In the Quartz backend, there are two methods by which windows are
resized. The first method is fully handled by Quartz and does not appear
in the event stream the application resizes. The second method is when
we resize windows by ourselves. In OS X this happens when a GTK+ resize
grip is used. This resize grip is larger than the Quartz resize grip.
When the resize is started outside the "Quartz area", we have to handle
it by ourselves.
This patch fixes this manual window resizing by ignoring events while we
are in the process of resizing (such that the events actually arrive at
the sendEvent handler of GdkQuartzWindow where this resize is handled).
When the resize has finished we break all grabs such that GDK is not
stuck thinking the cursor is still in the resize window.
_gdk_x11_moveresize_configure_done() isn't called for wmspec
moves/resizes so we don't have a way to notice when a wmspec
move/resize ends and consequently untrigger the sending of
_NET_WM_MOVERESIZE_CANCEL which results in this message always being
sent on the next button release event. In that case we are marking
that event as handled so it isn't processed further which breaks
button press/release event handling in several widgets.
To fix this we simply allow the normal event handling machinery to run
after sending the _NET_WM_MOVERESIZE_CANCEL message.
https://bugzilla.gnome.org/show_bug.cgi?id=673328
Since the order in which _NET_WM_STATE and _NET_WM_DESKTOP are set, or
even *if* they are set, isn't defined, we could end up unsetting
GDK_WINDOW_STATE_FOCUSED given that both handlers for these two X
properties end up doing window state changes for all states. As we
want GDK_WINDOW_STATE_FOCUSED to be set by default we need to set its
master flag by default as well.
https://bugzilla.gnome.org/show_bug.cgi?id=673125
We now have a proper MASTER/SLAVE input device split, where
the masters are virtual core input devices and we add fake hw
slave devices for the system pointer and real slave devices for
wintab devices.
We also set the proper source_device on the events so you can
tell which device sent it and properly decode the axis info.
The code for calculating the per-monitor workarea was ignoring
the fact that the EWMH workarea property can only handle rectangular
workareas, and thus can't really do justice to general monitor
arrangements. As a workaround, we ignore it for anything but
the primary monitor. And we ignore it for the primary monitor
as well if it does not even cover it.
https://bugzilla.gnome.org/show_bug.cgi?id=672163
We want to avoid handling focus events for the private focus window,
otherwise the keyboard grab taken by for example buttons will cause a
spurious FOCUS_OUT/FOCUS_IN on the toplevel.
The code that did this seems to have been lost in the XI2 transition for
GTK3.
This patch reapplies db4a6040af which was
backed out in 18406b7b04 to give
developers a chance to get their X servers fixed. As we want to get this
bugfix in for 3.4, we need to commit it now.
https://bugzilla.gnome.org/show_bug.cgi?id=657578
XI2 provides us with an increment for each scroll valuator,
and by dividing the delta by the increment, we obtain normalized
values in some abstract 'scroll unit'.
For mouse wheels, the evdev driver reports an increment of -1,
so doing this division fixes the inverted scrolling with wheels
that we've seen recently.
GtkRange was using GDK_POINTER_MOTION_MASK, and it was not
getting any emulated motion events, because we only translate
from GDK_BUTTON_MOTION_MASK to GDK_POINTER_MOTION_MASK, but not
the other way around, and emulated_mask only had
GDK_BUTTON_MOTION_MASK in it. Now we put GDK_POINTER_MOTION_MASK
in emulated_mask and successfully match for windows that
have GDK_POINTER_MOTION_MASK or any of the button motion masks
selected.
This fixes range sliders not following the finger and jumping
to the last position upon release.
If the Window Manager supports the _NET_WM_STATE_HIDDEN, we use it to use
the _NET_WM_STATE protocol when de-iconifying windows (iconification is
unchanged, via XIconifyWindow). Additionally, we no longer interpret all
UnmapNotify events for our window as the result of iconification.
(Based on patch by Tomas Frydrych <tf@linux.intel.com>)
NSEvent -scrollingDeltaX and -scrollingDeltaY aren't defined before
10.7, so objc assumes that they return a pointer. Trying to cast to a
float generates a compiler error.
XInput >= 2.1 allows for implementing smooth scrolling,
reporting the different scrolling axes as valuators.
Any change in those will be reported as GdkEventScroll
events with delta_x/y information.
the older kind of scroll events is still handled, and
emulated in devices able to provide smooth scrolling,
setting _gdk_event_set_pointer_emulated() in that case.
nsevent scrollingDeltaX/Y (available on OSX >= Lion) is used to
provide the smooth scrolling values. In any case, old fashioned
events are still sent, setting _gdk_event_set_pointer_emulated()
if the event contains both smooth and non-smooth values.
Events of type GDK_SCROLL will be received if the client side window
event mask has either GDK_SCROLL_MASK or GDK_SMOOTH_SCROLL_MASK.
GDK_BUTTON_PRESS_MASK has been removed from type_masks[GDK_SCROLL]
as that bit is often set for other-than-scrolling purposes, and
yet have the window receive scroll events. In GTK+, this forces
non-smooth events bubbling, even if the widgets above want smooth
events, and legitimately set GDK_[SMOOTH_]SCROLL_MASK.
If a device provides both smooth and non-smooth events, the latter will be
flagged with _gdk_event_set_pointer_emulated() so the client side window
receives one or the other. If a device is only able to deliver non-smooth
events, those will be sent, so both direction/deltas may need to be handled.
get_event_window() just checked on GDK_TOUCH_MASK, including for emulated
pointer events, so at the very least those should also match evmasks with
no touch events whatsoever
If an active grab kicks in on a different window, _gdk_display_has_device_grab()
would still find the former implicit grab for the window below the pointer, thus
sending events to an unrelated place.
If a grab with GDK_TOUCH_MASK kicks in due to a touch sequence emulating pointer
events, don't mutate the sequence into emitting touch events right away.
Create the backing GdkTouchGrabInfo for touches even if the pointer
emulating touch sequence is already holding an implicit grab on a
window that didn't select for touch events.
the backing GdkTouchGrabInfo will be needed if the overriding device
grab finishes before the touch does in order to send events back to
the implicit grab window. Instead, wait until the touch is physically
finished before removing the matching GdkTouchGrabInfo
GDK will only receive touch events when dealing with a multitouch
device, so these must be transformed to pointer events if the
client-side window receiving the event doesn't listen to touch
events, and the touch sequence the event is from does emulate
the pointer.
If a sequence emulates pointer events, it will result in a
button-press, N motions with GDK_BUTTON1_MASK set and a
button-release event, and it will deliver crossing events
as specified by the current device grab.
These are equivalent to an implicit grab (with !owner_events), so
if the touch leaves or enters the grab window, the other window
won't receive the corresponding counter-event.
If the touch sequence happens on a window with GDK_TOUCH_MASK set,
a GdkTouchGrabInfo is created to back it up. Else a device grab is
only created if the sequence emulates the pointer.
If both a device and a touch grab are present on a window, the later
of them both is obeyed, Any grab on the device happening after a
touch grab generates grab-broken on all the windows an implicit
touch grab was going on.
Anytime a touch device interacts, the crossing events generation
will change to a touch mode where only events with mode
GDK_CROSSING_TOUCH_BEGIN/END are handled, and those are sent
around touch begin/end. Those are virtual as the master
device may still stay on the window.
Whenever there is a switch of slave device (the user starts
using another non-touch device), a crossing event with mode
GDK_CROSSING_DEVICE_SWITCH may generated if needed, and the normal
crossing event handling is resumed.
Translate XI_TouchBegin/Update/End to GDK_TOUCH_BEGIN/UPDATE/END
events.
At the same time,
set pointer-emulated flags on button events with XIPointerEmulated
and on touch events emulating the pointer.
This commit introduces GDK_TOUCH_BEGIN/UPDATE/END/CANCEL
and a separate GdkEventTouch struct that they use. This
is closer to the touch event API of other platforms and
matches the xi2 events closely, too.
We introduce GDK_SOURCE_TOUCHSCREEN and GDK_SOURCE_TOUCHPAD
for direct and indirect touch devices, respecively. These
correspond to XIDirectTouch and XIDependentTouch in XI2.
My previous fix for this broke the progress bar in epiphany. This fix
makes it work again, and keeps the gimp bug fixed.
Basically, whenever we do a non-double-buffered rendering we have to
flush the entire window as it might be drawn outside the double
buffering machinery.
Once we've made them popup windows we must also implement the popup_done event
handler on the shell surface listener. The best we can currently do is to hide
the window. This will then signal up to GTK which could then deactivate the
appropriate menu (see https://bugzilla.gnome.org/show_bug.cgi?id=670881)
This allows us to get the device if we need to make the window a popup. This
relies on the side effect that GTK calls into GDK to take a grab before the
popup window is shown.
Since it's generated, we install the header by putting it into
gdkinclude_HEADERS, so it's wrong to put it again into
gdk_public_h_sources.
This fixes the build.
This patch changes all uses of GDK_DEPRECATED(_FOR) in gdk headers
by the versioned variants, GDK_DEPRECATED_IN_3_x(_FOR). At the same
time, we add GDK_AVAILABLE_IN_3_x annotations for all API additions
in 3.2 and 3.4.
These macros follow the recent changes in GLibs deprecation
setup. We now annotate deprecated functions with the version
they were deprecated in, and you can define the macro
GDK_VERSION_MIN_REQUIRED to cut off deprecation warnings for
'recent' deprecations.
At the same time, we introduce version annotations for new API
and allow you to avoid 'recent' API additions by defining
GDK_VERSION_MAX_ALLOWED.
This last slave device (stored per master) is used to fill
in the missing slave device in synthesized crossing events
that are not directly caused by a device event (ie due to
configure events or grabs).
The F keys have no unicode mapping, and UCKeyTranslate() returns
a bogus 0x10 as mapping to unicode. Instead of checking for this
random and undocumented return value, simply assign all function
keys explicitly. This patch also splits the ill-named "known_keys"
array into "modifier_keys" and "function_keys" which is much
more obvious.
(cherry picked from commit 55f9e5cbaf)
Move g_return_if_fail() stuff from the backends to the public
functions in gdkscreen.c itself, and some fixes for ugly formatting in
the various gdkscreen-backend.c files.
_gdk_x11_keymap_key_is_modifier() never tries to set min/max_keycode
if they haven't been set before, meaning that until another function
sets those, all the keys will be seen as non-modifiers.
This causes GdkKeyEvents to be wrongly tagged with "->is_modifier = 0"
when in actual fact the key is a modifier. This fixes keyboard
shortcuts captured with GtkCellRendererAccel in "raw" mode thinking
a modifier without any actual keys is a valid shortcut.
https://bugzilla.gnome.org/show_bug.cgi?id=670400
We used to set a flushed boolean whenever we flushing double buffered
areas to the window due to a non-db draw. We then read back from the
window if this was set. This broke when we were doing multiple paints
of the same area after a flush as we were re-reading the window each
time, overdrawing what was previously draw.
This fixes issues where the new default bg of transparent
didn't work, making offscreen windows black.
I don't think this is a practical performance problem.
Offscreen windows are rarely used and generally used for
graphics tricks like alpha anyway.
This implements the following part of the EWMH spec:
"The special value _NET_WM_MOVERESIZE_CANCEL also allows clients to cancel the
operation by sending such message if they detect the release themselves
(clients should send it if they get the button release after sending the move
resize message, indicating that the WM did not get a grab in time to get the
release)."
In particular, it fixes the case of clicking widgets that use
gdk_window_begin_[resize|move]_drag*() and the click "sticking", i.e. the
mouse button getting released but the resize or move operation remaining in
effect.
https://bugzilla.gnome.org/show_bug.cgi?id=669208
Sometimes we need to read back the window content into our double
buffer due to rendering a window with alpha when there is
no implicit paint or it has been flushed due to non-db drawing
before.
However, in this case we can't use gdk_cairo_set_source_window as
it might trigger an implicit paint flush as we detect what we
think is a direct non-double buffered window draw operation, which
will flush the implicit paint operation that we're just setting up.
To fix this we use the raw gdk_window_ref_impl_surface operation
to get the source surface.
There was a sign issue in a coordinate transform that made us
flush the wrong region when flushing an implicit paint.
The non-double buffered drawing would then be drawn over the
right area, but then at the end of the implicit paint this
would be overdrawn with the area we didn't properly remove
from the implicit paint.
Also, the translation from window coords to impl window
coords is now done before removing any active double
buffered paints, as these are also in impl window coords.
With the changes in default CSS to make the default background transparent
we ran into issues where intermediate GdkWindow (for instance the
view_window in GtkViewport) where we didn't set an explicit background
(because before they were always covered). So instead of showing throught
the transparent windows were showing the default backgroind of the intermediate
window (i.e. black).
With this change we also needed to fix GtkViewport, as it was previously
relying on the bin and view windows to cover widget->window so that the
border was not visible if shadow_type was NONE.
When calling gtk_window_present(), gdk_win32_window_raise did not
actually raise the window anymore. Replacing BringWindowToTop() with
SetForegroundWindow() fixes this.
During testing, we also discovered that sometimes SetForeGroundWindow()
will (correctly) refuse to raise the window and fail(for example: sometimes
when dragging a different application at the time of a gtk_window_present()
call). To prevent a GdkWarning from being produced, usage of the API_CALL
macro has been removed for this case.
Additional goodies of SetForeGroundWindow:
- it brings the window to the front when the process owning the
window to raise is the foreground process (for example when
gtk_window_present is called from a GtkStatusIcon's activate
signal handler)
- it limits itself to flashing the task bar button associated
with the window if the process owning the window to raise
is *not* the foreground process (for example when gtk_window_present
is called from a g_timeout_add callback function)
https://bugzilla.gnome.org/show_bug.cgi?id=665760
Due to changes in the behaviour of the virtual modifiers around MOD1 the
implementation of the map_virtual_modifiers vfunc was mangling the modifiers
and making keybindings not work correctly.
This change updates the implementation to match the X11 implementation's
behaviour.
Callers of this function were passing in -1, -1 for the width and height if
they just wanted the window moving - rather than the size changing. We need to
respect that behaviour and don't try and set the width/height to those
dimensions.
Now pop-up windows (ala combo-boxes) work!
"The child window MUST also have the _NET_SUPPORTING_WM_CHECK property set to
the ID of the child window. […] If the _NET_SUPPORTING_WM_CHECK window on the
client window is missing or not properly set, clients SHOULD assume that no
conforming Window Manager is present."
This commit implements that, which allows us to not have to do a
XGetWindowProperty() every N seconds when running under a compliant WM.
This is also a more correct fix for the bug handled in commit
daf29bffed.
https://bugzilla.gnome.org/show_bug.cgi?id=666921
The part in gdkwindow-x11.c which uses XIEvent and friends is "protected"
by HAVE_XGENERICEVENTS, i.e., XGetEventData() has been found. (Xlib.h)
XIEvent and friends are defined in <X11/extension/XInput2.h> which is
included by gdkdisplay-x11.h if XINPUT_2 is defined.
The patch makes sure XIEvent is only used if XINPUT_2 is defined.
https://bugzilla.gnome.org/show_bug.cgi?id=667534
When we receive a configure event from Wayland telling us to resize our
surface we check against the geometry constraints for the window to ensure we
do not resize below the minimum and maximum limits.
Now that grab and ungrab vfuncs are implemented on GdkDevice then we can use
gdk_device_ungrab to break the implicit grab created by the button press that
triggered the resize and move.
An implicit grab is created inside GTK+ when the button is pressed down on a
window. The semantics of wl_shell_surface_resize means that you don't get a
corresponding release event that would ordinarily break the implicit grab. So
we must do it as part of the resize request.
This change follows on from a change in semantics in Wayland where calling
wl_input_device_attach with nil would make the compositor set the pointer
sprite to it's default cursor sprite.
When the X server does not support the shape extension (as some
vnc implementations seem to), our DND code was always seeing
an empty input shape, so drops always missed their target.
http://bugzilla.gnome.org/show_bug.cgi?id=620240
Apparently the deprecation warning macros are placed into gdkconfig.h
during the configure stage, so put these in the pre-configured
gdkconfig.h.win32 as well, as their definitions are needed for all builds.
Reading a card32 property into a long may lead to undefined high
bits, so mask them off. Also, make the conditions for setting and
unsetting the stick flag opposites, to avoid unintended changes.
Patch by John Lindgren, bug 666842
The current EWMH has added 'source indication' fields to a number
of client messages. Set these to 1 to indicate a regular client.
Also fill the button field of _NET_WM_MOVERESIZE.
==23282== 64 bytes in 2 blocks are definitely lost in loss record 8,069 of 13,389
==23282== at 0x4A074CD: malloc (vg_replace_malloc.c:236)
==23282== by 0x39A1C3E2EA: cairo_region_create (cairo-region.c:196)
==23282== by 0x6D9AF3D: recompute_visible_regions_internal (gdkwindow.c:964)
==23282== by 0x6D9B4B8: recompute_visible_regions (gdkwindow.c:1126)
==23282== by 0x6DA3450: gdk_window_hide (gdkwindow.c:5689)
==23282== by 0x6D9CED9: _gdk_window_destroy_hierarchy (gdkwindow.c:2042)
==23282== by 0x6D9D040: gdk_window_destroy (gdkwindow.c:2109)
==23282== by 0x655B5E4: gtk_entry_unrealize (gtkentry.c:3012)
==23282== by 0x7068BF3: g_cclosure_marshal_VOID__VOID (gmarshal.c:85)
==23282== by 0x706710B: g_type_class_meta_marshal (gclosure.c:885)
==23282== by 0x7066DF9: g_closure_invoke (gclosure.c:774)
==23282== by 0x7080585: signal_emit_unlocked_R (gsignal.c:3340)
==23282== by 0x707F619: g_signal_emit_valist (gsignal.c:3033)
==23282== by 0x707FB71: g_signal_emit (gsignal.c:3090)
==23282== by 0x679E243: gtk_widget_unrealize (gtkwidget.c:4458)
==23282== by 0x64E83C7: gtk_bin_forall (gtkbin.c:172)
==23282== by 0x6548BBD: gtk_container_forall (gtkcontainer.c:2014)
==23282== by 0x67A966D: gtk_widget_real_unrealize (gtkwidget.c:10253)
==23282== by 0x672D002: gtk_tool_item_unrealize (gtktoolitem.c:474)
==23282== by 0x7068BF3: g_cclosure_marshal_VOID__VOID (gmarshal.c:85)
https://bugzilla.gnome.org/show_bug.cgi?id=666552
This is a boolean property that will be set to TRUE if the current
desktop environment is capable of displaying the application menu as
part of the desktop shell.
If it is FALSE then the application will need to display the menu for
itself.
We want to avoid handling focus events for the private focus window,
otherwise the keyboard grab taken by for example buttons will cause a
spurious FOCUS_OUT/FOCUS_IN on the toplevel.
The code that did this seems to have been lost in the XI2 transition for
GTK3.
https://bugzilla.gnome.org/show_bug.cgi?id=657578
The function returns the part of a monitors area that should be
used for positioning popups, menus, etc. The only non-trivial
implementation atm is in the X backend, all the other backends
just return the full monitor area. The X implementation is
currently suboptimal, since it requires roundtrips to collect
the necessary information. It should be changed to monitor
the properties for changes, when XFixes allows to monitor
individual properties.
https://bugzilla.gnome.org/show_bug.cgi?id=641999
Dealing with disabled devices may turn into hierarchy/device
changed events on device IDs with no backing GdkDevice yet,
so protect against that. The device attachment will be handled
correctly when the device is enabled later.
For maximized windows, titlebars cannot be used to reposition or
scale the window, so if an application does not use it to convey
useful information (other than the application name), the screen
space occupied by titlebars could be put to better use.
Add a new window property which requests from the window manager
to hide titlebars when windows are maximized to account for this.
https://bugzilla.gnome.org/show_bug.cgi?id=665616
Setup listener functions for the drag and drop events as well as the selection
events. Then create and save a data structure representing the data offer from
the other client.
This implementation is based on a hash table. The hard coded GtkSelection
atoms are preloaded into the hash table at the correct values. User generated
atoms start after the last preloaded atom.
The data device manager is a global object that provides the support
infrastructure around data devices. These data device objects are the basis
for handling drag and drop as well as selections in Wayland.
As pointed out in bug 665999, these were just not right.
Before this commit, the nicks were 'output' and 'only'.
After this commit, they are 'input-output' and 'input-only'.
This means we don't have to have hardcoded "/usr/share/wayland" to find the
cursors.
This change also fixes up the warning messages for when loading fails.
When an implicit paint is flushed during expose, e.g. because a
non-double buffered widget is painting, make sure to copy the existing
data from the window surface we rendered before flushing back to the
paint surface, instead of using an empty base.
Code was already handling that (and said so in the comment), but only
when no implicit paint was used at all, and not in the case when it's
flushed mid-expose.
Previously all the commands that acted on the shell took the surface that was
to be acted on as parameter. Now we retrieve an object from the shell that
represents its state for the surface. With that wl_shell_surface object we can
then call methods on that.
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
gdk_window_get_update_area is supposed to get the area where things
need painting, and remove them from the update areas. However, if
some area is covered by other windows with an alpha background we
can't just expect whatever the app choses to render in the update
area as correct, so we don't actually remove these areas, meaning
they will get correctly rendered when we get to the expose handlers.
gdk_window_move_region doesn't move children, so we can't copy
transparent child window regions with copyarea, so we remove these
from the copy region.
We track the areas that have alpha coverage so that we can
avoid using these as sources when copying window contents.
We also don't remove such areas from the clipping regions so
that they are painted both by parent and child.
This cleans up the expose handling a bit by using the existing
clip regions, and it allows us later to use painters algorithm
to do transparent windows.
This turns GdkWin32DragContext into a proper GdkDragContext subclass.
Because we now correctly initialize GdkWin32DragContext in
gdk_drag_context_new, we no longer crash immediatly when a DnD
operation is initialized (the find_window, drag_status, ... vfuncs
where all pointing to 0x0 instead of their proper win32 implementations).
We now try to consistently refer to GdkDragContext as "context",
GdkWin32DragContext as "win32_context" and the ole2 related
target_drag_context and source_drag_context as "ctx".
Members of GdkWin32DragContext only used by the ole2 DnD codepaths
are now explicitly marked with a ole2_dnd_ prefix.
gdk_cairo_region_create_from_surface doesn't work correctly on PPC.
This is most prominently seen with the GTK window resize grip, the
shape of which is mirrored every eight pixels horizontally.
At the same time, use an A1 surface for the resize grip shape to
eliminates an A8->A1 surface conversion.
Add GDK_MODIFIER_INTENT_SHIFT_GROUP to enum GdkModifierIntent
and handle it in gdk_keymap_get_modifier_mask(). Add an X11
impl of the method and return keymap_x11->group_switch_mask.
Return 0 from the default impl because we don't know.
If the keyboard group shifting modifier is *also* a normal
accelerator modifier, we need to special case it when calling
gdk_keymap_translate_keyboard_state(), so we get the right
key symbol for accelerators (for example we want Option-O,
not Option-Ø displayed in menu items). This patch should only
affect quartz where the Alt key both shifts the group and can
be used as accel modifier, and not X11 or Win32 where AltGr
is not used for accelerators.
- fix quartz' gdk_keymap_translate_keyboard_state() to return
the right consumed_modifiers
- add _gtk_translate_keyboard_accel_state() which does the
special casing
- use it everywhere instead of gdk_keymap_translate_keyboard_state()
g_checksum_get_digest checks to ensure that the passed digest_len is long
enough to hold the digest, before setting it to the actual length of the
digest returned. Digest_len is uninitialized in the code, so if you're
lucky it will be larger than 20 and everything will work fine. If you're
unlucky, g_checksum_get_digest will return either -1 or some number less
than 20, and the g_assert(digest_len==20) will fail.
Wake up the run loop unconditionally (don't check if it is waiting) because
it might go into waiting state right after we checked for it. Fixes GIMP
startup (which has a lot of GIOChannel I/O but zero NSEvents) from several
minutes to a few seconds.
(cherry picked from commit 0729cdc9a1)
We now do proper handling of existing invalid regions, and
we use ScrollDC which allows us to specify the right clip
region rather than just the bounding rect.
Positioning windows at 0,0 post creation failed, because it
was mapped with CW_USEDFAULT, but private->x/y still said 0,
so moving it to 0,0 did nothing. We now always position the
window at the right place, even when not mapped, but we
create it at CW_USEDEFAULT initially and store that position
before moving it to the right place.
This fixes the window sizing test in testgtk and the inital
position for the gimp toolbar.
The synaptics trackpad driver has some weird behaviour on scroll.
It pops up a window over the mouse pointer (looking like a scrollbar).
This has two problems:
* We get extra enter/leave events for the trackpad window
* We get back the trackpad window when we look for the window
under the mouse to deliver the mousewheel message.
So, we add some trackpad specific hacks to avoid this (sigh) based
on the trackpad window window class.
This fixes bug #542777 and was partially based on a patch there
from Peter Clifton.