UniDeskPluginInterface

Abstract base class that any C++ plugin must implement to be loaded by UniDeskPluginMgr. Any DLL plugin that wishes to be loaded must inherit this class and override its two pure virtual methods.

Item	Description
Type	C++ abstract interface (not a QML type)
Source File	UniDesk/CppExt/UniDeskPluginInterface.h
IID	com.unidesk.plugin.PluginInterface

Interface Definition

class UniDeskPluginInterface {
public:
    virtual ~UniDeskPluginInterface() = default;
    virtual void registerQmlTypes(QQmlApplicationEngine *engine) = 0;
    virtual void initialize() = 0;
};

Methods

virtual void registerQmlTypes(QQmlApplicationEngine *engine) = 0

Plugins register their C++ types, singletons, or QML file paths with the QML engine here. Typical usage:

void MyPlugin::registerQmlTypes(QQmlApplicationEngine *engine) {
    qmlRegisterType<MyComponent>("MyPlugin", 1, 0, "MyComponent");
    engine->addImportPath("qrc:/");
}

virtual void initialize() = 0

Plugin initialization entry point. Called after registerQmlTypes for starting background threads, loading resources, initializing state, etc.

Implementation Steps

1. Include UniDeskPluginInterface.h in your plugin project
2. Inherit UniDeskPluginInterface and override both methods
3. Declare the interface with Q_DECLARE_INTERFACE
4. Declare the IID with Q_PLUGIN_METADATA in the plugin source file

// MyPlugin.h
#include "UniDeskPluginInterface.h"

class MyPlugin : public QObject, public UniDeskPluginInterface {
    Q_OBJECT
    Q_PLUGIN_METADATA(IID "com.unidesk.plugin.PluginInterface")
    Q_INTERFACES(UniDeskPluginInterface)
public:
    void registerQmlTypes(QQmlApplicationEngine *engine) override;
    void initialize() override;
};

// MyPlugin.cpp
#include "MyPlugin.h"

void MyPlugin::registerQmlTypes(QQmlApplicationEngine *engine) {
    qmlRegisterType<MyClock>("MyPlugin", 1, 0, "MyClock");
}

void MyPlugin::initialize() {
    qDebug() << "MyPlugin initialized";
}

Loading Mechanism

1. UniDeskPluginMgr.loadPlugins() scans all DLLs in the plugins/ directory
2. Each DLL is loaded via QPluginLoader
3. qobject_cast<UniDeskPluginInterface*> checks whether the interface is implemented
4. For valid plugins, registerQmlTypes(engine) and initialize() are called in order

Related

• UniDeskPluginMgr — Plugin manager
• Plugin Development Guide — Full plugin authoring workflow
• Official Plugins — Official plugin pack