Find those properties of a widget which are shown in the Qt Designer

[Eager]

How can I find only those properties of a widget (e.g. QPushButton) which Qt Designer shows in the Property Editor?
I can find all properties including those which are not shown in the Qt Designer using the following code:

    // Print all available properties of a Widget:
    qDebug()<<qPrintable("Widget: QPushButton");
    QObject *object = new QPushButton;
    const QMetaObject *metaobject = object->metaObject();
    for (int i=0; i<metaobject->propertyCount(); ++i) {
        QMetaProperty metaproperty = metaobject->property(i);
        const char *name = metaproperty.name();
        QVariant value = object->property(name);
        qDebug()<<qPrintable("\n" + QString(name) + "\n" + QString(value.typeName()));
    }

[mrjj]

Hi
I think you can check with
https://doc.qt.io/Qt-5/qmetaproperty.html#isDesignable
as docs says
"The DESIGNABLE attribute indicates whether the property should be visible in the property editor of GUI design tool (e.g., Qt Designer). "

[Eager]

@mrjj It doesn't work as expected. For example, In the designer the following QPushButton properties are not shown but they are isDesignable: frameGeometry, normalGeometry, frameSize, childrenRect, etc

[mrjj]

@Eager
Ok, try to dump all attribute and see if you can find a red line.
Maybe they also need to be https://doc.qt.io/Qt-5/qmetaproperty.html#isStored

[Eager]

@mrjj isWritable() removed a lot of unrelated properties but still a few appear, for example:
windowModality, windowFilePath, windowModified, windowTitle etc.
I used isStored too but I still see the above properties.

[mrjj]

@Eager
Hmm. Im not sure how the Designer does it.
I tried to look around in
https://code.woboq.org/qt5/qt-creator/src/plugins/designer/
but found nothing.

[Eager]

@mrjj Right now I am trying to look around in
https://code.woboq.org/qt5/qttools/src/designer/src/
Can you please look around in this one too, if you don't mind?

[mrjj]

@Eager
sure. if we can find the actual property widget we should get a clue.

[SGaist]

Hi,

IIRC, that's because you are parsing the current class meta object for properties.

You have go back the chain up to the "root" meta object.

[Eager]

@SGaist For finding only those properties of QPushButton which the Qt Designer displays in Property Editor, I am currently doing like this:

    qDebug()<<qPrintable("Widget: QPushButton");
    QObject *object = new QPushButton;
    const QMetaObject *metaobject = object->metaObject();
    for (int i=0; i<metaobject->propertyCount(); ++i) {
        QMetaProperty metaproperty = metaobject->property(i);
        qDebug()<<metaproperty.isStored();
        if(metaproperty.isWritable() && metaproperty.isDesignable()) {
            qDebug()<<qPrintable(QString(metaproperty.name()) + " : " + QString(metaproperty.typeName()));
        }
    }

Can you please point out where I am doing wrong?

[Eager]

@SGaist

You have go back the chain up to the "root" meta object.

How can I do this? I wish I knew this concept! :(
Can you please explain this or share a sample code?
I am already highly obliged!

[SGaist]

To go through the chain, use QMetaObject::superClass.

[Eager]

@SGaist I tried that and I noticed that QMetaObject::superClass() gives me the properties of the base classes of the widget in question. I went through the chain in a loop and displayed the properties of each level and I found that properties like windowModality, windowFilePath, windowModified, windowTitle etc. are defined inside the base classes alongwith many other which should be displayed for the QPushButton in the Qt Designer.
I think Qt Designer uses some kind of fuzzy logic and somehow suppresses some of the properties for the child widgets.

[SGaist]

What are the differences ?

[Eager]

At last I found a working solution. Of course, it has some limitations but works for my use case.

    // Print all those properties of a widget which are shown in the Qt Designer:

    /* Main Container is the widget having no parent.
     * Main Container has the following extra properties:
     *  - windowTitle
     *  - windowIcon
     *  - windowIconText
     *  - windowOpacity
     *  - windowModified
     *  - windowFilePath
     *
     * In a ui form there can only be one Main Container.
     *
     * As we want to get the properties of the widgets which are not designed/intended
     * to be used as Main Container of a ui form so to avoid getting the above extra
     * properties we make them children of a fake main container widget.
     *
     * Qt Designer does not show read only properties so make sure you display only those
     * properties which are both readable and writable.
     *
     * Note also that property visibility in the Qt Designer can be set ON and OFF by
     * other properties. For example checked property is designable only if boolean
     * property setCheckable is set to true.
     *
     * As you can notice in the files:
     * qt5/qttools/src/designer/src/lib/shared/qdesigner_propertysheet.cpp
     * qt5/qttools/src/designer/src/components/formeditor/qdesigner_resource.cpp
     * that windowModality is set Visible only for the Main Container so manually remove that
     * property whenever you find it for the children widgets.
     */
       QWidget *fakeMainContainerWidget = new QWidget(); // No parent means main container.
       QObject *object = new QPushButton(fakeMainContainerWidget);
       const QMetaObject *metaobject = object->metaObject();
       qDebug() << qPrintable("-==" + QString(metaobject->className()) + " ==-");
       for (int i=0; i<metaobject->propertyCount(); ++i) {
           QMetaProperty metaproperty = metaobject->property(i);
           bool isReadOnly = metaproperty.isReadable() && !metaproperty.isWritable();
           bool isWinModal = metaproperty.name() == QString("windowModality"); // removed windowModality manually
           if( !isReadOnly && metaproperty.isDesignable(object) && !isWinModal ) {
               qDebug() <<  qPrintable(QString(metaproperty.name()) + " : " + QString(metaproperty.typeName()));
           }
       }

[Eager]

@SGaist I came up with a solution and I have posted it in this thread.