Mac OS X Lion how to hide the entire OS Dock Bar

[budda]

Not sure if I am stating the question correctly.
I am trying to get an Qt app to use 100% of the screen.
This includes the Dock Bar with all the programs at the bottom.
I would prefer not to use:

this->showFullScreen();
because I would like the app to use the entire desktop, including multiple monitors.
without showFullScreen() I have all of the screen real estate, but the OS Dock Bar is ontop of my app....
if I use showFullScreen() the app is fullscreen with the bottom Dock Bar hidden unless you hover at the bottom, but only for 1 monitor.....
is there a way to manually hide the OS Dock Bar? like how the showFullScreen() does it?

I am using Qt5.3.1 for Mac OS X 10.7.3 Lion, and also relevant is:

this->setWindowFlags(Qt::FramelessWindowHint|Qt::WindowS taysOnTopHint|Qt::X11BypassWindowManagerHint);

[d_stranz]

I don't know much about Mac OS, but I know that in Windows apps can go full-screen and hide the Windows task bar at the bottom of the screen. So if there are Mac apps that can do the same thing, then it must be possible. You might have to step outside of Qt to issue a Mac OS-specific call, though.

[budda]

I mostly code in Windows as well, all I have to do in Windows is get the desktop height and width and change the app size to that...
which then covers the task bar, but an app going full-screen on extended desktop monitors only goes full screen on 1 monitor. (regardless of the apps 3 monitor size)
I've been messing with 3 or 6 monitor systems and have been writing apps to take that into account, and I just got a Mac OSX Lion VirtualBox up and running and
am trying to duplicate what I've been doing in Windows... I'll keep searching....