Fork of QPushButton that emits rightClicked() signal when user clicks over it with right button.
Copy qrightclickbutton.cpp and qrightclickbutton.h to your project directory. Then add the following lines to projectname.pro.
SOURCES += qrightclickbutton.cpp
HEADERS += qrightclickbutton.h
Then include it in project directory.
#include <QRightClickButton>
And finally add it whereever you want.
QRightClickButton *button = new QRightClickButton(this);
ui->gridLayout->addWidget(button);
connect(button, SIGNAL(rightClicked()), this, SLOT(onRightClicked()));
Note that onRightClicked() is a slot in the class this button is used.
It would be easy to use if this button was available in Designer's widget box. I will write a plugin to do so. Please check back later.