CS 340 

Wednesday 5/8/13 at 10:30am

You are allowed 2 sides of notes on 8.5x11 inch paper

Final Exam Topic List

Qt Stuff
- Signals and Slots and Event driven programming
    connect(widget, signal, classInstance, slot)

- QPushButton
    clicked() signal
- QLabel
- QMessageBox (in its simplest form)

-   sender()

How to customize an existing Qt Widget for a special purpose


QTimer
    start()

    // often done in the constructor for the Application
     QTimer *timer = new QTimer(this);
     connect(timer, SIGNAL(timeout()), this, SLOT(update()));


    // often done is a slot for a button
    if (!timer->isActive())
     {
       upDateCount = 0;       
       timer->start(1000);// emit timeout() signal
                          //  after 1000 milliseconds
     }


    // the slot for the timeout signal
     void update()
      {
        QTimer* tm = (QTimer*) sender();

        // assume upDateCount is reset to zero when
        //  the time starts
        if (upDateCount < 10)
         {
          upDateCount ++;
          // perform desired action
         }
        else
         {
          tm->stop()
         }
      }
    
QThread
    must be inherited so we can define the run() method
    Call the constructor to create the needed internal
      information for the OS to run/operate the thread

    start() - initializes & starts the thread in the OS
                and calls the run() method 

    run() - contains the code that the thread will execute
         - we never should call run() explicitly

QTcpSocket
QTcpServer

1.   Set up the connection
    - on server side
         create QTcpServer instance
         listen()
         connect() with newConnection signal
        

    - on client side
         create QTcpSocket instance
         connectToHost()
    
    - on Server Side
         use nextPendingConnection() to get QTcpSocket Instance

2.   Send a message and receive the message
       only done with QTcpSockets instances

      - on Readers side
          connect() with readyRead signal

      - On Writers side
          write() of QTcpSocket instance

      - On readers side
          read() or set up QDataStream in the
            slot set up by the connect statement


templated function and how to use it

 template <class X>
 X min (const X& v1, const X& v2)
    {
      if (v1 < v2)
         return v1;
      else
         return v2;
    }


   Complex c1, c2, c3;  // assume op< is written for Complex
   Point p1, p2, p3;    // assume op< is NOT written for Point

      c1 = min (c2, c3);
      p1 = min (p2, p3);

    ==> compiler error (or Link error) for min(p2, p3)