Incompatible Changes from GTK+-1.0 to GTK+-1.2:

* GtkAcceleratorTable has been replaced with GtkAccelGroup

* GtkMenuFactory has been replaced with GtkItemFactory, although
  a version of GtkMenuFactory is currently still provided to ease
  the migration phase.

* The GtkTypeInfo structures used in the gtk_*_type_init() functions have
  changed a bit, the old format:  
      GtkTypeInfo bin_info =
      {
        "GtkBin",
        sizeof (GtkBin),
        sizeof (GtkBinClass),
        (GtkClassInitFunc) gtk_bin_class_init,
        (GtkObjectInitFunc) gtk_bin_init,
        (GtkArgSetFunc) NULL,
        (GtkArgGetFunc) NULL,
      };

  needs to be converted to:

      static const GtkTypeInfo bin_info =
      {
        "GtkBin",
        sizeof (GtkBin),
        sizeof (GtkBinClass),
        (GtkClassInitFunc) gtk_bin_class_init,
        (GtkObjectInitFunc) gtk_bin_init,
        /* reserved_1 */ NULL,
        /* reserved_2 */ NULL,
        (GtkClassInitFunc) NULL,
      };

  the GtkArgSetFunc and GtkArgGetFunc functions are not supported from the
  type system anymore, and you should make sure that your code only fills
  in these fields with NULL and doesn't use the deprecated function typedefs
  (GtkArgSetFunc) and (GtkArgGetFunc) anymore.

* A number of Gtk functions were renamed. For compatibility, gtkcompat.h
  #define's the old 1.0.x function names in terms of the new names.
  To assure your Gtk program doesn't rely on outdated function
  variants, compile your program with -DGTK_DISABLE_COMPAT_H to disable
  the compatibility aliases.

  Here is the list of the old names and replacements:

  Old:				      Replacement:

  gtk_accel_label_accelerator_width   gtk_accel_label_get_accel_width
  gtk_check_menu_item_set_state	      gtk_check_menu_item_set_active
  gtk_container_border_width	      gtk_container_set_border_width
  gtk_label_set  	              gtk_label_set_text
  gtk_notebook_current_page           gtk_notebook_get_current_page
  gtk_packer_configure                gtk_packer_set_child_packing
  gtk_paned_gutter_size	              gtk_paned_set_gutter_size
  gtk_paned_handle_size		      gtk_paned_set_handle_size
  gtk_scale_value_width               gtk_scale_get_value_width
  gtk_style_apply_default_pixmap      gtk_style_apply_default_background (1)
  gtk_toggle_button_set_state         gtk_toggle_button_set_active
  gtk_window_position		      gtk_window_set_position
 
  (1) gtk_style_apply_default_background() has an additional
      argument, gboolean set_bg. This parameter should be FALSE if
      the background is being set for a NO_WINDOW widget, otherwise
      true.

* During the development phase of the 1.1.x line of Gtk certain functions
  were deprecated and later removed. Functions affected are:

  Removed:                          Replacement:
  gtk_clist_set_border		    gtk_clist_set_shadow_type
  gtk_container_block_resize	    gtk_container_set_resize_mode
  gtk_container_unblock_resize	    gtk_container_set_resize_mode
  gtk_container_need_resize	    gtk_container_check_resize
  gtk_ctree_show_stub		    gtk_ctree_set_show_stub
  gtk_ctree_set_reorderable	    gtk_clist_set_reorderable
  gtk_ctree_set_use_drag_icons	    gtk_clist_set_use_drag_icons
  gtk_entry_adjust_scroll	    (1)
  gtk_object_class_add_user_signal  gtk_object_class_user_signal_new
  gtk_preview_put_row		    gtk_preview_put
  gtk_progress_bar_construct	    gtk_progress_set_adjustment
  gtk_scrolled_window_construct	    gtk_scrolled_window_set_{h|v}adjustment
  gtk_spin_button_construct	    gtk_spin_button_configure
  gtk_widget_thaw_accelerators	    gtk_widget_unlock_accelerators
  gtk_widget_freeze_accelerators    gtk_widget_lock_accelerators

(1) This function is no longer needed as GtkEntry should automatically
    keep the scroll adjusted properly.

* Additionally, all gtk_*_interp functions were removed.
  gtk_*_full versions were provided as of GTK+-1.0 and should
  be used instead.

* GtkButton has been changed to derive from GtkBin.
  To access a button's child, use GTK_BIN (button)->child, instead
  of the old GTK_BUTTON (button)->child.

* The selection API has been slightly modified:

 gtk_selection_add_handler() and gtk_selection_add_handler_full() 
 have been removed. To supply the selection, one now register
 the targets one is interested in with:

  void gtk_selection_add_target (GtkWidget           *widget, 
	  	                 GdkAtom              selection,
			         GdkAtom              target,
			         guint                info);

 or:
  
  void gtk_selection_add_targets (GtkWidget           *widget, 
	  			  GdkAtom              selection,
				  GtkTargetEntry      *targets,
				  guint                ntargets);

 When a request for a selection is received, the new "selection_get"
 signal will be called:

   void  "selection_get"           (GtkWidget          *widget,
				    GtkSelectionData   *selection_data,
				    guint               info,
				    guint               time);

 A "time" parameter has also been added to the "selection_received"
 signal.

  void  "selection_received"       (GtkWidget          *widget,
				    GtkSelectionData   *selection_data,
				    guint               time);

* The old drag and drop API has been completely removed and replaced.
  See the reference documentation for details on the new API.

* Support for Themes has been added. In general, this does
  not affect application code, however, a few new rules should
  be observed:

   - To set a shape for a window, you must use 
     gtk_widget_shape_combine_mask() instead of 
     gdk_window_shape_combine_mask(), or the shape will be
     reset when switching themes.

   - It is no longer permissable to draw directly on an arbitrary
     widget, or to set an arbitrary widget's background pixmap.
     If you need to do that, use a GtkDrawingArea or (for a 
     toplevel) the new GtkDrawWindow widget.

* The ScrolledWindow widget no longer creates a Viewport
  automatically. Instead, it has been generalized to accept
  any "self-scrolling" widget.

  The self-scrolling widgets in the Gtk+ core are GtkViewport,
  GtkCList, GtkCTree, GtkText, and GtkLayout. All of these widgets can
  be added to a scrolled window as normal children with
  gtk_container_add() and scrollbars will be set up automatically.

  To add scrollbars to a non self-scrolling widget, (such as a GtkList),
  first add it to a viewport, then add the viewport to a scrolled window.
  The scrolled window code provides a convenience function to do this:

  void gtk_scrolled_window_add_with_viewport (GtkScrolledWindow *scrollwin,
					      GtkWidget         *child);

  This does exactly what it says - it creates a Viewport, adds the child
  widget to it, then adds the Viewport to the scrolled window.

  The scrollbars have been removed from the GtkCList and GtkCTree,
  because they are now scrolled by simply adding them to a Scrolled
  Window. The scrollbar policy is set on the scrolled window with
  gtk_scrolled_window_set_policy() and not on the child widgets
  (e.g. GtkCList's gtk_clist_set_policy() was removed).
  
* The "main loop" of GTK+ has been moved to GLib. This should not
  affect existing programs, since compatibility functions have
  been provided. However, you may want to consider migrating
  your code to use the GLib main loop directly.

* the GTK_BASIC flag was removed, and with it the corresponding
  macro and function GTK_WIDGET_BASIC() and gtk_widget_basic().
  
* All freeze/thaw methods are now recursive - that is, if you
  freeze a widget n times, you must also thaw it n times.

  Therefore, if you have code like:

  gboolean frozen;
  frozen = GTK_CLIST_FROZEN (clist);
  gtk_clist_freeze (clist);
  [...]
  if (!frozen)
    gtk_clist_thaw (clist);

  it will not work anymore. It must be, simply:

  gtk_clist_freeze (clist);
  [...]
  gtk_clist_thaw (clist);

* The thread safety in GTK+ 1.2 is slightly different than
  that which appeared in early versions in the 1.1
  development track. The main difference is that it relies on 
  the thread primitives in GLib, and on the thread-safe 
  GLib main loop.

  This means:

   - You must call g_thread_init() before executing any
     other GTK+ or GDK functions in a threaded GTK+ program.

   - Idles, timeouts, and input functions are executed outside 
     of the main GTK+ lock. So, if you need to call GTK+ 
     inside of such a callback, you must surround the callback
     with a gdk_threads_enter()/gdk_threads_leave() pair.

     [ However, signals are still executed within the main
       GTK+ lock ]

     In particular, this means, if you are writing widgets
     that might be used in threaded programs, you _must_
     surround timeouts and idle functions in this matter.

     As always, you must also surround any calls to GTK+
     not made within a signal handler with a 
     gdk_threads_enter()/gdk_threads_leave() pair.
    
   - There is no longer a special --with-threads configure
     option for GTK+. To use threads in a GTK+ program, you
     must:

      a) If you want to use the native thread implementation,
         make sure GLib found this in configuration, otherwise,
         call you must provide a thread implementation to
	 g_thread_init().
   
      b) Link with the libraries returned by:
 
           gtk-config --libs gthread

         and use the cflags from:

            gtk-config --cflags gthread

     You can get these CFLAGS and LIBS by passing gthread
     as the fourth parameter to the AM_PATH_GTK automake
     macro.

* Prior to GTK+-1.2, there were two conflicting interpretations
  of widget->requistion. It was either taken to be
  the size that the widget requested, or that size
  modified by calls to gtk_widget_set_usize(). In GTK+-1.2,
  it is always interpreted the first way.

  Container widgets are affected in two ways by this:

   1) Container widgets should not pass widget->requisition
      as the second parameter to gtk_widget_size_request().
      Instead they should call it like:
   
      GtkRequisition child_requisition;
      gtk_widget_size_request (widget, &child_requisition);

   2) Container widgets should not access child->requisition
      directly. Either they should use the values returned
      by gtk_widget_size_request(), or they should call
      the new function:

    void gtk_widget_get_child_requisition (GtkWidget      *widget,
					   GtkRequisition *requisition);

      which returns the requisition of the given widget, modified
      by calls to gtk_widget_set_usize().