How to change widget shape in QtDesigner ?

[giorgik]

I created a new plugin in Qt 6.5 using Visual Studio C++ 2022 Community programming environment for Windows 10. This plugin creates the new widget QLed by P. Sereno. In this plugin you can change the shape and color of the led directly in Qt Designer (created for Visual Studio C++). The plugin would work, more precisely in changing the color, but it doesn't work in changing the shape, i.e. the shape chosen in Qt Designer is not maintained when I use this plugin in Qt Creator.
I can see this right away when in Qt Designer I create the form for the test application, where I choose a widget shape (which I see listed in the plugin panel) but that doesn't change the plugin shape on the form I'm building (see attached figure).
Below I put the qled.h file of the widget:

#pragma once
 
#include <Qt>
#include <QtWidgets/QWidget>
#include <QtUiPlugin/QDesignerExportWidget>
 
 
// My Qt designer widget plugin class
 
class QColor;
 
class QDESIGNER_WIDGET_EXPORT QLed : public QWidget
{
    Q_OBJECT
    Q_ENUMS (ledColor)
    Q_ENUMS (ledShape)
	Q_PROPERTY(bool value READ value WRITE setValue)
    Q_PROPERTY(ledColor onColor READ onColor WRITE setOnColor)
    Q_PROPERTY(ledColor offColor READ offColor WRITE setOffColor)
    //Q_PROPERTY(ledShape shape READ shape WRITE setShape NOTIFY shapeChanged)
    Q_PROPERTY(ledShape shape READ shape WRITE setShape)
 
public: 
    explicit QLed(QWidget *parent = 0);
 
    bool value() const { return m_value; }
 
    enum ledColor { Red = 0, Green, Yellow, Grey, Orange, Purple, Blue };
    enum ledShape { Circle = 0, Square, Triangle, Rounded };
 
    ledColor onColor() const { return m_onColor; }
    ledColor offColor() const { return m_offColor; }
    ledShape shape() const { return m_shape; }
 
public slots:
	void setValue(bool);
    void setOnColor(ledColor);
    void setOffColor(ledColor);   
    void setShape(ledShape);
	void toggleValue();
 
signals:
    void shapeChanged(ledShape);
 
protected:
    bool m_value;
 
    ledColor m_onColor, m_offColor;
 
    int id_Timer;
 
    ledShape m_shape;
 
    QStringList shapes;
    QStringList colors;
 
    void paintEvent(QPaintEvent *event) override;
};

#pragma once

#include <Qt>
#include <QtWidgets/QWidget>
#include <QtUiPlugin/QDesignerExportWidget>


// My Qt designer widget plugin class

class QColor;

class QDESIGNER_WIDGET_EXPORT QLed : public QWidget
{
    Q_OBJECT
    Q_ENUMS (ledColor)
    Q_ENUMS (ledShape)
	Q_PROPERTY(bool value READ value WRITE setValue)
    Q_PROPERTY(ledColor onColor READ onColor WRITE setOnColor)
    Q_PROPERTY(ledColor offColor READ offColor WRITE setOffColor)
    //Q_PROPERTY(ledShape shape READ shape WRITE setShape NOTIFY shapeChanged)
    Q_PROPERTY(ledShape shape READ shape WRITE setShape)

public: 
    explicit QLed(QWidget *parent = 0);

    bool value() const { return m_value; }

    enum ledColor { Red = 0, Green, Yellow, Grey, Orange, Purple, Blue };
    enum ledShape { Circle = 0, Square, Triangle, Rounded };

    ledColor onColor() const { return m_onColor; }
    ledColor offColor() const { return m_offColor; }
    ledShape shape() const { return m_shape; }
    
public slots:
	void setValue(bool);
    void setOnColor(ledColor);
    void setOffColor(ledColor);   
    void setShape(ledShape);
	void toggleValue();

signals:
    void shapeChanged(ledShape);

protected:
    bool m_value;

    ledColor m_onColor, m_offColor;

    int id_Timer;

    ledShape m_shape;

    QStringList shapes;
    QStringList colors;

    void paintEvent(QPaintEvent *event) override;
};

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Below I put the qled.cpp file of the widget:

#include <QColor>
#include <QtGlobal>
#include <QtGui>
#include <QPolygon>
#include <QtSvg>
#include <QSvgRenderer>
#include "qled.h"
 
/*!
  \brief QLed: this is the QLed constructor.
  \param parent: The Parent Widget
*/
QLed::QLed(QWidget *parent) : QWidget(parent)
{
   m_value = false;
   m_onColor = Red;
   m_offColor = Grey;
   m_shape = Circle;
 
   setMinimumSize(QSize(50,50));
 
   shapes << ":/resources/circle_" << ":/resources/square_" << ":/resources/triang_" << ":/resources/round_";
   colors << "red.svg" << "green.svg" << "yellow.svg" << "grey.svg" << "orange.svg" << "purple.svg" << "blue.svg";
}
 
 
/*!
  \brief paintEvent: painting method
  \param QPaintEvent *
  \return void
*/
void QLed::paintEvent(QPaintEvent *)
{
    QSvgRenderer *renderer = new QSvgRenderer();
    QString ledShapeAndColor;
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);
 
    ledShapeAndColor = shapes[m_shape];
 
    if(m_value)
        ledShapeAndColor.append(colors[m_onColor]);
    else
        ledShapeAndColor.append(colors[m_offColor]);
 
    renderer->load(ledShapeAndColor);
    renderer->render(&painter);
    renderer = nullptr;
    delete renderer;
}
 
/*!
  \brief setOnColor: this method allows to change the On color {Red,Green,Yellow,Grey,Orange,Purple,blue}
  \param ledColor newColor
  \return void
*/
void QLed::setOnColor(ledColor newColor)
{
   m_onColor = newColor;
   update();
}
 
 
/*!
  \brief setOffColor: this method allows to change the Off color {Red,Green,Yellow,Grey,Orange,Purple,blue}
  \param ledColor newColor
  \return void
*/
void QLed::setOffColor(ledColor newColor)
{
   m_offColor = newColor;
   update();
}
 
 
/*!
  \brief setShape: this method allows to change the led shape {Circle,Square,Triangle,Rounded rectangle}
  \param ledColor newColor
  \return void
*/
void QLed::setShape(ledShape newShape)
{
   m_shape = newShape;
   update();
}
 
/*!
  \brief setValue: this method allows to set the led value {true,false}
  \param ledColor newColor
  \return void
*/
void QLed::setValue(bool value)
{
   m_value = value;
   update();
}
 
 
/*!
  \brief toggleValue: this method toggles the led value
  \param ledColor newColor
  \return void
*/
void QLed::toggleValue()
{ 
	m_value =! m_value;
	update(); 
}

#include <QColor>
#include <QtGlobal>
#include <QtGui>
#include <QPolygon>
#include <QtSvg>
#include <QSvgRenderer>
#include "qled.h"

/*!
  \brief QLed: this is the QLed constructor.
  \param parent: The Parent Widget
*/
QLed::QLed(QWidget *parent) : QWidget(parent)
{
   m_value = false;
   m_onColor = Red;
   m_offColor = Grey;
   m_shape = Circle;

   setMinimumSize(QSize(50,50));

   shapes << ":/resources/circle_" << ":/resources/square_" << ":/resources/triang_" << ":/resources/round_";
   colors << "red.svg" << "green.svg" << "yellow.svg" << "grey.svg" << "orange.svg" << "purple.svg" << "blue.svg";
}


/*!
  \brief paintEvent: painting method
  \param QPaintEvent *
  \return void
*/
void QLed::paintEvent(QPaintEvent *)
{
    QSvgRenderer *renderer = new QSvgRenderer();
    QString ledShapeAndColor;
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);

    ledShapeAndColor = shapes[m_shape];

    if(m_value)
        ledShapeAndColor.append(colors[m_onColor]);
    else
        ledShapeAndColor.append(colors[m_offColor]);

    renderer->load(ledShapeAndColor);
    renderer->render(&painter);
    renderer = nullptr;
    delete renderer;
}

/*!
  \brief setOnColor: this method allows to change the On color {Red,Green,Yellow,Grey,Orange,Purple,blue}
  \param ledColor newColor
  \return void
*/
void QLed::setOnColor(ledColor newColor)
{
   m_onColor = newColor;
   update();
}


/*!
  \brief setOffColor: this method allows to change the Off color {Red,Green,Yellow,Grey,Orange,Purple,blue}
  \param ledColor newColor
  \return void
*/
void QLed::setOffColor(ledColor newColor)
{
   m_offColor = newColor;
   update();
}


/*!
  \brief setShape: this method allows to change the led shape {Circle,Square,Triangle,Rounded rectangle}
  \param ledColor newColor
  \return void
*/
void QLed::setShape(ledShape newShape)
{
   m_shape = newShape;
   update();
}

/*!
  \brief setValue: this method allows to set the led value {true,false}
  \param ledColor newColor
  \return void
*/
void QLed::setValue(bool value)
{
   m_value = value;
   update();
}


/*!
  \brief toggleValue: this method toggles the led value
  \param ledColor newColor
  \return void
*/
void QLed::toggleValue()
{ 
	m_value =! m_value;
	update(); 
}

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Below I put the qledplugin.h file of the widget:

#pragma once
 
#include <QDesignerCustomWidgetInterface>
 
// See Cusotm Widget Plugin Example in Qt online documentation to understand the meaning of this file
 
 
class QLedPlugin : public QObject, public QDesignerCustomWidgetInterface
{
    Q_OBJECT
    Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QDesignerCustomWidgetInterface")
    Q_INTERFACES(QDesignerCustomWidgetInterface)
 
public:
    QLedPlugin(QObject *parent = 0);
 
    bool isContainer() const override;
    bool isInitialized() const override;
 
    QIcon icon() const override;
 
    QString domXml() const override;
    QString group() const override;
    QString includeFile() const override;
    QString name() const override;
    QString toolTip() const override;
    QString whatsThis() const override;
 
    QWidget *createWidget(QWidget *parent) override;
 
    void initialize(QDesignerFormEditorInterface *core) override;
 
private:
    bool initialized = false;
};

#pragma once

#include <QDesignerCustomWidgetInterface>

// See Cusotm Widget Plugin Example in Qt online documentation to understand the meaning of this file


class QLedPlugin : public QObject, public QDesignerCustomWidgetInterface
{
    Q_OBJECT
    Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QDesignerCustomWidgetInterface")
    Q_INTERFACES(QDesignerCustomWidgetInterface)

public:
    QLedPlugin(QObject *parent = 0);

    bool isContainer() const override;
    bool isInitialized() const override;

    QIcon icon() const override;

    QString domXml() const override;
    QString group() const override;
    QString includeFile() const override;
    QString name() const override;
    QString toolTip() const override;
    QString whatsThis() const override;

    QWidget *createWidget(QWidget *parent) override;

    void initialize(QDesignerFormEditorInterface *core) override;

private:
    bool initialized = false;
};

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Below I put the qledplugin.cpp file of the widget:

#include "qled.h"
#include "qledplugin.h"
 
#include <QtPlugin>
 
using namespace Qt::StringLiterals;
 
// See Cusotm Widget Plugin Example in Qt online documentation to understand the meaning of this file
 
QLedPlugin::QLedPlugin(QObject *parent)
    : QObject(parent)
{
    initialized = false;
}
 
void QLedPlugin::initialize(QDesignerFormEditorInterface * /* core */)
{
    if (initialized)
        return;
 
    initialized = true;
}
 
bool QLedPlugin::isInitialized() const
{
    return initialized;
}
 
QWidget *QLedPlugin::createWidget(QWidget *parent)
{
    return new QLed(parent);
}
 
QString QLedPlugin::name() const
{
    return u"QLed"_s;
}
 
QString QLedPlugin::group() const
{
    return u"Lab Widgets"_s;  //change this if you want to put the custom widget plugin in another group
}
 
QIcon QLedPlugin::icon() const
{
    return QIcon(":resources/qled.png");
}
 
QString QLedPlugin::toolTip() const
{
    return u"Led Custom widget Plugin fot Qt Designer"_s;
}
 
QString QLedPlugin::whatsThis() const
{
    return u"Led Custom widget Plugin fot Qt Designer"_s;
}
 
bool QLedPlugin::isContainer() const
{
    return false;
}
 
QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"
 
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")
 
R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
      <enum>QLed::Green</enum>
      <enum>QLed::Yellow</enum>
      <enum>QLed::Grey</enum>
      <enum>QLed::Orange</enum>
      <enum>QLed::Purple</enum>
      <enum>QLed::Blue</enum>
    </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
      <enum>QLed::Square</enum>
      <enum>QLed::Triangle</enum>
      <enum>QLed::Rounded</enum>
    </property>
  </widget>
</ui>
)"_s;
}
 
QString QLedPlugin::includeFile() const
{
    return u"qled.h"_s;
}

#include "qled.h"
#include "qledplugin.h"

#include <QtPlugin>

using namespace Qt::StringLiterals;

// See Cusotm Widget Plugin Example in Qt online documentation to understand the meaning of this file

QLedPlugin::QLedPlugin(QObject *parent)
    : QObject(parent)
{
    initialized = false;
}

void QLedPlugin::initialize(QDesignerFormEditorInterface * /* core */)
{
    if (initialized)
        return;

    initialized = true;
}

bool QLedPlugin::isInitialized() const
{
    return initialized;
}

QWidget *QLedPlugin::createWidget(QWidget *parent)
{
    return new QLed(parent);
}

QString QLedPlugin::name() const
{
    return u"QLed"_s;
}

QString QLedPlugin::group() const
{
    return u"Lab Widgets"_s;  //change this if you want to put the custom widget plugin in another group
}

QIcon QLedPlugin::icon() const
{
    return QIcon(":resources/qled.png");
}

QString QLedPlugin::toolTip() const
{
    return u"Led Custom widget Plugin fot Qt Designer"_s;
}

QString QLedPlugin::whatsThis() const
{
    return u"Led Custom widget Plugin fot Qt Designer"_s;
}

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

QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"
           
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")

R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
      <enum>QLed::Green</enum>
      <enum>QLed::Yellow</enum>
      <enum>QLed::Grey</enum>
      <enum>QLed::Orange</enum>
      <enum>QLed::Purple</enum>
      <enum>QLed::Blue</enum>
    </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
      <enum>QLed::Square</enum>
      <enum>QLed::Triangle</enum>
      <enum>QLed::Rounded</enum>
    </property>
  </widget>
</ui>
)"_s;
}

QString QLedPlugin::includeFile() const
{
    return u"qled.h"_s;
}

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Where am I doing wrong ?

[d_stranz]

QSvgRenderer::load() returns a bool. In your paint event, you do not check this value. It is possible that the resource is not loading.

How have you packaged your QLed widget for use in the application? As a DLL or a static library (LIB)? If it is a static library, you may need to insert a call to initialize the resources in main(): Q_INIT_RESOURCE.

In paintEvent() this doesn't make any sense:

renderer = nullptr;
delete renderer;

renderer = nullptr;
delete renderer;

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If you set the pointer to null before you delete the instance, then delete does nothing and you have a memory leak. And since the renderer instance is local to the paint method, there is no need to set it to null at all. It gets re-recreated and re-initialized with every paintEvent() call. So just get rid of the "renderer = null" line completely.

I think you can simply create the QSvgRenderer instance on the stack instead of using new() to create a pointer:

void QLed::paintEvent(QPaintEvent *)
{
    QSvgRenderer renderer;
    QString ledShapeAndColor;
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);
 
    ledShapeAndColor = shapes[m_shape];
 
    if(m_value)
        ledShapeAndColor.append(colors[m_onColor]);
    else
        ledShapeAndColor.append(colors[m_offColor]);
 
    bool bLoaded = renderer.load(ledShapeAndColor);
    assert( bLoaded );
 
    renderer.render(&painter);
}

void QLed::paintEvent(QPaintEvent *)
{
    QSvgRenderer renderer;
    QString ledShapeAndColor;
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);

    ledShapeAndColor = shapes[m_shape];

    if(m_value)
        ledShapeAndColor.append(colors[m_onColor]);
    else
        ledShapeAndColor.append(colors[m_offColor]);

    bool bLoaded = renderer.load(ledShapeAndColor);
    assert( bLoaded );

    renderer.render(&painter);
}

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One other suggestion to improve efficiency: Your two QStringList member variables should be made static const, and probably just moved to the top of the qled.cpp file. Initialize them using list initialization during compilation. In your current code, you create and initialize the lists every time a QLed is created. If your UI has a lot of LEDs, this could slow down your program's startup.

static const QStringList sShapes { "shape1", "shape2", "shape3" };  // Don't remember what your shapes and colors are :-)
static const QStringList sColors { "color1", "color2", "color3" };
 
QLed::QLed( QWidget * parent )
: QWidget( parent )
{
// ...
}

static const QStringList sShapes { "shape1", "shape2", "shape3" };  // Don't remember what your shapes and colors are :-)
static const QStringList sColors { "color1", "color2", "color3" };

QLed::QLed( QWidget * parent )
: QWidget( parent )
{
// ...
}

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[giorgik]

QSvgRenderer::load() returns a bool. In your paint event, you do not check this value. It is possible that the resource is not loading.

How have you packaged your QLed widget for use in the application? As a DLL or a static library (LIB)? If it is a static library, you may need to insert a call to initialize the resources in main(): Q_INIT_RESOURCE.

In paintEvent() this doesn't make any sense:

renderer = nullptr;
delete renderer;

renderer = nullptr;
delete renderer;

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If you set the pointer to null before you delete the instance, then delete does nothing and you have a memory leak. And since the renderer instance is local to the paint method, there is no need to set it to null at all. It gets re-recreated and re-initialized with every paintEvent() call. So just get rid of the "renderer = null" line completely.

I think you can simply create the QSvgRenderer instance on the stack instead of using new() to create a pointer:

void QLed::paintEvent(QPaintEvent *)
{
    QSvgRenderer renderer;
    QString ledShapeAndColor;
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);
 
    ledShapeAndColor = shapes[m_shape];
 
    if(m_value)
        ledShapeAndColor.append(colors[m_onColor]);
    else
        ledShapeAndColor.append(colors[m_offColor]);
 
    bool bLoaded = renderer.load(ledShapeAndColor);
    assert( bLoaded );
 
    renderer.render(&painter);
}

void QLed::paintEvent(QPaintEvent *)
{
    QSvgRenderer renderer;
    QString ledShapeAndColor;
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);

    ledShapeAndColor = shapes[m_shape];

    if(m_value)
        ledShapeAndColor.append(colors[m_onColor]);
    else
        ledShapeAndColor.append(colors[m_offColor]);

    bool bLoaded = renderer.load(ledShapeAndColor);
    assert( bLoaded );

    renderer.render(&painter);
}

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One other suggestion to improve efficiency: Your two QStringList member variables should be made static const, and probably just moved to the top of the qled.cpp file. Initialize them using list initialization during compilation. In your current code, you create and initialize the lists every time a QLed is created. If your UI has a lot of LEDs, this could slow down your program's startup.

static const QStringList sShapes { "shape1", "shape2", "shape3" };  // Don't remember what your shapes and colors are :-)
static const QStringList sColors { "color1", "color2", "color3" };
 
QLed::QLed( QWidget * parent )
: QWidget( parent )
{
// ...
}

static const QStringList sShapes { "shape1", "shape2", "shape3" };  // Don't remember what your shapes and colors are :-)
static const QStringList sColors { "color1", "color2", "color3" };

QLed::QLed( QWidget * parent )
: QWidget( parent )
{
// ...
}

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First of all thanks for your advice. I create the plugin as a dynamic library (.dll). I would like to point out that I built the project within the Visual Studio C++ 2022 Community, with VS Tools for Qt. However, the problem I described has not been resolved.

[d_stranz]

However, the problem I described has not been resolved.

Can you post the SVG files?

What happens when you actually use this QLed widget in an application (not in Qt Designer, but in an actual app)? Does the shape change?

What happens in Qt Designer when you ask it to Preview the form?

[giorgik]

Can you post the SVG files?

What happens when you actually use this QLed widget in an application (not in Qt Designer, but in an actual app)? Does the shape change?

What happens in Qt Designer when you ask it to Preview the form?

An svg file is what I attach. When I start the application that makes use of the widget, it appears as it appears on the Designer, i.e. that of the first element of the Enum and not the one I select from the Designer (again as soon as I do enter after choosing the name, for example Triangle, it returns to Circle ).
screenshot.png

[giorgik]

To better understand my problem, I attach some pictures of my widget in QtDesigner of Qt 6.5.
In attachment 28_campo_shape_widget_QtDesigner I have highlighted the properties field of the widget that I want to set when creating the form of the test program. As you can see I clicked on the shape field to select a shape for my widget. When I selected it, I would expect to see that shape on the form I'm creating for the test, but in reality it always shows me the first item in the shape list, i.e. Circle and not Triangle for example. Can you explain to me why this happens ?

In the attachment you can see the Rounded shape which appears immediately when I drag my widget from the Widget Box and then deposit it on the form under construction, but as soon as I go to choose another shape, it is not displayed and Circle appears in its place.

[d_stranz]

The documentation for Q_ENUMS() says it is obsolete and that you should use Q_ENUM() instead. It is possible that the version of Qt Designer you are using depends on the enum being registered with Qt's meta type system. Q_ENUM() must be placed in the code after the enum has been declared.

#pragma once
 
#include <Qt>
#include <QtWidgets/QWidget>
#include <QtUiPlugin/QDesignerExportWidget>
 
 
// My Qt designer widget plugin class
 
class QColor;
 
class QDESIGNER_WIDGET_EXPORT QLed : public QWidget
{
    Q_OBJECT
 
    Q_PROPERTY(bool value READ value WRITE setValue)
    Q_PROPERTY(ledColor onColor READ onColor WRITE setOnColor)
    Q_PROPERTY(ledColor offColor READ offColor WRITE setOffColor)
    Q_PROPERTY(ledShape shape READ shape WRITE setShape)
 
public: 
    explicit QLed(QWidget *parent = 0);
 
    bool value() const { return m_value; }
 
    enum ledColor { Red = 0, Green, Yellow, Grey, Orange, Purple, Blue };
    Q_ENUM (ledColor)
 
    enum ledShape { Circle = 0, Square, Triangle, Rounded };
    Q_ENUM (ledShape)
 
    ledColor onColor() const { return m_onColor; }
    ledColor offColor() const { return m_offColor; }
    ledShape shape() const { return m_shape; }
 
public slots:
    void setValue(bool);
    void setOnColor(ledColor);
    void setOffColor(ledColor);   
    void setShape(ledShape);
    void toggleValue();
 
signals:
    void shapeChanged(ledShape);
 
protected:
    bool m_value;
 
    ledColor m_onColor, m_offColor;
 
    int id_Timer;
 
    ledShape m_shape;
 
 
    void paintEvent(QPaintEvent *event) override;
};

#pragma once

#include <Qt>
#include <QtWidgets/QWidget>
#include <QtUiPlugin/QDesignerExportWidget>


// My Qt designer widget plugin class

class QColor;

class QDESIGNER_WIDGET_EXPORT QLed : public QWidget
{
    Q_OBJECT
    
    Q_PROPERTY(bool value READ value WRITE setValue)
    Q_PROPERTY(ledColor onColor READ onColor WRITE setOnColor)
    Q_PROPERTY(ledColor offColor READ offColor WRITE setOffColor)
    Q_PROPERTY(ledShape shape READ shape WRITE setShape)

public: 
    explicit QLed(QWidget *parent = 0);

    bool value() const { return m_value; }

    enum ledColor { Red = 0, Green, Yellow, Grey, Orange, Purple, Blue };
    Q_ENUM (ledColor)

    enum ledShape { Circle = 0, Square, Triangle, Rounded };
    Q_ENUM (ledShape)

    ledColor onColor() const { return m_onColor; }
    ledColor offColor() const { return m_offColor; }
    ledShape shape() const { return m_shape; }
    
public slots:
    void setValue(bool);
    void setOnColor(ledColor);
    void setOffColor(ledColor);   
    void setShape(ledShape);
    void toggleValue();

signals:
    void shapeChanged(ledShape);

protected:
    bool m_value;

    ledColor m_onColor, m_offColor;

    int id_Timer;

    ledShape m_shape;

 
    void paintEvent(QPaintEvent *event) override;
};

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For your example with the 5 LEDs, can you post the XML .ui file that Qt Designer creates for this widget? In Qt Designer, be sure to select different shapes for the LEDs even if Qt Designer shows them all as circles.

[giorgik]

The documentation for Q_ENUMS() says it is obsolete and that you should use Q_ENUM() instead. It is possible that the version of Qt Designer you are using depends on the enum being registered with Qt's meta type system. Q_ENUM() must be placed in the code after the enum has been declared.

#pragma once
 
#include <Qt>
#include <QtWidgets/QWidget>
#include <QtUiPlugin/QDesignerExportWidget>
 
 
// My Qt designer widget plugin class
 
class QColor;
 
class QDESIGNER_WIDGET_EXPORT QLed : public QWidget
{
    Q_OBJECT
 
    Q_PROPERTY(bool value READ value WRITE setValue)
    Q_PROPERTY(ledColor onColor READ onColor WRITE setOnColor)
    Q_PROPERTY(ledColor offColor READ offColor WRITE setOffColor)
    Q_PROPERTY(ledShape shape READ shape WRITE setShape)
 
public: 
    explicit QLed(QWidget *parent = 0);
 
    bool value() const { return m_value; }
 
    enum ledColor { Red = 0, Green, Yellow, Grey, Orange, Purple, Blue };
    Q_ENUM (ledColor)
 
    enum ledShape { Circle = 0, Square, Triangle, Rounded };
    Q_ENUM (ledShape)
 
    ledColor onColor() const { return m_onColor; }
    ledColor offColor() const { return m_offColor; }
    ledShape shape() const { return m_shape; }
 
public slots:
    void setValue(bool);
    void setOnColor(ledColor);
    void setOffColor(ledColor);   
    void setShape(ledShape);
    void toggleValue();
 
signals:
    void shapeChanged(ledShape);
 
protected:
    bool m_value;
 
    ledColor m_onColor, m_offColor;
 
    int id_Timer;
 
    ledShape m_shape;
 
 
    void paintEvent(QPaintEvent *event) override;
};

#pragma once

#include <Qt>
#include <QtWidgets/QWidget>
#include <QtUiPlugin/QDesignerExportWidget>


// My Qt designer widget plugin class

class QColor;

class QDESIGNER_WIDGET_EXPORT QLed : public QWidget
{
    Q_OBJECT
    
    Q_PROPERTY(bool value READ value WRITE setValue)
    Q_PROPERTY(ledColor onColor READ onColor WRITE setOnColor)
    Q_PROPERTY(ledColor offColor READ offColor WRITE setOffColor)
    Q_PROPERTY(ledShape shape READ shape WRITE setShape)

public: 
    explicit QLed(QWidget *parent = 0);

    bool value() const { return m_value; }

    enum ledColor { Red = 0, Green, Yellow, Grey, Orange, Purple, Blue };
    Q_ENUM (ledColor)

    enum ledShape { Circle = 0, Square, Triangle, Rounded };
    Q_ENUM (ledShape)

    ledColor onColor() const { return m_onColor; }
    ledColor offColor() const { return m_offColor; }
    ledShape shape() const { return m_shape; }
    
public slots:
    void setValue(bool);
    void setOnColor(ledColor);
    void setOffColor(ledColor);   
    void setShape(ledShape);
    void toggleValue();

signals:
    void shapeChanged(ledShape);

protected:
    bool m_value;

    ledColor m_onColor, m_offColor;

    int id_Timer;

    ledShape m_shape;

 
    void paintEvent(QPaintEvent *event) override;
};

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For your example with the 5 LEDs, can you post the XML .ui file that Qt Designer creates for this widget? In Qt Designer, be sure to select different shapes for the LEDs even if Qt Designer shows them all as circles.

Yes, I forgot to tell you that I then changed Q_ENUMS to Q_ENUM placed after the declaration of the enum in question.
Here is the TestLed.ui file:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>TestLedClass</class>
 <widget class="QMainWindow" name="TestLedClass">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>602</width>
    <height>400</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>TestLed</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QCheckBox" name="checkBoxFlash">
    <property name="geometry">
     <rect>
      <x>50</x>
      <y>70</y>
      <width>76</width>
      <height>20</height>
     </rect>
    </property>
    <property name="text">
     <string>Flash led</string>
    </property>
   </widget>
   <widget class="QCheckBox" name="checkBoxLedBox">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>160</y>
      <width>76</width>
      <height>20</height>
     </rect>
    </property>
    <property name="text">
     <string>on/off led</string>
    </property>
   </widget>
   <widget class="Led" name="led_1">
    <property name="geometry">
     <rect>
      <x>140</x>
      <y>50</y>
      <width>61</width>
      <height>61</height>
     </rect>
    </property>
    <property name="diameter">
     <double>10.000000000000000</double>
    </property>
    <property name="color">
     <color>
      <red>255</red>
      <green>255</green>
      <blue>0</blue>
     </color>
    </property>
    <property name="state">
     <bool>false</bool>
    </property>
   </widget>
   <widget class="Led_0_6_1" name="led_0_6_1">
    <property name="geometry">
     <rect>
      <x>140</x>
      <y>140</y>
      <width>71</width>
      <height>71</height>
     </rect>
    </property>
    <property name="toolTip">
     <string>Binary Led</string>
    </property>
    <property name="whatsThis">
     <string>Led widget</string>
    </property>
    <property name="value">
     <bool>false</bool>
    </property>
    <property name="onColor">
     <enum>Led_0_6_1::Blue</enum>
    </property>
    <property name="offColor">
     <enum>Led_0_6_1::Grey</enum>
    </property>
    <property name="shape">
     <enum>Led_0_6_1::Circle</enum>
    </property>
   </widget>
   <widget class="QCheckBox" name="checkBox2">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>250</y>
      <width>91</width>
      <height>20</height>
     </rect>
    </property>
    <property name="text">
     <string>on/off led 2</string>
    </property>
   </widget>
   <widget class="Led_0_6_1" name="led_0_6_2">
    <property name="geometry">
     <rect>
      <x>150</x>
      <y>240</y>
      <width>50</width>
      <height>50</height>
     </rect>
    </property>
    <property name="toolTip">
     <string>Binary Led</string>
    </property>
    <property name="whatsThis">
     <string>Led widget</string>
    </property>
    <property name="value">
     <bool>false</bool>
    </property>
    <property name="onColor">
     <enum>Led_0_6_1::Red</enum>
    </property>
    <property name="offColor">
     <enum>Led_0_6_1::Grey</enum>
    </property>
    <property name="shape">
     <enum>Led_0_6_1::Rounded</enum>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>602</width>
     <height>22</height>
    </rect>
   </property>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <customwidgets>
  <customwidget>
   <class>Led</class>
   <extends>QWidget</extends>
   <header>Led.h</header>
  </customwidget>
  <customwidget>
   <class>Led_0_6_1</class>
   <extends>QWidget</extends>
   <header>Led_0_6_1.h</header>
  </customwidget>
 </customwidgets>
 <resources>
  <include location="TestLed.qrc"/>
 </resources>
 <connections>
  <connection>
   <sender>checkBoxFlash</sender>
   <signal>toggled(bool)</signal>
   <receiver>led_1</receiver>
   <slot>setFlashing(bool)</slot>
   <hints>
    <hint type="sourcelabel">
     <x>87</x>
     <y>113</y>
    </hint>
    <hint type="destinationlabel">
     <x>170</x>
     <y>114</y>
    </hint>
   </hints>
  </connection>
  <connection>
   <sender>checkBoxLedBox</sender>
   <signal>toggled(bool)</signal>
   <receiver>led_0_6_1</receiver>
   <slot>setValue(bool)</slot>
   <hints>
    <hint type="sourcelabel">
     <x>87</x>
     <y>253</y>
    </hint>
    <hint type="destinationlabel">
     <x>185</x>
     <y>259</y>
    </hint>
   </hints>
  </connection>
  <connection>
   <sender>checkBox2</sender>
   <signal>toggled(bool)</signal>
   <receiver>led_0_6_2</receiver>
   <slot>setValue(bool)</slot>
   <hints>
    <hint type="sourcelabel">
     <x>85</x>
     <y>293</y>
    </hint>
    <hint type="destinationlabel">
     <x>174</x>
     <y>298</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>TestLedClass</class>
 <widget class="QMainWindow" name="TestLedClass">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>602</width>
    <height>400</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>TestLed</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QCheckBox" name="checkBoxFlash">
    <property name="geometry">
     <rect>
      <x>50</x>
      <y>70</y>
      <width>76</width>
      <height>20</height>
     </rect>
    </property>
    <property name="text">
     <string>Flash led</string>
    </property>
   </widget>
   <widget class="QCheckBox" name="checkBoxLedBox">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>160</y>
      <width>76</width>
      <height>20</height>
     </rect>
    </property>
    <property name="text">
     <string>on/off led</string>
    </property>
   </widget>
   <widget class="Led" name="led_1">
    <property name="geometry">
     <rect>
      <x>140</x>
      <y>50</y>
      <width>61</width>
      <height>61</height>
     </rect>
    </property>
    <property name="diameter">
     <double>10.000000000000000</double>
    </property>
    <property name="color">
     <color>
      <red>255</red>
      <green>255</green>
      <blue>0</blue>
     </color>
    </property>
    <property name="state">
     <bool>false</bool>
    </property>
   </widget>
   <widget class="Led_0_6_1" name="led_0_6_1">
    <property name="geometry">
     <rect>
      <x>140</x>
      <y>140</y>
      <width>71</width>
      <height>71</height>
     </rect>
    </property>
    <property name="toolTip">
     <string>Binary Led</string>
    </property>
    <property name="whatsThis">
     <string>Led widget</string>
    </property>
    <property name="value">
     <bool>false</bool>
    </property>
    <property name="onColor">
     <enum>Led_0_6_1::Blue</enum>
    </property>
    <property name="offColor">
     <enum>Led_0_6_1::Grey</enum>
    </property>
    <property name="shape">
     <enum>Led_0_6_1::Circle</enum>
    </property>
   </widget>
   <widget class="QCheckBox" name="checkBox2">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>250</y>
      <width>91</width>
      <height>20</height>
     </rect>
    </property>
    <property name="text">
     <string>on/off led 2</string>
    </property>
   </widget>
   <widget class="Led_0_6_1" name="led_0_6_2">
    <property name="geometry">
     <rect>
      <x>150</x>
      <y>240</y>
      <width>50</width>
      <height>50</height>
     </rect>
    </property>
    <property name="toolTip">
     <string>Binary Led</string>
    </property>
    <property name="whatsThis">
     <string>Led widget</string>
    </property>
    <property name="value">
     <bool>false</bool>
    </property>
    <property name="onColor">
     <enum>Led_0_6_1::Red</enum>
    </property>
    <property name="offColor">
     <enum>Led_0_6_1::Grey</enum>
    </property>
    <property name="shape">
     <enum>Led_0_6_1::Rounded</enum>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>602</width>
     <height>22</height>
    </rect>
   </property>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <customwidgets>
  <customwidget>
   <class>Led</class>
   <extends>QWidget</extends>
   <header>Led.h</header>
  </customwidget>
  <customwidget>
   <class>Led_0_6_1</class>
   <extends>QWidget</extends>
   <header>Led_0_6_1.h</header>
  </customwidget>
 </customwidgets>
 <resources>
  <include location="TestLed.qrc"/>
 </resources>
 <connections>
  <connection>
   <sender>checkBoxFlash</sender>
   <signal>toggled(bool)</signal>
   <receiver>led_1</receiver>
   <slot>setFlashing(bool)</slot>
   <hints>
    <hint type="sourcelabel">
     <x>87</x>
     <y>113</y>
    </hint>
    <hint type="destinationlabel">
     <x>170</x>
     <y>114</y>
    </hint>
   </hints>
  </connection>
  <connection>
   <sender>checkBoxLedBox</sender>
   <signal>toggled(bool)</signal>
   <receiver>led_0_6_1</receiver>
   <slot>setValue(bool)</slot>
   <hints>
    <hint type="sourcelabel">
     <x>87</x>
     <y>253</y>
    </hint>
    <hint type="destinationlabel">
     <x>185</x>
     <y>259</y>
    </hint>
   </hints>
  </connection>
  <connection>
   <sender>checkBox2</sender>
   <signal>toggled(bool)</signal>
   <receiver>led_0_6_2</receiver>
   <slot>setValue(bool)</slot>
   <hints>
    <hint type="sourcelabel">
     <x>85</x>
     <y>293</y>
    </hint>
    <hint type="destinationlabel">
     <x>174</x>
     <y>298</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

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[d_stranz]

Your UI file:

<widget class="Led" name="led_1">
<widget class="Led_0_6_1" name="led_0_6_1">
 
...
 
<customwidget>
   <class>Led</class>
   <extends>QWidget</extends>
   <header>Led.h</header>
</customwidget>
 
<customwidget>
   <class>Led_0_6_1</class>
   <extends>QWidget</extends>
   <header>Led_0_6_1.h</header>
</customwidget>

<widget class="Led" name="led_1">
<widget class="Led_0_6_1" name="led_0_6_1">

...

<customwidget>
   <class>Led</class>
   <extends>QWidget</extends>
   <header>Led.h</header>
</customwidget>

<customwidget>
   <class>Led_0_6_1</class>
   <extends>QWidget</extends>
   <header>Led_0_6_1.h</header>
</customwidget>

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Your original code:

QString QLedPlugin::name() const
{
    return u"QLed"_s;
}
 
QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"
 
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")
 
R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
      <enum>QLed::Green</enum>
      <enum>QLed::Yellow</enum>
      <enum>QLed::Grey</enum>
      <enum>QLed::Orange</enum>
      <enum>QLed::Purple</enum>
      <enum>QLed::Blue</enum>
    </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
      <enum>QLed::Square</enum>
      <enum>QLed::Triangle</enum>
      <enum>QLed::Rounded</enum>
    </property>
  </widget>
</ui>
)"_s;
}
 
QString QLedPlugin::includeFile() const
{
    return u"qled.h"_s;
}

QString QLedPlugin::name() const
{
    return u"QLed"_s;
}

QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"
           
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")

R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
      <enum>QLed::Green</enum>
      <enum>QLed::Yellow</enum>
      <enum>QLed::Grey</enum>
      <enum>QLed::Orange</enum>
      <enum>QLed::Purple</enum>
      <enum>QLed::Blue</enum>
    </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
      <enum>QLed::Square</enum>
      <enum>QLed::Triangle</enum>
      <enum>QLed::Rounded</enum>
    </property>
  </widget>
</ui>
)"_s;
}

QString QLedPlugin::includeFile() const
{
    return u"qled.h"_s;
}

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You're wasting my time here, if the code you are now using is nothing like the code you originally posted. How is anyone supposed to help you determine what is wrong when your are looking at oranges while we are looking at apples?

[giorgik]

Your UI file:

<widget class="Led" name="led_1">
<widget class="Led_0_6_1" name="led_0_6_1">
 
...
 
<customwidget>
   <class>Led</class>
   <extends>QWidget</extends>
   <header>Led.h</header>
</customwidget>
 
<customwidget>
   <class>Led_0_6_1</class>
   <extends>QWidget</extends>
   <header>Led_0_6_1.h</header>
</customwidget>

<widget class="Led" name="led_1">
<widget class="Led_0_6_1" name="led_0_6_1">

...

<customwidget>
   <class>Led</class>
   <extends>QWidget</extends>
   <header>Led.h</header>
</customwidget>

<customwidget>
   <class>Led_0_6_1</class>
   <extends>QWidget</extends>
   <header>Led_0_6_1.h</header>
</customwidget>

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Your original code:

QString QLedPlugin::name() const
{
    return u"QLed"_s;
}
 
QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"
 
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")
 
R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
      <enum>QLed::Green</enum>
      <enum>QLed::Yellow</enum>
      <enum>QLed::Grey</enum>
      <enum>QLed::Orange</enum>
      <enum>QLed::Purple</enum>
      <enum>QLed::Blue</enum>
    </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
      <enum>QLed::Square</enum>
      <enum>QLed::Triangle</enum>
      <enum>QLed::Rounded</enum>
    </property>
  </widget>
</ui>
)"_s;
}
 
QString QLedPlugin::includeFile() const
{
    return u"qled.h"_s;
}

QString QLedPlugin::name() const
{
    return u"QLed"_s;
}

QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"
           
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")

R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
      <enum>QLed::Green</enum>
      <enum>QLed::Yellow</enum>
      <enum>QLed::Grey</enum>
      <enum>QLed::Orange</enum>
      <enum>QLed::Purple</enum>
      <enum>QLed::Blue</enum>
    </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
      <enum>QLed::Square</enum>
      <enum>QLed::Triangle</enum>
      <enum>QLed::Rounded</enum>
    </property>
  </widget>
</ui>
)"_s;
}

QString QLedPlugin::includeFile() const
{
    return u"qled.h"_s;
}

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You're wasting my time here, if the code you are now using is nothing like the code you originally posted. How is anyone supposed to help you determine what is wrong when your are looking at oranges while we are looking at apples?

You are absolutely right, I apologize. Only in the meantime I've been trying to get on with the code and try some changes. It just changed the name from QLed to Led_0_6_1, but it's still the same. Sorry, I forgot to tell you earlier...

I managed to solve the problem by editing the Test.ui file of my widget by hand, modifying it like this:

...
<property name="onColor">
     <enum>Led_0_6_1::Orange</enum>
</property>
...
<property name="shape">
     <enum>Led_0_6_1::Triangle</enum>
</property>
...

...
<property name="onColor">
     <enum>Led_0_6_1::Orange</enum>
</property>
...
<property name="shape">
     <enum>Led_0_6_1::Triangle</enum>
</property>
...

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this displays the right shape of the widget. However, this solution doesn't satisfy me much, as I wanted to do it in the Qt Designer environment through the properties of my widget.

[d_stranz]

Please do not reply by quoting my entire response. It makes the thread extremely long and difficult to read. Just click Reply, then add QUOTE tags for specific things. Thanks.

I wanted to do it in the Qt Designer environment through the properties of my widget.

OK, I am pretty sure the problem is in the domXml() method of your plugin. The XML code is supposed to be a template that Qt Designer uses when writing the widget's specification to the .ui file. I think your mistake is including all of the enum values in this XML, when there should only be one as a placeholder. So your domXml() should look like this:

QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"        
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")
R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
     </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
    </property>
  </widget>
</ui>
)"_s;
}

QString QLedPlugin::domXml() const
{
    return uR"(
<ui language="c++">
  <widget class="QLed" name="qLed">
)"        
R"(
    <property name="geometry">
      <rect>
        <x>0</x>
        <y>0</y>
        <width>50</width>
        <height>50</height>
      </rect>
    </property>
")
R"(
    <property name="toolTip">
      <string>Binary Led</string>
    </property>
    <property name="value">
      <bool>false</bool>
    </property>
    <property name="whatsThis">
      <string>Led widget</string>
    </property>
    <property name="onColor">
      <enum>QLed::Red</enum>
     </property>
    <property name="offColor">
      <enum>QLed::Grey</enum>
    </property>
    <property name="shape">
      <enum>QLed::Circle</enum>
    </property>
  </widget>
</ui>
)"_s;
}

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Qt Designer will understand from your Q_ENUM() and Q_PROPERTY() definitions what are the allowed values to substitute for the placeholder values in the template.

The Qt Designer UI file format is here. Near the bottom of the page is the specification for the Property type, which specifies what the <property> element can contain.

<xs:complexType name="Property">
                <xs:choice>
                        <xs:element name="bool" type="xs:string" />
                        <xs:element name="color" type="Color" />
                        <xs:element name="cstring" type="xs:string" />
                        <xs:element name="cursor" type="xs:integer" />
                        <xs:element name="cursorshape" type="xs:string" />
                        <xs:element name="enum" type="xs:string" />
                        <xs:element name="font" type ="Font" />
                        <xs:element name="iconset" type="ResourceIcon"/>
                        <xs:element name="pixmap" type="ResourcePixmap" />
                        <xs:element name="palette" type="Palette" />
                        <xs:element name="point" type="Point" />
                        <xs:element name="rect" type="Rect" />
                        <xs:element name="set" type="xs:string" />
                        <xs:element name="locale" type="Locale" />
                        <xs:element name="sizepolicy" type="SizePolicy" />
                        <xs:element name="size" type="Size" />
                        <xs:element name="string" type="String" />
                        <xs:element name="stringlist" type="StringList" />
                        <xs:element name="number" type="xs:integer" />
                        <xs:element name="float" type="xs:float" />
                        <xs:element name="double" type="xs:double" />
                        <xs:element name="date" type="Date" />
                        <xs:element name="time" type="Time" />
                        <xs:element name="datetime" type="DateTime" />
                        <xs:element name="pointf" type="PointF" />
                        <xs:element name="rectf" type="RectF" />
                        <xs:element name="sizef" type="SizeF" />
                        <xs:element name="longlong" type="xs:long" />
                        <xs:element name="char" type="Char" />
                        <xs:element name="url" type="Url" />
                        <xs:element name="uint" type="xs:unsignedInt" />
                        <xs:element name="ulonglong" type="xs:unsignedLong" />
                        <xs:element name="brush" type="Brush" />
                </xs:choice>
                <xs:attribute name="name" type="xs:string" />
                <xs:attribute name="stdset" type="xs:integer" />
        </xs:complexType>

<xs:complexType name="Property">
                <xs:choice>
                        <xs:element name="bool" type="xs:string" />
                        <xs:element name="color" type="Color" />
                        <xs:element name="cstring" type="xs:string" />
                        <xs:element name="cursor" type="xs:integer" />
                        <xs:element name="cursorshape" type="xs:string" />
                        <xs:element name="enum" type="xs:string" />
                        <xs:element name="font" type ="Font" />
                        <xs:element name="iconset" type="ResourceIcon"/>
                        <xs:element name="pixmap" type="ResourcePixmap" />
                        <xs:element name="palette" type="Palette" />
                        <xs:element name="point" type="Point" />
                        <xs:element name="rect" type="Rect" />
                        <xs:element name="set" type="xs:string" />
                        <xs:element name="locale" type="Locale" />
                        <xs:element name="sizepolicy" type="SizePolicy" />
                        <xs:element name="size" type="Size" />
                        <xs:element name="string" type="String" />
                        <xs:element name="stringlist" type="StringList" />
                        <xs:element name="number" type="xs:integer" />
                        <xs:element name="float" type="xs:float" />
                        <xs:element name="double" type="xs:double" />
                        <xs:element name="date" type="Date" />
                        <xs:element name="time" type="Time" />
                        <xs:element name="datetime" type="DateTime" />
                        <xs:element name="pointf" type="PointF" />
                        <xs:element name="rectf" type="RectF" />
                        <xs:element name="sizef" type="SizeF" />
                        <xs:element name="longlong" type="xs:long" />
                        <xs:element name="char" type="Char" />
                        <xs:element name="url" type="Url" />
                        <xs:element name="uint" type="xs:unsignedInt" />
                        <xs:element name="ulonglong" type="xs:unsignedLong" />
                        <xs:element name="brush" type="Brush" />
                </xs:choice>
                <xs:attribute name="name" type="xs:string" />
                <xs:attribute name="stdset" type="xs:integer" />
        </xs:complexType>

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The first part is an <xs:choice> element, which means that only one of the elements listed can appear in the <property> element. In other words, listing more than one <enum> entry violates the <ui> XML specification. So Qt Designer imported your plugin, but probably ignored the incorrect parts of your domXml().

[giorgik]

I understand. Thank you for the explanations. I will look at the document you indicated to me. So to solve my problem, that is to be able to select an item from the shape field list and keep that item as a choice, what should I do ?

[d_stranz]

to be able to select an item from the shape field list and keep that item as a choice, what should I do ?

I think all you need to do is to substitute the domXml() implementation from my last reply and it should all work with the original code you posted (Q_ENUM() instead of Q_ENUMS() of course). Qt Designer should match up the entries from your QLed enum{} lists and convert them to property value choices in the Designer. With the correct XML for the domXml() template, it will substitute the changes when it generates the .ui file for your widget form.

However, for the offColor property, since you have defined this to us the same enum type as onColor, all of the colors will be available to choose from, not only Grey. If all you will allow is Grey, then it doesn't need to be a user-configurable property at all. However, I can think of using QLed not as an on / off indicator, but as OK / not OK using Green and Red so having a choice would be better.

[giorgik]

I think all you need to do is to substitute the domXml() implementation from my last reply and it should all work with the original code you posted (Q_ENUM() instead of Q_ENUMS() of course). Qt Designer should match up the entries from your QLed enum{} lists and convert them to property value choices in the Designer. With the correct XML for the domXml() template, it will substitute the changes when it generates the .ui file for your widget form.

I already tried with changing the domXml like you said, but nothing changes. The .ui file always remains the same without having the new settings. I do not know what to do...

I know I'm asking too much, but could you give me your example project, simple simple with the voice selection feature like in my case? It's the only way to see what I forgot to do or if instead it's a problem related to using Qt6.5 in Visual Studio C++ 2022.

This was an old project of mine done directly in Qt4.8 using MinGw as compiler and it worked perfectly. Now that I've got it back but using Qt6.5 and Visual Studio C++ 2022, it doesn't work anymore :-(

In practice, it seems that the item I select in the properties panel of my widget in QtDesigner does not take it and does not update the .ui file

[d_stranz]

I know I'm asking too much, but could you give me your example project

Please make a ZIP file of all of your plugin and QLed code, including the SVG files used for drawing the LEDs - basically, everything I need to build your plugin and use it. Source code only, no compiled binary files. I don't have time to create a new plugin, but I can work on your code to try to get it working. You can attach the ZIP file to a reply in this forum.

[giorgik]

Please make a ZIP file of all of your plugin and QLed code, including the SVG files used for drawing the LEDs

OK, below I put the attachment of the project.Led.zip

[giorgik]

In the ui_TestLed.h should I vary the value passed to setProperty( ):

led_0_6_3->setProperty("shape", QVariant::fromValue(Led_0_6_1::Circle));

[d_stranz]

OK, thanks for the code. I did not make many changes to it except to change the Qt::StringLiterals to ordinary strings since I am using Qt 5 and this is not supported. I also found I needed to add QDESIGNER_EXPORT_WIDGETS in the project settings when building the plugin. (Led_6_0_1 -> Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions).

I designed a simple dialog widget to test the LED widget. The dialog has 5 LED widgets, with different properties set in Qt Designer. There are three push buttons. The first (Toggle LEDs) changes the on / off state for each LED. The second (Change Shapes) sets a new shape for each LED using the setShape() property. The third button (Change Colors) sets new on / off colors for each LED using setOnColor() and setOffColor(). These changes are implemented using a set of simple QLists whose contents are rotated with each click.

The test program demonstrates that setting shape, color, and value properties works both in Qt Designer (with correct values in the .ui file) and at run-time.

TestLed.png

I have attached a ZIP file with the code. I did not include the VS project files since those were changed for Qt 5 and won't apply for you and Qt 6. Just copy the source files. The test project needs to link with your plugin .lib file and include Qt core, gui, widgets, and svg in the configuration settings. The plugin .dll file must be in your path or where the program can load it at runtime.

Led.zip

It is probably not correct to have the code for the LED widget inside of the Qt Designer plugin itself. This means any application you write has to link to the plugin library. That is not right. You should separate the code for the widget from the code for the plugin, and create a LED DLL and a plugin DLL. The plugin DLL is linked to the LED library, and you must put the LED DLL where Qt Designer can find it. When you write an application, you should be linking only to the LED .lib and installing the LED DLL with your application.

[giorgik]

Thank you for your time for me, I copied your files to my project. Well, starting the test program, using the buttons everything works fine, while in Qt Designer, it still doesn't update the shape of the widget when I change the shape property. It's really a mystery...
Do you use the Qt Creator environment directly for the modifications you have made ?
So you always compile inside Qt Creator ?
Which compiler do you use MinGW or Visual C++ ?

[d_stranz]

while in Qt Designer, it still doesn't update the shape of the widget when I change the shape property. It's really a mystery...

It works fine for me, using Qt Designer 5.15.3.

Test1.pngTest3.pngTest2.pngTest4.png

If you still have a copy of Qt5 somewhere, copy your DLL into the plugins\designer directory and run the designer.exe you can find in the bin directory. Open the UI file and see what it looks like.

Edit: Do the colors change when you select different choices in Qt Designer? If not, I think that maybe Qt Designer is using the qled.png icon and not the actual widget. Are you linking your plugin DLL with QtSvg? It is possible that your version of Qt Designer was not built with SVG support linked in, so your SVG resources aren't loading. Try copying the Qt6Svg.dll file into the plugins\designer directory.