Windows to Linux

  • I've done various assignments on Qt Creator on Windows but have recently been told they must compile in Linux which they do not. Is there any general fix so that I can get them to compile and run on Linux machines at University. Since they are University machines I obviously cant install any software in order to so. I've tried the obvious stuff like making new files in Linux and copying the content over but this doesn't work. Below is a copy of one of the assignments. Any help would be appreciated. Thanks in advance.

    @#ifndef PAINT_WIDGET
    #define PAINT_WIDGET

    #include <QWidget>
    #include <QtGui>

    //maximum amount of points that can be painted
    #define PIXEL_POINTS 100000
    //These two set the boundary of what can be painted on as the origins of the images
    #define PAGE_WIDTH 0
    #define PAGE_HEIGHT 0

    class paintWidget : public QWidget


    paintWidget(QWidget* parent = 0);
    QImage *theImage = new QImage(10000, 10000, QImage::Format_RGB32);
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void paintEvent(QPaintEvent *event);

    //variables needed for routines
    int gi;
    #endif // PAINT_WIDGET@

    @#include <QtGui>
    #include "paintWidget.h"

    paintWidget::paintWidget(QWidget *parent):
    //set the image to white
    QColor whiteColour(255, 255, 255);


    void paintWidget::paintEvent(QPaintEvent *event)
    QPainter painter(this);
    //set image to screen
    QPointF imageOrigin(0.0, 0.0);
    painter.drawImage(imageOrigin, *theImage);
    int i;
    //sets the pointer to black
    painter.setPen(QPen(Qt::black, 5 ));
    for ( i = 0 ; i < gi-1 ; ++ i ){
    if ( gy[i] > PAGE_WIDTH + PAGE_HEIGHT )
    painter.drawPoint(QPointF( gx[i], gy[i]));

    void paintWidget::mouseMoveEvent( QMouseEvent *event){
    gx[gi] = (event->x());
    gy[gi] = (event->y());
    if ( gi < PIXEL_POINTS - 1)
    void paintWidget::mousePressEvent(QMouseEvent *event) {
    gx[gi] = (event->x());
    gy[gi] = (event->y());

    @#include "paintWidget.h"
    #include <QApplication>

    int main(int argc, char *argv[])
    //create the application, set the window size and set the window to show.
    QApplication app(argc, argv);
    paintWidget g;
    g.resize(500, 400);;

    //event loop
    return app.exec&#40;&#41;;


  • If your linux machines do not have Qt installed (which I assume is why your code does not compile on Linux), your only option is to install them to your home directory or other location that you have write access to. In any case, without describing the errors you get on Linux it would be hard for anyone to offer proper advice.

  • Not sure that installing Qt in your home directory would fix anything, because it has to compile on the machine your tutor/lecturer uses to compile your assignments. And if you can't convince him that installing the Qt dev package is good, you'll have to do your assignments without Qt. That shouldn't be a problem though, because then the assignments are obviously doable without help of Qt.

  • As they have mentioned Qt must be installed on the machine.Also what compiler were used on the windows machine?Some settings are compiler specific and don't work when you get it wrong.You might want to look into that too.This has burned me recently.
    Good luck.

  • Moderators

    You can compile Qt locally without installing, too. But best option would be to convince people that installing Qt is a good idea.

    Or you can compile the project on your PC and then deploy it on University machines without installing Qt.

  • It is not a problem of Linux or Windows. In fact I have been able to compile your code in Linux. The problem is the C++ 98 standard that do not let initialize non static data members in header. In fact only int statics can be initialized. To avoid problems initialize theImage in the constructor.

  • Thanks for all the replies. For all the people wondering if QT is installed on the Linux machines, it definitely is because everyone else seems to be able to compile and run their code and most people have done these assignments at University on the same Linux machines. Achab I had a feeling that was the problem since windows was compiling and running but giving me a warning about non static data members, I will do what you have suggested and hopefully it shall work. Once again thanks for your help, you have been more helpful then my lecturer who basically just told me to sort it out myself without any hints or advice.

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