Need some help porting from Qt3 to Qt4

[srikanthch]

Hi


I am new to the Qt environment.i am developing an application in Qt 4.4 under windows platform.i want my application to run when my system reboots or restarts.for this i have to load my application(.exe or .ini files) into windows registry.can i have some code snippets for this.

Thanks & regards,
Srikanthch
srikanthc49@gmail.com

[psadhukhan]

Thanks jacek
I was trying an approach whereby I will use QImage [cannot use QPixmap as I guess painting into QPixmap is not allowed from nonGUI thread] as my offscreen buffer and tried painting into that and in paintEvent trying to flush QImage into the Qt window.
Do you think this approach will work?

I am attaching the native application I tried to modify to use this approach

#include <pthread.h>
#include <Qt>
#include <QtCore>
#include <QtGui>
 
#include <QPainter>
#include <QWidget>
#include <QImage>
 
class QPen;
class QBrush;
class QImage;
 
#define qtApp	((QtApplication *)qApp)
void threadfunc(void *arg);
void AWT_drawline(int x1, int y1, int x2, int y2);
void getQtColorModel();
void Qtexec();
 
 
QImage img(800,600,QImage::Format_ARGB32);
 
class QtWindow : public QWidget
{
       QBitmap transMask;
 
public:
        QtWindow(int flags,
		const char *name = "Sun AWT/Qt",
             QWidget *parent = NULL) ;
	virtual void paintEvent(QPaintEvent *);
 
};
 
class QtApplication : public QApplication {
public :
	QtApplication(int &argc, char **argv);
	int exec(); //overloadded exec from QApplication
};
 
class QtScreen
{
protected :
    int m_x;
    int m_y;
    int m_width;
    int m_height;
    QtWindow *m_window;
    bool m_bounds_restricted;
/*    virtual char **getArgs(int *argc);
    virtual void computeBounds();
    virtual void createQtWindow();
    virtual void windowShown();
*/
 
public :
    QtScreen();
    bool init();
 /*   void close();
    void showWindow();
    void setMouseCursor(int cursor);
    void beep();
    int width();
    int height();
    int dotsPerInch();
    QtWindow *window();
    int x();
    int y();
*/
};
 
class QtScreenFactory
{
	static QtScreen *theScreen;
public:
	static QtScreen *getScreen();
};
 
 
QtWindow *m_window;
QtScreen *QtScreenFactory::theScreen = NULL;
QtApplication::QtApplication(int &argc, char **argv) : QApplication(argc, argv) {
}
 
int
QtApplication::exec(void) {
	printf("QApplication exec called\n");
	QApplication::exec();
	printf("QApplication exec done\n");
}
 
QtWindow::QtWindow(int flags, const char *name, QWidget *parent) :
	QWidget(parent, (Qt::WindowFlags)flags)
{
	setMouseTracking(true);
}
 
void
QtWindow::paintEvent(QPaintEvent *event)
{
	printf("paintEvent called\n");
#if 0
	QPen *qp = new QPen();
	QColor c(0xffff0000);
	qp->setColor(c);
	QBrush *qb = new QBrush();
	QPainter p(this);
	p.setCompositionMode(QPainter::CompositionMode_SourceOver);
	p.setPen(*qp);
	p.setClipRect(0,0,800,600);
	p.drawLine(30,135,790,135);
#endif
	QPainter p(m_window);
	QPoint pt(0,0);
	p.drawImage(pt, img);
}
 
int main(int argc, char **argv)
{
	printf("argc %d, argv %s\n",argc, *argv);
	QtScreen *screen = QtScreenFactory::getScreen();
//	 img = new QImage(800,600,QImage::Format_ARGB32);
}
 
QtScreen *
QtScreenFactory::getScreen() {
	if ( QtScreenFactory::theScreen == NULL ) {
        QtScreenFactory::theScreen = new QtScreen();
    	    if(QtScreenFactory::theScreen != NULL) {
	    	    QtScreenFactory::theScreen->init();
			}
	}
	return QtScreenFactory::theScreen;
}
 
QtScreen::QtScreen()
{
}
 
void getQtColorModel()
{
	int depth = 0;
	int amask=0,rmask=0,gmask=0,bmask=0;
 
	QWidget *d = QApplication::desktop();
	depth = d->depth();	
	printf ("Depth = %d\n", depth);
	switch(depth) {
		case 32:
			amask = 0xff000000;
		case 24:
			rmask = 0x00ff0000;
			gmask = 0x0000ff00;
			bmask = 0x000000ff;
				break;
	}
}
 
void Qtexec()
{
	qtApp->exec();
}
 
bool
QtScreen::init()
{
	pthread_t tid;
	int m_x = 0,m_y=0,m_width=800,m_height=600;
 
	int argc = 1;
	char *argv[3] = {"a.out", "-qws", NULL};
	new QtApplication(argc, argv);
	m_window = new QtWindow(Qt::FramelessWindowHint|Qt::Window);
	QBitmap bitmap(m_width, m_height);
	qtApp->setActiveWindow(m_window);
 
	QPaintDevice *qpd = m_window;
	printf("exec called\n");
	m_window->show();
	getQtColorModel();
#if 1
	pthread_create(&tid, NULL, (void *(*)(void *))threadfunc, NULL);
#endif
	Qtexec();
}
 
 
void threadfunc(void *arg)
{
	printf("threadfunc called\n");
	AWT_drawline(30,135,790,135);
}
 
void
AWT_drawline(int x1, int y1, int x2, int y2)
{
#if 0
	QPen *qp = new QPen();
	QBrush *qb = new QBrush();
	QPainter p(qpd);
	p.setCompositionMode(QPainter::CompositionMode_SourceOver);
	p.setPen(*qp);
	p.setClipRect(0,0,800,600);
	p.drawLine(30,135,790,135);
#endif
	QPainter p(&img);
	p.setCompositionMode(QPainter::CompositionMode_SourceOver);
	QPen *qp = new QPen();
	QColor c(0xffff0000);
	qp->setColor(c);
	QBrush *qb = new QBrush();
	p.setPen(*qp);
	p.setClipRect(0,0,800,600);
	p.drawLine(x1, y1, x2, y2);
	m_window->update(0,0,800,600);
}

#include <pthread.h>
#include <Qt>
#include <QtCore>
#include <QtGui>

#include <QPainter>
#include <QWidget>
#include <QImage>

class QPen;
class QBrush;
class QImage;

#define qtApp	((QtApplication *)qApp)
void threadfunc(void *arg);
void AWT_drawline(int x1, int y1, int x2, int y2);
void getQtColorModel();
void Qtexec();


QImage img(800,600,QImage::Format_ARGB32);

class QtWindow : public QWidget
{
       QBitmap transMask;

public:
        QtWindow(int flags,
		const char *name = "Sun AWT/Qt",
             QWidget *parent = NULL) ;
	virtual void paintEvent(QPaintEvent *);

};

class QtApplication : public QApplication {
public :
	QtApplication(int &argc, char **argv);
	int exec(); //overloadded exec from QApplication
};

class QtScreen
{
protected :
    int m_x;
    int m_y;
    int m_width;
    int m_height;
    QtWindow *m_window;
    bool m_bounds_restricted;
/*    virtual char **getArgs(int *argc);
    virtual void computeBounds();
    virtual void createQtWindow();
    virtual void windowShown();
*/

public :
    QtScreen();
    bool init();
 /*   void close();
    void showWindow();
    void setMouseCursor(int cursor);
    void beep();
    int width();
    int height();
    int dotsPerInch();
    QtWindow *window();
    int x();
    int y();
*/
};

class QtScreenFactory
{
	static QtScreen *theScreen;
public:
	static QtScreen *getScreen();
};


QtWindow *m_window;
QtScreen *QtScreenFactory::theScreen = NULL;
QtApplication::QtApplication(int &argc, char **argv) : QApplication(argc, argv) {
}

int
QtApplication::exec(void) {
	printf("QApplication exec called\n");
	QApplication::exec();
	printf("QApplication exec done\n");
}

QtWindow::QtWindow(int flags, const char *name, QWidget *parent) :
	QWidget(parent, (Qt::WindowFlags)flags)
{
	setMouseTracking(true);
}

void
QtWindow::paintEvent(QPaintEvent *event)
{
	printf("paintEvent called\n");
#if 0
	QPen *qp = new QPen();
	QColor c(0xffff0000);
	qp->setColor(c);
	QBrush *qb = new QBrush();
	QPainter p(this);
	p.setCompositionMode(QPainter::CompositionMode_SourceOver);
	p.setPen(*qp);
	p.setClipRect(0,0,800,600);
	p.drawLine(30,135,790,135);
#endif
	QPainter p(m_window);
	QPoint pt(0,0);
	p.drawImage(pt, img);
}

int main(int argc, char **argv)
{
	printf("argc %d, argv %s\n",argc, *argv);
	QtScreen *screen = QtScreenFactory::getScreen();
//	 img = new QImage(800,600,QImage::Format_ARGB32);
}

QtScreen *
QtScreenFactory::getScreen() {
	if ( QtScreenFactory::theScreen == NULL ) {
        QtScreenFactory::theScreen = new QtScreen();
    	    if(QtScreenFactory::theScreen != NULL) {
	    	    QtScreenFactory::theScreen->init();
			}
	}
	return QtScreenFactory::theScreen;
}

QtScreen::QtScreen()
{
}

void getQtColorModel()
{
	int depth = 0;
	int amask=0,rmask=0,gmask=0,bmask=0;

	QWidget *d = QApplication::desktop();
	depth = d->depth();	
	printf ("Depth = %d\n", depth);
	switch(depth) {
		case 32:
			amask = 0xff000000;
		case 24:
			rmask = 0x00ff0000;
			gmask = 0x0000ff00;
			bmask = 0x000000ff;
				break;
	}
}

void Qtexec()
{
	qtApp->exec();
}

bool
QtScreen::init()
{
	pthread_t tid;
	int m_x = 0,m_y=0,m_width=800,m_height=600;

	int argc = 1;
	char *argv[3] = {"a.out", "-qws", NULL};
	new QtApplication(argc, argv);
	m_window = new QtWindow(Qt::FramelessWindowHint|Qt::Window);
	QBitmap bitmap(m_width, m_height);
	qtApp->setActiveWindow(m_window);
	
	QPaintDevice *qpd = m_window;
	printf("exec called\n");
	m_window->show();
	getQtColorModel();
#if 1
	pthread_create(&tid, NULL, (void *(*)(void *))threadfunc, NULL);
#endif
	Qtexec();
}


void threadfunc(void *arg)
{
	printf("threadfunc called\n");
	AWT_drawline(30,135,790,135);
}

void
AWT_drawline(int x1, int y1, int x2, int y2)
{
#if 0
	QPen *qp = new QPen();
	QBrush *qb = new QBrush();
	QPainter p(qpd);
	p.setCompositionMode(QPainter::CompositionMode_SourceOver);
	p.setPen(*qp);
	p.setClipRect(0,0,800,600);
	p.drawLine(30,135,790,135);
#endif
	QPainter p(&img);
	p.setCompositionMode(QPainter::CompositionMode_SourceOver);
	QPen *qp = new QPen();
	QColor c(0xffff0000);
	qp->setColor(c);
	QBrush *qb = new QBrush();
	p.setPen(*qp);
	p.setClipRect(0,0,800,600);
	p.drawLine(x1, y1, x2, y2);
	m_window->update(0,0,800,600);
}

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But while executing this, I got a segv
(gdb) run
Starting program: /export/WorkSpaces/a.out
[Thread debugging using libthread_db enabled]
[New Thread -1208498480 (LWP 3723)]
argc 1, argv /export/WorkSpaces/a.out
Qt: gdb: -nograb added to command-line options.
Use the -dograb option to enforce grabbing.
exec called
Depth = 24
[New Thread -1212621936 (LWP 3727)]
QApplication exec called
threadfunc called

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1212621936 (LWP 3727)]
0x0077021d in QWidget::testAttribute (this=0x0,
attribute=Qt::WA_WState_Visible)
at ../../include/QtGui/../../src/gui/kernel/qwidget.h:986
986 return data->widget_attributes & (1<<attribute);
(gdb) bt
#0 0x0077021d in QWidget::testAttribute (this=0x0,
attribute=Qt::WA_WState_Visible)
at ../../include/QtGui/../../src/gui/kernel/qwidget.h:986
#1 0x007702e3 in QWidget::isVisible (this=0x0)
at ../../include/QtGui/../../src/gui/kernel/qwidget.h:948
#2 0x009632ee in QWidget::update (this=0x0, r=@0xb7b8d338)
at painting/qbackingstore.cpp:1203
#3 0x0804b2d7 in QWidget::update (this=0x0, ax=0, ay=0, aw=800, ah=600)
at /usr/local/Trolltech/QtDebug-4.4.3/include/QtGui/qwidget.h:945
#4 0x0804a8bb in AWT_drawline (x1=30, y1=135, x2=790, y2=135)
at drawline.cpp:214
#5 0x0804a924 in threadfunc (arg=0x0) at drawline.cpp:190
#6 0x0050044b in start_thread () from /lib/libpthread.so.0
#7 0x0047780e in clone () from /lib/libc.so.6
(gdb)

Can you please tell me as to what might be wrong in the application?

If you feel this is not the right approach, then can you please tell me how to use the event-driven approach. Which class to use and how in the above appln.?

Thanks in advance