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)