PropertyMap

PropertyMap playground source code for Qt World Summit 2019 speech "Fast C++-to-QML properties", modernized for Qt 6.11 and CMake.

Overview

This project benchmarks three different approaches for exposing dynamic C++ properties to QML:

Implementation	Description
StaticPropertyMap	Uses compile-time Q_PROPERTY macros — fastest at runtime but not dynamic
QmlPropertyMap	Uses Qt's QQmlOpenMetaObject to create properties on the fly
QuickPropertyMap	Custom QMetaObject built via QMetaObjectBuilder — designed for maximum performance

Switch between implementations by editing the using PropertyMap = ... alias in Player.h.

Requirements

• Qt 6.11+ (uses private APIs from CorePrivate and QmlPrivate)
• CMake 3.21+
• A C++17 compiler

Building

# Configure (point CMAKE_PREFIX_PATH to your Qt installation)
cmake -B build -DCMAKE_PREFIX_PATH=/path/to/Qt/6.11.0/gcc_64

# Build
cmake --build build

# Run
./build/propertymap

Key changes from the original (Qt 5 / qmake)

• Migrated from qmake (.pro) to CMake
• Replaced custom QmlOpenMetaObject with Qt 6's built-in QQmlOpenMetaObject
• Updated to C++17: QRandomGenerator instead of deprecated qrand(), QList instead of QVector, modern QMetaType APIs
• Modernized QML imports (unversioned import QtQuick)
• Fixed Keys.onPressed handler to use Qt 6's arrow-function syntax for the event parameter