Fullscreen WITHOUT window decoration

[Glynn Clements]

Philip Pflästerer wrote:

> i want to develop a fullscreen application by using the xlib functions.
> Fullscreen means also NO window decoration. Normaly the window
> decoration is provided by the window manager. To ignore the window
> manager, i set the override_redirect flag to TRUE.
> 
> XSetWindowAttributes setwinattr;
> setwinattr.override_redirect = True;
> 
> XChangeWindowAttributes(display, win, valuemask, &setwinattr);
> 
> 
> This works fine so far, i have total control over the size, position an
> decoration (none) of the window. Unfortunatly, the window doesn't
> disappear when i change the focus to another window (for example by
> pressing ALT+TAB). It alway stays mapped on top, so I can't see the
> other windows or even the desktop. If I unmap the window manually,
> there's no way to get it back on screen because there's no entry in the
> task-bar. I guess these features are controlled by the window manager I
> set to be ignored with the code above.
> 
> So my question is: How can I realize a fullscreen application WITHOUT
> ignoring the window manager?

You can ask the WM not to add any decorations using the following:

	typedef struct {
	    CARD32 flags;
	    CARD32 functions;
	    CARD32 decorations;
	    INT32 input_mode;
	    CARD32 status;
	} MotifWmHints, MwmHints;

	#define MWM_HINTS_DECORATIONS   (1L << 1)

	...

	Atom XA_MOTIF_WM_HINTS = XInternAtom(maindpy, "_MOTIF_WM_HINTS", False);
	MotifWmHints mwm_hints;

	mwm_hints.flags = MWM_HINTS_DECORATIONS;
	mwm_hints.decorations = 0;

	XChangeProperty(
		maindpy, mainwin,
		XA_MOTIF_WM_HINTS, XA_MOTIF_WM_HINTS,
		32, PropModeReplace,
		(char *) &mwm_hints, 5
	);

-- 
Glynn Clements <glynn at gclements.plus.com>