
             LablGTK 1.2.7 : an interface to the GIMP Tool Kit

Needed:
	ocaml-3.06 to 3.08
	gtk-1.2.x
	GNU make (there is no standard for conditionals)

Info/upgrades:
        http://wwwfun.kurims.kyoto-u.ac.jp/soft/olabl/lablgtk.html

How to compile:

	You should normally not need to modify Makefiles.
	First type "make configure <options>".
	Options are
                USE_DOTOPT=1    to use ocaml.opt and ocamlopt.opt
		USE_CC=1	to use $(CC) rather than gcc
		USE_GL=1	to compile with OpenGL support (see lower)
		USE_GNOME=1	to compile GdkPixbuf and GtkXmHTML support
                USE_GLADE=1     to compile libglade support
        The following variables will also be remembered if passed as options
                BINDIR INSTALLDIR DLLDIR DEBUG CC
                CAMLC CAMLOPT CAMLMKTOP CAMLMKLIB CAMLP40
        or you may directly edit config.make.
        Note that if you change DLLDIR, you should add the new directory
        either to OCAMLLIB/ld.conf or to CAML_LD_LIBRARY_PATH before
	running programs.
        If gtk-config has a different name, you can set the GTK_CONFIG
        variable  to it (e.g. FreeBSD).

	Then just type "make" to build the library and toplevels.

        If you are using the windows precompiled version, you must
        first obtain gtk-1.3-dlls-win32.zip from the above location,
        and then copy bin\lablgtk.bat, lib\stublibs\dlllablgtk.dll and
        lib\lablgtk to their respective locations in the OCaml
        distribution.

Contents:

	gdk.ml		low-level interface to the General Drawing Kit
	gtk.ml		low-level interface to the GIMP Tool Kit
	gtkThread.ml	main loop for threaded version
	g[A-Z]*.ml	object-oriented interface to GTK
	gdkObj.ml	object-oriented interface to GDK

	lablgtk		toplevel
        lablgladecc     glade compiler

	examples/*.ml	various examples
	applications/*	applications using the library
                camlirc         an IRC (chat) client
                                (by Nobuaki Yoshida)
		radtest		a very experimental RAD for lablgtk
				(by Hubert Fauque)
		browser		the begin of a port of OCamlBrowser
				(by Jacques Garrigue)
                unison          a frontend for the Unison file synchronizer
                                see the README for details.

How to run the examples:
  In the examples directory just type:
	lablgtk ???.ml

  Before installing lablgtk you have to be more explicit:
        setenv CAML_LD_LIBRARY_PATH ../src  (or export CAML..PATH=../src)
	../src/lablgtktop -w s -I ../src ???.ml

How to link them:
  lablgtktop contains an extra module GtkInit, whose only contents is:
        let locale = GtkMain.Main.init ()
  You must either add this line, or add this module to your link,
  before calling any Gtk function.
  ocamlc -I CAMLLIB/lablgtk -w s lablgtk.cma gtkInit.cmo ???.ml -o ???

How to use the threaded toplevel:

	% lablgtk -thread           (or ./lablgtktop_t before installing)
	        Objective Caml version 3.08.0
	
	# let w = GWindow.window ~show:true ();;
        # let b = GButton.button ~packing:w#add ~label:"Hello!" ();;

  You should at once see a window appear, and then a button.
  The GTK main loop is running in a separate thread. Any command
  is immediately reflected by the system.
  Beware that with bytecode threads, you cannot switch threads within
  a callback. The only thread related command you may use in a
  callback is Thread.create. Calling blocking operations may cause
  deadlocks. On the other hand, all newly created threads will be run
  outside of the callback, so they can use all thread operations.
  There is no such problem for posix and win32 threads, but win32
  threads have problems of their own. See the windows port section
  lower.

  When using threads in a stand-alone application, you must link with
  gtkThread.cmo and call GtkThread.main in place of GMain.main.

Locale or not locale ?
  Until version 1.2.0, lablgtk called setlocale automatically on
  intitialization. Unfortunately, this appears to have side effects
  in some cases, paritcularly when the locale defines a numeric
  format different from the standard one.
  Since locale must be set before initialization, you may do it in two
  ways:
    * set the GTK_SETLOCALE environment variable to a non-0 value
    * use the ~setlocale parameter to GMain.Main.init (if you do not link
      gtkInit.cmo)
  Note that GTK_SETLOCALE, when set, overrides ~setlocale.
  On some systems you may also need to link libxpg4.so for the locale to
  work.

Upgrading from lablgtk-1.00:
  There are a few incompatibilities between 1.00 and 1.2.x releases.
  We do not describe them all, since usually a type error message will
  inform you.
  * all signals are no longer under #connect. #connect#event changed
    to #event#connect, and some signals are under #misc#connect or
    #grab#connect. See lower for a description of the new widget
    structure.
  * some defaults changed. In particular GPack.box#pack have now all
    its parameters defaulting to false rather than true. See lower for
    the new default policy. Beware that this does not cause type
    errors, just changes in the aspect.
  * coerce functions disappeared from Gtk*.ml. You can now coerce with
    (w :> Gtk.mywidget Gtk.obj), thanks to variance annotations.

Structure of the (raw) Gtk* modules:

  These modules are composed of one submodule for each class.
  Signals specific to a widget are in a Signals inner module.
  A setter function is defined to give access to set_param functions.

Structure of the G[A-Z]* modules:

  These modules provide classes to wrap the raw function calls.
  Here are the widget classes contained in each module:

  GDraw         Gdk pixmaps, etc...
  GObj		gtkobj, widget, style
  GData		data, adjustment, tooltips
  GContainer	container, item_container
  GWindow	window, dialog, color_selection_dialog, file_selection, plug
  GPack		box, button_box, table, fixed, layout, packer, paned, notebook
  GBin  	scrolled_window, event_box, handle_box, frame,
		aspect_frame, viewport, socket
  GButton	button, toggle_button, check_button, radio_button, toolbar
  GMenu		menu_item, tearoff_item, check_menu_item, radio_menu_item,
		menu_shell, menu, option_menu, menu_bar, factory
  GMisc		separator, statusbar, calendar, drawing_area,
		misc, arrow, image, pixmap, label, tips_query,
                color_selection, font_selection
  GTree		tree_item, tree
  GList		list_item, liste, clist
  GEdit		editable, entry, spin_button, combo, text
  GRange	progress, progress_bar, range, scale, scrollbar

  While subtyping follows the Gtk widget hierarchy, you cannot always
  use width subtyping (i.e. #super is not unifiable with all the
  subclasses of super). Still, it works for some classes, like
  #widget and #container, and allows subtyping without coercion towards
  these classes (cf. #container in examples/pousse.ml for instance).

  Practically, each widget class is composed of:
  * a coerce method, returning the object coerced to the type widget.
  * an as_widget method, returning the raw Gtk widget used for packing, etc...
  * a connect sub-object, allowing one to widget specific
    signals (this is what prevents width subtyping in subclasses.)
  * a misc sub-object, giving access to miscellanous functionality of
    the basic gtkwidget class, and a misc#connect sub-object.
  * an event sub-object, for Xevent related functions (only if the widget
    has an Xwindow), and an event#connect sub-object.
  * a grab sub-object, containing drag and drop functions,
    and a grab#connect sub-object.
  * widget specific methods.

  Here is a diagram of the structure (- for methods, + for sub-objects)
        - coerce : widget
        - as_widget : Gtk.widget obj
        - destroy : unit -> unit
        - ...
        + connect : mywidget_signals
        |   - after
        |   - signal_name : callback:(... -> ...) -> GtkSignal.id
        + misc : misc_ops
        |   - show, hide, disconnect, ...
        |   + connect : misc_signals
        + event : event_ops
        |   - add, ...
        |   + connect : event_signals
        + grab : grab_ops
        |   - ...
        |   + connect : grab_signals

  You create a widget by [<Module>.<widget name> options ... ()].
  Many optional arguments are admitted. The last two of them, packing:
  and show:, allow you respectively to call a function on your newly
  created widget, and to decide wether to show it immediately or not.
  By default all widgets except toplevel windows (GWindow module) are
  shown immediately.

Default arguments:
  For many constructor or method arguments, default values are provided.
  Generally, this default value is defined by GTK, and you must refer
  to GTK's documentation.
  For ML defined defaults, usually default values are either false, 0, None
  or `NONE, according to the expected type.
  Important exceptions are ~show, which default to true in all widgets
  except those in GWindow, and ~fill, which defaults to true or `BOTH.

Note about unit as method argument:

  O'Caml introduces no distinction between methods having side-effects
  and methods simply returning a value. In practice, this is
  confusing, and awkward when used as callbacks. For this reason all
  methods having noticeable side-effects should take arguments, and
  unit if they have no argument.

ML-side signals:

  The GUtil module provides two kinds of utilities: a memo table, to be
  able to dynamically cast widgets to their original class, and more
  interesting ML-side signals.
  With ML-side signals, you can combine LablGTK widgets into your own
  components, and add signals to them. Later you can connect to these
  signals, just like GTK signals. This proved very efficient to
  develop complex applications, abstracting the plumbing between
  various components. Explanations are provided in GUtil.mli.

Contributed components:

  The GToolbox module contains contributed components to help you build
  your applications.

Memory management:

  Important efforts have been dedicated to cooperate with Gtk's
  reference counting mechanism. As a result you should generally be
  able to use Gdk/Gtk data structures without caring about memory
  management. They will be freed when nobody points to them any more.
  This also means that you do not need to pay too much attention to
  whether a data structure is still alive or not. If it is not, you
  should get an error rather than a core dump.
  The case of Gtk objects deserves special care. Since they are
  interactive, we cannot just destroy them when they are no longer
  referenced. They have to be explicitely destroyed. If a widget was
  added to a container widget, it will automatically be destroyed when
  its last container is destroyed. For this reason you need only
  destroy toplevel widgets.

LibGlade support:

  There is support for Glade generated XML UI description files, using
  libglade. You can read in a file, access to widgets, and define
  callbacks.
  A tool for extracting widget definitions from glade description is
  provided. It generates a wrapper class, and you can then generate an
  object corresponding to the intended layout, and access individual
  widgets through its methods. Example:

        % lablgladecc project1.glade > project1.ml
        % lablgtk -thread
        # #use "project1.ml" ;;
        class window1 : ...
        # let w1 = new window1 () ;;
        # w1#bind ~name:"on_paste1_activate"
            ~callback:(fun () -> w1#text1#insert "some text\n");;

  See lablgladecc -help for other features (tracing and source
  embedding).
  The xecutable must be linked with lablglade.cma.

External prototyping tools:
  Two other tools are available for GUI prototyping

  MLglade compiles a glade description file to lablgtk source code,
  rather than the dynamic interpretation of lablglade.
        http://www.lri.fr/~monate/mlglade

  Zoggy is GUI builder writte in OCaml, which also generates lablgtk
  source code. It is much more advanced than radtest, which is only
  left as code sample.
        http://pauillac.inria.fr/~guesdon/Tools/zoggy/zoggy.html
  
GL extension:

  You can use lablgtk in combination with LablGL

  * get and install lablGL 0.98 from
    http://wwwfun.kurims.kyoto-u.ac.jp/soft/olabl/lablgl.html
  * get and install gtkglarea-1.2.x.tar.gz from
    http://www.student.oulu.fi/~jlof/gtkglarea/index.html
  * reconfigure: "make configure USE_GL=1"
      You can also set the GLLIBS variable to the libraries you must
      link with. The default is "-lGLU -lGL". Due to a bug in ld.so,
      this should be empty on some systems, including Solaris 8.

  You can then use the widget GlGtk.gl_area as an OpenGL window.
  Some examples are in examples/GL, but basically any LablGL example
  can be easily ported.
  The executable must be linked with both lablgl.cma and lablgtkgl.cma.

Gnome support

  There is no real gnome support, but there is support for the
  gdk-pixbuf and GtkXmHtml libraries. See the GdkPixpuf and GHtml
  modules for details. you will need to link with lablgnome.cma.

Windows port

  A Win32 port is provided. A binary version for use with the
  precompiled version of Objective Caml on Windows is avilable on the
  LablGTK web site.
  If you want to compile it yourself, you will need to get and unpack
  libiconv-*.zip, libintl-*.zip, glib-*.zip and gtk+-1.3.0-*.zip from
        http://www.gimp.org/~tml/gimp/win32/
  Do not forget to get all the -dev- packages.
  The file include/gdk/win32/gdkwin32-private.h seems to be missing
  from the above distribution, so I included it in this
  package. Please copy it to its right location.

  Edit config.make.nt, then, using Visual C++ with cygwin tools,
        cd src
        make -f Makefile.nt
        make -f Makefile.nt opt        (if you have an MS Assembler)
  Then install with
        make -f Makefile.nt install

  Since the link is dynamic you will also need to have in your path:
  libintl-1.dll (extralibs), iconv.dll (iconv), libglib-2.0-0.dll and
  libgmodule-2.0-0.dll (glib), libgdk-0.dll and libgtk-0.dll (gtk+).

  I checked with the 2002-07-03 version of these libraries.
  Everything seems OK. In particular, you can run all examples, and build
  applications/unison as usual.

  However, if you want to use threads, you must be aware of windows
  specific restrictions; see for instance:
     http://groups.yahoo.com/group/gimpwin-dev/message/1828
  I.e. all GTK related calls must occur in the same thread, the one
  that runs the main loop. If you want to call them from other threads
  you need to do some forwarding. Fortunately, with a functional
  language this is easy. Two functions,
    val async : ('a -> unit) -> 'a -> unit
    val sync : ('a -> 'b) -> 'a -> 'b
  are available in the GtkThread module to help you. They will forward
  your call to the main thread (between handling two GUI events). This
  can be either asynchronous or synchronous. In the synchronous case,
  beware of deadlocks (the trivial case, when you are calling from the
  same thread, is properly avoided). Note also that since callbacks
  are always called from the main loop thread, you can freely use GTK
  in them. Also, non-graphical operations are thread-safe.
  Here is an example using the lablgtk toplevel with threads:
	% lablgtk -thread
	        Objective Caml version 3.08.0

        # open GtkThread;;	
	# let w = sync (GWindow.window ~show:true) ();;
        # let b = sync (GButton.button ~packing:w#add ~label:"Hello!") ();;
        # b#connect#clicked (fun () -> prerr_endline "Hello");;

Authors:
	Jacques Garrigue <garrigue@kurims.kyoto-u.ac.jp>
	Hubert Fauque  <hubert.fauque@wanadoo.fr>
	Jun Furuse     <Jun.Furuse@inria.fr>
	Koji Kagawa    <kagawa@eng.kagawa-u.ac.jp>
				   
Bug reports:
	Jacques Garrigue <garrigue@kurims.kyoto-u.ac.jp>

$Id: README,v 1.64.2.3 2004/07/15 08:38:15 garrigue Exp $
