Qwt examples

[jacek]

unix:LIBS += -L/qwt/lib -llibqwt

It should be:

unix:LIBS += -L/qwt/lib -lqwt

[31512]

It should be:

unix:LIBS += -L/qwt/lib -lqwt

My respect to you! It works! It must be admitted that, the truth is that I am old stupid monkey! Can you explain why it should be -L/qwt/lib -lqwt, but not -L/qwt/lib -llibqwt?

[31512]

All was good until I wrote

WidgetFrameCommonView::WidgetFrameCommonView( QWidget *parent )
    : QWidget( parent )
{
	setupUi( this );
 
        QwtPlotHistogram *histogram = new QwtPlotHistogram();
        //histogram->setStyle(QwtPlotHistogram::Columns);
        //histogram->setPen(QPen(Qt::black));
        //histogram->setBrush(QBrush(Qt::gray));
        //histogram->attach(Plot);
        //Plot->replot();
 
	CommonInfoPanel->SetBackGroundColor( Qt::lightGray );
	SeparatorsPanelsPanel->SetBackGroundColor( Qt::gray );
	gridLayout->setContentsMargins( 0, 0, 0, 0 );
	gridLayout->setSpacing( 0 );
}

WidgetFrameCommonView::WidgetFrameCommonView( QWidget *parent )
    : QWidget( parent )
{
	setupUi( this );

        QwtPlotHistogram *histogram = new QwtPlotHistogram();
        //histogram->setStyle(QwtPlotHistogram::Columns);
        //histogram->setPen(QPen(Qt::black));
        //histogram->setBrush(QBrush(Qt::gray));
        //histogram->attach(Plot);
        //Plot->replot();

	CommonInfoPanel->SetBackGroundColor( Qt::lightGray );
	SeparatorsPanelsPanel->SetBackGroundColor( Qt::gray );
	gridLayout->setContentsMargins( 0, 0, 0, 0 );
	gridLayout->setSpacing( 0 );
}

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linking RadosSeparatorQT (g++)
WidgetFrameCommonView.o: In function `WidgetFrameCommonView':
/home/Andrei/Projects/Rados/RadosSeparatorQT/Frames/WidgetFrameCommonView.cpp:9: undefined reference to `QwtPlotHistogram::QwtPlotHistogram(QString const&)'
/home/Andrei/Projects/Rados/RadosSeparatorQT/Frames/WidgetFrameCommonView.cpp:9: undefined reference to `QwtPlotHistogram::QwtPlotHistogram(QString const&)'
collect2: ld returned 1 exit status
gmake: *** [RadosSeparatorQT] Error 1
gmake: Target `first' not remade because of errors.
*** Exited with status: 2 ***

Without

QwtPlotHistogram *histogram = new QwtPlotHistogram();

QwtPlotHistogram *histogram = new QwtPlotHistogram();

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linking is successful. As I understood class QwtPlotHistogram have some bugs?

class QWT_EXPORT QwtPlotHistogram: public QwtPlotSeriesItem<QwtIntervalSample>
{
public:
    enum CurveStyle
    {
        NoCurve,
 
        Outline,
 
        Columns,
        Lines,
 
        UserCurve = 100
    };
 
    explicit QwtPlotHistogram(const QString &title = QString::null);
    explicit QwtPlotHistogram(const QwtText &title);
    virtual ~QwtPlotHistogram();
 
    ...
};
#endif

class QWT_EXPORT QwtPlotHistogram: public QwtPlotSeriesItem<QwtIntervalSample>
{
public:
    enum CurveStyle
    {
        NoCurve,

        Outline,

        Columns,
        Lines,

        UserCurve = 100
    };

    explicit QwtPlotHistogram(const QString &title = QString::null);
    explicit QwtPlotHistogram(const QwtText &title);
    virtual ~QwtPlotHistogram();

    ...
};
#endif

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[31512]

Histogram example was compiled and linked successfully. Executed successfully too. I`m perplexed... My program still generating link errors.

[31512]

OK. Problem solved successfully. Including examples.pri (with some modifications) to *.pro file of my project makes wonder...

[jacek]

Can you explain why it should be -L/qwt/lib -lqwt, but not -L/qwt/lib -llibqwt?

It's UNIX naming convention. All library file names start with "lib", so somebody in the Olde Days decided to skip it in linker options.

[31512]

It's UNIX naming convention. All library file names start with "lib", so somebody in the Olde Days decided to skip it in linker options.

Thanks a lot! Live and learn... RTFM for me.