Detect system tray\taskbar orientation(X11)

Question

I created a TrayPopupWidget that should pops up nearby the tray. Then I realized that if the user changes the orientation, or height of the taskbar it will pops up at the wrong place. So I created the TaskbarDetector class.

I tried to get the a window geometry of the tray|taskbar, but I only get wrong window property... I tried on KDE,LXDE -> same bad behaviour...

The code: http://bzfriendsplasm.svn.sourceforge.net/viewvc/bzfriendsplasm/BZFriends/taskbardetector.cpp?revision=156&view=markup

   //Getting screen resolutoin
int num_sizes;

Rotation original_rotation;

Display *display = XOpenDisplay(NULL);

Window root = RootWindow(display, 0);

XRRScreenSize *xrrs = XRRSizes(display, 0, &num_sizes);

XRRScreenConfiguration *conf = XRRGetScreenInfo(display, root);

XRRConfigCurrentRate(conf);

SizeID original_size_id = XRRConfigCurrentConfiguration(conf, &original_rotation);

p_screenWidth = xrrs[original_size_id].width;
p_screenHeight = xrrs[original_size_id].height;


//Getting tray position

unsigned long  sysTraySelection = 0;

Screen *screen = XDefaultScreenOfDisplay(display);


//FIXME !!!
QString  *net_sys_tray = new QString("_NET_SYSTEM_TRAY_S%i");


(*net_sys_tray) = net_sys_tray->replace ("%i",QString::number (XScreenNumberOfScreen(screen)));


sysTraySelection = XInternAtom(display, net_sys_tray->toLocal8Bit (), False);

if ( sysTraySelection == None)
    return  Unknown;

trayWindow = XGetSelectionOwner(display, sysTraySelection);

XWindowAttributes w_attr;
unsigned long status = XGetWindowAttributes (display,trayWindow,&w_attr);

if ( status == 0)
    return Unknown;

p_taskBarLeft       = w_attr.y;
p_taskBarTop       = w_attr.x;
p_taskBarBottom  = w_attr.x + w_attr.height;
p_taskBarRight     = w_attr.y + w_attr.width;


qDebug () << QString("Window id:  " ) + QString::number (trayWindow);
 qDebug() << QString("SysTraySelection: ") + QString::number (sysTraySelection );
 qDebug() << QString("Top ") + QString::number (p_taskBarTop);
 qDebug() << QString("Left ") + QString::number (p_taskBarLeft);
 qDebug() << QString("Bottom ") + QString::number (p_taskBarBottom);
 qDebug() << QString("Right " ) + QString::number (p_taskBarRight);

XCloseDisplay(display);

delete net_sys_tray;

return decideOrientation ();

Answer 1

Finally, I found a way to detect it!

1. I'm searching for a window, that has a dock property and visible, and then I call XGetWindowAttributes(...) on it.
2. If I set a filter method to the QApplication::setEventFilter() I can get every XEvent, _NET_WORKAREA event too(this event happens when you resize or move the taskbar), then I re-call taskbar/tray detection method.

However, this worked on KDE4 and GNOME and LXDE, I'm planning to allow the user to set the popup position by himself.

bool TaskBarDetector::lookUpDockWindow ( unsigned long &rootWindow, bool check)
{
Display *display = QX11Info::display ();

Window parent;
Window *children;
unsigned int noOfChildren;
int status;

if ( check && checkDockProperty(rootWindow)  )
{
    trayWindow = rootWindow;
    return true;
}

status = XQueryTree (display, rootWindow, &rootWindow, &parent, &children, &noOfChildren);

if (status == 0)
{
    qDebug() << "ERROR - Could not query the window tree. Aborting.";
    trayWindow = 0;
    return false;
}

if (noOfChildren == 0)
{
    trayWindow = 0;
    return false;
}

for (unsigned int ind = 0 ; ind < noOfChildren; ++ind )
{

    if ( lookUpDockWindow ( children[ind] ,true) )
        return true;
}

XFree ((char*) children);

trayWindow = 0;

return false;
}

bool TaskBarDetector::checkDockProperty(unsigned long window)
{
Display *x11display = QX11Info::display ();
Atom *atoms;
int numberAtoms = 0;

char *atomName;
XTextProperty prop;
XWindowAttributes windowattr;

atoms = XListProperties (x11display, window, &numberAtoms);

for (int ind = 0; ind < numberAtoms; ++ind )
{
    atomName = XGetAtomName(x11display, atoms[ind]);

    if (QString(atomName).compare ("_NET_WM_WINDOW_TYPE" )  != 0 )
        continue;

    unsigned long status = XGetTextProperty (x11display,window,&prop,atoms[ind]);

    if ( status == 0 )
        continue;

    int value = (int) (*prop.value);

    if (value != 151 )
        continue;

    if (XGetWindowAttributes(x11display,window,&windowattr) == 0)
       continue;

    return windowattr.map_state == 2;

}

return false;
}

 void TaskBarDetector::saveWindowAttr(unsigned long root)
{
XWindowAttributes windowattr;

Display *x11display =QX11Info::display ();

if (XGetWindowAttributes(x11display,trayWindow,&windowattr) == 0)
{
    trayWindow = 0;
    return;
}

int x = 0;
int y = 0;

Window *w = &trayWindow;

if(  XTranslateCoordinates(x11display,trayWindow,root,windowattr.x,windowattr.y,&x,&y,w) == True)
{

    p_taskBarTop = y;
    p_taskBarLeft = x;
    p_taskBarRight = p_taskBarLeft + windowattr.width;
    p_taskBarBottom = p_taskBarTop + windowattr.height;
    p_taskBarHeight = windowattr.height;
    p_taskBarWidth = windowattr.width;

} else
        {
           p_orientation           = Unknown;
           p_taskBarTop         = 0;
           p_taskBarLeft         = 0;
           p_taskBarRight       =  0;
           p_taskBarBottom    = 0;
           p_taskBarHeight     = 0;
           p_taskBarWidth      = 0;

        }

bool TaskBarDetector::appEventFilter(void *msg, long *result)
{


Q_UNUSED(result);

if ( !TaskBarDetector::hasInstance() )
    return false;

TaskBarDetector *detector = TaskBarDetector::getInstance();

#ifdef Q_WS_WIN
MSG *seged = static_cast<MSG*>(msg);
if ( seged->message == WM_SETTINGCHANGE && seged->wParam == SPI_SETWORKAREA )
{
    detector->processDetectEvent();
    return false;
}

return false;
#endif

#ifdef Q_WS_X11
XEvent *xevent = static_cast<XEvent*> (msg);


if ( xevent->type == PropertyNotify  )
{
    XPropertyEvent xpe = xevent->xproperty;

    char * ch_atom_name = XGetAtomName(QX11Info::display(),xpe.atom);

    QString atom_name = QString(ch_atom_name).trimmed ();

    if (  atom_name == "_NET_WORKAREA" )
    {
        detector->processDetectEvent ();
        return false;
    }


}

return false;

#endif
}

}