QTabBar - Context menu on tab

[gruszczy]

I would like to show a context menu, when someone clicks on the tab. It's easy - just intercept signal customContextMenuEvent. But I have no idea, how to get proper tab just from the position of a click and not pop up a context menu, when user clicks somewhere else, than on a tab. Could someone help me on this?

[elcuco]

Here is what I did here http://code.google.com/p/qtedit4/source/browse/tools/qmdilib/src/qmditabwidget.cpp



bool qmdiTabWidget::eventFilter(QObject *obj, QEvent *event)
{
if (obj != tabBar())
return QObject::eventFilter(obj, event);

if (event->type() != QEvent::MouseButtonPress)
return QObject::eventFilter(obj, event);

// compute the tab number
QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
QPoint position = mouseEvent->pos();
int c = tabBar()->count();
int clickedItem = -1;

for (int i=0; i<c; i++)
{
if ( tabBar()->tabRect(i).contains( position ) )
{
clickedItem = i;
break;
}
}

// just in case
if (clickedItem == -1)
return QObject::eventFilter(obj, event);

switch( mouseEvent->button() )
{
case Qt::LeftButton:
return QObject::eventFilter(obj, event);
break;

case Qt::RightButton:
on_rightMouse_pressed( clickedItem, position );
break;

case Qt::MidButton:
on_middleMouse_pressed( clickedItem, position );
break;

default:
return QObject::eventFilter(obj, event);
}

return true;
}


I assume I would use a binary approach to reduce the time from O(n) to O(log(n)) [where n is the number of tabs), but in such magnitudes this optimization is irrelevant IMHO.

[gruszczy]

That seems to be exactly what I need. Thanks a lot, love it :)

And yeah, no point in complicated the code with useless optimisation. This is just fine, so I'll just translate it to Python :)

[gruszczy]

One more thing.



if (obj != tabBar())
return QObject::eventFilter(obj, event);


Any time I click on the tab, it cannot pass through this condition. obj is QTabWidget (a class inheriting from this QTabWidget) instead of tabBar(). Do you have any idea, why it is so? From what I have read about your project, you are using Qt4. Does require doing something more?

[spirit]

look at this example


...
m_tabBar = new QTabBar();
m_tabBar->addTab(tr("OK"));
m_tabBar->addTab(tr("NO"));
m_tabBar->addTab(tr("IGNORE"));
m_tabBar->setContextMenuPolicy(Qt::CustomContextMenu);

connect(m_tabBar, SIGNAL(customContextMenuRequested(const QPoint &)), SLOT(showContextMenu(const QPoint &)));
...

void Test::showContextMenu(const QPoint &point)
{
if (point.isNull())
return;

int tabIndex = m_tabBar->tabAt(point);
QMenu menu(this);
if (!tabIndex)
menu.addAction(tr("OK"));
else if (tabIndex == 1)
menu.addAction(tr("NO"));
else if (tabIndex == 2)
menu.addAction(tr("IGNORE"));

menu.exec(m_tabBar->mapToGlobal(point));
}


works perfectly.

[pbek]

Thanks a lot, @spirit. Works like a charm!