MessageWindow.h Example File

    /**
     * @file MessageWindow.h
     * @brief Message Window.
     * @see MessageWindow
     * @author Micha? Policht
     */

    #ifndef MESSAGEWINDOW_H_
    #define MESSAGEWINDOW_H_

    #include <QDockWidget>
    #include <QTextEdit>
    #include <QEvent>

    /**
     * Message Window. Handling errors and other messages.
     */
    class MessageWindow: public QDockWidget
    {
        Q_OBJECT

        QTextEdit msgTextEdit;              ///< Main widget.
        static MessageWindow *MsgHandler;   ///< Set in constructor.
        static const char *WINDOW_TITLE;    ///< Window title.

    private:
        static QString QtMsgToQString(QtMsgType type, const char *msg);

    protected:
        /**
             * Handle custom events. MessageWindow hadles custom events listed in
             * EventType enum.
             */
        virtual void customEvent(QEvent* event);

    public:
        enum EventType {MessageEventType = QEvent::User};    ///< Custom event types.

        /**
             * Default constructor.
             *     @param parent parent widget.
             *     @param flags widget flags.
             */
        MessageWindow(QWidget* parent = 0, Qt::WindowFlags flags = 0);

        /**
             * Append message wrapper. Since ISO forbids casting member functions
             * to C functions, wrapper is needed to use this class as QtMsgHandler.
             * This method is thread-safe but not reentrant.
             *     @param type message type.
             *     @param msg message string.
             */
        static void AppendMsgWrapper(QtMsgType type, const char *msg);
    #if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
        static void AppendMsgWrapper(QtMsgType type, const QMessageLogContext &context, const QString &msg);
    #endif
        /**
             * Post message event to the main event loop. This function encapsulates
             * message into MessageEvent object and passes it to the main event loop.
             *     @param type message type.
             *     @param msg message string.
             */
        void postMsgEvent(QtMsgType type, const char *msg);

    };

    /**
     * Message Event. Custom event used by @ref MessageWindow to provide multi-threaded
     * access. Encapsulates message inside @a msg variable.
     */
    class MessageEvent: public QEvent
    {
    public:
        QString msg;    ///< Message string.

        /**
             * Contructor.
             *     @param msg message to post.
             */
        MessageEvent(QString &msg);
    };

    #endif /*MESSAGEWINDOW_H_*/