The current implementation of the glyph cache deals with atlases by
padding them with 1 pixel at the beginning, at the end, and between
each glyph.
That's cool and all, however, there's a very subtle problem with
this approach: the contents of the atlas are garbage, so this padding
is filled with garbage memory!
Rework the Vulkan glyph cache to draw each and every glyph in a
surface that has 1 pixel border of padding around it. Ensure the
surface is completely black by drawing a rectangle before handing
it to Pango to draw the glyph. Update tx and ty to pick the texture
position adjusted to the 1 pixel padding. The atlas now starts at
position (0, 0), since each glyph individually contains its own padding.
To improve legibility, add a PADDING define and use it everywhere.
Vulkan renders text using VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA and
VK_BLEND_FACTOR_SRC_ALPHA, but that implies per-channel alpha
blending, which currently produces the wrong results when blending
glyphs with the images beneath them.
Use the default pipeline constructors, which implies using the
ONE and ONE_MINUS_SRC_ALPHA.
When determining double-clicks, don't use the distance
threshold for touch events. It is very hard to double
touch reliably within a few pixels of the same position.
Fixes: #5580
Typically, a popover gets mapped when shown and unmapped when
hidden. A situation there that breaks is where the popover gets
recursively unmapped/unrealized when its root is destroyed.
In that situation, the popover does however unmap (without being
hidden first), moving the GTK grab from show/hide to map/unmap
will handle the previous situations, plus this one.
Fixes things being unclickable if e.g. a modal dialog got a
popover popped up, then got closed via Alt-F4.
Closes: https://gitlab.gnome.org/GNOME/gtk/-/issues/5730
we were not checking the return gboolean of
gtk_action_muxer_query_action() which was
returning FALSE for the crash case, meaning
it didn't set the passed in GVariant, but
we were still using it as it was non-null.
Fixes#5729
Calling gtk_list_box_remove_all() is a no-op with a bound model; after
the introduction of the remove_all() method in 49e56fc7, we were left
with row widgets after the dispose() call chained up.
We could restore the explicit unparenting inside dispose() instead of
calling remove_all(), but since the bound list model is provided by the
user of GtkListBox, it's more appropriate to unbind it in the dispose()
implementation, to avoid any potential reference cycle (especially in
higher level languages that have no explicit reference acquisition).
We clean up the bound model, and its associated state, if any; and then
we remove all the row widgets that are left.
