File indexing completed on 2024-04-21 16:13:18

 /*
 SPDX-FileCopyrightText: 1999 Martin R. Jones <mjones@kde.org>
 SPDX-FileCopyrightText: 2002 Luboš Luňák <l.lunak@kde.org>
 SPDX-FileCopyrightText: 2003 Oswald Buddenhagen <ossi@kde.org>
 SPDX-FileCopyrightText: 2008 Chani Armitage <chanika@gmail.com>
 SPDX-FileCopyrightText: 2011 Martin Gräßlin <mgraesslin@kde.org>
 
 SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "x11locker.h"
 #include "globalaccel.h"
 // KDE
 // Qt
 #include <QApplication>
 #include <QScreen>
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 #include <private/qtx11extras_p.h>
 #else
 #include <QDesktopWidget>
 #include <QX11Info>
 #endif
 // X11
 #include <X11/Xatom.h>
 #include <xcb/xcb.h>
 
 #include <kscreenlocker_logging.h>
 
 static Window gVRoot = 0;
 static Window gVRootData = 0;
 static Atom gXA_VROOT;
 static Atom gXA_SCREENSAVER_VERSION;
 
 namespace ScreenLocker
 {
 X11Locker::X11Locker(QObject *parent)
     : AbstractLocker(parent)
     , QAbstractNativeEventFilter()
     , m_focusedLockWindow(XCB_WINDOW_NONE)
 {
     initialize();
 }
 
 X11Locker::~X11Locker()
 {
     qApp->removeNativeEventFilter(this);
 }
 
 void X11Locker::initialize()
 {
     qApp->installNativeEventFilter(this);
 
     XWindowAttributes rootAttr;
     XGetWindowAttributes(QX11Info::display(), QX11Info::appRootWindow(), &rootAttr);
     XSelectInput(QX11Info::display(), QX11Info::appRootWindow(), SubstructureNotifyMask | rootAttr.your_event_mask);
     // Get root window size
     updateGeo();
 
     // virtual root property
     gXA_VROOT = XInternAtom(QX11Info::display(), "__SWM_VROOT", False);
     gXA_SCREENSAVER_VERSION = XInternAtom(QX11Info::display(), "_SCREENSAVER_VERSION", False);
 
     // read the initial information about all toplevel windows
     Window r, p;
     Window *real;
     unsigned nreal;
     if (XQueryTree(QX11Info::display(), QX11Info::appRootWindow(), &r, &p, &real, &nreal) && real != nullptr) {
         for (unsigned i = 0; i < nreal; ++i) {
             XWindowAttributes winAttr;
             if (XGetWindowAttributes(QX11Info::display(), real[i], &winAttr)) {
                 WindowInfo info;
                 info.window = real[i];
                 info.viewable = (winAttr.map_state == IsViewable);
                 m_windowInfo.append(info); // ordered bottom to top
             }
         }
         XFree(real);
     }
 
     // monitor for screen geometry changes
     connect(qGuiApp, &QGuiApplication::screenAdded, this, [this](QScreen *screen) {
         connect(screen, &QScreen::geometryChanged, this, &X11Locker::updateGeo);
         updateGeo();
     });
     connect(qGuiApp, &QGuiApplication::screenRemoved, this, &X11Locker::updateGeo);
     const auto screens = QGuiApplication::screens();
     for (auto *screen : screens) {
         connect(screen, &QScreen::geometryChanged, this, &X11Locker::updateGeo);
     }
 }
 
 void X11Locker::showLockWindow()
 {
     m_background->hide();
 
     // Some xscreensaver hacks check for this property
     const char *version = "KDE 4.0";
 
     XChangeProperty(QX11Info::display(),
                     m_background->winId(),
                     gXA_SCREENSAVER_VERSION,
                     XA_STRING,
                     8,
                     PropModeReplace,
                     (unsigned char *)version,
                     strlen(version));
 
     qCDebug(KSCREENLOCKER) << "Lock window Id: " << m_background->winId();
 
     m_background->setPosition(0, 0);
     XSync(QX11Info::display(), False);
 
     setVRoot(m_background->winId(), m_background->winId());
 }
 
 //---------------------------------------------------------------------------
 //
 // Hide the screen locker window
 //
 void X11Locker::hideLockWindow()
 {
     Q_EMIT userActivity();
     m_background->hide();
     m_background->lower();
     removeVRoot(m_background->winId());
     XDeleteProperty(QX11Info::display(), m_background->winId(), gXA_SCREENSAVER_VERSION);
     if (gVRoot) {
         unsigned long vroot_data[1] = {gVRootData};
         XChangeProperty(QX11Info::display(), gVRoot, gXA_VROOT, XA_WINDOW, 32, PropModeReplace, (unsigned char *)vroot_data, 1);
         gVRoot = 0;
     }
     XSync(QX11Info::display(), False);
     m_allowedWindows.clear();
 }
 
 //---------------------------------------------------------------------------
 static int ignoreXError(Display *, XErrorEvent *)
 {
     return 0;
 }
 
 //---------------------------------------------------------------------------
 //
 // Save the current virtual root window
 //
 void X11Locker::saveVRoot()
 {
     Window rootReturn, parentReturn, *children;
     unsigned int numChildren;
     Window root = QX11Info::appRootWindow();
 
     gVRoot = 0;
     gVRootData = 0;
 
     int (*oldHandler)(Display *, XErrorEvent *);
     oldHandler = XSetErrorHandler(ignoreXError);
 
     if (XQueryTree(QX11Info::display(), root, &rootReturn, &parentReturn, &children, &numChildren)) {
         for (unsigned int i = 0; i < numChildren; i++) {
             Atom actual_type;
             int actual_format;
             unsigned long nitems, bytesafter;
             unsigned char *newRoot = nullptr;
 
             if ((XGetWindowProperty(QX11Info::display(),
                                     children[i],
                                     gXA_VROOT,
                                     0,
                                     1,
                                     False,
                                     XA_WINDOW,
                                     &actual_type,
                                     &actual_format,
                                     &nitems,
                                     &bytesafter,
                                     &newRoot)
                  == Success)
                 && newRoot) {
                 gVRoot = children[i];
                 Window *dummy = (Window *)newRoot;
                 gVRootData = *dummy;
                 XFree((char *)newRoot);
                 break;
             }
         }
         if (children) {
             XFree((char *)children);
         }
     }
 
     XSetErrorHandler(oldHandler);
 }
 
 //---------------------------------------------------------------------------
 //
 // Set the virtual root property
 //
 void X11Locker::setVRoot(Window win, Window vr)
 {
     if (gVRoot) {
         removeVRoot(gVRoot);
     }
 
     unsigned long rw = QX11Info::appRootWindow();
     unsigned long vroot_data[1] = {vr};
 
     Window rootReturn, parentReturn, *children;
     unsigned int numChildren;
     Window top = win;
     while (1) {
         if (!XQueryTree(QX11Info::display(), top, &rootReturn, &parentReturn, &children, &numChildren)) {
             return;
         }
         if (children) {
             XFree((char *)children);
         }
         if (parentReturn == rw) {
             break;
         } else {
             top = parentReturn;
         }
     }
 
     XChangeProperty(QX11Info::display(), top, gXA_VROOT, XA_WINDOW, 32, PropModeReplace, (unsigned char *)vroot_data, 1);
 }
 
 //---------------------------------------------------------------------------
 //
 // Remove the virtual root property
 //
 void X11Locker::removeVRoot(Window win)
 {
     XDeleteProperty(QX11Info::display(), win, gXA_VROOT);
 }
 
 void X11Locker::fakeFocusIn(WId window)
 {
     if (window == m_focusedLockWindow) {
         return;
     }
 
     // We have keyboard grab, so this application will
     // get keyboard events even without having focus.
     // Fake FocusIn to make Qt realize it has the active
     // window, so that it will correctly show cursor in the dialog.
     XEvent ev;
     memset(&ev, 0, sizeof(ev));
     ev.xfocus.display = QX11Info::display();
     ev.xfocus.type = FocusIn;
     ev.xfocus.window = window;
     ev.xfocus.mode = NotifyNormal;
     ev.xfocus.detail = NotifyAncestor;
     XSendEvent(QX11Info::display(), window, False, NoEventMask, &ev);
     XFlush(QX11Info::display());
 
     m_focusedLockWindow = window;
 }
 
 template<typename T>
 void coordFromEvent(xcb_generic_event_t *event, int *x, int *y)
 {
     T *e = reinterpret_cast<T *>(event);
     *x = e->event_x;
     *y = e->event_y;
 }
 
 template<typename T>
 void sendEvent(xcb_generic_event_t *event, xcb_window_t target, int x, int y)
 {
     T e = *(reinterpret_cast<T *>(event));
     e.event = target;
     e.child = target;
     e.event_x = x;
     e.event_y = y;
     xcb_send_event(QX11Info::connection(), false, target, XCB_EVENT_MASK_NO_EVENT, reinterpret_cast<const char *>(&e));
 }
 
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 bool X11Locker::nativeEventFilter(const QByteArray &eventType, void *message, long int *)
 #else
 bool X11Locker::nativeEventFilter(const QByteArray &eventType, void *message, qintptr *)
 #endif
 {
     if (eventType != QByteArrayLiteral("xcb_generic_event_t")) {
         return false;
     }
     xcb_generic_event_t *event = reinterpret_cast<xcb_generic_event_t *>(message);
     const uint8_t responseType = event->response_type & ~0x80;
     if (globalAccel() && responseType == XCB_KEY_PRESS) {
         if (globalAccel()->checkKeyPress(reinterpret_cast<xcb_key_press_event_t *>(event))) {
             Q_EMIT userActivity();
             return true;
         }
     }
     bool ret = false;
     switch (responseType) {
     case XCB_BUTTON_PRESS:
     case XCB_BUTTON_RELEASE:
     case XCB_KEY_PRESS:
     case XCB_KEY_RELEASE:
     case XCB_MOTION_NOTIFY:
         Q_EMIT userActivity();
         if (!m_lockWindows.isEmpty()) {
             int x = 0;
             int y = 0;
             if (responseType == XCB_KEY_PRESS || responseType == XCB_KEY_RELEASE) {
                 coordFromEvent<xcb_key_press_event_t>(event, &x, &y);
             } else if (responseType == XCB_BUTTON_PRESS || responseType == XCB_BUTTON_RELEASE) {
                 coordFromEvent<xcb_button_press_event_t>(event, &x, &y);
             } else if (responseType == XCB_MOTION_NOTIFY) {
                 coordFromEvent<xcb_motion_notify_event_t>(event, &x, &y);
             }
             Window root_return;
             int x_return, y_return;
             unsigned int width_return, height_return, border_width_return, depth_return;
             for (WId window : qAsConst(m_lockWindows)) {
                 if (XGetGeometry(QX11Info::display(),
                                  window,
                                  &root_return,
                                  &x_return,
                                  &y_return,
                                  &width_return,
                                  &height_return,
                                  &border_width_return,
                                  &depth_return)
                     && (x >= x_return && x <= x_return + (int)width_return) && (y >= y_return && y <= y_return + (int)height_return)) {
                     // We need to do our own focus handling (see comment in fakeFocusIn).
                     // For now: Focus on clicks inside the window
                     if (responseType == XCB_BUTTON_PRESS) {
                         fakeFocusIn(window);
                     }
                     const int targetX = x - x_return;
                     const int targetY = y - y_return;
                     if (responseType == XCB_KEY_PRESS || responseType == XCB_KEY_RELEASE) {
                         sendEvent<xcb_key_press_event_t>(event, window, targetX, targetY);
                     } else if (responseType == XCB_BUTTON_PRESS || responseType == XCB_BUTTON_RELEASE) {
                         sendEvent<xcb_button_press_event_t>(event, window, targetX, targetY);
                     } else if (responseType == XCB_MOTION_NOTIFY) {
                         sendEvent<xcb_motion_notify_event_t>(event, window, targetX, targetY);
                     }
                     break;
                 }
             }
             ret = true;
         }
         break;
     case XCB_CONFIGURE_NOTIFY: { // from SubstructureNotifyMask on the root window
         xcb_configure_notify_event_t *xc = reinterpret_cast<xcb_configure_notify_event_t *>(event);
         if (xc->event == QX11Info::appRootWindow()) {
             int index = findWindowInfo(xc->window);
             if (index >= 0) {
                 int index2 = xc->above_sibling ? findWindowInfo(xc->above_sibling) : 0;
                 if (index2 < 0) {
                     qCDebug(KSCREENLOCKER) << "Unknown above for ConfigureNotify";
                 } else { // move just above the other window
                     if (index2 < index) {
                         ++index2;
                     }
                     m_windowInfo.move(index, index2);
                 }
             } else {
                 qCDebug(KSCREENLOCKER) << "Unknown toplevel for ConfigureNotify";
             }
             // kDebug() << "ConfigureNotify:";
             // the stacking order changed, so let's change the stacking order again to what we want
             stayOnTop();
             ret = true;
         }
         break;
     }
     case XCB_MAP_NOTIFY: { // from SubstructureNotifyMask on the root window
         xcb_map_notify_event_t *xm = reinterpret_cast<xcb_map_notify_event_t *>(event);
         if (xm->event == QX11Info::appRootWindow()) {
             qCDebug(KSCREENLOCKER) << "MapNotify:" << xm->window;
             int index = findWindowInfo(xm->window);
             if (index >= 0) {
                 m_windowInfo[index].viewable = true;
             } else {
                 qCDebug(KSCREENLOCKER) << "Unknown toplevel for MapNotify";
             }
             if (m_allowedWindows.contains(xm->window)) {
                 if (m_lockWindows.contains(xm->window)) {
                     qCDebug(KSCREENLOCKER) << "uhoh! duplicate!";
                 } else {
                     if (!m_background->isVisible()) {
                         // not yet shown and we have a lock window, so we show our own window
                         m_background->show();
                     }
                     m_lockWindows.prepend(xm->window);
                     fakeFocusIn(xm->window);
                 }
             }
             if (xm->window == m_background->winId()) {
                 m_background->update();
                 Q_EMIT lockWindowShown();
                 return false;
             }
             stayOnTop();
             ret = true;
         }
         break;
     }
     case XCB_UNMAP_NOTIFY: {
         xcb_unmap_notify_event_t *xu = reinterpret_cast<xcb_unmap_notify_event_t *>(event);
         if (xu->event == QX11Info::appRootWindow()) {
             qCDebug(KSCREENLOCKER) << "UnmapNotify:" << xu->window;
             int index = findWindowInfo(xu->window);
             if (index >= 0) {
                 m_windowInfo[index].viewable = false;
             } else {
                 qCDebug(KSCREENLOCKER) << "Unknown toplevel for MapNotify";
             }
             m_lockWindows.removeAll(xu->window);
             if (m_focusedLockWindow == xu->event && !m_lockWindows.empty()) {
                 // The currently focused window vanished, just focus the first one in the list
                 fakeFocusIn(m_lockWindows[0]);
             }
             ret = true;
         }
         break;
     }
     case XCB_CREATE_NOTIFY: {
         xcb_create_notify_event_t *xc = reinterpret_cast<xcb_create_notify_event_t *>(event);
         if (xc->parent == QX11Info::appRootWindow()) {
             qCDebug(KSCREENLOCKER) << "CreateNotify:" << xc->window;
             int index = findWindowInfo(xc->window);
             if (index >= 0) {
                 qCDebug(KSCREENLOCKER) << "Already existing toplevel for CreateNotify";
             } else {
                 WindowInfo info;
                 info.window = xc->window;
                 info.viewable = false;
                 m_windowInfo.append(info);
             }
             ret = true;
         }
         break;
     }
     case XCB_DESTROY_NOTIFY: {
         xcb_destroy_notify_event_t *xd = reinterpret_cast<xcb_destroy_notify_event_t *>(event);
         if (xd->event == QX11Info::appRootWindow()) {
             int index = findWindowInfo(xd->window);
             if (index >= 0) {
                 m_windowInfo.removeAt(index);
             } else {
                 qCDebug(KSCREENLOCKER) << "Unknown toplevel for DestroyNotify";
             }
             ret = true;
         }
         break;
     }
     case XCB_REPARENT_NOTIFY: {
         xcb_reparent_notify_event_t *xr = reinterpret_cast<xcb_reparent_notify_event_t *>(event);
         if (xr->event == QX11Info::appRootWindow() && xr->parent != QX11Info::appRootWindow()) {
             int index = findWindowInfo(xr->window);
             if (index >= 0) {
                 m_windowInfo.removeAt(index);
             } else {
                 qCDebug(KSCREENLOCKER) << "Unknown toplevel for ReparentNotify away";
             }
         } else if (xr->parent == QX11Info::appRootWindow()) {
             int index = findWindowInfo(xr->window);
             if (index >= 0) {
                 qCDebug(KSCREENLOCKER) << "Already existing toplevel for ReparentNotify";
             } else {
                 WindowInfo info;
                 info.window = xr->window;
                 info.viewable = false;
                 m_windowInfo.append(info);
             }
         }
         break;
     }
     case XCB_CIRCULATE_NOTIFY: {
         xcb_circulate_notify_event_t *xc = reinterpret_cast<xcb_circulate_notify_event_t *>(event);
         if (xc->event == QX11Info::appRootWindow()) {
             int index = findWindowInfo(xc->window);
             if (index >= 0) {
                 m_windowInfo.move(index, xc->place == PlaceOnTop ? m_windowInfo.size() - 1 : 0);
             } else {
                 qCDebug(KSCREENLOCKER) << "Unknown toplevel for CirculateNotify";
             }
         }
         break;
     }
     }
     return ret;
 }
 
 int X11Locker::findWindowInfo(Window w)
 {
     for (int i = 0; i < m_windowInfo.size(); ++i) {
         if (m_windowInfo[i].window == w) {
             return i;
         }
     }
     return -1;
 }
 
 void X11Locker::stayOnTop()
 {
     // this restacking is written in a way so that
     // if the stacking positions actually don't change,
     // all restacking operations will be no-op,
     // and no ConfigureNotify will be generated,
     // thus avoiding possible infinite loops
     QVector<Window> stack(m_lockWindows.count() + 1);
     int count = 0;
     for (WId w : qAsConst(m_lockWindows)) {
         stack[count++] = w;
     }
     // finally, the lock window
     stack[count++] = m_background->winId();
     // do the actual restacking if needed
     XRaiseWindow(QX11Info::display(), stack[0]);
     if (count > 1) {
         XRestackWindows(QX11Info::display(), stack.data(), count);
     }
     XFlush(QX11Info::display());
 }
 
 void X11Locker::updateGeo()
 {
     QRect geometry;
     const auto screens = QGuiApplication::screens();
     for (auto *screen : screens) {
         geometry |= screen->geometry();
     }
     m_background->setGeometry(geometry);
     m_background->update();
 }
 
 void X11Locker::addAllowedWindow(quint32 window)
 {
     m_allowedWindows << window;
     // test whether it's to show
     const int index = findWindowInfo(window);
     if (index == -1 || !m_windowInfo[index].viewable) {
         return;
     }
     if (m_lockWindows.contains(window)) {
         qCDebug(KSCREENLOCKER) << "uhoh! duplicate!";
     } else {
         if (!m_background->isVisible()) {
             // not yet shown and we have a lock window, so we show our own window
             m_background->show();
         }
 
         if (m_lockWindows.empty()) {
             // Make sure to focus the first window
             m_focusedLockWindow = XCB_WINDOW_NONE;
             fakeFocusIn(window);
         }
 
         m_lockWindows.prepend(window);
         stayOnTop();
     }
 }
 
 }