How to make QToolbar's icons change when clicked?

I'm now trying to make QT wallet client change icon into another one, when the icon is clicked (checked).

I've added the following line:

Code:

new QAction(QIcon(":/icons/" "/overview2"), tr("&"), (this));

to Bitcoingui.cpp file, it did compile, but it did not change anything. When I click on an icon it stays the same.

Code:

void BitcoinGUI::gotoOverviewPage()
{
overviewAction->setChecked(true);
if (walletFrame) walletFrame->gotoOverviewPage();
-> new QAction(QIcon(":/icons/" "/overview2"), tr("&"), (this));
}

Any ideas how to do it?