GTK 3 PuTTY/pterm has always assumed that if it was compiled with
_support_ for talking to the raw X11 layer underneath GTK and GDK,
then it was entitled to expect that raw X11 layer to exist at all
times, i.e. that GDK_DISPLAY_XDISPLAY would return a meaningful X
display that it could do useful things with. So if you ran it over the
GDK Wayland backend, it would immediately segfault.
Modern GTK applications need to cope with multiple GDK backends at run
time. It's fine for GTK PuTTY to _contain_ the code to find and use
underlying X11 primitives like the display and the X window id, but it
should be prepared to find that it's running on Wayland (or something
else again!) so those functions don't return anything useful - in
which case it should degrade gracefully to the subset of functionality
that can be accessed through backend-independent GTK calls.
Accordingly, I've centralised the use of GDK_DISPLAY_XDISPLAY into a
support function get_x_display() in gtkmisc.c, which starts by
checking that there actually is one first. All previous direct uses of
GDK_*_XDISPLAY now go via that function, and check the result for NULL
afterwards. (To save faffing about calling that function too many
times, I'm also caching the display pointer in more places, and
passing it as an extra argument to various subfunctions, mostly in
gtkfont.c.)
Similarly, the get_windowid() function that retrieves the window id to
put in the environment of pterm's child process has to be prepared for
there not to be a window id.
This isn't a complete fix for all Wayland-related problems. The other
one I'm currently aware of is that the default font is "server:fixed",
which is a bad default now that it won't be available on all backends.
And I expect that further problems will show up with more testing. But
it's a start.
It's obvious to the trained eye whether GTK PuTTY was compiled against
GTK2 or GTK3, but the untrained eye would probably appreciate a little
help, and even the trained eye probably can't tell GTK 3.18 from 3.19
at a glance :-)
The About box is where it showed up most obviously that I'd hastily
bunged a GtkBox inside another GtkBox without considering their
margins: the 'action area' had twice the margin it should have had and
the rightmost button didn't align with the right edge of the rest of
the window contents.
Easily fixed by giving the inner hbox margin 0 (fixing the right align
and the excessive space around all the buttons), and using the
'spacing' property of GtkBox to ensure multiple buttons in it are
nicely separated without having to take care over that in the client
code that adds them.
gtk_misc_set_alignment was deprecated in GTK 3.14. But my replacement
code using gtk_label_set_xalign doesn't work there, because that
function wasn't introduced until GTK 3.16, so there are two minor
versions in the middle where a third strategy is needed.
When I abandoned GtkDialog for GtkWindow (in dc11417ae), I manually
added a horizontal GtkSeparator between the content and action areas.
Or rather, I tried to - but I forgot that gtk_box_pack_end works in
the opposite order, so that you have to add the bottom-most element
first and then the one you want to appear above it. So my separator
was below the action area, rather than between it and the content
area.
Several utility functions I've written over the last few weeks were in
rather random places because I didn't have a central gtkmisc.c to put
them in. Now I've got one, put them there!
They've now deprecated gtk_dialog_get_action_area, because they really
want a dialog box's action area to be filled with nothing but buttons
controlled by GTK which end the dialog with a response code. But we're
accustomed to putting all sorts of other things in our action area -
non-buttons, buttons that don't end the dialog, and sub-widgets that
do layout - and so I think it's no longer sensible to be trying to
coerce our use cases into GtkDialog.
Hence, I'm introducing a set of wrapper functions which equivocate
between a GtkDialog for GTK1 and GTK2, and a GtkWindow with a vbox in
it for GTK3, and I'll lay out the action area by hand.
(Not everything has sensible layout and margins in the new GTK3 system
yet, but I can sort that out later.)
Because the new functions are needed by gtkask.c, which doesn't link
against gtkdlg.c or include putty.h, I've put them in a new source
file and header file pair gtkmisc.[ch] which is common to gtkask and
the main GTK edifice.
