Why custom widget can't be added to Qt Designer's plugin

nimingzhe2008

The book Foundations of Qt Development said after building the custom widget plugin project,the widget will be added to Qt Designer as plugin.But when I built the book's example project,I can't find widget in Qt Designer and building succeeded. My Qt Creator is 2.4.1

andre

Your plugin needs to be build with the exact same configuration as your IDE (designer/creator). That means: using the same Qt version, the same compiler and the same compiler settings. Is that the case?

You can see the overview of plugins from Creator. Open a designer window, and go to the Tools Menu -> Form Editor -> About Qt Designer plugins...

You will get a tree with the plugins found, and also see what problems there are with the ones that can't be loaded.

nimingzhe2008

I did as what you said,and I can't find my plugin in Plugin Information dialog.Here is the book's example code
plugin.pro

@TEMPLATE = lib
CONFIG += designer plugin release

DEPENDPATH += .

TARGET = circlebarplugin

HEADERS += circlebar.h circlebarplugin.h
SOURCES += circlebar.cpp circlebarplugin.cpp

DESTDIR = $$[QT_INSTALL_DATA]/plugins/designer

FORMS +=
@

circlebar.h
@

#ifndef CIRCLEBAR_H
#define CIRCLEBAR_H

#include <QWidget>
#include <QtDesigner>

class QDESIGNER_WIDGET_EXPORT CircleBar : public QWidget
{
Q_OBJECT

public:
CircleBar( QWidget *parent = 0 );
CircleBar( int value = 0, QWidget *parent = 0 );

int value() const;

int heightForWidth( int ) const;
QSize sizeHint() const;
public slots:
void setValue( int );

signals:
void valueChanged( int );

protected:
void paintEvent( QPaintEvent* );
void wheelEvent( QWheelEvent* );

private:
int m_value;
};

#endif // CIRCLEBAR_H
@

nimingzhe2008

circlebar.cpp
@#include <QPaintEvent>
#include <QWheelEvent>

#include <QPainter>

#include "circlebar.h"

CircleBar::CircleBar( QWidget *parent ) : QWidget( parent )
{
m_value = 0;

QSizePolicy policy( QSizePolicy::Preferred, QSizePolicy::Preferred );
policy.setHeightForWidth( true );
setSizePolicy( policy );
}

CircleBar::CircleBar( int value, QWidget *parent ) : QWidget( parent )
{
m_value = value;

QSizePolicy policy( QSizePolicy::Preferred, QSizePolicy::Preferred );
policy.setHeightForWidth( true );
setSizePolicy( policy );
}

int CircleBar::heightForWidth( int width ) const
{
return width;
}

QSize CircleBar::sizeHint() const
{
return QSize( 100, 100 );
}

int CircleBar::value() const
{
return m_value;
}

void CircleBar::setValue( int value )
{
if( value < 0 )
value = 0;

if( value > 100 )
value = 100;

if( m_value == value )
return;

m_value = value;

update();

emit valueChanged( m_value );
}

void CircleBar::paintEvent( QPaintEvent *event )
{
int radius = width()/2;
double factor = m_value/100.0;

QPainter p( this );
p.setPen( Qt::black );
p.drawEllipse( 0, 0, width()-1, width()-1 );
p.setBrush( Qt::black );
p.drawEllipse( int(radius*(1.0-factor)), int(radius*(1.0-factor)), int((width()-1)*factor)+1, int((width()-1)*factor)+1 );
}

void CircleBar::wheelEvent( QWheelEvent *event )
{
event->accept();
setValue( value() + event->delta()/20 );
}@

nimingzhe2008

circlebarplugin.h
@#ifndef CIRCLEBARPLUGIN_H
#define CIRCLEBARPLUGIN_H

#include <QDesignerCustomWidgetInterface>

class QExtensionManager;

class CircleBarPlugin : public QObject, public QDesignerCustomWidgetInterface
{
Q_OBJECT
Q_INTERFACES(QDesignerCustomWidgetInterface)

public:
CircleBarPlugin( QObject *parent = 0 );

bool isContainer() const;
bool isInitialized() const;
QIcon icon() const;
QString codeTemplate() const;
QString domXml() const;
QString group() const;
QString includeFile&#40;&#41; const;
QString name() const;
QString toolTip() const;
QString whatsThis() const;
QWidget *createWidget( QWidget *parent );
void initialize( QDesignerFormEditorInterface *core );

private:
bool m_initialized;
};

#endif /* CIRCLEBARPLUGIN_H */@

circlebarplugin.cpp
@#include <QtPlugin>
#include <QExtensionManager>
#include <QDesignerFormEditorInterface>
#include <QTimer>

#include "circlebar.h"
#include "circlebarplugin.h"

CircleBarPlugin::CircleBarPlugin( QObject *parent )
{
m_initialized = false;
}

bool CircleBarPlugin::isInitialized() const
{
return m_initialized;
}

void CircleBarPlugin::initialize( QDesignerFormEditorInterface *core )
{
if( m_initialized )
return;

m_initialized = true;

}

bool CircleBarPlugin::isContainer() const
{
return false;
}

QIcon CircleBarPlugin::icon() const
{
return QIcon();
}

QString CircleBarPlugin::toolTip() const
{
return "";
}

QString CircleBarPlugin::whatsThis() const
{
return "";
}

QString CircleBarPlugin::codeTemplate() const
{
return "";
}

QString CircleBarPlugin::includeFile() const
{
return "circlebar.h";
}

QString CircleBarPlugin::name() const
{
return "CircleBar";
}

QString CircleBarPlugin::domXml() const
{
return "<widget class="CircleBar" name="circleBar">\n"
"</widget>\n";
}

QString CircleBarPlugin::group() const
{
return "Book Widgets";
}

QWidget *CircleBarPlugin::createWidget( QWidget *parent )
{
return new CircleBar( parent );
}

Q_EXPORT_PLUGIN2( circleBarPlugin, CircleBarPlugin )@