We only keep one align flag per child, so it seems odd to
keep separate h/v expand flags. Just keep one expand flag
and interpret it according to orientation. Allow setting
the expand flag for child widgets too, though, so we can
make widget expand without interfering with the recursive
widget expand flag.
Update all callers.
Use the new possibility of expanding child widgets to make
the label of check and radio buttons expand. This fixes
unexpected behavior of these widgets in RTL in some places.
https://bugzilla.gnome.org/show_bug.cgi?id=765742
In RTL, we want to interpret GTK_ALIGN_START and _END
in the opposite way. Since we don't give gadgets a text
direction, just allow setting an align_reverse flag
to the box gadget.
This is necessary for GtkNotebook so that the stack is always drawn
before the header.
And that is necessary so that the active tab can use negative
margins to overdraw the border of the stack to create a gap and
simulate old GTK2-style visuals for notebooks.
So far, the box gadget is always allocating all children the
full size in the cross axis. This behavior corresponds to the
align-items: stretch behavior in
https://www.w3.org/TR/css-flexbox-1/#align-items-property
This commit implements the other modes described there.
While widgets have halign/valign properties that we can use for
this, the API for inserting gadgets has to change to take an
extra align parameter. All callers have been updated to pass
GTK_ALIGN_FILL, since that corresponds to the previous behavior.
https://bugzilla.gnome.org/show_bug.cgi?id=760668
