Tried to redirect cout & cerr to QTextEdit instead of Console, but not working!

[Krish]

Hello! Friends,
I have designed a GUI in which i have lots of cout & cerr messages. Right now am able to see all those in console window but i want them to be displayed in my GUI's QTextEdit widget.

For this i made forum search and found this from where i got to know that i will have to make my own streaming class that inherits std:stream and outputs everything using qDebug or some completely different mechanism. Also here i found that i can use qdebugstream.h header to do the needful, but its not working May be i might have made mistake in implementing it.

Here is what i tried: -

#include <QtGui> 
#include <iostream>
#include "qdebugstream.h"
 
using namespace std;
 
#include "log.h"
 
mylog::mylog(QWidget *parent)
:QWidget( parent )
{
	setupUi(this); // this sets up GUI
	mylog::setWindowTitle(QString("Checking log"));
 
	connect( Start, SIGNAL( clicked() ), this, SLOT( examine() ) );
}
 
void mylog::examine()
{
	cout <<"Hello! We are ready for working" << endl;
	QDebugStream cout(std::cout,logTextEdit);
	QDebugStream cerr(std::cerr,logTextEdit);
}

#include <QtGui> 
#include <iostream>
#include "qdebugstream.h"

using namespace std;

#include "log.h"

mylog::mylog(QWidget *parent)
:QWidget( parent )
{
	setupUi(this); // this sets up GUI
	mylog::setWindowTitle(QString("Checking log"));
		
	connect( Start, SIGNAL( clicked() ), this, SLOT( examine() ) );
}

void mylog::examine()
{
	cout <<"Hello! We are ready for working" << endl;
	QDebugStream cout(std::cout,logTextEdit);
	QDebugStream cerr(std::cerr,logTextEdit);
}

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Can anyone please let me know where am i making mistake. Or is there any other way to do the needful.

I will be grateful if helped--> Thanks in advance.

[Stukfruit]

You're setting the stream after sending the text to cout. You should do it the other way around: first, set the streams, then, start sending text to it.

[Krish]

Hello! Stukfruit,
Thanks for suggesting me that, but i have already tried that out by which i got following error's: -

void mylog::examine()
{
	QDebugStream cout(std::cout,logTextEdit);
	QDebugStream cerr(std::cerr,logTextEdit);
	cout <<"Hello! We are ready for working" << endl;
}

void mylog::examine()
{
	QDebugStream cout(std::cout,logTextEdit);
	QDebugStream cerr(std::cerr,logTextEdit);
	cout <<"Hello! We are ready for working" << endl;
}

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#########error's#########

In file included from log.cpp:5:
qdebugstream.h: In member function `virtual std::streamsize QDebugStream::xsputn
(const char*, std::streamsize)':
qdebugstream.h:50: warning: comparison between signed and unsigned integer expre
ssions
qdebugstream.h:53: warning: comparison between signed and unsigned integer expre
ssions
In file included from log.cpp:5:
qdebugstream.h:74:7: warning: no newline at end of file
log.cpp: In member function `void mylog::examine()':
log.cpp:27: error: no match for 'operator<<' in 'cout << "Hello! We are ready fo
r working"'
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qchar.h:365: note: cand
idates are: QDataStream& operator<<(QDataStream&, const QChar&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qbytearray.h:534: note:
QDataStream& operator<<(QDataStream&, const QByteArray&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qstring.h:1008: note:
QDataStream& operator<<(QDataStream&, const QString&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/kernel/qobject.h:457: note:
QDebug operator<<(QDebug, const QObject*)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/io/qiodevice.h:244: note:
QDebug operator<<(QDebug, QFlags<QIODevice::OpenModeFlag>)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/io/qtextstream.h:286: note:
QTextStream& operator<<(QTextStream&, QTextStream&(*)(QTextStream
&))
../../../Qt/4.3.4/include/QtCore/../../src/corelib/io/qtextstream.h:289: note:
QTextStream& operator<<(QTextStream&, QTextStreamManipulator)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qregexp.h:141: note:
QDataStream& operator<<(QDataStream&, const QRegExp&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qstringlist.h:229: note
: QDataStream& operator<<(QDataStream&, const QStringList&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qlocale.h:579: note:
QDataStream& operator<<(QDataStream&, const QLocale&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/io/qurl.h:250: note:
QDataStream& operator<<(QDataStream&, const QUrl&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/io/qurl.h:255: note:
QDebug operator<<(QDebug, const QUrl&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/kernel/qvariant.h:590: note:
QDebug operator<<(QDebug, const QVariant&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/kernel/qvariant.h:496: note:
QDataStream& operator<<(QDataStream&, const QVariant&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/kernel/qvariant.h:498: note:
QDataStream& operator<<(QDataStream&, QVariant::Type)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/kernel/qvariant.h:591: note:
QDebug operator<<(QDebug, QVariant::Type)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qpoint.h:102: note:
QDataStream& operator<<(QDataStream&, const QPoint&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qpoint.h:182: note:
QDebug operator<<(QDebug, const QPoint&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qpoint.h:236: note:
QDataStream& operator<<(QDataStream&, const QPointF&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qpoint.h:357: note:
QDebug operator<<(QDebug, const QPointF&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qline.h:161: note:
QDebug operator<<(QDebug, const QLine&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qline.h:165: note:
QDataStream& operator<<(QDataStream&, const QLine&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qline.h:321: note:
QDebug operator<<(QDebug, const QLineF&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qline.h:325: note:
QDataStream& operator<<(QDataStream&, const QLineF&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qsize.h:101: note:
QDataStream& operator<<(QDataStream&, const QSize&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qsize.h:196: note:
QDebug operator<<(QDebug, const QSize&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qsize.h:252: note:
QDataStream& operator<<(QDataStream&, const QSizeF&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qsize.h:357: note:
QDebug operator<<(QDebug, const QSizeF&)
../../../Qt/4.3.4/include/QtCore/../../src/corelib/tools/qrect.h:198: note:
QDataStream& operator<<(QDataStream&, const QRect&)
........
..........
..............
...............This continues & finally ../..

../../../Qt/4.3.4/include/QtGui/../../src/gui/itemviews/qtreewidget.h:248: note:
QDataStream& operator<<(QDataStream&, const QTreeWidgetItem&)
../../../Qt/4.3.4/include/QtGui/../../src/gui/graphicsview/qgraphicsitem.h:910:
note: QDebug operator<<(QDebug, QGraphicsItem*)
../../../Qt/4.3.4/include/QtGui/../../src/gui/widgets/qsplitter.h:152: note:
QTextStream& operator<<(QTextStream&, const QSplitter&)
mingw32-make[1]: *** [release/log.o] Error 1

Please help me in solving the problem.
Thanks again.

[danadam]

QDebugStream cout(std::cout, textEdit);
    QDebugStream cerr(std::cerr, textEdit);
    cout <<"Hello! We are ready for working" << endl;

QDebugStream cout(std::cout, textEdit);
    QDebugStream cerr(std::cerr, textEdit);
    cout <<"Hello! We are ready for working" << endl;

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You are trying to write to QDebugStream and you should write to std::cout, so try this:

std::cout <<"Hello! We are ready for working" << std::endl;

std::cout <<"Hello! We are ready for working" << std::endl;

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instead.

[Krish]

Hello! danadam,
Thanks for taking out time & replying me. I had include the std namespace at the beginning of the implementation, but it wasn't working.
But now i tried to separately add std::cout its working.

Thanks again & Best Regards.