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IABSD.fr/xenocara/xserver/dix/enterleave.c

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  • Author : matthieu
    Date : 2025-11-03 09:57:22
    Hash : b48f2471
    Message : Update to xserver 21.1.20.

  • xserver/dix/enterleave.c
  • /*
     * Copyright © 2008 Red Hat, Inc.
     *
     * Permission is hereby granted, free of charge, to any person obtaining a
     * copy of this software and associated documentation files (the "Software"),
     * to deal in the Software without restriction, including without limitation
     * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     * and/or sell copies of the Software, and to permit persons to whom the
     * Software is furnished to do so, subject to the following conditions:
     *
     * The above copyright notice and this permission notice (including the next
     * paragraph) shall be included in all copies or substantial portions of the
     * Software.
     *
     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     * DEALINGS IN THE SOFTWARE.
     *
     * Authors: Peter Hutterer
     *
     */
    
    #ifdef HAVE_DIX_CONFIG_H
    #include <dix-config.h>
    #endif
    
    #include <X11/X.h>
    #include <X11/extensions/XI2.h>
    #include <X11/extensions/XIproto.h>
    #include <X11/extensions/XI2proto.h>
    #include "inputstr.h"
    #include "windowstr.h"
    #include "scrnintstr.h"
    #include "exglobals.h"
    #include "enterleave.h"
    #include "eventconvert.h"
    #include "xkbsrv.h"
    #include "inpututils.h"
    
    /**
     * @file
     * This file describes the model for sending core enter/leave events and
     * focus in/out in the case of multiple pointers/keyboard foci.
     *
     * Since we can't send more than one Enter or Leave/Focus in or out event per
     * window to a core client without confusing it, this is a rather complicated
     * approach.
     *
     * For a full description of the enter/leave model from a window's
     * perspective, see
     * http://lists.freedesktop.org/archives/xorg/2008-August/037606.html
     *
     * For a full description of the focus in/out model from a window's
     * perspective, see
     * https://lists.freedesktop.org/archives/xorg/2008-December/041684.html
     *
     * Additional notes:
     * - The core protocol spec says that "In a LeaveNotify event, if a child of the
     * event window contains the initial position of the pointer, then the child
     * component is set to that child. Otherwise, it is None.  For an EnterNotify
     * event, if a child of the event window contains the final pointer position,
     * then the child component is set to that child. Otherwise, it is None."
     *
     * By inference, this means that only NotifyVirtual or NotifyNonlinearVirtual
     * events may have a subwindow set to other than None.
     *
     * - NotifyPointer events may be sent if the focus changes from window A to
     * B. The assumption used in this model is that NotifyPointer events are only
     * sent for the pointer paired with the keyboard that is involved in the focus
     * events. For example, if F(W) changes because of keyboard 2, then
     * NotifyPointer events are only sent for pointer 2.
     */
    
    static WindowPtr PointerWindows[MAXDEVICES];
    static WindowPtr FocusWindows[MAXDEVICES];
    
    /**
     * Return TRUE if 'win' has a pointer within its boundaries, excluding child
     * window.
     */
    static BOOL
    HasPointer(DeviceIntPtr dev, WindowPtr win)
    {
        int i;
    
        /* FIXME: The enter/leave model does not cater for grabbed devices. For
         * now, a quickfix: if the device about to send an enter/leave event to
         * a window is grabbed, assume there is no pointer in that window.
         * Fixes fdo 27804.
         * There isn't enough beer in my fridge to fix this properly.
         */
        if (dev->deviceGrab.grab)
            return FALSE;
    
        for (i = 0; i < MAXDEVICES; i++)
            if (PointerWindows[i] == win)
                return TRUE;
    
        return FALSE;
    }
    
    /**
     * Return TRUE if at least one keyboard focus is set to 'win' (excluding
     * descendants of win).
     */
    static BOOL
    HasFocus(WindowPtr win)
    {
        int i;
    
        for (i = 0; i < MAXDEVICES; i++)
            if (FocusWindows[i] == win)
                return TRUE;
    
        return FALSE;
    }
    
    /**
     * Return the window the device dev is currently on.
     */
    static WindowPtr
    PointerWin(DeviceIntPtr dev)
    {
        return PointerWindows[dev->id];
    }
    
    /**
     * Search for the first window below 'win' that has a pointer directly within
     * its boundaries (excluding boundaries of its own descendants).
     *
     * @return The child window that has the pointer within its boundaries or
     *         NULL.
     */
    static WindowPtr
    FirstPointerChild(WindowPtr win)
    {
        int i;
    
        for (i = 0; i < MAXDEVICES; i++) {
            if (PointerWindows[i] && IsParent(win, PointerWindows[i]))
                return PointerWindows[i];
        }
    
        return NULL;
    }
    
    /**
     * Search for the first window below 'win' that has a focus directly within
     * its boundaries (excluding boundaries of its own descendants).
     *
     * @return The child window that has the pointer within its boundaries or
     *         NULL.
     */
    static WindowPtr
    FirstFocusChild(WindowPtr win)
    {
        int i;
    
        for (i = 0; i < MAXDEVICES; i++) {
            if (FocusWindows[i] && FocusWindows[i] != PointerRootWin &&
                IsParent(win, FocusWindows[i]))
                return FocusWindows[i];
        }
    
        return NULL;
    }
    
    /**
     * Set the presence flag for dev to mark that it is now in 'win'.
     */
    void
    EnterWindow(DeviceIntPtr dev, WindowPtr win, int mode)
    {
        PointerWindows[dev->id] = win;
    }
    
    /**
     * Unset the presence flag for dev to mark that it is not in 'win' anymore.
     */
    void
    LeaveWindow(DeviceIntPtr dev)
    {
        PointerWindows[dev->id] = NULL;
    }
    
    /**
     * Set the presence flag for dev to mark that it is now in 'win'.
     */
    void
    SetFocusIn(DeviceIntPtr dev, WindowPtr win)
    {
        FocusWindows[dev->id] = win;
    }
    
    /**
     * Unset the presence flag for dev to mark that it is not in 'win' anymore.
     */
    void
    SetFocusOut(DeviceIntPtr dev)
    {
        FocusWindows[dev->id] = NULL;
    }
    
    /**
     * Return the common ancestor of 'a' and 'b' (if one exists).
     * @param a A window with the same ancestor as b.
     * @param b A window with the same ancestor as a.
     * @return The window that is the first ancestor of both 'a' and 'b', or the
     *         NullWindow if they do not have a common ancestor.
     */
    static WindowPtr
    CommonAncestor(WindowPtr a, WindowPtr b)
    {
        for (b = b->parent; b; b = b->parent)
            if (IsParent(b, a))
                return b;
        return NullWindow;
    }
    
    /**
     * Send enter notifies to all windows between 'ancestor' and 'child' (excluding
     * both). Events are sent running up the window hierarchy. This function
     * recurses.
     */
    static void
    DeviceEnterNotifies(DeviceIntPtr dev,
                        int sourceid,
                        WindowPtr ancestor, WindowPtr child, int mode, int detail)
    {
        WindowPtr parent = child->parent;
    
        if (ancestor == parent)
            return;
        DeviceEnterNotifies(dev, sourceid, ancestor, parent, mode, detail);
        DeviceEnterLeaveEvent(dev, sourceid, XI_Enter, mode, detail, parent,
                              child->drawable.id);
    }
    
    /**
     * Send enter notifies to all windows between 'ancestor' and 'child' (excluding
     * both). Events are sent running down the window hierarchy. This function
     * recurses.
     */
    static void
    CoreEnterNotifies(DeviceIntPtr dev,
                      WindowPtr ancestor, WindowPtr child, int mode, int detail)
    {
        WindowPtr parent = child->parent;
    
        if (ancestor == parent)
            return;
        CoreEnterNotifies(dev, ancestor, parent, mode, detail);
    
        /* Case 3:
           A is above W, B is a descendant
    
           Classically: The move generates an EnterNotify on W with a detail of
           Virtual or NonlinearVirtual
    
           MPX:
           Case 3A: There is at least one other pointer on W itself
           P(W) doesn't change, so the event should be suppressed
           Case 3B: Otherwise, if there is at least one other pointer in a
           descendant
           P(W) stays on the same descendant, or changes to a different
           descendant. The event should be suppressed.
           Case 3C: Otherwise:
           P(W) moves from a window above W to a descendant. The subwindow
           field is set to the child containing the descendant. The detail
           may need to be changed from Virtual to NonlinearVirtual depending
           on the previous P(W). */
    
        if (!HasPointer(dev, parent) && !FirstPointerChild(parent))
            CoreEnterLeaveEvent(dev, EnterNotify, mode, detail, parent,
                                child->drawable.id);
    }
    
    static void
    CoreLeaveNotifies(DeviceIntPtr dev,
                      WindowPtr child, WindowPtr ancestor, int mode, int detail)
    {
        WindowPtr win;
    
        if (ancestor == child)
            return;
    
        for (win = child->parent; win != ancestor; win = win->parent) {
            /*Case 7:
               A is a descendant of W, B is above W
    
               Classically: A LeaveNotify is generated on W with a detail of Virtual
               or NonlinearVirtual.
    
               MPX:
               Case 3A: There is at least one other pointer on W itself
               P(W) doesn't change, the event should be suppressed.
               Case 3B: Otherwise, if there is at least one other pointer in a
               descendant
               P(W) stays on the same descendant, or changes to a different
               descendant. The event should be suppressed.
               Case 3C: Otherwise:
               P(W) changes from the descendant of W to a window above W.
               The detail may need to be changed from Virtual to NonlinearVirtual
               or vice-versa depending on the new P(W). */
    
            /* If one window has a pointer or a child with a pointer, skip some
             * work and exit. */
            if (HasPointer(dev, win) || FirstPointerChild(win))
                return;
    
            CoreEnterLeaveEvent(dev, LeaveNotify, mode, detail, win,
                                child->drawable.id);
    
            child = win;
        }
    }
    
    /**
     * Send leave notifies to all windows between 'child' and 'ancestor'.
     * Events are sent running up the hierarchy.
     */
    static void
    DeviceLeaveNotifies(DeviceIntPtr dev,
                        int sourceid,
                        WindowPtr child, WindowPtr ancestor, int mode, int detail)
    {
        WindowPtr win;
    
        if (ancestor == child)
            return;
        for (win = child->parent; win != ancestor; win = win->parent) {
            DeviceEnterLeaveEvent(dev, sourceid, XI_Leave, mode, detail, win,
                                  child->drawable.id);
            child = win;
        }
    }
    
    /**
     * Pointer dev moves from A to B and A neither a descendant of B nor is
     * B a descendant of A.
     */
    static void
    CoreEnterLeaveNonLinear(DeviceIntPtr dev, WindowPtr A, WindowPtr B, int mode)
    {
        WindowPtr X = CommonAncestor(A, B);
    
        /* Case 4:
           A is W, B is above W
    
           Classically: The move generates a LeaveNotify on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 3A: There is at least one other pointer on W itself
           P(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise, if there is at least one other pointer in a
           descendant of W
           P(W) changes from W to a descendant of W. The subwindow field
           is set to the child containing the new P(W), the detail field
           is set to Inferior
           Case 3C: Otherwise:
           The pointer window moves from W to a window above W.
           The detail may need to be changed from Ancestor to Nonlinear or
           vice versa depending on the the new P(W)
         */
    
        if (!HasPointer(dev, A)) {
            WindowPtr child = FirstPointerChild(A);
    
            if (child)
                CoreEnterLeaveEvent(dev, LeaveNotify, mode, NotifyInferior, A,
                                    None);
            else
                CoreEnterLeaveEvent(dev, LeaveNotify, mode, NotifyNonlinear, A,
                                    None);
        }
    
        CoreLeaveNotifies(dev, A, X, mode, NotifyNonlinearVirtual);
    
        /*
           Case 9:
           A is a descendant of W, B is a descendant of W
    
           Classically: No events are generated on W
           MPX: The pointer window stays the same or moves to a different
           descendant of W. No events should be generated on W.
    
           Therefore, no event to X.
         */
    
        CoreEnterNotifies(dev, X, B, mode, NotifyNonlinearVirtual);
    
        /* Case 2:
           A is above W, B=W
    
           Classically: The move generates an EnterNotify on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 2A: There is at least one other pointer on W itself
           P(W) doesn't change, so the event should be suppressed
           Case 2B: Otherwise, if there is at least one other pointer in a
           descendant
           P(W) moves from a descendant to W. detail is changed to Inferior,
           subwindow is set to the child containing the previous P(W)
           Case 2C: Otherwise:
           P(W) changes from a window above W to W itself.
           The detail may need to be changed from Ancestor to Nonlinear
           or vice-versa depending on the previous P(W). */
    
        if (!HasPointer(dev, B)) {
            WindowPtr child = FirstPointerChild(B);
    
            if (child)
                CoreEnterLeaveEvent(dev, EnterNotify, mode, NotifyInferior, B,
                                    None);
            else
                CoreEnterLeaveEvent(dev, EnterNotify, mode, NotifyNonlinear, B,
                                    None);
        }
    }
    
    /**
     * Pointer dev moves from A to B and A is a descendant of B.
     */
    static void
    CoreEnterLeaveToAncestor(DeviceIntPtr dev, WindowPtr A, WindowPtr B, int mode)
    {
        /* Case 4:
           A is W, B is above W
    
           Classically: The move generates a LeaveNotify on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 3A: There is at least one other pointer on W itself
           P(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise, if there is at least one other pointer in a
           descendant of W
           P(W) changes from W to a descendant of W. The subwindow field
           is set to the child containing the new P(W), the detail field
           is set to Inferior
           Case 3C: Otherwise:
           The pointer window moves from W to a window above W.
           The detail may need to be changed from Ancestor to Nonlinear or
           vice versa depending on the the new P(W)
         */
        if (!HasPointer(dev, A)) {
            WindowPtr child = FirstPointerChild(A);
    
            if (child)
                CoreEnterLeaveEvent(dev, LeaveNotify, mode, NotifyInferior, A,
                                    None);
            else
                CoreEnterLeaveEvent(dev, LeaveNotify, mode, NotifyAncestor, A,
                                    None);
        }
    
        CoreLeaveNotifies(dev, A, B, mode, NotifyVirtual);
    
        /* Case 8:
           A is a descendant of W, B is W
    
           Classically: A EnterNotify is generated on W with a detail of
           NotifyInferior
    
           MPX:
           Case 3A: There is at least one other pointer on W itself
           P(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise:
           P(W) changes from a descendant to W itself. The subwindow
           field should be set to the child containing the old P(W) <<< WRONG */
    
        if (!HasPointer(dev, B))
            CoreEnterLeaveEvent(dev, EnterNotify, mode, NotifyInferior, B, None);
    
    }
    
    /**
     * Pointer dev moves from A to B and B is a descendant of A.
     */
    static void
    CoreEnterLeaveToDescendant(DeviceIntPtr dev, WindowPtr A, WindowPtr B, int mode)
    {
        /* Case 6:
           A is W, B is a descendant of W
    
           Classically: A LeaveNotify is generated on W with a detail of
           NotifyInferior
    
           MPX:
           Case 3A: There is at least one other pointer on W itself
           P(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise:
           P(W) changes from W to a descendant of W. The subwindow field
           is set to the child containing the new P(W) <<< THIS IS WRONG */
    
        if (!HasPointer(dev, A))
            CoreEnterLeaveEvent(dev, LeaveNotify, mode, NotifyInferior, A, None);
    
        CoreEnterNotifies(dev, A, B, mode, NotifyVirtual);
    
        /* Case 2:
           A is above W, B=W
    
           Classically: The move generates an EnterNotify on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 2A: There is at least one other pointer on W itself
           P(W) doesn't change, so the event should be suppressed
           Case 2B: Otherwise, if there is at least one other pointer in a
           descendant
           P(W) moves from a descendant to W. detail is changed to Inferior,
           subwindow is set to the child containing the previous P(W)
           Case 2C: Otherwise:
           P(W) changes from a window above W to W itself.
           The detail may need to be changed from Ancestor to Nonlinear
           or vice-versa depending on the previous P(W). */
    
        if (!HasPointer(dev, B)) {
            WindowPtr child = FirstPointerChild(B);
    
            if (child)
                CoreEnterLeaveEvent(dev, EnterNotify, mode, NotifyInferior, B,
                                    None);
            else
                CoreEnterLeaveEvent(dev, EnterNotify, mode, NotifyAncestor, B,
                                    None);
        }
    }
    
    static void
    CoreEnterLeaveEvents(DeviceIntPtr dev, WindowPtr from, WindowPtr to, int mode)
    {
        if (!IsMaster(dev))
            return;
    
        LeaveWindow(dev);
    
        if (IsParent(from, to))
            CoreEnterLeaveToDescendant(dev, from, to, mode);
        else if (IsParent(to, from))
            CoreEnterLeaveToAncestor(dev, from, to, mode);
        else
            CoreEnterLeaveNonLinear(dev, from, to, mode);
    
        EnterWindow(dev, to, mode);
    }
    
    static void
    DeviceEnterLeaveEvents(DeviceIntPtr dev,
                           int sourceid, WindowPtr from, WindowPtr to, int mode)
    {
        if (IsParent(from, to)) {
            DeviceEnterLeaveEvent(dev, sourceid, XI_Leave, mode, NotifyInferior,
                                  from, None);
            DeviceEnterNotifies(dev, sourceid, from, to, mode, NotifyVirtual);
            DeviceEnterLeaveEvent(dev, sourceid, XI_Enter, mode, NotifyAncestor, to,
                                  None);
        }
        else if (IsParent(to, from)) {
            DeviceEnterLeaveEvent(dev, sourceid, XI_Leave, mode, NotifyAncestor,
                                  from, None);
            DeviceLeaveNotifies(dev, sourceid, from, to, mode, NotifyVirtual);
            DeviceEnterLeaveEvent(dev, sourceid, XI_Enter, mode, NotifyInferior, to,
                                  None);
        }
        else {                      /* neither from nor to is descendent of the other */
            WindowPtr common = CommonAncestor(to, from);
    
            /* common == NullWindow ==> different screens */
            DeviceEnterLeaveEvent(dev, sourceid, XI_Leave, mode, NotifyNonlinear,
                                  from, None);
            DeviceLeaveNotifies(dev, sourceid, from, common, mode,
                                NotifyNonlinearVirtual);
            DeviceEnterNotifies(dev, sourceid, common, to, mode,
                                NotifyNonlinearVirtual);
            DeviceEnterLeaveEvent(dev, sourceid, XI_Enter, mode, NotifyNonlinear,
                                  to, None);
        }
    }
    
    /**
     * Figure out if enter/leave events are necessary and send them to the
     * appropriate windows.
     *
     * @param fromWin Window the sprite moved out of.
     * @param toWin Window the sprite moved into.
     */
    void
    DoEnterLeaveEvents(DeviceIntPtr pDev,
                       int sourceid, WindowPtr fromWin, WindowPtr toWin, int mode)
    {
        if (!IsPointerDevice(pDev))
            return;
    
        if (fromWin == toWin)
            return;
    
        if (mode != XINotifyPassiveGrab && mode != XINotifyPassiveUngrab)
            CoreEnterLeaveEvents(pDev, fromWin, toWin, mode);
        DeviceEnterLeaveEvents(pDev, sourceid, fromWin, toWin, mode);
    }
    
    static void
    FixDeviceValuator(DeviceIntPtr dev, deviceValuator * ev, ValuatorClassPtr v,
                      int first)
    {
        int nval = v->numAxes - first;
    
        ev->type = DeviceValuator;
        ev->deviceid = dev->id;
        ev->num_valuators = nval < 6 ? nval : 6;
        ev->first_valuator = first;
        switch (ev->num_valuators) {
        case 6:
            ev->valuator5 = v->axisVal[first + 5];
            /* fallthrough */
        case 5:
            ev->valuator4 = v->axisVal[first + 4];
            /* fallthrough */
        case 4:
            ev->valuator3 = v->axisVal[first + 3];
            /* fallthrough */
        case 3:
            ev->valuator2 = v->axisVal[first + 2];
            /* fallthrough */
        case 2:
            ev->valuator1 = v->axisVal[first + 1];
            /* fallthrough */
        case 1:
            ev->valuator0 = v->axisVal[first];
            break;
        }
    }
    
    static void
    FixDeviceStateNotify(DeviceIntPtr dev, deviceStateNotify * ev, KeyClassPtr k,
                         ButtonClassPtr b, ValuatorClassPtr v, int first)
    {
        ev->type = DeviceStateNotify;
        ev->deviceid = dev->id;
        ev->time = currentTime.milliseconds;
        ev->classes_reported = 0;
        ev->num_keys = 0;
        ev->num_buttons = 0;
        ev->num_valuators = 0;
    
        if (b) {
            ev->classes_reported |= (1 << ButtonClass);
            ev->num_buttons = b->numButtons;
            memcpy((char *) ev->buttons, (char *) b->down, 4);
        }
        if (k) {
            ev->classes_reported |= (1 << KeyClass);
            ev->num_keys = k->xkbInfo->desc->max_key_code -
                k->xkbInfo->desc->min_key_code;
            memmove((char *) &ev->keys[0], (char *) k->down, 4);
        }
        if (v) {
            int nval = v->numAxes - first;
    
            ev->classes_reported |= (1 << ValuatorClass);
            ev->classes_reported |= valuator_get_mode(dev, 0) << ModeBitsShift;
            ev->num_valuators = nval < 3 ? nval : 3;
            switch (ev->num_valuators) {
            case 3:
                ev->valuator2 = v->axisVal[first + 2];
                /* fallthrough */
            case 2:
                ev->valuator1 = v->axisVal[first + 1];
                /* fallthrough */
            case 1:
                ev->valuator0 = v->axisVal[first];
                break;
            }
        }
    }
    
    /**
     * The device state notify event is split across multiple 32-byte events.
     * The first one contains the first 32 button state bits, the first 32
     * key state bits, and the first 3 valuator values.
     *
     * If a device has more than that, the server sends out:
     * - one deviceButtonStateNotify for buttons 32 and above
     * - one deviceKeyStateNotify for keys 32 and above
     * - one deviceValuator event per 6 valuators above valuator 4
     *
     * All events but the last one have the deviceid binary ORed with MORE_EVENTS,
     */
    static void
    DeliverStateNotifyEvent(DeviceIntPtr dev, WindowPtr win)
    {
        /* deviceStateNotify, deviceKeyStateNotify, deviceButtonStateNotify
         * and one deviceValuator for each 6 valuators */
        deviceStateNotify sev[3 + (MAX_VALUATORS + 6)/6];
        int evcount = 1;
        deviceStateNotify *ev = sev;
    
        KeyClassPtr k;
        ButtonClassPtr b;
        ValuatorClassPtr v;
        int nval = 0, nkeys = 0, nbuttons = 0, first = 0;
    
        if (!(wOtherInputMasks(win)) ||
            !(wOtherInputMasks(win)->inputEvents[dev->id] & DeviceStateNotifyMask))
            return;
    
        if ((b = dev->button) != NULL) {
            nbuttons = b->numButtons;
            if (nbuttons > 32) /* first 32 are encoded in deviceStateNotify */
                evcount++;
        }
        if ((k = dev->key) != NULL) {
            nkeys = k->xkbInfo->desc->max_key_code - k->xkbInfo->desc->min_key_code;
            if (nkeys > 32) /* first 32 are encoded in deviceStateNotify */
                evcount++;
        }
        if ((v = dev->valuator) != NULL) {
            nval = v->numAxes;
            /* first three are encoded in deviceStateNotify, then
             * it's 6 per deviceValuator event */
            evcount += ((nval - 3) + 6)/6;
        }
    
        BUG_RETURN(evcount > ARRAY_SIZE(sev));
    
        FixDeviceStateNotify(dev, ev, k, b, v, first);
    
        if (b != NULL && nbuttons > 32) {
            deviceButtonStateNotify *bev = (deviceButtonStateNotify *) ++ev;
            (ev - 1)->deviceid |= MORE_EVENTS;
            bev->type = DeviceButtonStateNotify;
            bev->deviceid = dev->id;
            memcpy((char *) &bev->buttons[0], (char *) &b->down[4],
                   DOWN_LENGTH - 4);
        }
    
        if (k != NULL && nkeys > 32) {
            deviceKeyStateNotify *kev = (deviceKeyStateNotify *) ++ev;
            (ev - 1)->deviceid |= MORE_EVENTS;
            kev->type = DeviceKeyStateNotify;
            kev->deviceid = dev->id;
            memmove((char *) &kev->keys[0], (char *) &k->down[4], 28);
        }
    
        first = 3;
        nval -= 3;
        while (nval > 0) {
            ev->deviceid |= MORE_EVENTS;
            FixDeviceValuator(dev, (deviceValuator *) ++ev, v, first);
            first += 6;
            nval -= 6;
        }
    
        DeliverEventsToWindow(dev, win, (xEvent *) sev, evcount,
                              DeviceStateNotifyMask, NullGrab);
    }
    
    void
    DeviceFocusEvent(DeviceIntPtr dev, int type, int mode, int detail,
                     WindowPtr pWin)
    {
        deviceFocus event;
        xXIFocusInEvent *xi2event;
        DeviceIntPtr mouse;
        int btlen, len, i;
    
        mouse = IsFloating(dev) ? dev : GetMaster(dev, MASTER_POINTER);
    
        /* XI 2 event contains the logical button map - maps are CARD8
         * so we need 256 bits for the possibly maximum mapping */
        btlen = (mouse->button) ? bits_to_bytes(256) : 0;
        btlen = bytes_to_int32(btlen);
        len = sizeof(xXIFocusInEvent) + btlen * 4;
    
        xi2event = calloc(1, len);
        BUG_RETURN(xi2event == NULL);
        xi2event->type = GenericEvent;
        xi2event->extension = IReqCode;
        xi2event->evtype = type;
        xi2event->length = bytes_to_int32(len - sizeof(xEvent));
        xi2event->buttons_len = btlen;
        xi2event->detail = detail;
        xi2event->time = currentTime.milliseconds;
        xi2event->deviceid = dev->id;
        xi2event->sourceid = dev->id;       /* a device doesn't change focus by itself */
        xi2event->mode = mode;
        xi2event->root_x = double_to_fp1616(mouse->spriteInfo->sprite->hot.x);
        xi2event->root_y = double_to_fp1616(mouse->spriteInfo->sprite->hot.y);
    
        for (i = 0; mouse && mouse->button && i < mouse->button->numButtons; i++)
            if (BitIsOn(mouse->button->down, i))
                SetBit(&xi2event[1], mouse->button->map[i]);
    
        if (dev->key) {
            xi2event->mods.base_mods = dev->key->xkbInfo->state.base_mods;
            xi2event->mods.latched_mods = dev->key->xkbInfo->state.latched_mods;
            xi2event->mods.locked_mods = dev->key->xkbInfo->state.locked_mods;
            xi2event->mods.effective_mods = dev->key->xkbInfo->state.mods;
    
            xi2event->group.base_group = dev->key->xkbInfo->state.base_group;
            xi2event->group.latched_group = dev->key->xkbInfo->state.latched_group;
            xi2event->group.locked_group = dev->key->xkbInfo->state.locked_group;
            xi2event->group.effective_group = dev->key->xkbInfo->state.group;
        }
    
        FixUpEventFromWindow(dev->spriteInfo->sprite, (xEvent *) xi2event, pWin,
                             None, FALSE);
    
        DeliverEventsToWindow(dev, pWin, (xEvent *) xi2event, 1,
                              GetEventFilter(dev, (xEvent *) xi2event), NullGrab);
    
        free(xi2event);
    
        /* XI 1.x event */
        event = (deviceFocus) {
            .deviceid = dev->id,
            .mode = mode,
            .type = (type == XI_FocusIn) ? DeviceFocusIn : DeviceFocusOut,
            .detail = detail,
            .window = pWin->drawable.id,
            .time = currentTime.milliseconds
        };
    
        DeliverEventsToWindow(dev, pWin, (xEvent *) &event, 1,
                              DeviceFocusChangeMask, NullGrab);
    
        if (event.type == DeviceFocusIn)
            DeliverStateNotifyEvent(dev, pWin);
    }
    
    /**
     * Send focus out events to all windows between 'child' and 'ancestor'.
     * Events are sent running up the hierarchy.
     */
    static void
    DeviceFocusOutEvents(DeviceIntPtr dev,
                         WindowPtr child, WindowPtr ancestor, int mode, int detail)
    {
        WindowPtr win;
    
        if (ancestor == child)
            return;
        for (win = child->parent; win != ancestor; win = win->parent)
            DeviceFocusEvent(dev, XI_FocusOut, mode, detail, win);
    }
    
    /**
     * Send enter notifies to all windows between 'ancestor' and 'child' (excluding
     * both). Events are sent running up the window hierarchy. This function
     * recurses.
     */
    static void
    DeviceFocusInEvents(DeviceIntPtr dev,
                        WindowPtr ancestor, WindowPtr child, int mode, int detail)
    {
        WindowPtr parent = child->parent;
    
        if (ancestor == parent || !parent)
            return;
        DeviceFocusInEvents(dev, ancestor, parent, mode, detail);
        DeviceFocusEvent(dev, XI_FocusIn, mode, detail, parent);
    }
    
    /**
     * Send FocusIn events to all windows between 'ancestor' and 'child' (excluding
     * both). Events are sent running down the window hierarchy. This function
     * recurses.
     */
    static void
    CoreFocusInEvents(DeviceIntPtr dev,
                      WindowPtr ancestor, WindowPtr child, int mode, int detail)
    {
        WindowPtr parent = child->parent;
    
        if (ancestor == parent)
            return;
        CoreFocusInEvents(dev, ancestor, parent, mode, detail);
    
        /* Case 3:
           A is above W, B is a descendant
    
           Classically: The move generates an FocusIn on W with a detail of
           Virtual or NonlinearVirtual
    
           MPX:
           Case 3A: There is at least one other focus on W itself
           F(W) doesn't change, so the event should be suppressed
           Case 3B: Otherwise, if there is at least one other focus in a
           descendant
           F(W) stays on the same descendant, or changes to a different
           descendant. The event should be suppressed.
           Case 3C: Otherwise:
           F(W) moves from a window above W to a descendant. The detail may
           need to be changed from Virtual to NonlinearVirtual depending
           on the previous F(W). */
    
        if (!HasFocus(parent) && !FirstFocusChild(parent))
            CoreFocusEvent(dev, FocusIn, mode, detail, parent);
    }
    
    static void
    CoreFocusOutEvents(DeviceIntPtr dev,
                       WindowPtr child, WindowPtr ancestor, int mode, int detail)
    {
        WindowPtr win;
    
        if (ancestor == child)
            return;
    
        for (win = child->parent; win != ancestor; win = win->parent) {
            /*Case 7:
               A is a descendant of W, B is above W
    
               Classically: A FocusOut is generated on W with a detail of Virtual
               or NonlinearVirtual.
    
               MPX:
               Case 3A: There is at least one other focus on W itself
               F(W) doesn't change, the event should be suppressed.
               Case 3B: Otherwise, if there is at least one other focus in a
               descendant
               F(W) stays on the same descendant, or changes to a different
               descendant. The event should be suppressed.
               Case 3C: Otherwise:
               F(W) changes from the descendant of W to a window above W.
               The detail may need to be changed from Virtual to NonlinearVirtual
               or vice-versa depending on the new P(W). */
    
            /* If one window has a focus or a child with a focuspointer, skip some
             * work and exit. */
            if (HasFocus(win) || FirstFocusChild(win))
                return;
    
            CoreFocusEvent(dev, FocusOut, mode, detail, win);
        }
    }
    
    /**
     * Send FocusOut(NotifyPointer) events from the current pointer window (which
     * is a descendant of pwin_parent) up to (excluding) pwin_parent.
     *
     * NotifyPointer events are only sent for the device paired with dev.
     *
     * If the current pointer window is a descendant of 'exclude' or an ancestor of
     * 'exclude', no events are sent. If the current pointer IS 'exclude', events
     * are sent!
     */
    static void
    CoreFocusOutNotifyPointerEvents(DeviceIntPtr dev,
                                    WindowPtr pwin_parent,
                                    WindowPtr exclude, int mode, int inclusive)
    {
        WindowPtr P, stopAt;
    
        P = PointerWin(GetMaster(dev, POINTER_OR_FLOAT));
    
        if (!P)
            return;
        if (!IsParent(pwin_parent, P))
            if (!(pwin_parent == P && inclusive))
                return;
    
        if (exclude != None && exclude != PointerRootWin &&
            (IsParent(exclude, P) || IsParent(P, exclude)))
            return;
    
        stopAt = (inclusive) ? pwin_parent->parent : pwin_parent;
    
        for (; P && P != stopAt; P = P->parent)
            CoreFocusEvent(dev, FocusOut, mode, NotifyPointer, P);
    }
    
    /**
     * DO NOT CALL DIRECTLY.
     * Recursion helper for CoreFocusInNotifyPointerEvents.
     */
    static void
    CoreFocusInRecurse(DeviceIntPtr dev,
                       WindowPtr win, WindowPtr stopAt, int mode, int inclusive)
    {
        if ((!inclusive && win == stopAt) || !win)
            return;
    
        CoreFocusInRecurse(dev, win->parent, stopAt, mode, inclusive);
        CoreFocusEvent(dev, FocusIn, mode, NotifyPointer, win);
    }
    
    /**
     * Send FocusIn(NotifyPointer) events from pwin_parent down to
     * including the current pointer window (which is a descendant of pwin_parent).
     *
     * @param pwin The pointer window.
     * @param exclude If the pointer window is a child of 'exclude', no events are
     *                sent.
     * @param inclusive If TRUE, pwin_parent will receive the event too.
     */
    static void
    CoreFocusInNotifyPointerEvents(DeviceIntPtr dev,
                                   WindowPtr pwin_parent,
                                   WindowPtr exclude, int mode, int inclusive)
    {
        WindowPtr P;
    
        P = PointerWin(GetMaster(dev, POINTER_OR_FLOAT));
    
        if (!P || P == exclude || (pwin_parent != P && !IsParent(pwin_parent, P)))
            return;
    
        if (exclude != None && (IsParent(exclude, P) || IsParent(P, exclude)))
            return;
    
        CoreFocusInRecurse(dev, P, pwin_parent, mode, inclusive);
    }
    
    /**
     * Focus of dev moves from A to B and A neither a descendant of B nor is
     * B a descendant of A.
     */
    static void
    CoreFocusNonLinear(DeviceIntPtr dev, WindowPtr A, WindowPtr B, int mode)
    {
        WindowPtr X = CommonAncestor(A, B);
    
        /* Case 4:
           A is W, B is above W
    
           Classically: The change generates a FocusOut on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 3A: There is at least one other focus on W itself
           F(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise, if there is at least one other focus in a
           descendant of W
           F(W) changes from W to a descendant of W. The detail field
           is set to Inferior
           Case 3C: Otherwise:
           The focus window moves from W to a window above W.
           The detail may need to be changed from Ancestor to Nonlinear or
           vice versa depending on the the new F(W)
         */
    
        if (!HasFocus(A)) {
            WindowPtr child = FirstFocusChild(A);
    
            if (child) {
                /* NotifyPointer P-A unless P is child or below */
                CoreFocusOutNotifyPointerEvents(dev, A, child, mode, FALSE);
                CoreFocusEvent(dev, FocusOut, mode, NotifyInferior, A);
            }
            else {
                /* NotifyPointer P-A */
                CoreFocusOutNotifyPointerEvents(dev, A, None, mode, FALSE);
                CoreFocusEvent(dev, FocusOut, mode, NotifyNonlinear, A);
            }
        }
    
        CoreFocusOutEvents(dev, A, X, mode, NotifyNonlinearVirtual);
    
        /*
           Case 9:
           A is a descendant of W, B is a descendant of W
    
           Classically: No events are generated on W
           MPX: The focus window stays the same or moves to a different
           descendant of W. No events should be generated on W.
    
           Therefore, no event to X.
         */
    
        CoreFocusInEvents(dev, X, B, mode, NotifyNonlinearVirtual);
    
        /* Case 2:
           A is above W, B=W
    
           Classically: The move generates an EnterNotify on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 2A: There is at least one other focus on W itself
           F(W) doesn't change, so the event should be suppressed
           Case 2B: Otherwise, if there is at least one other focus in a
           descendant
           F(W) moves from a descendant to W. detail is changed to Inferior.
           Case 2C: Otherwise:
           F(W) changes from a window above W to W itself.
           The detail may need to be changed from Ancestor to Nonlinear
           or vice-versa depending on the previous F(W). */
    
        if (!HasFocus(B)) {
            WindowPtr child = FirstFocusChild(B);
    
            if (child) {
                CoreFocusEvent(dev, FocusIn, mode, NotifyInferior, B);
                /* NotifyPointer B-P unless P is child or below. */
                CoreFocusInNotifyPointerEvents(dev, B, child, mode, FALSE);
            }
            else {
                CoreFocusEvent(dev, FocusIn, mode, NotifyNonlinear, B);
                /* NotifyPointer B-P unless P is child or below. */
                CoreFocusInNotifyPointerEvents(dev, B, None, mode, FALSE);
            }
        }
    }
    
    /**
     * Focus of dev moves from A to B and A is a descendant of B.
     */
    static void
    CoreFocusToAncestor(DeviceIntPtr dev, WindowPtr A, WindowPtr B, int mode)
    {
        /* Case 4:
           A is W, B is above W
    
           Classically: The change generates a FocusOut on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 3A: There is at least one other focus on W itself
           F(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise, if there is at least one other focus in a
           descendant of W
           F(W) changes from W to a descendant of W. The detail field
           is set to Inferior
           Case 3C: Otherwise:
           The focus window moves from W to a window above W.
           The detail may need to be changed from Ancestor to Nonlinear or
           vice versa depending on the the new F(W)
         */
        if (!HasFocus(A)) {
            WindowPtr child = FirstFocusChild(A);
    
            if (child) {
                /* NotifyPointer P-A unless P is child or below */
                CoreFocusOutNotifyPointerEvents(dev, A, child, mode, FALSE);
                CoreFocusEvent(dev, FocusOut, mode, NotifyInferior, A);
            }
            else
                CoreFocusEvent(dev, FocusOut, mode, NotifyAncestor, A);
        }
    
        CoreFocusOutEvents(dev, A, B, mode, NotifyVirtual);
    
        /* Case 8:
           A is a descendant of W, B is W
    
           Classically: A FocusOut is generated on W with a detail of
           NotifyInferior
    
           MPX:
           Case 3A: There is at least one other focus on W itself
           F(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise:
           F(W) changes from a descendant to W itself. */
    
        if (!HasFocus(B)) {
            CoreFocusEvent(dev, FocusIn, mode, NotifyInferior, B);
            /* NotifyPointer B-P unless P is A or below. */
            CoreFocusInNotifyPointerEvents(dev, B, A, mode, FALSE);
        }
    }
    
    /**
     * Focus of dev moves from A to B and B is a descendant of A.
     */
    static void
    CoreFocusToDescendant(DeviceIntPtr dev, WindowPtr A, WindowPtr B, int mode)
    {
        /* Case 6:
           A is W, B is a descendant of W
    
           Classically: A FocusOut is generated on W with a detail of
           NotifyInferior
    
           MPX:
           Case 3A: There is at least one other focus on W itself
           F(W) doesn't change, the event should be suppressed
           Case 3B: Otherwise:
           F(W) changes from W to a descendant of W. */
    
        if (!HasFocus(A)) {
            /* NotifyPointer P-A unless P is B or below */
            CoreFocusOutNotifyPointerEvents(dev, A, B, mode, FALSE);
            CoreFocusEvent(dev, FocusOut, mode, NotifyInferior, A);
        }
    
        CoreFocusInEvents(dev, A, B, mode, NotifyVirtual);
    
        /* Case 2:
           A is above W, B=W
    
           Classically: The move generates an FocusIn on W with a detail of
           Ancestor or Nonlinear
    
           MPX:
           Case 2A: There is at least one other focus on W itself
           F(W) doesn't change, so the event should be suppressed
           Case 2B: Otherwise, if there is at least one other focus in a
           descendant
           F(W) moves from a descendant to W. detail is changed to Inferior.
           Case 2C: Otherwise:
           F(W) changes from a window above W to W itself.
           The detail may need to be changed from Ancestor to Nonlinear
           or vice-versa depending on the previous F(W). */
    
        if (!HasFocus(B)) {
            WindowPtr child = FirstFocusChild(B);
    
            if (child) {
                CoreFocusEvent(dev, FocusIn, mode, NotifyInferior, B);
                /* NotifyPointer B-P unless P is child or below. */
                CoreFocusInNotifyPointerEvents(dev, B, child, mode, FALSE);
            }
            else
                CoreFocusEvent(dev, FocusIn, mode, NotifyAncestor, B);
        }
    }
    
    static BOOL
    HasOtherPointer(WindowPtr win, DeviceIntPtr exclude)
    {
        int i;
    
        for (i = 0; i < MAXDEVICES; i++)
            if (i != exclude->id && PointerWindows[i] == win)
                return TRUE;
    
        return FALSE;
    }
    
    /**
     * Focus moves from PointerRoot to None or from None to PointerRoot.
     * Assumption: Neither A nor B are valid windows.
     */
    static void
    CoreFocusPointerRootNoneSwitch(DeviceIntPtr dev,
                                   WindowPtr A,     /* PointerRootWin or NoneWin */
                                   WindowPtr B,     /* NoneWin or PointerRootWin */
                                   int mode)
    {
        WindowPtr root;
        int i;
        int nscreens = screenInfo.numScreens;
    
    #ifdef PANORAMIX
        if (!noPanoramiXExtension)
            nscreens = 1;
    #endif
    
        for (i = 0; i < nscreens; i++) {
            root = screenInfo.screens[i]->root;
            if (!HasOtherPointer(root, GetMaster(dev, POINTER_OR_FLOAT)) &&
                !FirstFocusChild(root)) {
                /* If pointer was on PointerRootWin and changes to NoneWin, and
                 * the pointer paired with dev is below the current root window,
                 * do a NotifyPointer run. */
                if (dev->focus && dev->focus->win == PointerRootWin &&
                    B != PointerRootWin) {
                    WindowPtr ptrwin = PointerWin(GetMaster(dev, POINTER_OR_FLOAT));
    
                    if (ptrwin && IsParent(root, ptrwin))
                        CoreFocusOutNotifyPointerEvents(dev, root, None, mode,
                                                        TRUE);
                }
                CoreFocusEvent(dev, FocusOut, mode,
                               A ? NotifyPointerRoot : NotifyDetailNone, root);
                CoreFocusEvent(dev, FocusIn, mode,
                               B ? NotifyPointerRoot : NotifyDetailNone, root);
                if (B == PointerRootWin)
                    CoreFocusInNotifyPointerEvents(dev, root, None, mode, TRUE);
            }
    
        }
    }
    
    /**
     * Focus moves from window A to PointerRoot or to None.
     * Assumption: A is a valid window and not PointerRoot or None.
     */
    static void
    CoreFocusToPointerRootOrNone(DeviceIntPtr dev, WindowPtr A,
                                 WindowPtr B,        /* PointerRootWin or NoneWin */
                                 int mode)
    {
        WindowPtr root;
        int i;
        int nscreens = screenInfo.numScreens;
    
    #ifdef PANORAMIX
        if (!noPanoramiXExtension)
            nscreens = 1;
    #endif
    
        if (!HasFocus(A)) {
            WindowPtr child = FirstFocusChild(A);
    
            if (child) {
                /* NotifyPointer P-A unless P is B or below */
                CoreFocusOutNotifyPointerEvents(dev, A, B, mode, FALSE);
                CoreFocusEvent(dev, FocusOut, mode, NotifyInferior, A);
            }
            else {
                /* NotifyPointer P-A */
                CoreFocusOutNotifyPointerEvents(dev, A, None, mode, FALSE);
                CoreFocusEvent(dev, FocusOut, mode, NotifyNonlinear, A);
            }
        }
    
        /* NullWindow means we include the root window */
        CoreFocusOutEvents(dev, A, NullWindow, mode, NotifyNonlinearVirtual);
    
        for (i = 0; i < nscreens; i++) {
            root = screenInfo.screens[i]->root;
            if (!HasFocus(root) && !FirstFocusChild(root)) {
                CoreFocusEvent(dev, FocusIn, mode,
                               B ? NotifyPointerRoot : NotifyDetailNone, root);
                if (B == PointerRootWin)
                    CoreFocusInNotifyPointerEvents(dev, root, None, mode, TRUE);
            }
        }
    }
    
    /**
     * Focus moves from PointerRoot or None to a window B.
     * Assumption: B is a valid window and not PointerRoot or None.
     */
    static void
    CoreFocusFromPointerRootOrNone(DeviceIntPtr dev,
                                   WindowPtr A,   /* PointerRootWin or NoneWin */
                                   WindowPtr B, int mode)
    {
        WindowPtr root;
        int i;
        int nscreens = screenInfo.numScreens;
    
    #ifdef PANORAMIX
        if (!noPanoramiXExtension)
            nscreens = 1;
    #endif
    
        for (i = 0; i < nscreens; i++) {
            root = screenInfo.screens[i]->root;
            if (!HasFocus(root) && !FirstFocusChild(root)) {
                /* If pointer was on PointerRootWin and changes to NoneWin, and
                 * the pointer paired with dev is below the current root window,
                 * do a NotifyPointer run. */
                if (dev->focus && dev->focus->win == PointerRootWin &&
                    B != PointerRootWin) {
                    WindowPtr ptrwin = PointerWin(GetMaster(dev, POINTER_OR_FLOAT));
    
                    if (ptrwin)
                        CoreFocusOutNotifyPointerEvents(dev, root, None, mode,
                                                        TRUE);
                }
                CoreFocusEvent(dev, FocusOut, mode,
                               A ? NotifyPointerRoot : NotifyDetailNone, root);
            }
        }
    
        root = B;                   /* get B's root window */
        while (root->parent)
            root = root->parent;
    
        if (B != root) {
            CoreFocusEvent(dev, FocusIn, mode, NotifyNonlinearVirtual, root);
            CoreFocusInEvents(dev, root, B, mode, NotifyNonlinearVirtual);
        }
    
        if (!HasFocus(B)) {
            WindowPtr child = FirstFocusChild(B);
    
            if (child) {
                CoreFocusEvent(dev, FocusIn, mode, NotifyInferior, B);
                /* NotifyPointer B-P unless P is child or below. */
                CoreFocusInNotifyPointerEvents(dev, B, child, mode, FALSE);
            }
            else {
                CoreFocusEvent(dev, FocusIn, mode, NotifyNonlinear, B);
                /* NotifyPointer B-P unless P is child or below. */
                CoreFocusInNotifyPointerEvents(dev, B, None, mode, FALSE);
            }
        }
    
    }
    
    static void
    CoreFocusEvents(DeviceIntPtr dev, WindowPtr from, WindowPtr to, int mode)
    {
        if (!IsMaster(dev))
            return;
    
        SetFocusOut(dev);
    
        if (((to == NullWindow) || (to == PointerRootWin)) &&
            ((from == NullWindow) || (from == PointerRootWin)))
            CoreFocusPointerRootNoneSwitch(dev, from, to, mode);
        else if ((to == NullWindow) || (to == PointerRootWin))
            CoreFocusToPointerRootOrNone(dev, from, to, mode);
        else if ((from == NullWindow) || (from == PointerRootWin))
            CoreFocusFromPointerRootOrNone(dev, from, to, mode);
        else if (IsParent(from, to))
            CoreFocusToDescendant(dev, from, to, mode);
        else if (IsParent(to, from))
            CoreFocusToAncestor(dev, from, to, mode);
        else
            CoreFocusNonLinear(dev, from, to, mode);
    
        SetFocusIn(dev, to);
    }
    
    static void
    DeviceFocusEvents(DeviceIntPtr dev, WindowPtr from, WindowPtr to, int mode)
    {
        int out, in;                /* for holding details for to/from
                                       PointerRoot/None */
        int i;
        int nscreens = screenInfo.numScreens;
        SpritePtr sprite = dev->spriteInfo->sprite;
    
        if (from == to)
            return;
        out = (from == NoneWin) ? NotifyDetailNone : NotifyPointerRoot;
        in = (to == NoneWin) ? NotifyDetailNone : NotifyPointerRoot;
        /* wrong values if neither, but then not referenced */
    
    #ifdef PANORAMIX
        if (!noPanoramiXExtension)
            nscreens = 1;
    #endif
    
        if ((to == NullWindow) || (to == PointerRootWin)) {
            if ((from == NullWindow) || (from == PointerRootWin)) {
                if (from == PointerRootWin) {
                    DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyPointer,
                                     sprite->win);
                    DeviceFocusOutEvents(dev, sprite->win,
                                         GetCurrentRootWindow(dev), mode,
                                         NotifyPointer);
                }
                /* Notify all the roots */
                for (i = 0; i < nscreens; i++)
                    DeviceFocusEvent(dev, XI_FocusOut, mode, out,
                                     screenInfo.screens[i]->root);
            }
            else {
                if (IsParent(from, sprite->win)) {
                    DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyPointer,
                                     sprite->win);
                    DeviceFocusOutEvents(dev, sprite->win, from, mode,
                                         NotifyPointer);
                }
                DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyNonlinear, from);
                /* next call catches the root too, if the screen changed */
                DeviceFocusOutEvents(dev, from, NullWindow, mode,
                                     NotifyNonlinearVirtual);
            }
            /* Notify all the roots */
            for (i = 0; i < nscreens; i++)
                DeviceFocusEvent(dev, XI_FocusIn, mode, in,
                                 screenInfo.screens[i]->root);
            if (to == PointerRootWin) {
                DeviceFocusInEvents(dev, GetCurrentRootWindow(dev), sprite->win,
                                    mode, NotifyPointer);
                DeviceFocusEvent(dev, XI_FocusIn, mode, NotifyPointer, sprite->win);
            }
        }
        else {
            if ((from == NullWindow) || (from == PointerRootWin)) {
                if (from == PointerRootWin) {
                    DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyPointer,
                                     sprite->win);
                    DeviceFocusOutEvents(dev, sprite->win,
                                         GetCurrentRootWindow(dev), mode,
                                         NotifyPointer);
                }
                for (i = 0; i < nscreens; i++)
                    DeviceFocusEvent(dev, XI_FocusOut, mode, out,
                                     screenInfo.screens[i]->root);
                if (to->parent != NullWindow)
                    DeviceFocusInEvents(dev, GetCurrentRootWindow(dev), to, mode,
                                        NotifyNonlinearVirtual);
                DeviceFocusEvent(dev, XI_FocusIn, mode, NotifyNonlinear, to);
                if (IsParent(to, sprite->win))
                    DeviceFocusInEvents(dev, to, sprite->win, mode, NotifyPointer);
            }
            else {
                if (IsParent(to, from)) {
                    DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyAncestor, from);
                    DeviceFocusOutEvents(dev, from, to, mode, NotifyVirtual);
                    DeviceFocusEvent(dev, XI_FocusIn, mode, NotifyInferior, to);
                    if ((IsParent(to, sprite->win)) &&
                        (sprite->win != from) &&
                        (!IsParent(from, sprite->win)) &&
                        (!IsParent(sprite->win, from)))
                        DeviceFocusInEvents(dev, to, sprite->win, mode,
                                            NotifyPointer);
                }
                else if (IsParent(from, to)) {
                    if ((IsParent(from, sprite->win)) &&
                        (sprite->win != from) &&
                        (!IsParent(to, sprite->win)) &&
                        (!IsParent(sprite->win, to))) {
                        DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyPointer,
                                         sprite->win);
                        DeviceFocusOutEvents(dev, sprite->win, from, mode,
                                             NotifyPointer);
                    }
                    DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyInferior, from);
                    DeviceFocusInEvents(dev, from, to, mode, NotifyVirtual);
                    DeviceFocusEvent(dev, XI_FocusIn, mode, NotifyAncestor, to);
                }
                else {
                    /* neither from or to is child of other */
                    WindowPtr common = CommonAncestor(to, from);
    
                    /* common == NullWindow ==> different screens */
                    if (IsParent(from, sprite->win))
                        DeviceFocusOutEvents(dev, sprite->win, from, mode,
                                             NotifyPointer);
                    DeviceFocusEvent(dev, XI_FocusOut, mode, NotifyNonlinear, from);
                    if (from->parent != NullWindow)
                        DeviceFocusOutEvents(dev, from, common, mode,
                                             NotifyNonlinearVirtual);
                    if (to->parent != NullWindow)
                        DeviceFocusInEvents(dev, common, to, mode,
                                            NotifyNonlinearVirtual);
                    DeviceFocusEvent(dev, XI_FocusIn, mode, NotifyNonlinear, to);
                    if (IsParent(to, sprite->win))
                        DeviceFocusInEvents(dev, to, sprite->win, mode,
                                            NotifyPointer);
                }
            }
        }
    }
    
    /**
     * Figure out if focus events are necessary and send them to the
     * appropriate windows.
     *
     * @param from Window the focus moved out of.
     * @param to Window the focus moved into.
     */
    void
    DoFocusEvents(DeviceIntPtr pDev, WindowPtr from, WindowPtr to, int mode)
    {
        if (!IsKeyboardDevice(pDev))
            return;
    
        if (from == to && mode != NotifyGrab && mode != NotifyUngrab)
            return;
    
        CoreFocusEvents(pDev, from, to, mode);
        DeviceFocusEvents(pDev, from, to, mode);
    }