[SOLVED] Trying to enable OVERRIDE

Trying to enable OVERRIDE_REDIRECT in XCB

I am trying to make a very simple window that doesn't get resized or positioned by a window manager. I thought what I wrote below would work, am I missing something?

    // Create a window
    xcb_window_t \
    window = xcb_generate_id(connection);
    uint32_t \
    mask = \
        XCB_CW_BACK_PIXEL      | \
        XCB_CW_BORDER_PIXEL    | \
        XCB_CW_EVENT_MASK      | \
        XCB_CW_OVERRIDE_REDIRECT;
    uint32_t \
    win_values[] = {
        default_screen->white_pixel, 
        0,
        XCB_EVENT_MASK_EXPOSURE,
        1
    };
    xcb_create_window(
        connection,
        default_screen->root_depth,
        window,
        default_screen->root,
        0, 0, 500, 500, 0,
        XCB_WINDOW_CLASS_INPUT_OUTPUT,
        default_screen->root_visual,
        mask, win_values
    );

it seems to work if I remove the event mask, how can I handle events then?

Solution

You have to switch the event mask and override redirect:

    uint32_t \
    win_values[] = {
        default_screen->white_pixel, 
        0,
        1,
        XCB_EVENT_MASK_EXPOSURE
    };

For clarity, you should also switch the order in mask, but it does not really matter there. The value would not change.

How did I find this? I look at /usr/include/xcb/xproto.h and search for XCB_CW_BACK_PIXEL. This leads to the xcb_cw_t enum. The values you provide must be in the same order as in this enum.

(And no, I do not know a simpler way to figure this out. I know other ways, but no simpler one.)