CC插件初探

1、实现一个应用程序插架框架关键点有：

一个插件的标准接口，在主程序中存在一个插件的集合。主程序通过循环读取每个插件，将插件对象通过多态的机制转换为插件接口，实现插件的装载。

主程序对象或者主程序接口需要作为参数传递到插件对象中，以方便插件对象调用主程序的内容，如主视图、工具栏、树视图、状态栏等。

2、开源点云处理软件CloudCompare也是一个插件框架，因此也必然包括这些内容。

插件接口：ccPluginInterface，每个插件对象有在ccPluginInterface基础上定义了一个新的接口类class ccStdPluginInterface : public ccPluginInterface

具体的插件则继承自ccStdPluginInterface 累，比如这样，class qMyPlugin : public QObject, public ccStdPluginInterface

主程序对象：class ccMainAppInterface，MainWindow主窗体类实现了ccMainAppInterface接口。

MainWindow::loadPlugins()方法负责插件的调用。（mainwindow.cpp文件中）

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1 void MainWindow::loadPlugins()

2 {

3 menuPlugins->setEnabled(false);

4 menuShadersAndFilters->setEnabled(false);

5 toolBarPluginTools->setVisible(false);

6 toolBarGLFilters->setVisible(false);

7

8 //“static” plugins

9 foreach (QObject plugin, QPluginLoader::staticInstances())

10 dispatchPlugin(plugin);

11

12 ccConsole::Print(QString(“Application path: “)+QCoreApplication::applicationDirPath());

13

14 #if defined(Q_OS_MAC)

15 // plugins are in the bundle

16 QString path = QCoreApplication::applicationDirPath();

17 path.remove( “MacOS” );

18 m_pluginsPath = path + “Plugins/ccPlugins”;

19 #else

20 //plugins are in bin/plugins

21 m_pluginsPath = QCoreApplication::applicationDirPath()+QString(”/plugins”);

22 #endif

23

24 ccConsole::Print(QString(“Plugins lookup dir.: %1”).arg(m_pluginsPath));

25

26 QStringList filters;

27 #if defined(Q_OS_WIN)

28 filters << ".dll";

29 #elif defined(Q_OS_LINUX)

30 filters << “.so";

31 #elif defined(Q_OS_MAC)

32 filters << ".dylib”;

33 #endif

34 QDir pluginsDir(m_pluginsPath);

35 pluginsDir.setNameFilters(filters);

36 foreach (QString filename, pluginsDir.entryList(filters))

37 {

38 QPluginLoader loader(pluginsDir.absoluteFilePath(filename));

39 QObject* plugin = loader.instance();

40 if (plugin)

41 {

42 ccConsole::Print(QString(“Found new plugin: ‘%1’”).arg(filename));

43 if (dispatchPlugin(plugin))

44 {

45 m_pluginFileNames += filename;

46 }

47 else

48 {

49 delete plugin;

50 plugin = 0;

51 ccConsole::Warning("\tUnsupported or invalid plugin type");

52 }

53 }

54 else

55 {

56 delete plugin;

57 plugin = 0;

58 ccConsole::Warning(QString("[Plugin] %1")/.arg(pluginsDir.absoluteFilePath(filename))/.arg(loader.errorString()));

59 }

60 }

61

62 if (menuPlugins)

63 {

64 menuPlugins->setEnabled(!m_stdPlugins.empty());

65 }

66

67 if (toolBarPluginTools->isEnabled())

68 {

69 actionDisplayPluginTools->setEnabled(true);

70 actionDisplayPluginTools->setChecked(true);

71 }

72 else

73 {

74 //DGM: doesn’t work ?

75 //actionDisplayPluginTools->setChecked(false);

76 }

77

78 if (toolBarGLFilters->isEnabled())

79 {

80 actionDisplayGLFiltersTools->setEnabled(true);

81 actionDisplayGLFiltersTools->setChecked(true);

82 }

83 else

84 {

85 //DGM: doesn’t work ?

86 //actionDisplayGLFiltersTools->setChecked(false);

87 }

88 }

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　　　　　　主程序在加载插件时会调用插件的setMainAppInterface方法，将主程序参数传入，这样插件就可以获取主程序的内容了。

1 //! Sets application entry point

2 /** Called just after plugin creation by qCC

3 */

4 virtual void setMainAppInterface(ccMainAppInterface app);

3、获取主窗体中的点云图层

在doAction中的代码：

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1 const ccHObject::Container& selectedEntities = m_app->getSelectedEntities();

2 size_t selNum = selectedEntities.size();

3 if (selNum!=1)

4 {

5 m_app->dispToConsole(“Select only one cloud!”,ccMainAppInterface::ERR_CONSOLE_MESSAGE);

6 return;

7 }

8

9 ccHObject* ent = selectedEntities[0];

10 assert(ent);

11 if (!ent || !ent->isA(CC_TYPES::POINT_CLOUD))

12 {

13 m_app->dispToConsole(“Select a real point cloud!”,ccMainAppInterface::ERR_CONSOLE_MESSAGE);

14 return;

15 }

16

17 ccPointCloud* pc = static_cast<ccPointCloud*>(ent);

18

19 //input cloud

20 unsigned count = pc->size();

21 bool hasNorms = pc->hasNormals();

22 CCVector3 bbMin, bbMax;

23 pc->getBoundingBox(bbMin,bbMax);

24 const CCVector3d& globalShift = pc->getGlobalShift();

25 double globalScale = pc->getGlobalScale();

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