implementation files from lightweight .qobj definition files. Instead of writing repetitive boilerplate code for Qt properties, signals, and slots, you can define your classes declaratively and let QObject Class Generator handle the rest.

Features

• 🚀 Fast Development: Generate complete Qt classes from simple definitions
• 📝 Declarative Syntax: Clean, readable .qobj file format
• 🎯 Multiple Templates: Support for QObject, QAbstractListModel, and QSettings-based classes
• 🔧 Customizable: Flexible template system using Jinja2

Installation

Prerequisites

• Python 3.6 or higher
• Jinja2 template engine

pip install jinja2

Clone the Repository

git clone https://github.com/yourusername/qobjgen.git
cd qobjgen

Quick Start

1. Create a .qobj file describing your Qt class:

class Person
prop QString name RWN
prop int age RWN
prop QString email RWN

2. Generate the C++ files:

python qobjgen.py person.qobj -o output/

3. Use the generated files in your Qt project:
   • person.qobj.h - Header file with class declaration
   • person.qobj.cpp - Implementation file with getters, setters, and signals

Usage

python qobjgen.py [OPTIONS] QOBJFILE [QOBJFILE ...]

Options

Option	Description
--tpldir TPLDIR	Custom template directory
--nosuffix	Don't add .qobj suffix to output files
--suffix SUFFIX	Custom suffix for output files (default: .qobj)
-f, --force	Overwrite existing files
-o OUTDIR	Output directory for generated files
-h, --help	Show help message

Examples

# Generate files with default settings
python qobjgen.py examples/message.qobj

# Generate multiple files to specific directory
python qobjgen.py examples/*.qobj -o output/

# Use custom suffix and overwrite existing files
python qobjgen.py person.qobj --suffix .gen -f -o src/

QObj File Format

Basic Syntax

# Comments start with #
class ClassName [BaseClass]
prop PropertyType propertyName [Access] [key1 value1 key2 value2 ...]
tpl templateName
var variableName value

Class Definition

class MyClass              # Inherits from QObject (default)
class MyClass QWidget      # Inherits from QWidget

Properties

Properties support different access modes:

• R - Read-only (generates getter and signal)
• W - Write-only (generates setter)
• N - Notify (generates change signal)
• RW - Read-Write (default if not specified)
• RWN - Read-Write with notification

prop int id R                    # Read-only
prop QString name RW             # Read-Write
prop bool enabled RWN            # Read-Write with notifications
prop double value W              # Write-only

Templates

Choose different code generation templates:

tpl qobject      # Standard QObject (default)
tpl listmodel    # QAbstractListModel subclass
tpl settings     # QSettings-based configuration class

Variables

Define template variables for customization:

var section main                 # For settings template
var namespace MyApp              # Custom namespace

Examples

Simple Data Model

class Person
prop QString firstName RWN
prop QString lastName RWN
prop int age RWN
prop QString email RWN

Generates a Qt class with:

• Properties with getters, setters, and change signals
• Q_PROPERTY macros for QML integration
• Proper const-correctness

Settings Class

class AppSettings
tpl settings
var section main
prop bool debug R qvartype Bool default false
prop QString host qvartype String section network default "localhost"
prop QString username qvartype String section auth
prop QString password qvartype String section auth

Generates a QSettings-based configuration class with:

• Automatic loading/saving to settings file
• Section-based organization
• Default values
• Type-safe property access

List Model

class MessagesModel
tpl listmodel
prop QList<Message*> messages RWN

Generates a QAbstractListModel subclass for use with QML ListView.

Template System

QObject Class Generator uses Jinja2 templates located in the templates/ directory:

• qobject_h.tpl / qobject_cpp.tpl - Standard QObject classes
• listmodel_h.tpl / listmodel_cpp.tpl - List model classes
• settings_h.tpl / settings_cpp.tpl - Settings classes

Custom Templates

You can create custom templates and use them with --tpldir:

python qobjgen.py myclass.qobj --tpldir /path/to/custom/templates/

Generated Code Features

• Qt Properties: Full Q_PROPERTY declarations for QML binding
• Getters/Setters: Const-correct getters and type-safe setters
• Signals: Change notification signals for reactive programming
• Memory Safe: Proper RAII and Qt parent-child relationships
• QML Ready: Properties automatically exposed to QML

License

This project is licensed under the MIT License - see the LICENSE file for details.