Window not going quite fullscreen

SDL Development
1

Hi everyone !
I seem to have a bug with my current window class. I’m trying to create a
window given a WindowConfguration struct. It should try to create a SDL
window, but if the video mode is not supported, it will default to windowed
mode of requested size.
I’m having problems on ubuntu 10.10 LTS. When I give a valid video mode,
the desktop resolution changes, but the window decoration and gnome bars
still show. I still have expected fullscreen behaviour, the desktop
resolution changes back when I alt tab, and back again when I go back to my
SDL window. But I’m not quite fullscreen.

here’s my code so far

void WindowSDL::create(WindowConfiguration p_configuration)
{
//No need to create if we already have a window
if(m_window) return;

//Is the screen correct ? if not, use default screen
if(p_configuration.screen>=getNumScreens()) p_configuration.screen=0;

//Pre-set some opengl attributes
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, p_configuration.depthBuffer);

unsigned flags = SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN;
if(p_configuration.fullscreen)
{
    //Check video mode
    SDL_DisplayMode mode, modematch;
    mode.format = SDL_PIXELFORMAT_UNKNOWN;
    mode.w = p_configuration.mode.width;
    mode.h = p_configuration.mode.height;
    mode.refresh_rate = p_configuration.mode.refreshRate;
    ///Find a video mode that matches params, or stay windowed
    if(SDL_GetClosestDisplayMode(p_configuration.screen, &mode,

&modematch))
{
//Set fullscreen flag
flags |=SDL_WINDOW_FULLSCREEN;
p_configuration.mode.width = modematch.w;
p_configuration.mode.height = modematch.h;
p_configuration.mode.refreshRate = modematch.refresh_rate;
}
else p_configuration.fullscreen=false;
}

//We have what we need, let's create the window
m_window = SDL_CreateWindow ("Entropy Engine",
    SDL_WINDOWPOS_UNDEFINED_DISPLAY(p_configuration.screen),

SDL_WINDOWPOS_UNDEFINED_DISPLAY(p_configuration.screen),
p_configuration.mode.width, p_configuration.mode.height, flags );

///No window : fail
if(m_window == NULL)
{
    std::cout << "Failed to create window" << std::endl;
    return;
}

//Add an opengl context
m_context = SDL_GL_CreateContext(m_window);
//Vsync
SDL_GL_SetSwapInterval(p_configuration.vsync);
//Glew
glewInit();
m_windows[m_window] = this;
m_running=true;

}

I’ve confirmed that the “flags |=SDL_WINDOW_FULLSCREEN;” part is executed,
so I did find a matching mode.
I’m running SDL HG head.
Is there anything I’m doing wrong ?