This is not really needed. The gl context is totally tied to the
window it is created from by virtue of sharing the context with the
paint context of that window and that context always has the visual
of the window (which we already can get).
Also, all user visible contexts are essentially offscreen contexts, so
a visual doesn't make sense for them. They only use FBOs which have
whatever format that the users sets up.
To properly support multithreaded use we use a global GPrivate
to track the current context. Since we also don't need to track
the current context on the display we move gdk_display_destroy_gl_context
to GdkGLContext::discard.
We used to have a weak ref to the cairo surface and it was keep
alive by the references in the normal windows, but that reference
was removed by d48adf9cee, causing
us to constantly create and destroy the surface.
https://bugzilla.gnome.org/show_bug.cgi?id=738648
We want to create windows with the default visuals such that we then
have the right visual for GLX when we want to create the paint GL
context for the window.
For instance, (in bug 738670) the default rgba visual we picked for the
NVidia driver had an alpha size of 0 which gave us a BadMatch when later
trying to initialize a gl context on it with a alpha FBConfig.
Instead of just picking what the Xserver likes for the default, and just
picking the first rgba visual we now actually call into GLX to pick
an appropriate visual.
The visuals are typically sorted by some sort of "most useful first"
order. And picking the last one is likely to give us the weirdest
matching glx visual.
Commits 314b6abbe8 and eb9223c008 were ignoring
the fact that the code where found is set to 1 was modifying
col - which was an ok thing to do when that part of the code
was still breaking out of the loop, but it is no longer doing
that (since 2003 !). Fix things up by storing the final col
value in a separate variable and using that after the loop.
https://bugzilla.gnome.org/show_bug.cgi?id=738886
Its not really reasonable to handle failures to make_current, it
basically only happens if you pass invalid arguments to it, and
thats not something we trap on similar things on the X drawing side.
If GL is not supported that should be handled by the context creation
failing, and anything going wrong after that is essentially a critical
(or an async X error).
We make user facing gl contexts not attached to a surface if possible,
or attached to dummy surfaces. This means nothing can accidentally
read/write to the toplevel back buffer.
This adds the new type GdkGLContext that wraps an OpenGL context for a
particular native window. It also adds support for the gdk paint
machinery to use OpenGL to draw everything. As soon as anyone creates
a GL context for a native window we create a "paint context" for that
GdkWindow and switch to using GL for painting it.
This commit contains only an implementation for X11 (using GLX).
The way painting works is that all client gl contexts draw into
offscreen buffers rather than directly to the back buffer, and the
way something gets onto the window is by using gdk_cairo_draw_from_gl()
to draw part of that buffer onto the draw cairo context.
As a fallback (if we're doing redirected drawing or some effect like a
cairo_push_group()) we read back the gl buffer into memory and composite
using cairo. This means that GL rendering works in all cases, including
rendering to a PDF. However, this is not particularly fast.
In the *typical* case, where we're drawing directly to the window in
the regular paint loop we hit the fast path. The fast path uses opengl
to draw the buffer to the window back buffer, either by blitting or
texturing. Then we track the region that was drawn, and when the draw
ends we paint the normal cairo surface to the window (using
texture-from-pixmap in the X11 case, or texture from cairo image
otherwise) in the regions where there is no gl painted.
There are some complexities wrt layering of gl and cairo areas though:
* We track via gdk_window_mark_paint_from_clip() whenever gtk is
painting over a region we previously rendered with opengl
(flushed_region). This area (needs_blend_region) is blended
rather than copied at the end of the frame.
* If we're drawing a gl texture with alpha we first copy the current
cairo_surface inside the target region to the back buffer before
we blend over it.
These two operations allow us full stacking of transparent gl and cairo
regions.
Before 5e325c4, the default BitGravity was NorthWestGravity.
When static gravities were removed in 5e325c4, the BitGravity regressed
to the X11 default, Forget. Forget causes giant graphical glitches and
black flashes when resizing, especially in some environments that aren't
synchronized to a paint clock yet, like XWayland.
I'm assuming that the author assumed that the default of BitGravity was
NorthWestGravity, which is the default of WinGravity. Just go ahead and
fix this regression to make resizing look smooth again.
Remove checks for NULL before g_free() and g_clear_object().
Merge check for NULL, freeing of pointer and its setting
to NULL by g_clear_pointer().
https://bugzilla.gnome.org/show_bug.cgi?id=733157
The warning may have had some value at some point, but if
people uninstall large icons just to make the warning go
away, it does more harm than good. So just remove it.
If we have a fullscreen window that covers a monitor, desktop
chrome is not relevant for placing of menus and other popups.
Therefore, return the full monitor geometry instead of the
workarea in this case.
https://bugzilla.gnome.org/show_bug.cgi?id=737251
gdk_x11_display_set_window_scale() affects the interpretation of the
Xft/DPI XSETTING - it is substituted inside GDK with the value of
Gdk/UnscaledDPI xsetting. However, this change is not propagated to
GTK+ and from GTK+ back to gdk_screen_set_resolution() until the
main loop is run.
Fix this by handling the screen resolution directly in gdk/x11.
This requires duplication of code between GDK and GTK+ since we still
have to handle DPI in GTK+ in the case that GdkSettings:gtk-xft-dpi
is set by the application.
https://bugzilla.gnome.org/show_bug.cgi?id=733076
Traditionally, the way painting was done in GTK+ was with the
"expose-event" handler, where you'd use GDK methods to do drawing on
your surface. In GTK+ 2.24, we added cairo support with gdk_cairo_create,
so you could paint your graphics with cairo.
Since then, we've added client-side windows, double buffering, the paint
clock, and various other enhancements, and the modern way to do drawing
is to connect to the "draw" signal on GtkWidget, which hands you a
cairo_t. To do double-buffering, the cairo_t we hand you is actually on
a secret surface, not the actual backing store of the window, and when
the draw handler completes we blit it into the main backing store
atomically.
The code to do this is with the APIs gdk_window_begin_paint_region,
which creates the temporary surface, and gdk_window_end_paint which
blits it back into the backing store. GTK+'s implementation of the
"draw" signal uses these APIs.
We've always sort-of supported people calling gdk_cairo_create
"outside" of a begin_paint / end_paint like old times, but then you're
not getting the benefit of double-buffering, and it's harder for GDK to
optimize.
Additionally, newer backends like Mir and Wayland can't actually support
this model, since they're based on double-buffering and swapping buffers
at various points in time. If we hand you a random cairo_t, we have no
idea when is a good time to swap.
Remove support for this.
This is technically a GDK API break: a warning is added in cases where
gdk_cairo_create is called outside of a paint cycle, and the returned
surface is a dummy that won't ever be composited back onto the main
surface. Testing with complex applications like Ardour didn't produce
any warnings.
This avoids a bunch of policy problems with deciding how to lay
out the window menu under different WMs.
For now, we use the special event _GTK_SHOW_WINDOW_MENU, but we
hope to have this standardized in wm-spec quite soon, as KDE wants
it as well.
It seems that some backends implemented get_root_origin wrong
and returned the client window coordinates, not the frame window
coordinates. Since it's possible to implement generically for all
windows, let's do that instead of having a separate impl vfunc.
And the counterpart to unmaximize when dragging a maximized window, if
touch devices aren't going to use EWMH moveresize, having this one at least
makes things feel a bit less awkward.
https://bugzilla.gnome.org/show_bug.cgi?id=709914
Sadly, EWMH moveresize mechanism can't work with touch devices for two
reasons:
1) As a mutter implementation detail, the device is queried in order
to check whether the dragging button is still pressed. Touch devices
won't report the button 1 being pressed through pointer emulation.
2) Even bypassing that check, on X11 touch events are selected prior
to sequences being started, either through XISelectEvents or
XIGrabTouchBegin, no late registering through active grabs is allowed,
as WMs do on reaction to EWMH moveresize messages.
So for the time being, make touch devices fallback on emulated window
dragging, which at least allows for moving windows.
https://bugzilla.gnome.org/show_bug.cgi?id=709914
We have a hack in the XSETTINGS code to substitute gtk-xft-dpi
with gdk-unscaled-dpi unless the screen has a fixed window scale,
in which case we just use gtk-xft-dpi.
But if the screen is changed to have a fixed window scale, then
the substituted value of gdk-unscaled-dpi will stick around until
the next (coincidental) change to XSETTINGS. To fix this, force
an immediate reread of the XSETTINGS property when
gdk_x11_display_set_window_scale() is used.
https://bugzilla.gnome.org/show_bug.cgi?id=725754
Instead of destroying the surface in the backend if this is
unable to resize, let the core code do it, and do it properly.
Based on a patch by Benjamin Otte.
https://bugzilla.gnome.org/show_bug.cgi?id=725172
This setting will let us keep traditional appearance
of dialogs on platforms where this is expected.
The new setting is called gtk-dialogs-use-header, backed
by the Gtk/DialogsUseHeader xsetting.
The EWMH defines _NET_WM_MOVERESIZE_SIZE_KEYBOARD and
_NET_WM_MOVERESIZE_MOVE_KEYBOARD for operations that are not
initiated by a button-press event. Allow using these by passing
a button of 0 to gdk_window_begin_move/resize_drag.
fvwm seems to have problems keeping _NET_WORKAREA in sync with
the number of desktops. Instead of reading garbage, silently use
the full screen as workarea for desktops that are not covered
by the _NET_WORKAREA property.
https://bugzilla.gnome.org/show_bug.cgi?id=698248
Applications need a way to fix or adapt the decoration layout,
for situations like split header bars. Setting the layout from
the theme with a style property did not offer a good way to do
this, and the ::show-close-button property does not provide
fine-grained control.
To improve the situation, move the layout string to a property of
GtkHeaderBar which is backed by a setting. This allows platforms to
set a default button layout independent of the theme, while applications
can override the default.
The style GtkWindow style property is now deprecated and ignored.
And deprecate the X11-specific version of it.
We call this new API _set_shadow_width() and not _set_frame_extents()
because we already have a gdk_window_get_frame_extents() with a
different meaning and different type of value.
https://bugzilla.gnome.org/show_bug.cgi?id=720374
The focus handling code is shared between core and XI2 implementations,
so just handle the extra XI2 types for passive grabs. Those must be dealt
with in the same way than active grabs. Focus events with this crossing
mode could happen currently through the XIGrabFocusIn passive grab.
https://bugzilla.gnome.org/show_bug.cgi?id=719762
This fixes potential assertions if a GTK+ app gets to receive
a XINotifyPassiveGrab/Ungrab pointer crossing event, currently
triggerable by XIGrabEnter passive grabs.
http://bugzilla.gnome.org/show_bug.cgi?id=719762
This is so we always have the latest information given by XRandR (or other), and not
rely on Core protocol information that might not have been updated yet.
This is specially visible when a monitor is connected (less frequent) or disconnected
(much more frequent), callbacks on GdkScreen::monitors-changed that call
gdk_screen_get_width/height() could get the screen size previous to the monitor
rearrangement.
So in order to fix this, keep track of the latest monitors information, and calculate
the bounding box in order to know the screen size.
https://bugzilla.gnome.org/show_bug.cgi?id=715029
Scroll valuators were being just appended again and again, leading
to 1) a growing memory issue anytime a device changed 2) the first
scroll valuators to stay permanent on the application lifetime, as
the first stored valuators would always match.
https://bugzilla.gnome.org/show_bug.cgi?id=705203
Passive grabs may take pointer focus out of the application, even though
the pointer didn't leave the window, but those events still trigger resetting
of the scroll axes. This is most visible with compiz, and possibly other
reparenting WMs, where passive grabs happen on the WM-managed window that
is a parent of the application toplevel.
As it is not possible to have scrolling happening on the timespan a passive
grab takes action, it is entirely safe for GTK+ to assume none happened if
it gets a crossing event of that nature.
https://bugzilla.gnome.org/show_bug.cgi?id=699574#c33
This information will be useful in case someone stumbles on a situation
similar to https://bugzilla.gnome.org/show_bug.cgi?id=699574, so we can
figure out where do the crossing events come from or go to easily.
It's been reported in several applications that scrolling feels jerky
since commit cc7b3985b3.
Investigation reported that the combination of passive 4-7 button grabs
on the toplevel and the presence of native subwindows might trigger
too often crossing events from the child window to the toplevel and
back as scroll "buttons" trigger the passive grab. Those crossing events
would reset the scroll valuators rendering scrolling from jerky on
touchpads (where there's intermediate smooth events between the emulated
button ones) to ineffective on regular mouse wheels (where the crossing
event would reset the valuators right before the single smooth scroll
event we get is delivered)
So, only reset scroll valuators when the pointer enters the toplevel
(we only care about this when the pointer is on the window after it's
been possibly scrolling somewhere else), and it doesn't come from an
inferior.
The situations where this happened varied though, the native subwindow
could be one created explicitly by the application, or created indirectly
through gdk_window_ensure_native(). The latter was mainly the case for
evolution (through gtk_selection_set_owner()) and any GtkScrolledWindow
under the oxygen-gtk3 theme (through gdk_window_set_composited())
https://bugzilla.gnome.org/show_bug.cgi?id=699574
Add a GtkSetting for whether the desktop shell is showing the desktop
folder icons.
This is on by default because most desktop shells do show the icons on
the desktop. We already have a patch in gnome-settings-daemon to bind
this to the org.gnome.desktop.background show-desktop-icons GSettings
key which is off by default on GNOME.
https://bugzilla.gnome.org/show_bug.cgi?id=712302
If a motion event handler (or other handler running from the flush-events
phase of the frame clock) recursed the main loop then flushing wouldn't
complete until after the recursed main loop returned, and various aspects
of the state would get out of sync.
To fix this, change flushing of the event queue to simply mark events as
ready to flush, and let normal event delivery handle the rest.
https://bugzilla.gnome.org/show_bug.cgi?id=705176
I have been convinced that it is a bad idea to change the behaviour
at the same time as deprecating it, so go back to respecting the
Gtk/ButtonImages xsetting in buttons created with
gtk_button_new_from_stock() when it is set.
The setting as well as the function are still deprecated, and the
default value of the setting will remain FALSE.
I have been convinced that it is a bad idea to change the behaviour
at the same time as deprecating it, so go back to respecting the
Gtk/MenuImages xsetting in GtkImageMenuItem when it is set.
The setting as well as the widget are still deprecated, and the
default value of the setting will remain FALSE.
Pass the master device instead if the last slave is NULL. This is
unlikely to happen in most of the cases, but can happen when running
unit tests where there's no pointer interaction to update the last
slave.
https://bugzilla.gnome.org/show_bug.cgi?id=696756
This lets you force a specific window scale, this is needed
for mutter to be able to disable the scaling as it needs access
to unmangled X window/screen sizes. It can also be useful to
force a specific scale in e.g. tests.
This reverts commit b2e666bf8f.
We need to keep cursor blinking configurable for accessibility
reasons.
https://bugzilla.gnome.org/show_bug.cgi?id=704134
Conflicts:
gdk/win32/gdkproperty-win32.c
gdk/x11/gdksettings.c
gtk/gtksettings.c
gtk/gtktextview.c
We want a surface so we can properly represent the scale factor for it.
All backends are converted to use surfaces and we reimplement the
backwards compat code in the generic code.
Xsun is no longer shipped to customers, and Oracle/Sun's Xorg distribution
uses "Sun Microsystems" as the vendor name, so this hack is incorrect in
the more common recent cases.
Plug windows weren't redrawing properly because the embedded
window was expecting to get messages for each frame from the
compositor, but the compositor doesn't know about embedded
windows. Simply disable frame sync for GtkPlug's GdkWindow -
extending XEMBED to handle frame sync isn't interesting
at this point.
A new API gdk_x11_window_set_frame_sync_enabled() is added
to allow this to be done.
https://bugzilla.gnome.org/show_bug.cgi?id=701613
We've long had double precision mouse coordinates on wayland (e.g.
when rotating a window) but with the new scaling we even have it on
X (and, its also in Xinput2), so convert all the internal mouse/device
position getters to use doubles and add new accessors for the
public APIs that take doubles instead of ints.
This lets use use a scaled Xft/DPI for old apps while not
blowing up the size of scaled windows. Only apps supporting
Gdk/WindowScaleFactor should supprt Gdk/UnscaledDPI.
If you set GDK_SCALE=2 in the environment then all windows will be
scaled by 2. Its not an ideal solution as it doesn't handle
multi-monitors at different scales, and only affects gtk apps.
But it is a good starting points and will help a lot on HiDPI
laptops.
Move the call to gdk_x11_atom_to_xatom_for_display() outside of the
search loop in gdk_x11_screen_supports_net_wm_hint(). In my test case
(running Audacious for about a minute), this reduced the total number of
hash table lookups performed from 370,000 to 230,000.
https://bugzilla.gnome.org/show_bug.cgi?id=702913
Calling XIQueryPointer() on a slave device is going to trigger a
BadDevice X error. So in case we query a slave device state, ask the
master device instead.
https://bugzilla.gnome.org/show_bug.cgi?id=700233
Add missing check in gdk_x11_device_manager_xi2_get_window(), returning
NULL if no valid XI2Event* has been found. Calling code seems to be
prepared to handle NULLs coming from this function, so it should be
safe enough (e.g. check gdk_event_source_get_filter_window()).
https://bugzilla.gnome.org/show_bug.cgi?id=700465
Change the visibility handling to be the same way we do it in
GLib now. We pass -fvisibility=hidden to gcc and decorate public
functions with __attribute__((visibility("default"))).
This commit just does this for GDK, GTK+ will follow later.
Move it from GdkDisplayManagerX11.init to GdkDisplay.class_init.
This shouldn't cause any problems, but who knows, so keep this patch
small.
Reason for this is the unification of display managers.
This makes Wayland and X11 no longer call into XKB and libX11 for these
functions but use GDK's own copy of these functions, just like the
win32, quartz and broadway backends.
This is another step towards making GdkDisplayManager backend-agnostic.
Most of the backends profit from this as their atom implementations
where generic anyway - x11 needed that to allow multiple X displays and
broadway, quartz and wayland don't have the concept of displays.
The X11 backend still did things, so I only #if 0'd some code but did
not actually update anything.
On crossing events resulting from moving windows (eg. workspace switch),
deviceid equals sourceid, so make those reset scroll valuators on all
slave devices to avoid misleading jumps in scroll events
Fixes https://bugzilla.gnome.org/show_bug.cgi?id=690275
The macros we had for checking for toplevel windows were passing
through the root window, which was not intentional and meant that
for the root window WINDOW_IS_TOPLEVEL() returned TRUE but
window->impl->toplevel was NULL, causing gdk_window_create_cairo_surface()
to crash.
* remove gdk_frame_clock_get_frame_time_val(); a convenience
function that would rarely be used.
* remove gdk_frame_clock_get_requested() and
::frame-requested signal; while we might want to eventually
be able to track the requested phases for a clock, we don't
have a current use case.
* Make gdk_frame_clock_freeze/thaw() private: they are only
used within GTK+ and have complex semantics.
* Remove gdk_frame_clock_get_last_complete(). Another convenience
function that I don't have a current use case for.
* Rename:
gdk_frame_clock_get_start() => gdk_frame_clock_get_history_start()
gdk_frame_clocK_get_current_frame_timings() => gdk_frame_clock_get_timings()
Since we're not exporting the ability to create your own frame
clock for now, remove the setters for GdkFrameTimings fields.
Also remove all setters and getters for fields that are more
about implementation than about quantities that are meaningful
to the applcation and just access the fields directly within
GDK.
Now that GdkFrameClock is a class, not interface, there's no real advantage
to splitting the frame history into an aggregate object, so directly
merge it into GdkFrameClock.
Instead of making the frame clock a settable property of a window, make
toplevel windows inherently have a frame clock when created (getting
rid of the default frame clock.) We need to create or destroy frame
clocks when reparenting a window to be a toplevel, or to not be a
toplevel, but otherwise the frame clock for a window is immutable.
If we get a focus event for a X window we don't recognize, just
ignore it and avoid a g-critical when
_gdk_device_manager_core_handle_focus() is called with a NULL window.
Deprecate gdk_window_enable_synchronized_configure() and
gdk_window_configure_done() and make them no-ops. Implement the
handling of _NET_WM_SYNC_REQUEST in terms of the frame cycle -
we know that all processing will be finished in the next frame
cycle after the ConfigureNotify is received.
For an operation like synchronizing audio to video playback, we need to
be able to predict the time that a frame will be presented. The details
of this depend on the windowing system, so make the backend predict
a presentation time for ::begin-frame and set it on the GdkFrameTimings.
The timing algorithm of GdkFrameClockIdle is adjusted to give predictable
presentation times for frames that are not throttled by the windowing
system.
Helper functions:
gdk_frame_clock_get_current_frame_timings()
gdk_frame_clock_get_refresh_info()
are added for operations that would otherwise be needed multiple times
in different locations.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
We want the compositor to do different things for frames where
"slept before" is TRUE. Communicate to the compositor that
frame is a no-delay frame (slept_before=FALSE) by ending the frame
by increasing the counter value by 1, and that the frame is a
normal frame (slept_before=TRUE) by increasing the counter value
by 3.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
In order to be able to track statistics about how well we are drawing,
and in order to be able to do sophisticated things with frame timing
like predicting per-frame latencies and synchronizing audio with video,
we need to be able to track exactly when previous frames were drawn
to the screen.
Information about each frame is stored in a new GdkFrameTimings object.
A new GdkFrameHistory object is added which keeps a queue of recent
GdkFrameTimings (this is added to avoid further complicating the
implementation of GdkFrameClock.)
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Instead of communicating the start of a frame to the window manager
as soon as we begin a frame, start a frame only when we know we've
actually created damage to the contents of a window.
(This uses cairo_set_mime_data() as a notification mechanism - a
clever suggestion from Uli Schlachter.)
The advantage of this is that we aren't forcing the compositor to
do a frame cycle and send _NET_WM_FRAME_DRAWN - depending on how the
compositor is structured that might either cause it to do extra
work or it might send _NET_WM_FRAME_DRAWN early and upset frame
timing.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Unqueuing events from the windowing system when paused could result
in weird reordering if event filters resulted in application-visible
behavior. Since we now resume events when the frame clock is frozen,
we now no longer count on low-level event handling running while
event handling is paused.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
By starting with an odd frame counter value, we make the mapping
and initial paint of the window an atomic operation, avoiding
any visual artifacts from an unpainted window.
Possible improvement: start the frame when doing gdk_window_show(),
so that the same improvement occurs for windows that were previously
shown and are being mapped again.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
When a window is unmapped, freeze its frame clock. This avoids doing
unnecessary work, but also means that we won't block waiting for
_NET_WM_FRAME_DRAWN messages that will never be received since the
frame ended while the window was withdrawn.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
As part of the extended _NET_WM_SYNC_REQUEST_COUNTER protocol,
we get a _NET_WM_FRAME_DRAWN message for each frame we draw. Use this
to synchronize the updates we are doing with the compositing manager's
drawing, and ultimately with with display refresh.
We now set the sync request counters on all windows, including
override-redirect windows, since it is also useful to do synchronized,
atomic updates for such windows.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
By exporting two XSync counters on a toplevel window, we subscribe
to an extended form of the _NET_WM_SYNC_REQUEST_COUNTER protocol,
where the window manager can initiate an atomic frame, as previously,
but the application can also do so by incrementing the new counter to
an odd value, and then to an even value to finish the frame.
See:
https://mail.gnome.org/archives/wm-spec-list/2011-October/msg00006.html
The support for 64-bit integers that GLib requires is used to
simplify the logic.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Add the ability to freeze a frame clock, which pauses its operation,
then thaw it again later to resume.
Initially this is used to implement freezing updates when we are
waiting for ConfigureNotify in response to changing the size of
a toplevel.
We need a per-window clock for this to work properly, so add that
for the X11 backend.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
We may receive events because SubstructureNotifyMask has been selected
for the root window. (Most likely, this would occur because GTK+
is being used inside a window manager like Metacity or Mutter.)
This can confuse various types of internal accounting, so detect
such events and comprehensively ignore them for GDK's internal
purposes. We still need to generate GDK events for these cases
because you can select for substructure events with
GDK_SUBSTRUCTURE_MASK.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Since XIQueryVersion, the bad API that it is, enforces the version from
the first client that requests it, for clients to be able to use the new
features in XI2.3, we need to ensure that we pass XIQueryVersion 2.3 as
the version that we support. We know that GTK+ won't be confused by the
new features.
https://bugzilla.gnome.org/show_bug.cgi?id=692467
The X server should fill in the minor version that it supports in the
case where it only supports the older version, so we can safely always
pass a higher version number than is potentially supported by the
server.
libXi was designed to be stable in the case where it doesn't recognize
requests or events/replies, so this should still work in a case where
we have new versions of the X server, and GTK+, but an old version of
libXi, at least for however well that setup should work.
https://bugzilla.gnome.org/show_bug.cgi?id=692467
