Системный монитор

SystemMonitor.h:1:1: error: ‘SystemMonitor’ does not name a type
1 | SystemMonitor::SystemMonitor(QWidget *parent) :
| ^~~~~~~~~~~~~
main.cpp: In function ‘int main(int, char**)’:
main.cpp:4:9: error: ‘QTextCodec’ has not been declared
4 | QTextCodec::setCodecForLocale(QTextCodec ::codecForName("UTF-8"));
| ^~~~~~~~~~
main.cpp:4:39: error: ‘QTextCodec’ has not been declared
4 | QTextCodec::setCodecForLocale(QTextCodec ::codecForName("UTF-8"));
| ^~~~~~~~~~
main.cpp:5:9: error: ‘QTextCodec’ has not been declared
5 | QTextCodec::setCodecForTr(QTextCodec::co decForName("UTF-8"));
| ^~~~~~~~~~
main.cpp:5:35: error: ‘QTextCodec’ has not been declared
5 | QTextCodec::setCodecForTr(QTextCodec::co decForName("UTF-8"));
| ^~~~~~~~~~
main.cpp:6:9: error: ‘QTextCodec’ has not been declared
6 | QTextCodec::setCodecForCStrings(QTextCod ec::codecForName("UTF-8"));
| ^~~~~~~~~~
main.cpp:6:41: error: ‘QTextCodec’ has not been declared
6 | QTextCodec::setCodecForCStrings(QTextCod ec::codecForName("UTF-8"));
| ^~~~~~~~~~
main.cpp:7:9: error: ‘QApplication’ was not declared in this scope
7 | QApplication app(argc,argv);
| ^~~~~~~~~~~~
main.cpp:8:9: error: ‘QStyle’ was not declared in this scope
8 | QStyle * style = QStyleFactory::create("Cleanlooks");
| ^~~~~~
main.cpp:8:18: error: ‘style’ was not declared in this scope
8 | QStyle * style = QStyleFactory::create("Cleanlooks");
| ^~~~~
main.cpp:8:26: error: ‘QStyleFactory’ has not been declared
8 | QStyle * style = QStyleFactory::create("Cleanlooks");
| ^~~~~~~~~~~~~
main.cpp:9:9: error: ‘app’ was not declared in this scope
9 | app.setStyle(style);
| ^~~
main.cpp:10:9: error: ‘SystemMonitor’ was not declared in this scope
10 | SystemMonitor sys;
| ^~~~~~~~~~~~~