The Polar Game in Haskell, Day 6: Towards a GUI

So, I have some time today to program and I want to see how far I can get in starting to develop a GUI for my game, incomplete as it is. Can I get a window displayed and reacting to mouse or keyboard events, and drive the game logic with it?

I came across the paper FranTk -- A Declarative GUI Language for Haskell (PDF file link) by Meurig Sage and it looked interesting, so I considered trying FranTk. However, that led to broken links. Moving on...

Let's see if I can get somewhere with FG. That needs gtk2hs. Hmmm... cabal update, cabal install gtk2hs-buildtools, cabal install gtk.

[1 of 2] Compiling Gtk2HsSetup
    ( Gtk2HsSetup.hs, dist/setup-wrapper/Gtk2HsSetup.o )
[2 of 2] Compiling Main
    ( SetupMain.hs, dist/setup-wrapper/Main.o )
Linking dist/setup-wrapper/setup ...
Configuring cairo-0.12.4...
setup: The program pkg-config version >=0.9.0 is required but it
could not be found.
Failed to install cairo-0.12.4

I tried downloading pkg-config-0.28 source from here and that got me as far as running ./configure --prefix=/usr/local/ and seeing:

configure: error: Either a previously installed
pkg-config or "glib-2.0 >= 2.16" could not be found.
Please set GLIB_CFLAGS and GLIB_LIBS to the correct
values or pass --with-internal-glib to configure to use
the bundled copy.

So I tried ./configure --prefix=/usr/local/ --with-internal-glib and that seemed to go OK; I was able to do make, make check -- one failure out of 25 tests in "check-path" -- and sudo make install. Back to cabal install gtk == nope.

Configuring cairo-0.12.4...
setup: The pkg-config package cairo-pdf is required but it
could not be found.
Failed to install cairo-0.12.4

Configuring glib-0.12.4...
setup: The pkg-config package glib-2.0 is required but it
could not be found.
Failed to install glib-0.12.4
cabal: Error: some packages failed to install:
cairo-0.12.4 failed during the configure step. The exception was:
ExitFailure 1
gio-0.12.4 depends on glib-0.12.4 which failed to install.
glib-0.12.4 failed during the configure step. The exception was:
ExitFailure 1
gtk-0.12.4 depends on glib-0.12.4 which failed to install.
pango-0.12.4 depends on glib-0.12.4 which failed to install.

OK... so I guess it's time to install MacPorts because the Cairo page suggests using it to install cairo. I know there are competing tools -- fink and Homebrew and I've used both of them at some point, years ago, but removed them, for reasons I can no longer remember... I think it had something to do with the way they insisted on installing things under /opt and it was clear to me if they would interfere with each other. But anyway, I'll try the MacPorts installer for 2.13 for Mountain Lion... and then sudo port install cairo... oh, wow, it's installing the universe... bzip2, zlib, libpng, free type, perl5, python27... oh, the humanity...

OK, where are we... oh, cabal install gtk again. "The pkg-config package cairo-pdif is required but it could not be found." Let's try glib again.

Pauls-Mac-Pro:Gitit Wiki paul$ sudo port install glib2
--->  Computing dependencies for glib2
--->  Cleaning glib2
--->  Scanning binaries for linking errors: 100.0%
--->  No broken files found.

But cabal install gtk is still broken. Is there a MacPorts version of gtk2? Yes, apparently OH GOD IT'S BUILDING THE WHOLE WORLD...

(Musical interlude...)

But then cabal install gtk seems to go OK. A lot of deprecated function warnings. Another twenty minutes go by... what was I doing again? You know, I'm getting all confused, why don't I start with gtk2hs because Real World Haskell uses it... I need to sudo port install glade3... and OH GOD IT'S BUILDING THE WHOLE WORLD AGAIN... aaand welcome to hour three of "The Polar Game in Haskell, Day 6: Towards a GUI..."

OK, glade and glade3 don't have any executables in my path. Oh, it's glade-3, how silly of me, even though the port is called glade3. And it says Gtk-WARNING **: cannot open display:. Oh yeah, it's X-Windows JUST SHOOT ME IN THE GODDAMN FACE... oh, I mean now I will happily go down another rabbit hole, thank you sir may I have another? So... the older X server is not supported in Mountain Lion anymore but there's something called XQuartz. XQuartz-2.7.4.dmg... "you need to log out and log back in to make XQuartz your default X11 server." Oh, thanks, I'll just close these FOURTEEN browser tabs, SEVEN bash terminal sessions, and other apps... you know, it's time for a food break anyway...

...aaand we're back. It launches, but I get "an error occurred while loading or saving configuration information for glade-3. Some of your configuration settings may not work properly." There's a "Details" button:

Failed to contact configuration server; the most common
cause is a missing or misconfigured D-Bus session bus daemon.
See http://projects.gnome.org/gconf/ for information. (Details -
1: Failed to get connection to session: Session D-Bus not running.
Try running `launchctl load -w 
/Library/LaunchAgents/org.freedesktop.dbus-session.plist'.)
Failed to contact configuration server; the most common cause 
is a missing or misconfigured D-Bus session bus daemon. See 
http://projects.gnome.org/gconf/ for information. (Details -
1: Failed to get connection to session: Session D-Bus not running. 
Try running `launchctl load -w 
/Library/LaunchAgents/org.freedesktop.dbus-session.plist'.)
Failed to contact configuration server; the most common cause 
is a missing or misconfigured D-Bus session bus daemon. See 
http://projects.gnome.org/gconf/ for information. (Details -
1: Failed to get connection to session: Session D-Bus not running. 
Try running `launchctl load -w 
/Library/LaunchAgents/org.freedesktop.dbus-session.plist'.)
Failed to contact configuration server; the most common cause 
is a missing or misconfigured D-Bus session bus daemon. See 
http://projects.gnome.org/gconf/ for information. (Details -
1: Failed to get connection to session: Session D-Bus not running.
Try running `launchctl load -w 
/Library/LaunchAgents/org.freedesktop.dbus-session.plist'.)
Failed to contact configuration server; the most common cause
is a missing or misconfigured D-Bus session bus daemon. See
http://projects.gnome.org/gconf/ for information. (Details -
1: Failed to get connection to session: Session D-Bus not running.
Try running `launchctl load -w 
/Library/LaunchAgents/org.freedesktop.dbus-session.plist'.)

Gaaah! Well, OK, I can do that... and I'm able to edit a little file. Now to look at some tutorials. I get 404s on http://www.haskell.org/gtk2hs/docs/tutorial/glade/ and also http://dmwit.com/gtk2hs/%7C -- ooof. My first attempt at adapting a little code from Real World Haskell -- not going so well. This tutorial is still available: http://www.haskell.org/haskellwiki/Gtk2Hs/Tutorials/ThreadedGUIs but as to how useful it is... I'm gonna have to get back to you on that. There's also this tutorial: http://home.telfort.nl/sp969709/gtk2hs/chap2.html so I can create a little GTK GUI entirely in code rather than using a Glade file. Something like this:

import qualified Graphics.UI.Gtk

main :: IO ()
main = do
    Graphics.UI.Gtk.initGUI
    window <- Graphics.UI.Gtk.windowNew
    Graphics.UI.Gtk.widgetShowAll window
    Graphics.UI.Gtk.mainGUI

Aaand I get an immediate segmentation fault. Hmmm. I think I read about running with "-threaded..."

Pauls-Mac-Pro:arctic-slide-haskell paul$ ghci -threaded
GHCi, version 7.4.1: http://www.haskell.org/ghc/  :? for help
Warning: -debug, -threaded and -ticky are ignored by GHCi

OK, how about GHC?

Pauls-Mac-Pro:arctic-slide-haskell paul$ ghc basic-gui.hs -threaded
[1 of 1] Compiling Main             ( basic-gui.hs, basic-gui.o )
Linking basic-gui ...
Undefined symbols for architecture x86_64:
  "_iconv", referenced from:
      _hs_iconv in libHSbase-4.5.0.0.a(iconv.o)
     (maybe you meant: _hs_iconv_open, 
_base_GHCziIOziEncodingziIconv_iconvEncoding6_info , 
_hs_iconv , _base_GHCziIOziEncodingziIconv_iconvEncoding4_closure , _base_GHCziIOziEncodingziIconv_iconvEncoding3_info , 
_base_GHCziIOziEncodingziIconv_iconvEncoding5_closure , 
_base_GHCziIOziEncodingziIconv_iconvEncoding6_closure , 
_base_GHCziIOziEncodingziIconv_iconvEncoding3_closure , 
_base_GHCziIOziEncodingziIconv_iconvEncoding2_closure , 
_base_GHCziIOziEncodingziIconv_iconvEncoding2_info , 
_base_GHCziIOziEncodingziIconv_iconvEncoding5_info , 
_base_GHCziIOziEncodingziIconv_iconvEncoding7_closure , 
_hs_iconv_close , 
_base_GHCziIOziEncodingziIconv_iconvEncoding7_info )
  "_iconv_close", referenced from:
      _hs_iconv_close in libHSbase-4.5.0.0.a(iconv.o)
     (maybe you meant: _hs_iconv_close)
  "_iconv_open", referenced from:
      _hs_iconv_open in libHSbase-4.5.0.0.a(iconv.o)
     (maybe you meant: _hs_iconv_open)
  "_locale_charset", referenced from:
      _localeEncoding in libHSbase-4.5.0.0.a(PrelIOUtils.o)
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

Hmmm. It seems like this might take longer than I thought...