9780 Commits

Author SHA1 Message Date
Jonas Ådahl
9de36fed4d virtual-input-device/native: Verify device cleanup in impl_state_free()
We free it in the task function, so it's already NULL when freeing the
state struct. Change the redudant unref to a NULL check warning.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1688>
2021-02-23 10:05:32 +00:00
Jonas Ådahl
671bda2509 virtual-input-device/native: Emit added/removed events
Without these devices, things that depend on the existance of input
device classes won't know about the existance of e.g. pointer devices,
if the only pointer device is from a virtual one.

This requires handling situations where e.g. a device doesn't have a
device node thus can't be matched against a udev device.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1688>
2021-02-23 10:05:32 +00:00
Jonas Ådahl
5e34ae2154 backend: Only create idle monitors for added physical input devices
The rest of the things we do aren't applicable, e.g. mapping tablet
devices/tools to monitors and hiding cursors.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1688>
2021-02-23 10:05:32 +00:00
Jonas Ådahl
e6b70f1a2b seat-impl: Dispatch source also when there are already queued events
Libinput will queue a few initial events when a seat is assigned to the
udev backend; a result of it probing udev adding detected devices. For
us to see these events, we need to dispatch libinput before going idle,
as nothing will show up on the libinput file descriptor until something
else (e.g. keyboard event or mouse movement) wakes us up.

Do this by adding a prepare() function to the libinput GSource, that
checks whether there are any events in the queue already, and return
TRUE if so is the case, causing us to dispatch before going fully idle.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1688>
2021-02-23 10:05:32 +00:00
Pascal Nowack
9b5fb1b593 remote-desktop: Clarify the type of keycode for NotifyKeyboardKeycode()
The API for NotifyKeyboardKeycode() does not mention what type of
keycode is expected to be submitted.
So, clarify in the API that the keycode to submit is expected to be an
evdev keycode.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1732>
2021-02-23 08:18:05 +00:00
Pascal Nowack
72cfe9b3fd backends/x11: Interpret keycode correctly
Currently, when a remote desktop user submits a keycode, it will be
interpreted differently, when using the x11 session, instead of a
wayland session.
In a wayland session, submitting a keycode will have the expected
result (as if the key was pressed locally).
In a x11 session, this is not the case. Instead of getting the expected
key, some other key will be pressed (or sometimes even none).
The reason for this is that the native backend interprets the keycode
as evdev keycode and the x11 backend interprets the keycode as xkb
keycode.

To ensure that both backends produce the same behaviour when submitting
a keycode, fix the x11 backend to always interpret the keycode as evdev
keycode, instead of a xkb keycode.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1732>
2021-02-23 08:18:05 +00:00
Pascal Nowack
ff48f6c26b remote-desktop: Fix typo in API description
For NotifyKeyboardKeycode() the API user submits keycodes instead of
keysyms.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1732>
2021-02-23 08:18:05 +00:00
Robert Mader
aa6b7ed468 monitor-manager-xrandr: Change g_memdup() to g_memdup2()
This was propably overlooked in 30e1c51b33eabba3e233293d66648903e2a6d65d

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1512>
2021-02-22 13:52:27 +01:00
Robert Mader
6eeeffdc68 src: Stop using GSlice
It has been inofficially deprecated for years, is known to cause issues
with valgrind and potentially hides memory corruption.
Lets stop using it.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1512>
2021-02-22 13:52:27 +01:00
Jonas Dreßler
9512d58c28 display: Don't add MetaDisplay argument to grab-op-* signals twice
GObject signals pass the emitting GObject as the first argument to
signal handler callbacks. When refactoring the grab-op-begin/end signals
to remove MetaScreen with commit 1d5e37050df2b8e1db8b5ea301ee0162d77d4b74,
the "screen" argument was replaced with a "display" argument instead of
being removed completely. This made us call the signal handlers with two
identical MetaDisplay arguments, which is very confusing and actually
wasn't handled in a grab-op-begin handler in gnome-shell.

So fix this by not adding the MetaDisplay as an argument to those
signals, GObject will take care of that for us.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1734>
2021-02-19 14:52:22 +01:00
Jonas Dreßler
5527b6e483 background-content: Add support for rounded clipping when drawing
We're going to round the workspace backgrounds in the new overview for
gnome-shell 40.

So far corner-rounding was only possible for StWidgets because the
rounded clipping was done using cairo drawing. We now need rounded
clipping for ClutterActors too because backgrounds are drawn using
ClutterActors (or more specifically a ClutterContent). To implement
that, first a ClutterOffscreenEffect subclass together with a fragment
shader from GSK (see gskSetOutputColor() [1] in the GSK GL renderer
code) was investigated, and while that was generic and worked quite
well, it was extremely slow for the case of drawing wallpapers because
of all the FBOs that had to be allocated.

This is the new, more performant approach: Use the same fragment shader,
but perform the rounded clipping right in MetaBackgroundContent while
we're painting the wallpaper. This has almost no performance impact,
with the downside of not being a generic solution.

To allow for rounded clipping not only at the edges of the wallpaper,
but using any given bounding rectangle, the API exposes not only the
radius, but also a bounding rect.

[1] https://gitlab.gnome.org/GNOME/gtk/-/blob/master/gsk/resources/glsl/preamble.fs.glsl

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1717>
2021-02-18 20:26:42 +00:00
Pascal Nowack
7076945488 remote-desktop: Document NotifyPointerAxis() more explicit
Currently, the documentation for NotifyPointerAxis() just mentions that
a smooth scroll event is emitted.
However, this is not entirely correct. For each NotifyPointerAxis(),
mutter emits an emulated discrete scrolling event based on the
submitted accumulated smooth scrolling deltas.
Additionally, it doesn't mention how the motion deltas need to be
interpreted.

So, document the NotifyPointerAxis() notification better by mentioning
the emulation of discrete scroll events, how these discrete scroll
events are calculated and how the motion deltas need to be interpreted.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1727>
2021-02-17 21:47:00 +01:00
Pascal Nowack
c77e943ce2 backends/native: Handle triple resolution mouse wheels better
When a remote desktop user emits a virtual smooth scrolling event, a
smooth scroll event, that is not emulated, is emitted and on occasion
a discrete scroll event, that is emulated, is emitted.
As base for the discrete scrolling event, the smooth scrolling steps
are accumulated.
When the accumulated smooth scrolling steps surpass the
DISCRETE_SCROLL_STEP, the discrete scrolling event is emitted.

Currently, mutter uses for DISCRETE_SCROLL_STEP the value 10, which is
a terrible value to work with, especially for high resolution mouse
wheels.
When a triple resolution mouse wheel is used, each scrolling step will
have the value 3 1/3.
Three of such events won't however surpass the DISCRETE_SCROLL_STEP.

To fix this situation, add DBL_EPSILON to the calculation step, when
checking for the discrete scroll event to ensure that 3 smooth scroll
events, with each having the value 3 1/3, emit a discrete scrolling
event.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1727>
2021-02-17 21:39:03 +01:00
Pascal Nowack
a5d692582d backends/x11: Emit discrete scroll events for accumulated smooth events
MetaVirtualInputDeviceX11 currently doesn't handle smooth scroll events
at all.
So, if a user of the remote desktop API uses smooth scroll events, then
only the wayland backend handles these events.
The user of the remote desktop API however, might not know which
backend is being used and actually the user should not even have to
care about it.

Actual smooth events cannot be emulated in the X11 events.
What can be done however is accumulating smooth events and then when
the accumulated steps surpass the DISCRETE_SCROLL_STEP value, emit a
discrete scroll event.
So, do exactly that, to make smooth scroll events work when the remote
desktop API is used with the x11 backend.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1727>
2021-02-17 21:39:03 +01:00
Carlos Garnacho
a5db9ee2d7 backends/x11: Emulate pointer motion while the pointer is off stage
Given X11 nature, the pointer "leaves" the stage anytime it wanders into
a client window, or any other areas that are not deemed part of the
stage input region.

Yet we want to stay correct in those situations, e.g. have the clutter
side reasonably in sync, picking and highlighting to work properly, etc.

In order to achieve that, emulate motion events on XI_RawMotion. These
are as much throttled as our pointer tracking for a11y, in order to avoid
too many XIQueryPointer sync calls. This emulation only kicks in anytime
that X11 notifies us that we are not "on" the stage.

This replaces some sync_pointer() calls in GNOME Shell code that are
there just to compensate for this trait of X11, e.g. in the message tray
code.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1659>
2021-02-14 13:23:29 +00:00
Carlos Garnacho
437f5d1c66 compositor: Sync pointer after begin/end modal on X11
Ensure we issue a motion event for the current pointer position,
as there might be situations where compositor modals get X grabs
from other clients stacked on top, or missed events in between
otherwise.

Ensure the Clutter state is still up-to-date afterwards here. This
replaces some sync_pointer() calls done in GNOME Shell code, always
done after modality changes.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1659>
2021-02-14 13:23:29 +00:00
Carlos Garnacho
00c7f45a0f compositor: Refactor backend-specific code into MetaCompositor vfuncs
Do these Wayland operations (that apply on both native and nested backends)
in the MetaCompositorServer subclass. We want to add more backend specific
behavior here in the future.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1659>
2021-02-14 13:23:29 +00:00
Carlos Garnacho
698fe3f1a9 wayland: Avoid automatically decoupling source/offer after grab
In the case that DnD is performed and succeeds, we want to release
the grab early, and let the transfer IPC happen in the back. For
that to happen without a hitch, drag source and offer must be left
related to each other after undoing the grab, even though the default
ungrabbing code does that automatically (indirectly, by unsetting the
drag focus).

In these cases, we used to manually unset the current source, so
this decoupling was skipped. Notably, one missed case is X11 DnD,
so we might end up with the situation there that DnD did succeed,
transfer is ongoing, but the source and offer are already decoupled,
this confused the machinery and missed the finishing XdndFinished
to be emitted to the X11 drag source.

The prior commits prepared for this source/offer decoupling being
a manual operation, this commit avoids doing this automatically
when ungrabbing.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1720>
2021-02-09 19:33:13 +00:00
Carlos Garnacho
0f9dc84d3b wayland: Manually detach source/offer on failure paths
Adapt more paths to manual detaching of source/offer. This is still
done automatically when the grab is finished.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1720>
2021-02-09 19:33:13 +00:00
Carlos Garnacho
8e01ea1e04 wayland: Plug XDnD drag source leak
This object is just being detached, with no code unref'ing it. Do
this whenever the XDnD selection goes unowned, usually a good
indication that the drag source no longer is one.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1720>
2021-02-09 19:33:13 +00:00
Carlos Garnacho
3799606fc2 wayland: Make XDnD grab unlink source/offer manually
This currently happens by default whenever the grab is finished.
We want to eventually do this manually everywhere, so start here.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1720>
2021-02-09 19:33:13 +00:00
Olivier Fourdan
3322e4fa54 surface-actor-wayland: Handle Xwayland vanishing gracefully
When a game is playing fullscreen, mutter may use a direct scanout of
the surface.

However, if that surface is from Xwayland and Xwayland had vanished (now
that mutter can survive that), the actual surface might be NULL, so
check for that case to avoid a crash.

Close: https://gitlab.gnome.org/GNOME/mutter/-/issues/1638
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1718>
2021-02-09 19:06:22 +00:00
Olivier Fourdan
445373d028 x11: Check for XCB reply
Now that mutter can survive Xwayland vanishing in mid-flight, we need to
actually check if the Xserver reply fetched though XCB is not NULL,
otherwise we may crash, that would be a shame.

Close: https://gitlab.gnome.org/GNOME/mutter/-/issues/1638
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1718>
2021-02-09 19:06:22 +00:00
Dor Askayo
9b8cff8673 renderer/native: Remove unnecessary field and logic
This field was never set and only ever cleared.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1715>
2021-02-09 08:27:11 +00:00
Dor Askayo
5d32b251ed renderer/native: Remove unused field
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1715>
2021-02-09 08:27:11 +00:00
Dor Askayo
80fd030f10 onscreen/native: Move function declaration to the correct header file
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1715>
2021-02-09 08:27:11 +00:00
Dor Askayo
d6abea3ba7 onscreen/native: Add missing error messages
g_set_error_literal() asserts that the provided message is not NULL.
If it is NULL, the function is entirely no-op.

This resulted in a NULL dereference of the GError, which remained
NULL in this case, when trying to print a warning in
clutter_stage_cogl_redraw_view().

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1715>
2021-02-09 08:27:11 +00:00
Dor Askayo
2c0bd98f21 connector/kms: Add missing else statement
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1715>
2021-02-09 08:27:11 +00:00
Björn Daase
7a75c7ea1f core: Don't show copyright when printing version
Fixes: https://gitlab.gnome.org/GNOME/mutter/-/issues/86
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1702>
2021-02-09 07:46:10 +00:00
Jonas Ådahl
c60cba4eeb tests: Add test for destroyed frame clock free timeline actor
This would without 'clutter/timeline: Clear stage view listener when
actor destroyed' result in backtraces such as

Program terminated with signal SIGSEGV, Segmentation fault.
  #0  on_stage_stage_views_changed ()
  #1  g_closure_invoke ()
  #2  signal_emit_unlocked_R ()
  #3  g_signal_emit_valist ()
  #4  g_signal_emit ()
  #5  update_stage_views ()
  #6  clutter_actor_update_stage_views ()
  #7  clutter_stage_update_actor_stage_views ()
  #8  handle_frame_clock_frame ()
  #9  clutter_frame_clock_dispatch ()
  #10 frame_clock_source_dispatch ()
  #11 g_main_dispatch ()

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1719>
2021-02-08 19:40:05 +00:00
Jonas Ådahl
b838ba8166 tests/stage-view-tests: Make 'wait_for_paint()' block
Otherwise it's a busy loop, skipping any poll():ing.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1719>
2021-02-08 19:40:05 +00:00
Georges Basile Stavracas Neto
aa2cb8a4f7 screen-cast-*-stream-src: Switch to cogl_framebuffer_flush()
PipeWire recently introduced busy buffers, which actually fixes the last remaining
issue that blocked us from downgrading these cogl_framebuffer_finish() calls into
cogl_framebuffer_flush() ones.

Switch to cogl_framebuffer_flush() in all three stream sources.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1701>
2021-02-08 08:37:08 +00:00
Ivan Molodetskikh
dae089f79e clutter: Remove CLUTTER_ENABLE_EXPERIMENTAL_API
It is no longer used anywhere.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1707>
2021-02-05 17:05:19 +00:00
Ivan Molodetskikh
9b44aa77b6 clutter: Remove clutter_stage_set_sync_delay
The sync_delay field is never accessed.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1707>
2021-02-05 17:05:19 +00:00
Jonas Ådahl
2cdb0414c2 remote-desktop/session: Maybe emit 'owner-changed' after clipboard enabled
If there is a clipboard owner when enabling the clipboard integration
without immediately overriding the owner, send an initial owner-changed
event.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
2021-02-05 16:44:27 +00:00
Jonas Ådahl
5104a9b2ce remote-desktop/session: Add support for SelectionTransfer/Write
When a transfer request is done to the MetaSelectionSourceRemote source,
it's translated to a SelectionTransfer signal, which the remote desktop
server is supposed to respond to with SelectionWrite.

A timeout (set to 15 seconds) is added to handle too long timeouts,
which cancels the transfer request.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
2021-02-05 16:44:27 +00:00
Jonas Ådahl
d7c8535ac6 remote-desktop/session: Implement SelectionRead()
This makes it possible to retrieve the clipboard content from the
current selection clipboard source.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
2021-02-05 16:44:27 +00:00
Jonas Ådahl
a220506bf7 remote-desktop: Add dummy remote selection source
It doesn't yet fetch data from the remote desktop session, but hooks up
correctly.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
2021-02-05 16:44:27 +00:00
Jonas Ådahl
6398d5a109 remote-desktop/session: Forward MetaSelection::owner-changed
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
2021-02-05 16:44:27 +00:00
Jonas Ådahl
ac1a5366b1 remote-desktop/session: Added boiler plate for clipboard integration
Nothing is hooked up, it only does basic sanity checking i.e. whether
the clipboard was enabled when interacting with it. No actual clipboard
integration is hooked up yet.

This also syncs org.gnome.Mutter.RemoteDesktop.xml from
gnome-remote-desktop.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
2021-02-05 16:44:27 +00:00
Jonas Ådahl
54b024465e util: Add 'remote-desktop' debug topic
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
2021-02-05 16:44:27 +00:00
Carlos Garnacho
b2b66aa8c6 backends/native: Disable touch-mode with pointer presence
The original implementation of ::touch-mode tested for keyboard
presence to know whether the OSK and other touch-only features were
enabled.

However that didn't pan out, every webcam, card reader and kitchen
sink like to live a second life as EV_KEY devices. This made the
detection of actual external keyboards a much harder task than it
sounds, and was thus removed in commit f8e2234ce59fbb.

Try a different approach here, and test for pointer devices, it
doesn't matter if internal or external devices, the rationales:

- It is significantly easier to get this right, there's virtually
  no devices with abs/rel axes that don't try to be a real input
  device of some sorts.
- It's not as good as testing for keyboard presence, but it's the
  next best thing. These usually come in pairs, except in weird
  setups.
- It is better than not having anything for a number of situations:
  - Non-convertible laptops with a touchscreen will get touch-mode
    disabled due to touchpad presence (plus keyboard). There's
    been complains about OSK triggering with those.
  - Same for desktop machines with USB touchscreens, the mouse
    (and presumably keyboard) attached would make touch-mode
    get in the middle.
  - Convertible laptops with a broken tablet-mode switch get a
    chance to work on tablet modes that do disable input devices
    (e.g. detachable keyboards, or via firmware)
  - Kiosk machines, tablets, and other devices that have a
    touchscreen but will not regularly have a mouse/keyboard
    will get the touch-mode enabled.

All in all, this seems to cover more situations the way we expect it,
there's only one situation that the OSK would show where it might
not be desirable, and one that might not show when it better should:

- Tablets and kiosk machines that get one keyboard plugged, but not a
  mouse, will still show the OSK, despite being able to type right
  away.
- Convertible laptops with broken/unreliable tablet-mode switch (e.g.
  ignored by the kernel) rely entirely on the device/firmware
  characteristics to work. If after folding into tablet mode the
  touchpad remains active, touch-mode will not turn on.
  Fixing the tablet-mode switch on these devices should be preferred,
  as that'll also make libinput magically disable the touchpad.

The latter can be worked around with the a11y toggle. The former is
merely inconvenient, and nothing prevents the user from plugging a mouse
in addition.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1710>
2021-02-05 16:07:55 +01:00
Robert Mader
7da34f154b compositor/dnd-actor: Take geometry scale into account on DnD-cancel
Technically this is still wrong if the source actor or dnd actor are
transformed in other ways. However geometry scale is the by far most
common case and we currently lack convenience API in Clutter to
easily compute the right values.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1683>
2021-02-05 09:51:56 +00:00
Robert Mader
04eeeb78d1 wayland/dnd-surface: Use new API to set geometry scale of feedback actor
The removed parts are now all handled in MetaFeedbackActor.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1683>
2021-02-05 09:51:56 +00:00
Robert Mader
dfa659b5b5 feedback-actor: Add API to set and get geometry scale
Analogous to MetaWindowActor. Also take it into account for positioning
when an anchor is set.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1683>
2021-02-05 09:51:56 +00:00
Jonas Dreßler
04c6934363 screencast: Log a debug message when we can't get a buffer from pipewire
When recording the screen and real time encoding it using a gstreamer
pipeline, that pipeline can stall when the encoder is too slow. Log a
debug message using the new SCREEN_CAST debug topic in that case so we
know when framedrops are happening.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1709>
2021-02-05 09:27:38 +00:00
Jonas Dreßler
a869df1dd7 util: Add a SCREEN_CAST debug topic
This is going to be useful to log dropped frames and other more common
errors about screencasting.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1709>
2021-02-05 09:27:38 +00:00
Florian Müllner
ee3d26f228 keybindings: Reset modifier-only-pressed on scroll
Since commit c255031b6d6, we allow some modifier+scroll events to
pass through to Clutter to enable gnome-shell to handle them. That
action shouldn't trigger a modifier-only action at the same time, so
reset the corresponding tracking just like we do for modifier+click.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1695>
2021-02-04 19:26:18 +00:00
Florian Müllner
ac3d9a0641 events: Process modifier+scroll after keybindings
Allowing the keybindings code to see the event enables it to
process it for its internal modifier-only-pressed state.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1695>
2021-02-04 19:26:18 +00:00
Florian Müllner
7901b98808 display: Expose window_grab_modifiers
Since commit c255031b6d6 we pass scroll-events through to
the compositor if the window_grab_modifiers are pressed;
in order to allow gnome-shell to check for those events,
expose the struct member as a MetaDisplay property.

Also take the opportunity to pick a more generic name, now
that the modifier is no longer used exclusively for mouse
clicks (unless we maintain the notion of scroll events as
button 4 and 5 "clicks").

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1695>
2021-02-04 19:26:18 +00:00