目录
QGCApplication
QGroundControlQmlGlobal
在QGC的main函数里面我们看到
QGCApplication* app = new QGCApplication(argc, argv, runUnitTests);QGCApplication是QGC数据交互的主体，QGC将相关的类在其中构造并将App作为一个全局的静态变量通过qgcApp()来访问。在该类的QGCApplication的_initCommon()实现名称为QGroundControlQmlGlobal的单例，也就是我们在qml文件中常常看到的QGroundControl 1.0模块了，通过该单例，我们可以在qml中访问C++的接口和一些属性信息。下面我们一起看一下它们的主要实现：
void QGCApplication::_initCommon(void)
{
QSettings settings;
// Register our Qml objects
qmlRegisterType<QGCPalette> ("QGroundControl.Palette", 1, 0, "QGCPalette");
qmlRegisterType<QGCMapPalette> ("QGroundControl.Palette", 1, 0, "QGCMapPalette");
qmlRegisterUncreatableType<CoordinateVector> ("QGroundControl", 1, 0, "CoordinateVector", "Reference only");
qmlRegisterUncreatableType<QmlObjectListModel> ("QGroundControl", 1, 0, "QmlObjectListModel", "Reference only");
qmlRegisterUncreatableType<MissionCommandTree> ("QGroundControl", 1, 0, "MissionCommandTree", "Reference only");
qmlRegisterUncreatableType<CameraCalc> ("QGroundControl", 1, 0, "CameraCalc", "Reference only");
qmlRegisterUncreatableType<AutoPilotPlugin> ("QGroundControl.AutoPilotPlugin", 1, 0, "AutoPilotPlugin", "Reference only");
qmlRegisterUncreatableType<VehicleComponent> ("QGroundControl.AutoPilotPlugin", 1, 0, "VehicleComponent", "Reference only");
qmlRegisterUncreatableType<Vehicle> ("QGroundControl.Vehicle", 1, 0, "Vehicle", "Reference only");
qmlRegisterUncreatableType<MissionItem> ("QGroundControl.Vehicle", 1, 0, "MissionItem", "Reference only");
qmlRegisterUncreatableType<MissionManager> ("QGroundControl.Vehicle", 1, 0, "MissionManager", "Reference only");
qmlRegisterUncreatableType<ParameterManager> ("QGroundControl.Vehicle", 1, 0, "ParameterManager", "Reference only");
qmlRegisterUncreatableType<QGCCameraManager> ("QGroundControl.Vehicle", 1, 0, "QGCCameraManager", "Reference only");
qmlRegisterUncreatableType<QGCCameraControl> ("QGroundControl.Vehicle", 1, 0, "QGCCameraControl", "Reference only");
qmlRegisterUncreatableType<LinkInterface> ("QGroundControl.Vehicle", 1, 0, "LinkInterface", "Reference only");
qmlRegisterUncreatableType<JoystickManager> ("QGroundControl.JoystickManager", 1, 0, "JoystickManager", "Reference only");
qmlRegisterUncreatableType<Joystick> ("QGroundControl.JoystickManager", 1, 0, "Joystick", "Reference only");
qmlRegisterUncreatableType<QGCPositionManager> ("QGroundControl.QGCPositionManager", 1, 0, "QGCPositionManager", "Reference only");
qmlRegisterUncreatableType<QGCMapPolygon> ("QGroundControl.FlightMap", 1, 0, "QGCMapPolygon", "Reference only");
qmlRegisterUncreatableType<MissionController> ("QGroundControl.Controllers", 1, 0, "MissionController", "Reference only");
qmlRegisterUncreatableType<GeoFenceController> ("QGroundControl.Controllers", 1, 0, "GeoFenceController", "Reference only");
qmlRegisterUncreatableType<RallyPointController>("QGroundControl.Controllers", 1, 0, "RallyPointController", "Reference only");
qmlRegisterUncreatableType<VisualMissionItem> ("QGroundControl.Controllers", 1, 0, "VisualMissionItem", "Reference only");
qmlRegisterUncreatableType<FactValueSliderListModel>("QGroundControl.FactControls", 1, 0, "FactValueSliderListModel","Reference only");
qmlRegisterType<ParameterEditorController> ("QGroundControl.Controllers", 1, 0, "ParameterEditorController");
qmlRegisterType<ESP8266ComponentController> ("QGroundControl.Controllers", 1, 0, "ESP8266ComponentController");
qmlRegisterType<ScreenToolsController> ("QGroundControl.Controllers", 1, 0, "ScreenToolsController");
qmlRegisterType<PlanMasterController> ("QGroundControl.Controllers", 1, 0, "PlanMasterController");
qmlRegisterType<ValuesWidgetController> ("QGroundControl.Controllers", 1, 0, "ValuesWidgetController");
qmlRegisterType<QGCFileDialogController> ("QGroundControl.Controllers", 1, 0, "QGCFileDialogController");
qmlRegisterType<RCChannelMonitorController> ("QGroundControl.Controllers", 1, 0, "RCChannelMonitorController");
qmlRegisterType<JoystickConfigController> ("QGroundControl.Controllers", 1, 0, "JoystickConfigController");
qmlRegisterType<LogDownloadController> ("QGroundControl.Controllers", 1, 0, "LogDownloadController");
qmlRegisterType<SyslinkComponentController> ("QGroundControl.Controllers", 1, 0, "SyslinkComponentController");
qmlRegisterType<EditPositionDialogController> ("QGroundControl.Controllers", 1, 0, "EditPositionDialogController");
qmlRegisterType<QGCMapCircle> ("QGroundControl.FlightMap", 1, 0, "QGCMapCircle");
#ifndef __mobile__
qmlRegisterType<ViewWidgetController> ("QGroundControl.Controllers", 1, 0, "ViewWidgetController");
qmlRegisterType<CustomCommandWidgetController> ("QGroundControl.Controllers", 1, 0, "CustomCommandWidgetController");
qmlRegisterType<FirmwareUpgradeController> ("QGroundControl.Controllers", 1, 0, "FirmwareUpgradeController");
qmlRegisterType<GeoTagController> ("QGroundControl.Controllers", 1, 0, "GeoTagController");
qmlRegisterType<MavlinkConsoleController> ("QGroundControl.Controllers", 1, 0, "MavlinkConsoleController");
#endif
// Register Qml Singletons
qmlRegisterSingletonType<QGroundControlQmlGlobal> ("QGroundControl", 1, 0, "QGroundControl", qgroundcontrolQmlGlobalSingletonFactory);
qmlRegisterSingletonType<ScreenToolsController> ("QGroundControl.ScreenToolsController", 1, 0, "ScreenToolsController", screenToolsControllerSingletonFactory);
qmlRegisterSingletonType<KMLFileHelper> ("QGroundControl.KMLFileHelper", 1, 0, "KMLFileHelper", kmlFileHelperSingletonFactory);
}构造了一个QGCToolbox* _toolbox,是一个主要的模块。在QGCToolBox的构造函数中，我们可以看到下面的代码
_settingsManager = new SettingsManager(app, this);
_audioOutput = new AudioOutput (app, this); //语音播报
_factSystem = new FactSystem (app, this);
_firmwarePluginManager = new FirmwarePluginManager (app, this);
#ifndef __mobile__
_gpsManager = new GPSManager (app, this);
#endif
_imageProvider = new QGCImageProvider (app, this);
_joystickManager = new JoystickManager (app, this); //虚拟遥感
_linkManager = new LinkManager (app, this); //连接管理，UDP、TCP、串口、MOCK
_mavlinkProtocol = new MAVLinkProtocol (app, this); //MAVLink消息处理入口
_missionCommandTree = new MissionCommandTree (app, this); //Mission默认配置
_multiVehicleManager = new MultiVehicleManager (app, this); //飞机管理
_mapEngineManager = new QGCMapEngineManager (app, this); //地图引擎
_uasMessageHandler = new UASMessageHandler (app, this); //UAS
_qgcPositionManager = new QGCPositionManager (app, this);
_followMe = new FollowMe (app, this);
_videoManager = new VideoManager (app, this);
_mavlinkLogManager = new MAVLinkLogManager (app, this); //Log管理在其中实现的类均继承于QGCTool，其状态都维护于protected的_toolbox变量，在其他模块，我们可以简单通过qgcApp()->toolbox()来访问其中的变量。接下来我重点介绍一下MAVLunk协议、飞机管理、Mission、电子围栏、Rally等关系可以通过 
它将需要在前端访问的C++类注册为它的属性，如下面的代码所示：
Q_PROPERTY(LinkManager* linkManager READ linkManager CONSTANT)
Q_PROPERTY(MultiVehicleManager* multiVehicleManager READ multiVehicleManager CONSTANT)
Q_PROPERTY(QGCMapEngineManager* mapEngineManager READ mapEngineManager CONSTANT)
Q_PROPERTY(QGCPositionManager* qgcPositionManger READ qgcPositionManger CONSTANT)
Q_PROPERTY(MissionCommandTree* missionCommandTree READ missionCommandTree CONSTANT)
Q_PROPERTY(VideoManager* videoManager READ videoManager CONSTANT)
Q_PROPERTY(MAVLinkLogManager* mavlinkLogManager READ mavlinkLogManager CONSTANT)
Q_PROPERTY(QGCCorePlugin* corePlugin READ corePlugin CONSTANT)
Q_PROPERTY(SettingsManager* settingsManager READ settingsManager CONSTANT)
Q_PROPERTY(FactGroup* gpsRtk READ gpsRtkFactGroup CONSTANT)同时将toolBox中的C++类指针指向它内部的指针，从而保证C++和qml前端访问相同的信息。
void QGroundControlQmlGlobal::setToolbox(QGCToolbox* toolbox)
{
QGCTool::setToolbox(toolbox);
_linkManager = toolbox->linkManager();
_multiVehicleManager = toolbox->multiVehicleManager();
_mapEngineManager = toolbox->mapEngineManager();
_qgcPositionManager = toolbox->qgcPositionManager();
_missionCommandTree = toolbox->missionCommandTree();
_videoManager = toolbox->videoManager();
_mavlinkLogManager = toolbox->mavlinkLogManager();
_corePlugin = toolbox->corePlugin();
_firmwarePluginManager = toolbox->firmwarePluginManager();
_settingsManager = toolbox->settingsManager();
......
}