Use custom widget button in QMessageBox

[John_38]

Hello everybody,
I now appeal to your acquaintances because I find it difficult to achieve something.
I have a custom button. I would like this button to be the button that is in the QMessageBox.
I would like to promote the QMessageBox buttons by my custom buttons.
For my custom button, I have already create a class (for custom widget).

Thank you for your help.

Regards,
John.

[Chris Kawa]

There's no widget promotion involved because you can't use QMessageBox in the designer, but you can do it from code.
QMessageBox supports all widgets derived from QAbstractButton as custom buttons. For example:

class MyFancyButton : public QPushButton {
public:
    MyFancyButton(const QString& text, QWidget* parent = nullptr) : QPushButton(text, parent) {}
};

QMessageBox box(QMessageBox::Warning, "Hello", "I'm using a fancy button!", QMessageBox::NoButton, parent);
box.addButton(new MyFancyButton("Foo"), QMessageBox::AcceptRole);
box.addButton(new MyFancyButton("Bar"), QMessageBox::RejectRole);
box.exec();

[John_38]

Thank for you answer.
I have 3 errors now..
Screenshot: http://prntscr.com/dq3mip

[Chris Kawa]

I have 3 errors now.

Sorry, but have you bothered to read them? ;)

The first one: parent is a wrong identifier in this scope. I just used 'parent' as a placeholder. You need to put an actual parent in there. In your case it might be this for example.
The other two - I have a constructor in MyFancyButton example that takes a string literal as a parameter. Do you have such a constructor in your MsgButton class? Can you show your constructor's signature?

[John_38]

Yes.
My class "MsgButton" is here.

#ifndef MSGBUTTON_H
#define MSGBUTTON_H


#include <QPushButton>
#include <QPropertyAnimation>
#include <QMessageBox>


class MsgButton : public QPushButton
{
       Q_OBJECT
       Q_PROPERTY( QColor   BackgroundColor    READ backgroundColor  WRITE setBackgroundColor DESIGNABLE true )

public:
      MsgButton(const QString& text, QWidget* parent) : QPushButton(text, parent)
      {
           m_Animation = new QPropertyAnimation(this, "BackgroundColor", this);
           m_Animation->setDuration( 275 );
           m_Animation->setEasingCurve( QEasingCurve::InCurve );
           m_BackgroundColor = Qt::transparent;
           this->setBackgroundColor( QColor(55,55,58) );
      }

       QColor backgroundColor() const
       {
            return m_BackgroundColor;
       }

       void setBackgroundColor( const QColor & color )
       {
           if( m_BackgroundColor != color )
           {
               m_BackgroundColor = color;
               this->setStyleSheet( QString("MsgButton { border: 1px solid; color: rgb(200,200,200); background-color: rgb(55,55,58); border-color: %1;  }").arg(color.name()) );
            }
       }

protected:

       virtual void enterEvent( QEvent * event )
       {
            QPushButton::enterEvent(event);

            if( m_Animation->state() == QAbstractAnimation::Running )
                m_Animation->stop();

            m_Animation->setEndValue( QColor(44,122,205) );
            m_Animation->start();
       }

       virtual void leaveEvent( QEvent* event )
       {
            QPushButton::leaveEvent(event);

            QVariant currentColor = m_Animation->currentValue();

            if( m_Animation->state() == QAbstractAnimation::Running )
                m_Animation->stop();

            m_Animation->setEndValue( QColor(55,55,58) );
            m_Animation->start();

       }

       QPropertyAnimation*     m_Animation;
       QColor                   m_BackgroundColor;
};


#endif // MSGBUTTON_H

[Chris Kawa]

The difference is you didn't make your second parameter optional, so there' s no constructor taking only string literal.

The fix is to either give the parameter default value (that's usually the case with Qt's widgets):

MsgButton(const QString& text, QWidget* parent = nullptr) : QPushButton(text, parent)

or actually specify the parameter at call site:

box.addButton(new MsgButton("Foo", nullptr), QMessageBox::AcceptRole);

Btw. You should move your implementation into a .cpp file or you'll get a lot of linker errors when you include your header in more than one place.

[John_38]

Oh ok thanks.
Now i have actually 1 error (2 but is the same)..
Screenshot : http://prntscr.com/dq4rwf

[Chris Kawa]

nullptr is a C++11 keyword. To use it add CONFIG += c++11 in the .pro file and click Build->Run qmake. If you don't want to use C++11 (why not?) just change nullptr to Q_NULLPTR, or, as a last resort, to 0.

[John_38]

T H A N K.
Happy new year! :-)