QPushButton with icon, dressing size?

[SPlatten]

I want to set a push button to a specific width using the following logic:

//Get the default size of a QPushButton
const QSize cobjPBtnSize(QPushButton::size());
//Only need the height
const int cintHeight(cobjPBtnSize.height());
//The size of the icon that will appear in the button
const QSize cobjSize(24, cintHeight);
setIcon(objIcon);
setIconSize(cobjSize);
setFixedSize(crobjSize);

I know this isn't quite right, what I want to do before setFixedSize is adjust the size of to allow for the border and shading, the sharing a typical button has...how or where do I get these figures?

[mpergand]

class Button : public QPushButton
{
    public:
    
    Button(const QString& iconPath)
        {
        icon=QIcon(iconPath);
        }
    
    void paintEvent(QPaintEvent *ev) 
        {
        QPushButton::paintEvent(ev);
        
        QPainter painter(this);
        QRect rec=contentsRect();
        rec.adjust(0,8,-0,-10);     // margins specific to MacOs 
        
        int h=rec.size().height();
        QSize size(h,h);
        QPoint top=rec.topLeft();
        top.setX((rec.width()-h)/2);

        // draw the outline rec of the button to visualise the real size of the widget !
        painter.drawRect(rect().adjusted(0,0,-1,-1));
        
        painter.drawPixmap(QRect(top,size), icon.pixmap(size));
        
        qDebug()<<QRect(top,size)<<contentsRect();
        }
    
    private:
    QIcon icon;
};

svg drawn as image in a QPushButton
The problem are the extra margins around the button on Mac (not portable)

[ChrisW67]

@SPlatten said in QPushButton with icon, dressing size?:

const QSize cobjPBtnSize(QPushButton::size());

There is no static size() function, so I am not sure what this would even compile.

The size of the push button will be dictated by the layout it is placed in and the constraint imposed by that layout and the push button itself. The closest thing to a "default" size is the sizeHint() the button returns. Since most push buttons will not expand vertically the height of the size hint should be a reasonable guide.

The precise borders and buffers and surround any icon applied are a function of the style in use (which can vary). They are available inside the widget rendering code through the QStyle and QStyleOption classes. They are not generally available elsewhere I am aware of.

What are you trying to achieve by forcing the icon size?

[SPlatten]

@ChrisW67 , it does compile:
https://doc.qt.io/qt-5/qpushbutton.html

Just enter the text into Qt Creator QPushButton:: then add size it pops up and does compile.

Actually the size property is part of QWidget which is obviously inherited by the push button widget:
https://doc.qt.io/qt-5/qwidget.html

What I want is a button that is the size of the toolbar icon with enough space around it for the borders so it looks like a regular button just with the icon in it instead of text.

[JonB]

@SPlatten
You mean your const QSize cobjPBtnSize(QPushButton::size());, and the whole code, is inside a subclass of QPushButton you have, don't you? I think @ChrisW67 missed that. One of the C++ syntaxes I don't like: a call to to a base class method looks identical to a call to a static method :(

[ChrisW67]

I did miss that. Whether it makes sense inside a QPushButton subclass is a different question.

What I want is a button that is the size of the toolbar icon with enough space around it for the borders so it looks like a regular button just with the icon in it instead of text.

Have you considered (ab)using a QToolButton? This is a no-text rendering by default: button fits icon.

[SPlatten]

@ChrisW67 , thank you, I will investigate, where I want to use this is in a button bar at the bottom of a dialog where I could have the following:

• Button to apply changes (with Apply text).
• Buttons to Undo and Redo with the icon inside for each
• Button with OK text to apply and close dialog
• Button with Cancel text to cancel any changes and close dialog

This is what I have so far:

What I want is for all the buttons to have the same appearance, not the square boxes that are currently around the icons, but the same looking buttons with the white background as the icons are PNG resources with transparent backgrounds.

I think I'm going to replace all of these with buttons containing SVG images.

[mpergand]

class Button : public QPushButton
{
    public:
    
    Button(const QString& iconPath)
        {
        icon=QIcon(iconPath);
        }
    
    void paintEvent(QPaintEvent *ev) 
        {
        QPushButton::paintEvent(ev);
        
        QPainter painter(this);
        QRect rec=contentsRect();
        rec.adjust(0,8,-0,-10);     // margins specific to MacOs 
        
        int h=rec.size().height();
        QSize size(h,h);
        QPoint top=rec.topLeft();
        top.setX((rec.width()-h)/2);

        // draw the outline rec of the button to visualise the real size of the widget !
        painter.drawRect(rect().adjusted(0,0,-1,-1));
        
        painter.drawPixmap(QRect(top,size), icon.pixmap(size));
        
        qDebug()<<QRect(top,size)<<contentsRect();
        }
    
    private:
    QIcon icon;
};

svg drawn as image in a QPushButton
The problem are the extra margins around the button on Mac (not portable)

[SPlatten]

@mpergand , thank you, that's great!

[SPlatten]

@mpergand , with regard to the magic numbers 0,8,-0,-10, isn't there anything defined in Qt for this? I would have thought that somewhere in the depths of Qt that this information is defined?

This is what I have now:

@mpergand , actually, don't need the numbers now, my code for the above:

    if ( strAPI.isEmpty() != true ) {
    //Set the text according to the API
        QString strText;
        QIcon objIcon;
        pobjNode->getAPIcontent(strAPI, strText, objIcon);
        if ( strText.isEmpty() != true ) {
            setText(strText);
        } else if ( objIcon.isNull() != true ) {
            setIcon(objIcon);            
        }
    }

The above is in my constructor for my overridden instance of QPushButton, I didn't need to do anything to the paintEvent.

[mpergand]

@SPlatten
You're right, I missed setIcon() in QAbstractButton.
No need to paint anything, good to know.