Remove icon space from QMenu - c++

Question

I'm working on a Qt application (in C++). Without appyling any styles, my menu looks like this:
I'd like it to look like this:
How do I achieve this? Either using qss, or programmatically?
I already tried this, without success:
menu->addAction(tr("Add"), this, SLOT(CreateNewWaypoint()))->setIconVisibleInMenu(false);
Answers for both Qt4.8 and Qt5 are needed to get the full bounty!

Answer 1

One way to solve the problem is to use QProxyStyle:
customstyle.h
#ifndef CUSTOMSTYLE_H
#define CUSTOMSTYLE_H
#include <QProxyStyle>
#include <QStyleOptionMenuItem>
class CustomStyle : public QProxyStyle{
public:
using QProxyStyle::QProxyStyle;
void drawControl(ControlElement element, const QStyleOption *opt, QPainter *p, const QWidget *w) const override
{
if(element == QStyle::CE_MenuItem){
QStyleOptionMenuItem myMenuOption;
const QStyleOptionMenuItem *menuOption =
qstyleoption_cast<const QStyleOptionMenuItem *>(opt);
if (menuOption) {
const int width = pixelMetric(PM_SmallIconSize)+6;
myMenuOption = *menuOption;
QRect r(myMenuOption.rect);
r.setLeft(-width);
myMenuOption.rect = r;
}
QProxyStyle::drawControl(element, &myMenuOption, p, w);
return;
}
QProxyStyle::drawControl(element, opt, p, w);
}
};
#endif // CUSTOMSTYLE_H
then you install it in the QApplication:
QApplication a(argc, argv);
QApplication::setStyle(new CustomStyle);

Answer 2

You can influence on how your menu appears by playing with its style sheet. With you example code you can do the following:
menu.setStyleSheet("QMenu::item {"
"padding: 2px 5px 2px 2px;"
"}"
"QMenu::item:selected {"
"background-color: rgb(0, 85, 127);"
"color: rgb(255, 255, 255);"
"}");
Note the padding property, which sets the offsets of your menu item rectangles.

Answer 3

I wanted to get rid of the icons in the standard context menu for a QPlainTextEdit.
Just using setIconVisibleInMenu(false) for all the actions in the QMenu still left the icon space as shown in the question.
I was only able to get rid of the icon space when I set the icon for the menu actions to a null icon.
Full example:
void CustomPlainTextEdit::contextMenuEvent(QContextMenuEvent *event)
{
QMenu *menu = createStandardContextMenu();
foreach (QAction *action, menu->actions()) {
action->setIcon(QIcon());
}
menu->exec(event->globalPos());
delete menu;
}