QWebPage::swallowContextMenuEvent?

[zeveck]

Can somebody explain the behavior of QWebPage::swallowContextMenuEvent? "As documented":http://harmattan-dev.nokia.com/docs/platform-api-reference/xml/daily-docs/libqt4/qwebpage.html#swallowContextMenuEvent it seems it should return true if the JS suppresses the context menu, but when I try
@window.oncontextmenu = function() {
return false;
}@
it still returns false. When should it be expected to actually return true?