The GtkFlowBoxCreateWidgetFunc type lacked GObject Introspection
annotations for its arguments. This made gtk_flow_box_bind_model()
unusable from Python as the callback function would be passed useless
values.
The annotations that I've added match those of the similar callback
type GtkListBoxCreateWidgetFunc.
https://bugzilla.gnome.org/show_bug.cgi?id=780758
Those should be interpreted by widget-local gestures, not guessed at a
high level with no notions of the specific context. Users will want
GtkGestureMultiPress to replace these events.
Those worked similarly to those in GtkFlowBox, but would additionally
handle "active" state for child rows. Simplify this to just enabling/
disabling active state on gesture press/release, we don't get the
nice state updates when hovering around with a mouse button pressed,
but the rationale from flowbox applies here, and makes a nice cleanup.
They just maintain priv->in_button and widget state up-to-date, this
basically matters during user interaction, and is already maintained
in the gesture ::update handler. This seems to be sufficient.
Those basically controlled priv->active_child_active, which would
1) trigger a redraw when the pointer enters/leaves it, and 2) ensure
that press/release happen on the same child for it to be activated.
The former is not necessary, and the latter can be simplified by
just checking again the child on the coordinates given by the
::release gesture handler. This makes all enter/leave/motion_notify
event handlers unneeded.
All kinetic scrolling initial velocity calculations are now
taken from the scroll controller. The handling of timeouts
to snap back when overshooting has been also made to just
apply on devices that can't emit ::scroll-begin/end.
This is a GtkEventController implementation to handle mouse
scrolling. It handles both smooth and discrete events and
offers a way for callers to tell their preference too, so
smooth events shall be accumulated and coalesced on request.
On capable devices, it can also emit ::scroll-begin and
::scroll-end enclosing all ::scroll events for a scroll
operation.
It also has builtin kinetic scrolling capabilities, reporting
the initial velocity for both axes after ::scroll-end if
requested.
This change is made for consistency, it doesn't make sense to expose
one-way propagation, as it can only break expectations from GTK+. This
function might be made entirely private in the future, but it still
makes sense to do this in one go for our internal usecases.
This will allow further cleanups and optimizations in capture/target/bubble
event delivery. For simplicity, ATM every widget will receive its own
GtkEventControllerLegacy, it could be desirable to add finer control over
this in the future, so widgets that fully use event controllers for input
management can do away without this legacy piece.
As Benjamin says, ident should only be used if any value
is valid, which is not the case here. So use enums instead,
which should also be more efficient. To handle the more
complicated cases like font-variant-ligatures, we have to
introduce flags-like values.
Clarify that ::destroy, not ::hide*, removes a window from its app, by
replacing the mention of open windows with the blurb on destruction from
:application, completing commit 7db4bee4b6
Also link to the equivalent gtk_application_(add|remove)_window() calls,
since Application.add_window() already links back to Window:application.
* unless you use gtkmm…
https://bugzilla.gnome.org/show_bug.cgi?id=639931
It was never unref()d, either when replacing the existing GObject in
set_property(), cleaning up in finalize(), or becoming a placeholder.
Fix by using g_set_object() and g_clear_object() to unref as needed.
This also drops the check that the newly set object is a valid cloud
provider account, as we don’t do the equivalent for any of the other
object-typed properties, and Carlos didn’t think this was important.
https://bugzilla.gnome.org/show_bug.cgi?id=787600
Drop the current css2-style font-variant property and
replace it with a shorthand as specified in the css3 fonts
module. Currently, we fully support the font-variant-ligatures,
font-variant-position, font-variant-caps, font-variant-numeric
and font-variant-east-asian subproperties. font-variant-alternatives
is only partially supported.
Instead of relying on special values of edge constraints, this
patch adds an internal-only gdk_window_supports_edge_constraints()
function that by default returns FALSE, and is implemented by
GdkWindowWayland and GdkWindowX11.
This way, we can properly detect server-side support for this
feature and adapt accordingly.
https://bugzilla.gnome.org/show_bug.cgi?id=783669
The last touch on this patch series is making GtkWindow able to
selectively adjust various UI details based on the different
tiled edges. The main driver here is that we don't want to show
shadows on edges that are constrained.
This patch adds the necessary code to do that, while still
maintaining compatibility with the old ways.
https://bugzilla.gnome.org/show_bug.cgi?id=783669
GTK windows don't have their tiling states really
hooked into the client-side decoration code, and
the only effect it has is disabling the resizing
edges.
With the introduction of per-edge tiling information,
we are backed by much more precise data on how the
window manager wants the app to behave.
This patch, then, fixes GtkWindow to take into account
per-edge tiling information. For compatibility purposes,
the previous tiled field was kept, and thing will just
continue working if no edge information is supplied.
https://bugzilla.gnome.org/show_bug.cgi?id=783669
The outline-{top,bottom}-{left,right}-radius names have been
deprecated for a while, so lets remove them. Everybody should
just use the -gtk-prefixed names for these properties.
The focus outline disappeared as the colour of the swatch got close to
the normal focus outline colour, which is alpha(currentColor, 0.3).
Fix by making the outline an alpha’d version of the tick colour, but
more opaque than normal outlines. 0.6 seems good enough; feel free to
improve it, but at least this ensures the outline can’t vanish anymore.
HighContrast achieves this already because it applies the color property
to the main node, not the overlay. Doing that means the outline is fully
opaque, which is fine for HC obviously but was excessive for Adwaita.
https://bugzilla.gnome.org/show_bug.cgi?id=787757
It used $text_color unconditionally, but in :dark, text is white, so we
overlaid a white tick on any light colours, all the way to white itself.
Using these named colours doesn’t make practical or semantic sense.
Instead, use white/black over dark/light swatches, as in HC, so all
variant–swatch combos work. Light looks the same, & :dark works now.
For backdrop, use alpha 0.5, unlike 0.7 in HC, as that seemed excessive
& different from the current effect. 0.5 is almost identical to how
$backdrop_fg_colour is a 50% mix of $fg_color, & matches backdrop text.
https://bugzilla.gnome.org/show_bug.cgi?id=787531
On Python-3.x, we need to set the encoding when opening files, when this
script is run, as it might contain items that are not supported by the
system's locale (for example, non-English Windows). So, we use a
wrapper to set the encoding on Python 3.x, but open the file as we did
when using Python 2.x, since file encodings are not supported there.
https://bugzilla.gnome.org/show_bug.cgi?id=785210
along the orthogonal orientation. It seems a FlowBox on its own can only
handle being shrunk along its main orientation. The orthogonal requests
a huge min size – reserving what it would need if the main orientation
got its min size, which would flow all children in 1 line orthogonally.
Adding it to a ScrolledWindow (any policy) enables free shrinking, so
size_allocate() can reflow how users in this situation probably expect.
https://bugzilla.gnome.org/show_bug.cgi?id=787021
Without specifically connecting ::delete-event to something, the dialog
will be destroyed when it is closed, for example by pressing Esc. This
meant that when dismissing it this way, unlike by pressing Cancel, any
custom palette would be lost when the dialog was next opened, and so on.
Resolve this by making ::delete-event just do GTK_RESPONSE_CANCEL, so
closing the dialog has the same effect as clicking its Cancel button.
https://bugzilla.gnome.org/show_bug.cgi?id=787444
Make it slightly more obvious when things are about to slide sideways
because a NULL GtkSettings has been returned to a caller. This is a
valid return value, but is rarely handled correctly.
https://bugzilla.gnome.org/show_bug.cgi?id=778382
As reported in https://github.com/ibus/ibus/issues/1944,
typing u201e while holding Ctrl+Shift used to give a „
when letting go of Ctrl+Shift. This broke when we introduced
Ctrl+Shift+e to start Emoji sequences. Fix this by only
looking for Ctrl+Shift+e if we are not already in a hex
sequence.
This commit takes several steps towards rendering text
like we want to.
The creation of the cairo surface and texture is moved
to the backend (in GskVulkanRenderer). We add a mask
shader that is used in the next text pipeline to use
the texture as a mask, like cairo_mask_surface does.
There is a separate color text pipeline that uses the
already existing blend shaders to use the texture as
a source, like cairo_paint does.
The text node api is simplified to have just a single
offset, which determines the left end of the text baseline,
like all our other text drawing APIs.
We were only selecting a section’s button if the adjustment y coord was
within its heading, so scrolling slightly into it unchecked all buttons.
This also fixes how we could end up with the first 2 selected, somehow.
https://bugzilla.gnome.org/show_bug.cgi?id=787172
Add integration of the libcloudproviders DBus API to the
GtkPlacesSidebar by showing name and sync status of the cloud providers.
The exported menu is rendered as a GtkPopover.
The sidebar will be updated if the list of cloudproviders changes e.g.
by adding or removing an account. If any cloud provider changes detailed
information like sync status only the individual sidebar row gets
updated.
Co-authored-by: Carlos Soriano <csoriano@gnome.org>
Co-authored-by: Daniel Boles <dboles@src.gnome.org>
https://bugzilla.gnome.org/show_bug.cgi?id=786123
Use opacity to differentiate unselected/hovered/selected buttons. It had
assumed bg < border < fg colours, which may be false, as in Adwaita:dark
This also means we do not need to special-case for the backdrop state.
https://bugzilla.gnome.org/show_bug.cgi?id=786956
I see 'out of memory' errors and crashes inside libvulkan when
creating nodes that have empty bounds and end up in the fallback
paths, like a shadow around an empty text node. Prevent this
by not creating text nodes in that case.
in a specific case, which was applying .slider as a class on the parent
switch, instead of correctly selecting on its child node named slider.
This makes the border on the outside of a switch in a selected listbox
row look better in the light variant. Since the code was never removed,
it was clearly meant to work, and making it work is a clear improvement.
The emoji chooser gets disposed already, because it is attached
to the toplevel as a popover. Doing it again when the object data
is cleared is leading to a crash.
https://bugzilla.gnome.org/show_bug.cgi?id=787103
Copy the PangoCairoRenderer into GTK+, rename it to GskPangoRenderer,
and strip it down far enough to build without private pango apis.
This means we currently don't support hexboxes or shapes.
Currently, this lives in gtk, but it might be nicer to put it
in gsk eventually.
• Use disconnect_by_data() to catch both _adjustment_changed() and now
_adjustment_value_changed(), as the latter had been missed until now.
• Also disconnect from indicator_value_changed(), which was not done in
destroy() due to indicator_reset() and remove_indicator() disagreeing.
https://bugzilla.gnome.org/show_bug.cgi?id=775074
Do not connect to get_settings_for_screen() if we have no screen…
Use g_signal_connect(), not connect_object(), to match how set_screen()
makes this same connection, and how finalize() already disconnects it.
https://bugzilla.gnome.org/show_bug.cgi?id=705640
Since the move from button-press to gesture events, Shift-clicking did
not work to start a selection (from none) or truncate an existing one.
This was due to the code being copy-pasted around and some logic being
broken in the process. This makes both of those work as they should, by
shuffling it again so the end result is the same as before. Highlights:
(1) ::button-press if extending due to a single press would call
set_positions(tmp_pos, tmp_pos), which is what made the Shift+click to
create a selection work. That was lost. Add it back to make that work.
(2) ::button-press in the “Truncate current selection” branch would not
execute all the stuff around “extend_to_left”, as that was the else
case. So, set extend_selection = FALSE so we skip over that later on.
(3) BUT! This Truncate case never fired because it was in the else
branch of if (in_selection())! Of course, it must be in the true branch.
(4) The IM context was not reset if the Shift-click occurred within an
existing selection, only if it did not. In ::button-press this was the
first thing done if extending a selection, regardless. Make it so again.
https://bugzilla.gnome.org/show_bug.cgi?id=780750
Themes should not enforce min sizes on blocks in continuous mode; in
this case, the filled block should be as large as it needs to be to
reflect the current value, and no larger or smaller than that. So, the
fact that the minimal size was selected on just levelbar block is wrong:
we should also require the levelbar.discrete class to apply min sizes.
The widget should enforce whatever correct minimum size results from the
above fix, by reapplying commit 78b4885fe8
Except: we should not allocate/draw the filled block if the value is 0,
as in this case, the LevelBar should be empty, not have a min-size fill.
This partially reverts commit 96062ffeae,
as it makes sense to set min sizes for discrete blocks, so keep that in.
https://bugzilla.gnome.org/show_bug.cgi?id=783649
This reverts commit 8c0e5adaab.
This is actually needed since GtkHeaderBar will allocate and snapshot
widget that coun_visible_children does not consider.
Subsurfaces don't currently work with our new rendering,
and this makes popovers unusable. We can go back to using
subsurfaces for popovers when this is fixed.
.update_position() enforces that non-Wayland platforms must position a
Popover within its parent Window. We use the allocation of the Window
to translate the position and check for overshoot on each of its sides.
Calling Widget.get_allocation() of a CSD Window includes its shadows.
But shadows were not excluded from the area in which we can position.
Thus, Popovers could get positioned in the shadow of CSD windows, where,
at least on X11, no input is received. Therefore, positioning a Popover
over a shadow meant its child widgets within that area became unusable.
Fix by calling Window.get_shadow() and including it in the overshoot on
each side. This adjusts for how the allocation includes shadows, making
overshoots with and without shadows the same. Thus, we avoid considering
shadows as viable for positioning, favouring a side where input works.
https://bugzilla.gnome.org/show_bug.cgi?id=786209
This prevents the load_fonts() function from switching to the "no fonts"
page and back when the model is reloaded. Given
GtkSettings::gtk-fontconfig-timestamp is 0 on Wayland and style changes
happen often, the stack change messes up popovers and pointer focus
on the fonts treeview and test entry.
https://bugzilla.gnome.org/show_bug.cgi?id=784723 introduced support for
native file chooser dialogs on macOS, but due to the use of generics in
the patch, there will be compilation errors on pre-Xcode 7 platforms,
such as Mountain Lion and Mavericks.
I strongly recommend to revert this patch when the oldest supported
macOS release is bumped to Yosemite (10.10).
https://bugzilla.gnome.org/show_bug.cgi?id=785306
Instead of gtk_widget_draw'in the inspected widget inside the
magnifier's ::draw handler, just create a new GtkSnapshot and snapshot
in its snapshot handler, similar to what GtkStack is doing.
gtk_widget_draw_internal is now only used inside gtkwidget.c, so remove
the prototype from gtkwidgetprivate.h. And since all incovacations call
it with clip_to_size=TRUE, remove that parameter.
They are not usually yellow anymore, the previous advice about how to
style them was for pre-3.20 versions, and the immediate replacement (CSS
class .tooltip) does not seem ready for primetime.
https://bugzilla.gnome.org/show_bug.cgi?id=784421
No longer store variation sequences explicitly. Instead, put a 0
in the sequence where the modifiers will be inserted. This is more
compact, and it allows us to put variations directly into the
recent section.
Update the type of the recent-emoji setting to match these changes.
Add an "Insert Emoji" item to the context menu in entries.
We also add a show-emoji-icon property, which when set to
TRUE, will add an icon that can be clicked to bring up
the Emoji chooser.
When the popover is dismissed, we return the focus to
where it came from. However, by using gtk_widget_grab_focus,
we were messing up the selection if that widget happens to
be an entry. Special-case GtkEntry and use
gtk_entry_grab_focus_without_selecting to avoid this issue.
The json file is imported from the (MIT-licensed) emoji.json[0] node
module, which generates it from the emoji list published by the
Unicode Consortium.
This commit also adds a little tool to convert the data into
a compact GVariant, and the result of that conversion, which is
added to libgtk as a resource. The following commits will make use
of it.
[0] https://github.com/amio/emoji.json
menu margins have been added has a hack to mitigate bug:
https://bugzilla.gnome.org/show_bug.cgi?id=591258 with gtk+4 this
doesn't work anymore on gtk+4, the margin should probably be moved
to the parent window node, but it's not selectable, commenting out
for now.
Since gtk+ draws more than the widget and allocates more size to it than
it knows about, this flag doesn't work anymore. Removing it (or setting
it to TRUE for widgets that used to set it to FALSE) fixes drawing
invalidation when these widgets get allocated a new size.
In gtk_container_real_set_focus_child(), we try to scroll to the
position of the new :focus-child if we have h or v adjustments.
gtk_widget_translate_coordinates() returns FALSE if neither widget is
realized or in other situations that cause output parameters x and y not
to be set. Thus, if the caller did not initialise x/y and uses them even
if the function returned FALSE, they are using uninitialised variables.
In gtk_container_real_set_focus_child(), we did not check the return
value but merrily went ahead and used x and y regardless. This is UB, as
revealed by Valgrind, as well as being pointless.
The trivial fix is to exit early if (!gtk_widget_translate_coordinates).
https://bugzilla.gnome.org/show_bug.cgi?id=776909
Commit 885bcd9fe4 trampled the bit here
that is meant to translate between the nominated focus child and the
actual innermost one that is used for updating the h/v adjustments.
So, we need to save the passed focus child before diving into its
children, then translate and get allocations between them both. This
makes GTK+ 4 behave like GTK+ 3 again: instead of priv->focus_child and
focus_child, we now have focus_child and child, serving the roles of the
nominated focus child and its innermost focus child respectively.
This also ditches the unnecessary call to Widget:get_focus_child(), as
Container::set_focus_child() gets that same new child as an argument.
process-stop-symbolic is unintuitive if represented as a stop sign as in
Adwaita, and completely ambiguous if represented as a cross like the
window close button in other icon themes.
Instead, use application-x-executable, which is already used elsewhere
as a fallback if no specific icon can be found for the application.
https://bugzilla.gnome.org/show_bug.cgi?id=784624
Don't beep when modifiers are released in entries.
This was an inadvertent change that snuck in with
the emoji support.
Also, don't beep while entering an emoji name.
There is entirely too much beeping here.
In GTK+ 2, the ch < 0x80 was ORd with klass->latin1_to_char, and that
was unconditionally set to TRUE in the class init function, so
effectively the ch < 0x80 never mattered before or served any purpose.
When klass->latin1_to_char was deleted from the class in commit
f760538f17, this check’s sense changed.
The resuls was that accel keyvals with gunichar value >= 0x80 stopped
being rendered as symbols, instead falling back to their keysym name.
Instead of recognisable symbols for these, we get raw, often obscure,
and untranslatable keysym names. This breaks accessibility as well as
client users who may be parsing such accels and migrating from GTK+ 2.
So, remove the < 0x80 to restore the behaviour from before said commit.
https://bugzilla.gnome.org/show_bug.cgi?id=783906
This commit adds some basic support for entering emoji by name
to GtkIMContextSimple. To begin an emoji sequence, use Ctrl-Shift-e
instead of Ctrl-Shift-u that is used for hex input. Otherwise, the
behavior is the same: you can can let go of the modifier keys and
end the sequence with space or enter, or hold on to the modifier
keys and end the sequence by releasing them.
Only a limited, fixed set of names is supported at this time, see
the GtkIMContextSimple docs for a full list.
• Add GtkLayout as a @See_also since it includes fixed-pos functionality
• Drop mention of the long-gone Linux framebuffer port
• Explain how to work around the problems with RTL text
Being addable to a ScrolledWindow is not interesting; now that SW
auto-adds a Viewport if needed, so can DrawingArea and any other widget.
Mention GtkFixed in case the reader just wants that bit of functionality
If query.return_type is not one we want, binding_compose_params() is
not called, and so params remains a NULL pointer. However, the code was
then unconditionally iterating it regardless. Don't if it is still NULL.
CID 1452218 (#1 of 1): Explicit null dereferenced (FORWARD_NULL)
15. var_deref_op: Dereferencing null pointer params.
This would only happen if the last element was deprecated, but it should
be avoided anyway.
CID 1388852 (#1 of 1): Out-of-bounds read (OVERRUN)
12. overrun-local: Overrunning array pseudo_classes of 16 32-byte
elements at element index 16 (byte offset 512) using index i + 1U (which
evaluates to 16).
This function clearly assumes the parameter children cannot be NULL, and
the call sites seem to perform enough checks to confirm this.
CID 1388869 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking children suggests that it may be null,
but it has already been dereferenced on all paths leading to the check.
CID 1432024 (#1 of 1): Uninitialized scalar variable (UNINIT)
2. uninit_use_in_call: Using uninitialized value rect.x when calling
calendar_arrow_rectangle.
Add a default case to the switch which will bail out with
g_assert_not_reached(), which should reassure Coverity that the method
is always called with a valid value that is handled in the switch.
If value->values[i] is NULL, then values[i] was left uninitialised.
The code then reads each element of values[].
CID 1432029 (#1 of 1): Uninitialized pointer read (UNINIT)
11. uninit_use: Using uninitialized value values[i].
Our ::query-tooltip handler first checks whether the pointer is over any
of the icons, returning their tooltip if so, and if not chains up to
Widget::query-tooltip in order to show the text for the widget overall.
But ensure_has_tooltip(), which exists to update :has-tooltip based on
whether ::query-tooltip is needed, only set :has-tooltip to TRUE if any
icon had a tooltip, without caring whether the widget as a whole does.
That is asymmetrical and meant that if the Entry had a tooltip, but
subsequently all icons had their tooltips unset, :has-tooltip would be
set to FALSE, and hence the tooltip for the widget would become lost.
The fix is to set :has-tooltip to TRUE if the widget has a tooltip of
its own, and we only need to check the icons if that is not the case.
https://bugzilla.gnome.org/show_bug.cgi?id=785672
Refactor the code updating the active link under the current coordinates
into a separate function, and call it on GtkGestureMultiPress::pressed
so the link is updated on GDK_TOUCH_BEGIN. Based on a patch by
Jan-Michael Brummer <jan.brummer@tabos.org>.
https://bugzilla.gnome.org/show_bug.cgi?id=776903
It is not necessary to (re)set the cursor on every crossing
event, and can probably yield the wrong results if there are
multiple master devices involved. Just set it on init(), and
let the inner machinery update the cursor whenever necessary.
This patch is an adaption of commit 0daf79676 in gtk-3-22, the
side effects are not as bad here because the cursor was already
being set on the widget specifically instead of the parent
widget's, but there's still some nonetheless (plus, it's simpler)
https://bugzilla.gnome.org/show_bug.cgi?id=785375
Since gtk_bin_add does a gtk_widget_set_parent call, we cannot use it in
a GtkBin implementation that has multiple child widgets and cares about
their order.
So we can avoid creating a GtkCssPathNode in _init and then throwing it
away right after when using the _new_with_node constructor, which is the
one we use for all widgets.
Since setting a clip is mandatory for almost all widgets, we can as well
change the size-allocate signature to include a out_clip parameter, just
like GtkCssGadget did. And since we now always propagate baselines, we
might as well pass that one on to size-allocate.
This way we can also make sure to transform the clip returned from
size-allocate to parent-coordinates, i.e. the same coordinate space
priv->allocation is in.
Remove the special case in gtkwidget.c where we didn't draw any css
background/border for popovers. Instead, rely on themes to not style the
popover node and add a contents gizmo that gets the actual css styling.
We then requeste enough space for the popover to draw both the contents
and the arrow on the side.
The reported minimum baseline is for the reported min height, but if the
css min-height is greater than that, we need to account for that fact
when saving the baseline.
Since the reported baseline is relative to the widget's origin, we also
need to add the top values for margin, border and padding to the
reported baseline.
We claimed the gesture previously to keep it from propagating to the
underlying entry, but now that the entry is in a box with the two
buttons, we can do this properly and restore the previous long-press
behavior.
Previously, we would request a size of 0×0 when the transition type was
NONE and the child un-revealed, making the revealer in this case a
gtk_widget_set_visible replacement. Instead, to the exact same thing we
do in the CROSSFADE case and request the child size instead. This also
keeps the revealer from under allocating the child when the transition
type is set to NONE.
Instead of hopping through 7 different functions to do that, just
remove all rows directly. This also mean we'll only remove rows and not
other children that've been added like placeholders.
Add :dir(ltr) where expected, i.e. everywhere we now have a widget but
had a gadget before.
Also, fix the expected output to expect mark subnodes in the order
specified in the GtkScale does, i.e.
├── mark
├── [label]
╰── indicator
for marks at the top of the scale and
├── mark
├── indicator
╰── [label]
For marks at the bottom of the scale.
Checking the given GtkAllocation against the current allocation insize
::size-allocate doesn't really work anymore. They are only different if
the content allocation (the one passed) and the widget allocation (the
current one) are different, so e.g. when the widget has padding >0
applied.
Since we get offset automatically to the widget allocation before
->snapshot is called, we still have to offset the difference to the
position of the content allocation.
We don't need to care in this case since the default values should
always be assumed to be 0, and setting a baseline of 0 is just wrong
when orientation == HORIZONTAL, it should be -1 (or unset).
This is optional for positive margins as they just increase the widget
allocation. However, with negative css margins, the allocation is
smaller than the clip.
This fixes scale sliders leaving a small trail behind.
This fixes the expansion not working. As a GtkBin, GtkExpander can only
have one child and if that's a GtkBox (and not the one added through
gtk_expander_add), things go wrong.
always initialize clips to the (content) allocation, don't walk up the
widget hierarchy in gtk_widget_set_clip, implement
gtk_widget_size_allocate in GtkSeparator. This way we don't end up using
uninitialized clip values.
The entire clip handling is up for major rework since we can't and don't
want to force every single widget to call _set_clip in size-allocate
implementations.
If widgets chain up in their size-allocate implementation, they pass the
content allocation and not the widget allocation which will cause the
wrong allocation to be set.
