workspace/plasma/dataengines/mouse/cursornotificationhandler.cpp

   1 /*
   2  *   Copyright © 2007 Fredrik Höglund <fredrik@kde.org>
   3  *
   4  *   This program is free software; you can redistribute it and/or modify
   5  *   it under the terms of the GNU Library General Public License version 2 as
   6  *   published by the Free Software Foundation
   7  *
   8  *   This program is distributed in the hope that it will be useful,
   9  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  *   GNU General Public License for more details
  12  *
  13  *   You should have received a copy of the GNU Library General Public
  14  *   License along with this program; if not, write to the
  15  *   Free Software Foundation, Inc.,
  16  *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  */
  18
  19 #include "cursornotificationhandler.h"
  20
  21 #include <QX11Info>
  22
  23 #include <X11/extensions/Xfixes.h>
  24
  25
  26 /*
  27  * This class is a QWidget because we need an X window to
  28  * be able to receive XFixes events. We don't actually map
  29  * the widget.
  30  */
  31
  32 CursorNotificationHandler::CursorNotificationHandler()
  33     : QWidget(), currentName(0)
  34 {
  35     Display *dpy = QX11Info::display();
  36     int errorBase;
  37     haveXfixes = false;
  38
  39     // Request cursor change notification events
  40     if (XFixesQueryExtension(dpy, &fixesEventBase, &errorBase))
  41     {
  42         int major, minor;
  43         XFixesQueryVersion(dpy, &major, &minor);
  44
  45         if (major >= 2)
  46         {
  47             XFixesSelectCursorInput(dpy, winId(), XFixesDisplayCursorNotifyMask);
  48             haveXfixes = true;
  49         }
  50     }
  51 }
  52
  53
  54 CursorNotificationHandler::~CursorNotificationHandler()
  55 {
  56 }
  57
  58
  59 QString CursorNotificationHandler::cursorName()
  60 {
  61     if (!haveXfixes)
  62         return QString();
  63
  64     if (!currentName)
  65     {
  66         // Xfixes doesn't have a request for getting the current cursor name,
  67         // but it's included in the XFixesCursorImage struct.
  68         XFixesCursorImage *image = XFixesGetCursorImage(QX11Info::display());
  69         currentName = image->atom;
  70         XFree(image);
  71     }
  72
  73     return cursorName(currentName);
  74 }
  75
  76
  77 QString CursorNotificationHandler::cursorName(Atom cursor)
  78 {
  79     QString name;
  80
  81     // XGetAtomName() is a synchronous call, so we cache the name
  82     // in an atom<->string map the first time we see a name
  83     // to keep the X server round trips down.
  84     if (names.contains(cursor))
  85         name = names[cursor];
  86     else
  87     {
  88         char *data = XGetAtomName(QX11Info::display(), cursor);
  89         name = QString::fromUtf8(data);
  90         XFree(data);
  91
  92         names.insert(cursor, name);
  93     }
  94
  95     return name;
  96 }
  97
  98
  99 bool CursorNotificationHandler::x11Event(XEvent* event)
 100 {
 101     if (event->type != fixesEventBase + XFixesCursorNotify)
 102         return false;
 103
 104     XFixesCursorNotifyEvent *xfe = reinterpret_cast<XFixesCursorNotifyEvent*>(event);
 105     currentName = xfe->cursor_name;
 106
 107     emit cursorNameChanged(cursorName(currentName));
 108
 109     return false;
 110 }
 111
 112 #include "cursornotificationhandler.moc"
 113