I'm trying to get a list of all top level desktop windows in an X11 session. Basically, I want to get a list of all windows that are shown in the window managers application-switching UI (commonly opened when the user presses ALT+TAB).
I've never done any X11 programming before, but so far I've managed to enumerate through the entire window list, with code that looks something like this:
void CSoftwareInfoLinux::enumerateWindows(Display *display, Window rootWindow)
{
Window parent;
Window *children;
Window *child;
quint32 nNumChildren;
XTextProperty wmName;
XTextProperty wmCommand;
int status = XGetWMName(display, rootWindow, &wmName);
if (status && wmName.value && wmName.nitems)
{
int i;
char **list;
status = XmbTextPropertyToTextList(display, &wmName, &list, &i);
if (status >= Success && i && *list)
{
qDebug() << "Found window with name:" << (char*) *list;
}
status = XGetCommand(display, rootWindow, &list, &i);
if (status >= Success && i && *list)
{
qDebug() << "... and Command:" << i << (char*) *list;
}
Window tf;
status = XGetTransientForHint(display, rootWindow, &tf);
if (status >= Success && tf)
{
qDebug() << "TF set!";
}
XWMHints *pHints = XGetWMHints(display, rootWindow);
if (pHints)
{
qDebug() << "Flags:" << pHints->flags
<< "Window group:" << pHints->window_group;
}
}
status = XQueryTree(display, rootWindow, &rootWindow, &parent, &children, &nNumChildren);
if (status == 0)
{
// Could not query window tree further, aborting
return;
}
if (nNumChildren == 0)
{
// No more children found. Aborting
return;
}
for (int i = 0; i < nNumChildren; i++)
{
enumerateWindows(display, children[i]);
}
XFree((char*) children);
}
enumerateWindows()
is called initially with the root window.
This works, in so far as it prints out information about hundreds of windows - what I need, is to work out which property I can interrogate to determine if a given Window
is a top-level Desktop application window (not sure what the official terminology is), or not.
Can anyone shed some light on this? All the reference documentation I've found for X11 programming has been terribly dry and hard to understand. Perhaps someone could point be to a better resource?