hi, im having a strange problem when trying to emit a signal from a thread.

thread.h:

Qt Code: 
  1. #ifndef USBCOM_H
  2. #define USBCOM_H
  3.  
  4. #include <QObject>
  5. #include <QThread>
  6.  
  7. class UsbCom : public QThread
  8. {
  9. public:
  10.     UsbCom();
  11.     void run();
  12.  
  13.     signals:
  14.         void error(QString error);
  15. };
  16.  
  17. #endif // USBCOM_H
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thread.cpp:

Qt Code: 
  1. #include "usbcom.h"
  2. #include <QtGui>
  3.  
  4. UsbCom::UsbCom()
  5. {
  6. }
  7.  
  8. void UsbCom::run()
  9. {
  10.     emit error("error!");
  11. }
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now when trying to compile this program i am getting an undefined refference error from the compiler.

Qt Code: 
  1. Running build steps for project Project...
  2. Configuration unchanged, skipping QMake step.
  3. Starting: /usr/bin/make -w 
  4. make: Entering directory `/home/sisco/Documents/School/Project 3/Project Software/Project'
  5. g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/home/sisco/qtsdk-2009.04/qt/mkspecs/linux-g++-64 -I. -I/home/sisco/qtsdk-2009.04/qt/include/QtCore -I/home/sisco/qtsdk-2009.04/qt/include/QtGui -I/home/sisco/qtsdk-2009.04/qt/include -I../../src -I../../src -Imoc -I. -o obj/project.o project.cpp
  6. g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/home/sisco/qtsdk-2009.04/qt/mkspecs/linux-g++-64 -I. -I/home/sisco/qtsdk-2009.04/qt/include/QtCore -I/home/sisco/qtsdk-2009.04/qt/include/QtGui -I/home/sisco/qtsdk-2009.04/qt/include -I../../src -I../../src -Imoc -I. -o obj/usbcom.o usbcom.cpp
  7. g++ -m64 -Wl,-rpath,/home/sisco/qtsdk-2009.04/qt/lib -o ../../examples/bin/Project obj/main.o obj/project.o obj/savedialog.o obj/overwritedialog.o obj/tables.o obj/usbcom.o obj/moc_project.o obj/moc_savedialog.o obj/moc_overwritedialog.o obj/moc_tables.o obj/qrc_icons.o -L/home/sisco/qtsdk-2009.04/qt/lib -L../../lib -lqwt -lusb-1.0 -lQtGui -L/home/sisco/qtsdk-2009.04/qt/lib -L/usr/X11R6/lib64 -pthread -lfreetype -lgobject-2.0 -lSM -lICE -pthread -pthread -lXrender -lfontconfig -lXext -lX11 -lQtCore -lm -pthread -lgthread-2.0 -lrt -lglib-2.0 -ldl -lpthread
  8. obj/usbcom.o: In function `UsbCom::run()':
  9. /home/sisco/Documents/School/Project 3/Project Software/Project/usbcom.cpp:10: undefined reference to `UsbCom::error(QString)'
  10. collect2: ld returned 1 exit status
  11. make: Leaving directory `/home/sisco/Documents/School/Project 3/Project Software/Project'
  12. make: *** [../../examples/bin/Project] Error 1
  13. Exited with code 2.
  14. Error while building project Project
  15. When executing build step 'Make'
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code used in my main class:

Qt Code: 
  1. usbcom = new UsbCom();
  2.     connect(usbcom, SIGNAL(error(QString)), SLOT(usbError(QString)));
  3.     usbcom->start();
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what am i doing wrong?