2 works, thanks!
But why 1 icon isNull() ?

Is possible 1 and 2 under Linux? Linux has something like mime or/and Elf binaries can holds icons?

Bad:

QPixmap extractMime(const QString &sourceFile) { QMimeDatabase mime_database; const QString nativeName = QDir::toNativeSeparators(sourceFile); QIcon icon; QList<QMimeType> mime_types = mime_database.mimeTypesForFileName(nativeName); icon = QIcon::fromTheme(mime_types[0].iconName()); if (icon.isNull()) qDebug() << "null"; qDebug() << mime_types[0].iconName(); return icon.pixmap(16); }

Maybe this work for Linux, but for Windows I need registers. Sample C# application https://www.codeproject.com/Articles/29137/Get-Registered-File-Types-and-Their-Associated-Ico

for example:
Computer\HKEY_CLASSES_ROOT.mp3 has
OpenWithProgIds/WMP11.AssocFile.MP3

Computer\HKEY_CLASSES_ROOT\WMP11.AssocFile.MP3 has DefaultIcon = %SystemRoot%\system32\wmploc.dll,-732
wmploc.dll is resources and 732 index of icon?

Good to know, so my solution to store this in the last column and hide this one is the best solution for me.

It's good when it's more friendly :)

@IL
you can add a widget to an item. So just create a for example frame that contains your icon and add it to the list item.

QListWidget *list = new QListWidget(this); //... QFrame *custom = new QFrame; //add whatever you need to the frame QListWidgetItem *i = new QListWidgetItem; list->addItem(i); list->setWidgetItem(i,custom);

I used this for a list where each item needed several buttons to get for example detailed information about the item or delete the item from the list with one click

Please have some patience, this forum is community driven and not all users live in the same timezone as you.

The picture you are linking to doesn't show a hovered button but a checked button. You will have that visual effect if you set the checkable property of the action to corresponding to the button as true and you check it.

@maximo
Agree.
I wonder if there is something secret I missed in some Doc.

Something like:

QIcon icon = style()->standardIcon(QStyle::SP_DialogOkButton); QPixmap pixmap = icon.pixmap(QSize(64, 64));

@marlenet15 See the docs : http://doc.qt.io/qt-5/qabstractbutton.html#iconSize-prop

What is the stack trace when this happens ?

After scouring the web, it appears that the only way to do this is the very complex technique of subclassing the widget. It's easier to just put another button on it, but then I had the problem where I couldn't pass a hover event to the QPushButton underneath it. This lead me to learn the technique on StackOverflow of building an eventFilter.

The thing is that toolbars don't really display icons. They display widgets (that can have icons). By default when you add an action to a toolbar a QToolButton is created for it, but you are not limited to that and can add any widget e.g. an expanding line edit, combobox or a button with an icon and text. All of these can have different size policies, be expanding or have a custom stylesheet applied.
All of this makes calculating such size not feasible because how would you calculate it if a widget can change its size.

What I'm saying is that yours is a special, very specific case (with just icons), and as such you need to handle it yourself if you want to.

To answer your questions:

It's not one thing that adds the space. There are couple of aspects that can contribute. You can control some(or all?) of them with stylesheets e.g. set padding of the toolbar and toolbuttons to 0 and margins and borders of the toolbuttons. By default all of these depend on a style and will vary across computers. You also need to be careful to consider the size of the toolbar handle (if it's movable) as its size depends on the active style. You also need to consider that if the icon is narrower than the iconSize then there's gonna by space left anyway. nope, AFAIK it can vary from one item of the toolbar to another if you set it this way nope and just out of curiosity - why do you need that? The bar will display an arrow button that will let you see the overflowing items. Also such calculated size would be useless as the window can be resized and thus the toolbar too (unless you're doing some really fancy layout).

Hi

I would say a Delegate would be the way to do it.
Have a look at
"Star Delegate Example"

For your fancy hand, you can use
QApplication::setOverrideCursor(QCursor(Qt::PointingHandCursor));
QApplication::restoreOverrideCursor();

Its also possible via the model
http://daniel-albuschat.blogspot.dk/2009/09/setting-mouse-cursor-for-qts-item-views.html

Hi and welcome to devnet,

Why not just call setIcon with your current icon ? No need for a style sheet

Good, glad ya got it sorted out. Sorry I've been super busy lately and haven't lurked the forums here. :)

After all this time, I don't fin a way to do it properly.

I'm using QML and it's fine now. For people intereested in, this is my QML component:

import QtQuick 2.5
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.4

Button
{
property color backgroundColor
property alias tooltip : buttonAction.tooltip
property string imageSource
signal buttonClicked ( )

action : buttonAction activeFocusOnPress : true Keys.onPressed : { if ( (event.key == Qt.Key_Return||event.key == Qt.Key_Enter) && activeFocus) { buttonClicked ( ); event.accepted = true; } } style : ButtonStyle { background: Rectangle { id : backgroundRectangle color : backgroundColor Rectangle { id : roundedRectangle color : control.pressed?Qt.darker(backgroundColor, 1.1):backgroundColor anchors.fill : parent radius : 10 scale : ( control.hovered||control.activeFocus )?1:0.9 Image { id : buttonImage anchors.fill: parent fillMode : Image.PreserveAspectFit source : imageSource } } } } Action { id : buttonAction onTriggered : buttonClicked () }

}

@didu You're Welcome :)
Happy Coding...

Deleting the output directory and rebuilding does not work.
Now I created a new project and now it works.

Thank You :)