Installing (or using?) Qwt without compiling the Qt Creator

[r2com]

Is there any way for me to use the Qwt without compiling the Qt Creator?

And by the way my Qt Creator is: Based on Qt 5.7.0 (MSVC 2013, 32 bit)

And even if I still must build Qwt in order to use it, can it be done by building it from Qt Creator itself?

Again, all I want is to be able to generate plots inside my program, if I do not get those drag/drop Qwt controls (which I do not need anyway) I am perfectly fine with it.
I just need to be able to call Qwt functions to plot data inside my window widgets (and also plot using OpenGL)

I even tried this, I extracted the qwt-6.1.3 folder, and opened its .pro file with my Qt Creator, built it. then created a simple gui project in QtCreator, and:

.pro file:

#-------------------------------------------------
#
# Project created by QtCreator 2016-08-09T16:55:09
#
#-------------------------------------------------
 
QT       += core gui
CONFIG += qwt
QWT_LOCATION = C:\Qwt-6.1.3
INCLUDEPATH += $${QWT_LOCATION}/src
LIBS = -L$${QWT_LOCATION}/lib \
-lqwt
 
 
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 
TARGET = QwtTest2
TEMPLATE = app
 
 
SOURCES += main.cpp
 
HEADERS  +=
 
FORMS    +=

#-------------------------------------------------
#
# Project created by QtCreator 2016-08-09T16:55:09
#
#-------------------------------------------------

QT       += core gui
CONFIG += qwt
QWT_LOCATION = C:\Qwt-6.1.3
INCLUDEPATH += $${QWT_LOCATION}/src
LIBS = -L$${QWT_LOCATION}/lib \
-lqwt


greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = QwtTest2
TEMPLATE = app


SOURCES += main.cpp

HEADERS  +=

FORMS    +=

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And here is the main.cpp (some code I took as example from some of the threads in here)

#include <qapplication.h>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_grid.h>
#include <qwt_symbol.h>
#include <qwt_legend.h>
 
int main( int argc, char **argv )
{
    QApplication a( argc, argv );
 
    QwtPlot plot;
    plot.setTitle( "Plot Demo" );
    plot.setCanvasBackground( Qt::white );
    plot.setAxisScale( QwtPlot::yLeft, 0.0, 10.0 );
    plot.insertLegend( new QwtLegend() );
 
    QwtPlotGrid *grid = new QwtPlotGrid();
    grid->attach( &plot );
 
    QwtPlotCurve *curve = new QwtPlotCurve();
    curve->setTitle( "Some Points" );
    curve->setPen( Qt::blue, 4 ),
    curve->setRenderHint( QwtPlotItem::RenderAntialiased, true );
 
    QwtSymbol *symbol = new QwtSymbol( QwtSymbol::Ellipse,
        QBrush( Qt::yellow ), QPen( Qt::red, 2 ), QSize( 8, 8 ) );
    curve->setSymbol( symbol );
 
    QPolygonF points;
    points << QPointF( 0.0, 4.4 ) << QPointF( 1.0, 3.0 )
        << QPointF( 2.0, 4.5 ) << QPointF( 3.0, 6.8 )
        << QPointF( 4.0, 7.9 ) << QPointF( 5.0, 7.1 );
    curve->setSamples( points );
 
    curve->attach( &plot );
 
    plot.resize( 600, 400 );
    plot.show();
 
    return a.exec();
}

#include <qapplication.h>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_grid.h>
#include <qwt_symbol.h>
#include <qwt_legend.h>

int main( int argc, char **argv )
{
    QApplication a( argc, argv );

    QwtPlot plot;
    plot.setTitle( "Plot Demo" );
    plot.setCanvasBackground( Qt::white );
    plot.setAxisScale( QwtPlot::yLeft, 0.0, 10.0 );
    plot.insertLegend( new QwtLegend() );

    QwtPlotGrid *grid = new QwtPlotGrid();
    grid->attach( &plot );

    QwtPlotCurve *curve = new QwtPlotCurve();
    curve->setTitle( "Some Points" );
    curve->setPen( Qt::blue, 4 ),
    curve->setRenderHint( QwtPlotItem::RenderAntialiased, true );

    QwtSymbol *symbol = new QwtSymbol( QwtSymbol::Ellipse,
        QBrush( Qt::yellow ), QPen( Qt::red, 2 ), QSize( 8, 8 ) );
    curve->setSymbol( symbol );

    QPolygonF points;
    points << QPointF( 0.0, 4.4 ) << QPointF( 1.0, 3.0 )
        << QPointF( 2.0, 4.5 ) << QPointF( 3.0, 6.8 )
        << QPointF( 4.0, 7.9 ) << QPointF( 5.0, 7.1 );
    curve->setSamples( points );

    curve->attach( &plot );

    plot.resize( 600, 400 );
    plot.show();

    return a.exec();
}

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It compiles without error, but when I run it it shows this in Application Output:

QWidget: Must construct a QApplication before a QWidget

ANy ideas how can I get it to work?

[Uwe]

Is there any way for me to use the Qwt without compiling the Qt Creator?

As long as you don't want to get the designer plugin running ( where I don't see, that you need it ) the Qt Creator is unrelated to the application and the libraries ( f.e Qwt ) used for building it. So recompiling the Creator won't change anything.

QWidget: Must construct a QApplication before a QWidget

This is a standard symptom, when linking incompatible binaries. The incompatibility should be between the Qt library you are building your application with and the version you have used for building the Qwt library - often simply a debug/release mismatch.

Your project file also indicates, that you didn't follow the installation process - skipping the "make install" step. Most of the problems with building and running Qwt applications have to do with not doing it carefully, then trying to fix things manually ( like adding include + link paths to the source directory ) ...

http://qwt.sourceforge.net/qwtinstal...PILEANDLINKAPP is all that needs to be done - as soon as you have to add extra include/link paths to your project files you know, that something is wrong.

Uwe