Qt 5.6 | Qt Multimedia | QML Video Shader Effects Example | trace.h Example File

Qt 5.6.2 Reference Documentation

# trace.h Example File

multimedia/video/qmlvideofx/trace.h

      /****************************************************************************
      **
      ** Copyright (C) 2015 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** This file is part of the Qt Mobility Components.
      **
      ** $QT_BEGIN_LICENSE:LGPL21$
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      #ifndef TRACE_H
      #define TRACE_H

      #include <QDebug>

      #define ENABLE_TRACE
      //#define VERBOSE_TRACE

      namespace Trace {

      class NullDebug
      {
      public:
          template <typename T>
          NullDebug &operator<<(const T &) { return *this; }
      };

      inline NullDebug nullDebug() { return NullDebug(); }

      template <typename T>
      struct PtrWrapper
      {
          PtrWrapper(const T *ptr) : m_ptr(ptr) { }
          const T *const m_ptr;
      };

      } // namespace Trace

      template <typename T>
      inline QDebug &operator<<(QDebug &debug, const Trace::PtrWrapper<T> &wrapper)
      {
          QDebugStateSaver saver(debug);
          debug.nospace() << '[' << static_cast<const void *>(wrapper.m_ptr) << ']';
          return debug;
      }

      #ifdef ENABLE_TRACE
              inline QDebug qtTrace() { return qDebug() << "[qmlvideofx]"; }
      #    ifdef VERBOSE_TRACE
              inline QDebug qtVerboseTrace() { return qtTrace(); }
      #    else
              inline Trace::NullDebug qtVerboseTrace() { return Trace::nullDebug(); }
      #    endif
      #else
          inline Trace::NullDebug qtTrace() { return Trace::nullDebug(); }
          inline Trace::NullDebug qtVerboseTrace() { return Trace::nullDebug(); }
      #endif

      #endif // TRACE_H