How to use function actualSize() from QIcon?

TomNow99

Hi,

I would like to get size of icon in my QComboBox item and I think I have to use function actualSize(), but I don't how.

(const QSize &size, QIcon::Mode mode = Normal, QIcon::State state = Off)

What is size param?

jsulm

@TomNow99 said in How to use function actualSize() from QIcon?:

What is size param?

The size you want to have
https://doc.qt.io/qt-5/qicon.html#actualSize

TomNow99

@jsulm This function return current icon size. Ok. And why I have to add size, which I would like?

jsulm

@TomNow99 said in How to use function actualSize() from QIcon?:

And why I have to add size, which I would like?

Because you want to have the icon in a specific size? An icon can contain several versions of the icon each in a different size. If you want to know which sizes are available use https://doc.qt.io/qt-5/qicon.html#availableSizes

TomNow99

@jsulm So when I have icon in item in QCombBox, what I have to add as size? I would like only get the size of icon in this item.

jsulm

@TomNow99 You can use huge size as parameter, like QSize(10000, 10000)

TomNow99

@jsulm When I do that I get original size of my image. When I add it to comboBox, my image is smaller. So I can use this function to get that smaller size?

Christian Ehrlicher

Why do you need this icon size at all? QComboBox has a function iconSize() but even this can be wrong when a stylesheet is set.

TomNow99

@Christian-Ehrlicher I have items with icons in QComboBox. I would like to know when I click on icon, so I would like to have a position on this icons.

Christian Ehrlicher

Strange requirement... and not that easy to accomplish. You first need access to the view and then calc where the icons are. Happy coding :)

TomNow99

@Christian-Ehrlicher I think I have a good height, but I have problem with a width. I would like to know how many pixels is between end of icon and end of item comboBox ( look at the picture - this place is where is the yellow arrow ):

When I change width of comboBox this size is the same, so I try find this value here:

https://code.woboq.org/qt5/qtbase/src/widgets/widgets/qcombobox.cpp.html

but I can't. I look at good place?

mrjj

@TomNow99
Hi
How do you get the icon painted there ?

TomNow99

@mrjj I don't paint icon here. I just setIcon in QStandardItem and I change position to right using delegate

mrjj

@TomNow99
Ok, so its just a RightAlign so delegate dont know more about where it is ?

But if you dont use StyleSheets, is the size not correct (actualSize) when/after you create the icon ?

Christian Ehrlicher

The position depends on the style, as I already said it's a nice task without a real advantage. I would simply use the n right pixels as area of interest.

TomNow99

@mrjj I use this code to move icon to right:

class StyledItemDelegate: public QStyledItemDelegate{
public:
   using QStyledItemDelegate::QStyledItemDelegate;
protected:
    void initStyleOption(QStyleOptionViewItem *option, const QModelIndex &index) const{
        QStyledItemDelegate::initStyleOption(option, index);
        option->decorationPosition = QStyleOptionViewItem::Right;
    } 
};

I don't use StyleSheets. I don't use actualSize(). I use iconSize() from QComboBox.

mrjj

@TomNow99
Hi
I can't find anything in QStyle that would give the actual Rect so I agree with
Mr Ehrlicher that it would be far easier to assume the icon is as width as its height even it's not pixel
accurate.

TomNow99

This post is deleted!

TomNow99

@mrjj Is it possible to get QPixmap from item in QComboBox? I try using grab in combo->view(), but when I would like to do it my combo must be shown ( I would like to hide this combo ).

So my question is: can I grab / render QWidget when it is hidden?

mrjj

@TomNow99
Hi
yes, you can call render to have it draw itself to say a pixmap.
https://doc.qt.io/qt-5/qwidget.html#render-1
(for a full widget)