title: Qt 4.7 Symbols not found error
body: <p>Can anyone explain this error to me? It seems as though it is an error occurring with moc:</p>
  
  <pre><code>Undefined symbols:
  make: Leaving directory `/Users/Dylan/Documents/programming/qt/Clock-build-desktop'
    "ClockDelegate::ClockDelegate(QObject*)", referenced from:
        AnalogClockDelegate::AnalogClockDelegate(QObject*)in AnalogClockDelegate.o
  ld: symbol(s) not found
  collect2: ld returned 1 exit status
  make: *** [Clock.app/Contents/MacOS/Clock] Error 1
  The process "/usr/bin/make" exited with code 2.
  Error while building project Clock (target: Desktop)
  When executing build step 'Make'
  </code></pre>
  
  <p>ClockDelegate:</p>
  
  <pre><code>#ifndef CLOCKDELEGATE_H
  #define CLOCKDELEGATE_H
  
  #include &lt;QObject&gt;
  
  class QTime;
  class QWidget;
  
  class ClockDelegate : public QObject
  {
      Q_OBJECT
  
  public:
  
      explicit ClockDelegate(QObject *parent);
  
      virtual void paintClock(QWidget *, QTime *) = 0;
  };
  
  #endif // CLOCKDELEGATE_H
  </code></pre>
  
  <p>AnalogClockDelegate:</p>
  
  <pre><code>#ifndef ANALOGCLOCKDELEGATE_H
  #define ANALOGCLOCKDELEGATE_H
  
  #include &lt;QColor&gt;
  #include &lt;QPoint&gt;
  
  #include "ClockDelegate.h"
  
  class QWidget;
  
  class AnalogClockDelegate : public ClockDelegate
  {
      Q_OBJECT
  
  public:
  
      explicit AnalogClockDelegate(QObject *parent);
  
      void paintClock(QWidget *, QTime *);
  
  private:
  
      void setupClockHands();
  
      void drawClockSurface(QWidget *clockView, QTime *);
  
      void drawHourComponent(QWidget *clockView);
  
      void drawMinuteComponent(QWidget *clockView, QTime *);
  
      void drawSecondComponent(QWidget *clockView, QTime *);
  
      QPoint   m_center;
      QPoint   m_hourHand[3];
      QPoint   m_minuteHand[3];
      QPoint   m_secondHand[2];
  
      QColor   m_hourColor;
      QColor   m_minuteColor;
      QColor   m_secondColor;
      QColor   m_clockFaceColor;
  };
  
  #endif // ANALOGCLOCKDELEGATE_H
  </code></pre>