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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
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<refentry id="gtk-changes-2-0" revision="1 Jan 2002">
<refmeta>
<refentrytitle>Changes from 1.2 to 2.0</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>Changes from 1.2 to 2.0</refmiscinfo>
</refmeta>
<refnamediv>
<refname>Changes from 1.2 to 2.0</refname>
<refpurpose>
Incompatible changes made between version 1.2 and version 2.0
</refpurpose>
</refnamediv>
<refsect1>
<title>Incompatible changes from 1.2 to 2.0</title>
<para>
The <ulink url="http://developer.gnome.org/dotplan/porting/">GNOME 2.0
porting guide</ulink> on <ulink
url="http://developer.gnome.org">http://developer.gnome.org</ulink>
has some more detailed discussion of porting from 1.2 to 2.0.
See the sections on GLib and GTK+.
</para>
<para>
GTK+ changed fairly substantially from version 1.2 to 2.0, much more
so than from 1.0 to 1.2. Subsequent updates (possibilities are 2.0 to
2.2, 2.2 to 2.4, then to 3.0) will almost certainly be much, much
smaller. Nonetheless, most programs written for 1.2 compile against
2.0 with few changes. The bulk of changes listed below are to obscure
features or very specialized features, and compatibility interfaces
exist whenever possible.
</para>
<itemizedlist>
<listitem>
<para>
<function>gtk_container_get_toplevels()</function> was removed and replaced
with <function>gtk_window_list_toplevels()</function>, which has different
memory management on the return value
(<function>gtk_window_list_toplevels()</function> copies the
<structname>GList</structname> and also references each widget in the list,
so you have to <function>g_list_free()</function> the list after first
unref'ing each list member).
</para>
</listitem>
<listitem>
<para>
The <function>gdk_time*</function> functions have been removed. This
functionality has been unused since the main loop was moved into GLib
prior to 1.2.
</para>
</listitem>
<listitem>
<para>
The signature for <function>GtkPrintFunc</function> (used for
<function>gtk_item_factory_dump_items()</function>)
has been changed to take a <type>const gchar *</type> instead of
<type>gchar *</type>, to match what we do for GLib, and other similar cases.
</para>
</listitem>
<listitem>
<para>
The detail arguments in the <structname>GtkStyleClass</structname> structure
are now <type>const gchar *</type>.
</para>
</listitem>
<listitem>
<para>
<function>gtk_paned_set_gutter_size()</function> has been removed, since the
small handle tab has been changed to include the entire area previously
occupied by the gutter.
</para>
</listitem>
<listitem>
<para>
<function>gtk_paned_set_handle_size()</function> has been removed, in favor of
a style property, since this is an option that only makes sense for themes
to adjust.
</para>
</listitem>
<listitem>
<para>
GDK no longer selects OwnerGrabButtonMask for button presses. This means
that the automatic grab that occurs when the user presses a button
will have <literal>owner_events = FALSE</literal>, so all events are
redirected to the grab window, even events that would normally go to
other windows of the window's owner.
</para>
</listitem>
<listitem>
<para>
<structname>GtkColorSelectionDialog</structname> has now been moved into it's
own set of files, <filename>gtkcolorseldialog.c</filename> and
<filename>gtkcolorseldialog.h</filename>.
</para>
</listitem>
<listitem>
<para>
<function>gtk_widget_shape_combine_mask()</function> now keeps a reference
count on the mask pixmap that is passed in.
</para>
</listitem>
<listitem>
<para>
The <structname>GtkPatternSpec</structname> has been moved to GLib as
<structname>GPatternSpec</structname>, the pattern
arguments to <function>gtk_item_factory_dump_items()</function> and
<function>gtk_item_factory_dump_rc()</function>
have thusly been changed to take a <structname>GPatternSpec</structname>
instead of a <structname>GtkPatternSpec</structname>.
</para>
</listitem>
<listitem>
<para>
Type system changes:
<itemizedlist>
<listitem>
<para>
<literal>GTK_TYPE_OBJECT</literal> is not a fundamental type anymore. Type checks of the
style <literal>(GTK_FUNDAMENTAL_TYPE (some_type) == GTK_TYPE_OBJECT)</literal>
will not work anymore. As a replacement, <literal>(GTK_TYPE_IS_OBJECT (some_type))</literal>
can be used now.
</para>
</listitem>
<listitem>
<para>
The following types vanished: <literal>GTK_TYPE_ARGS</literal>, <literal>GTK_TYPE_CALLBACK</literal>,
<literal>GTK_TYPE_C_CALLBACK</literal>, <literal>GTK_TYPE_FOREIGN</literal>. The corresponding <structname>GtkArg</structname>
fields and field access macros are also gone.
</para>
</listitem>
<listitem>
<para>
The following type aliases vanished: <literal>GTK_TYPE_FLAT_FIRST</literal>,
<literal>GTK_TYPE_FLAT_LAST</literal>, <literal>GTK_TYPE_STRUCTURED_FIRST</literal>,
<literal>GTK_TYPE_STRUCTURED_LAST</literal>.
</para>
</listitem>
<listitem>
<para>
The type macros <function>GTK_TYPE_MAKE()</function> and <function>GTK_TYPE_SEQNO()</function> vanished, use of
<function>GTK_FUNDAMENTAL_TYPE()</function> is discouraged. Instead, the corresponding <structname>GType</structname>
API should be used: <function>G_TYPE_FUNDAMENTAL()</function>, <function>G_TYPE_DERIVE_ID()</function>,
<function>G_TYPE_BRANCH_SEQNO()</function>. Note that the GLib type system doesn't build new
type ids based on a global incremental sequential number anymore, but
numbers new type ids sequentially per fundamental type branch.
</para>
</listitem>
<listitem>
<para>
The following type functions vanished/were replaced:
<informaltable>
<tgroup cols="2">
<thead>
<row><entry>Old Function</entry><entry>Replacement</entry></row>
</thead>
<tbody>
<row><entry><function>gtk_type_query()</function></entry><entry>being investigated</entry></row>
<row><entry><function>gtk_type_set_varargs_type()</function></entry><entry>-</entry></row>
<row><entry><function>gtk_type_get_varargs_type()</function></entry><entry>-</entry></row>
<row><entry><function>gtk_type_check_object_cast()</function></entry><entry><function>g_type_check_instance_cast()</function></entry></row>
<row><entry><function>gtk_type_check_class_cast()</function></entry><entry><function>g_type_check_class_cast()</function></entry></row>
<row><entry><function>gtk_type_describe_tree()</function></entry><entry>-</entry></row>
<row><entry><function>gtk_type_describe_heritage()</function></entry><entry>-</entry></row>
<row><entry><function>gtk_type_free()</function></entry><entry>-</entry></row>
<row><entry><function>gtk_type_children_types()</function></entry><entry><function>g_type_children()</function></entry></row>
<row><entry><function>gtk_type_set_chunk_alloc()</function></entry><entry><structfield>GTypeInfo.n_preallocs</structfield></entry></row>
<row><entry><function>gtk_type_register_enum()</function></entry><entry><function>g_enum_register_static()</function></entry></row>
<row><entry><function>gtk_type_register_flags()</function></entry><entry><function>g_flags_register_static()</function></entry></row>
<row><entry><function>gtk_type_parent_class()</function></entry><entry><function>g_type_parent()</function>/<function>g_type_class_peek_parent()</function></entry></row>
</tbody>
</tgroup>
</informaltable>
Use of <function>g_type_class_ref()</function>/<function>g_type_class_unref()</function> and <function>g_type_class_peek()</function>
is recommended over usage of <function>gtk_type_class()</function>.
Use of <function>g_type_register_static()</function>/<function>g_type_register_dynamic()</function> is recommended
over usage of <function>gtk_type_unique()</function>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Object system changes:
<structname>GtkObject</structname> derives from <structname>GObject</structname>, so is not the basic object type anymore.
This imposes the following source incompatible changes:
<itemizedlist>
<listitem>
<para>
<structname>GtkObject</structname> has no <structfield>klass</structfield> field anymore, an object's class can be retrieved
with the object's coresponding <literal>GTK_<OBJECT>_GET_CLASS (object)</literal>
macro.
</para>
</listitem>
<listitem>
<para>
<structname>GtkObjectClass</structname> has no <structfield>type</structfield> field anymore, a class's type can be retrived
with the <literal>GTK_CLASS_TYPE (class)</literal> macro.
</para>
</listitem>
<listitem>
<para>
<structname>GtkObjectClass</structname> does not introduce the <function>finalize()</function> and <function>shutdown()</function> methods
anymore. While <function>shutdown()</function> is intended for GTK+ internal use only, <function>finalize()</function>
is required by a variety of object implementations. <function>GObjectClass.finalize</function>
should be overriden here, e.g.:
<informalexample><programlisting>
static void gtk_label_finalize (GObject *gobject)
{
GtkLabel *label = GTK_LABEL (gobject);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void gtk_label_class_init (GtkLabelClass *class)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (class);
gobject_class->finalize = gtk_label_finalize;
}
</programlisting></informalexample>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
The GtkObject::destroy signal can now be emitted multiple times on an object.
::destroy implementations should check that make sure that they take this
into account, by checking to make sure that resources are there before
freeing them. For example:
<informalexample><programlisting>
if (object->foo_data)
{
g_free (object->foo_data);
object->foo_data = NULL;
}
</programlisting></informalexample>
Also, ::destroy implementations have to release object references that
the object holds. Code in finalize implementations such as:
<informalexample><programlisting>
if (object->adjustment)
{
gtk_object_unref (object->adjustment);
object->adjustment = NULL;
}
</programlisting></informalexample>
have to be moved into the ::destroy implementations. The reason for doing
this is that all object reference cycles should be broken at destruction
time.
Because the ::destroy signal can be emitted multiple times, it no longer
makes sense to check if a widget has been destroyed using the
<function>GTK_OBJECT_DESTROYED()</function> macro, and this macro has been
removed. If catching destruction is still needed, it can be done with a
signal connection to ::destroy.
</para>
</listitem>
<listitem>
<para>
Signal system changes:
The GTK+ 2.0 signal system merely proxies the <structname>GSignal</structname>
system now. For future usage, direct use of the
<structname>GSignal</structname> API is recommended,
this avoids significant performance hits where <structname>GtkArg</structname>
structures have to be converted into <structname>GValue</structname>s. For
language bindings, <structname>GSignal</structname>+<structname>GClosure</structname>
provide a much more flexible and convenient mechanism to hook into signal
emissions or install class default handlers, so the old
<structname>GtkSignal</structname> API for language bindings is not
supported anymore.
</para>
<para>
Functions that got removed in the GTK+ signal API:
<function>gtk_signal_n_emissions()</function>,
<function>gtk_signal_n_emissions_by_name()</function>,
<function>gtk_signal_set_funcs()</function>,
<function>gtk_signal_handler_pending_by_id()</function>,
<function>gtk_signal_add_emission_hook()</function>,
<function>gtk_signal_add_emission_hook_full()</function>,
<function>gtk_signal_remove_emission_hook()</function>,
<function>gtk_signal_query()</function>.
Also, the <structname>GtkCallbackMarshal</structname> argument to
<function>gtk_signal_connect_full()</function> is
not supported anymore.
For many of the removed functions, similar variants are available
in the <function>g_signal_*</function> namespace.
The <structname>GSignal</structname> system performs emissions in a
slightly different manner than the old <structname>GtkSignal</structname>
code. Signal handlers that are connected to signal "foo"
on object "bar" while "foo" is being emitted, will not be called anymore
during the emission they were connected within.
</para>
</listitem>
<listitem>
<para>
Inserting and deleting text in <structname>GtkEntry</structname> though
functions such as <function>gtk_entry_insert_text()</function> now leave
the cursor at its original position in the text instead of moving it to
the location of the insertion/deletion.
</para>
</listitem>
<listitem>
<para>
The <structfield>label</structfield> field of <structname>GtkFrame</structname>
widgets has been removed (as part of a change to allow arbitrary widgets
in the title position). The text can now be retrieved with the new function
<function>gtk_frame_get_text()</function>.
</para>
</listitem>
<listitem>
<para>
The 'font' and 'font_set' declarations in RC files are now ignored. There
is a new 'font_name' field that holds the string form of a Pango font.
</para>
</listitem>
<listitem>
<para>
A number of types in GDK have become subclasses of
<structname>GObject</structname>. For the most part, this should not break
anyone's code. However, it's now possible/encouraged to use
<function>g_object_ref()</function>/<function>g_object_unref()</function> and
other <structname>GObject</structname> features with these GDK types. The
converted types are:
<structname>GdkWindow</structname>, <structname>GdkDrawable</structname>,
<structname>GdkPixmap</structname>, <structname>GdkImage</structname>,
<structname>GdkGC</structname>, <structname>GdkDragContext</structname>,
<structname>GdkColormap</structname>.
</para>
</listitem>
<listitem>
<para>
All drawables including pixmaps used to have a type tag, the
<structname>GdkWindowType</structname> enumeration, which included
<literal>GDK_WINDOW_PIXMAP</literal>.
<structname>GdkWindowType</structname> is now a property of
<structname>GdkWindow</structname> <emphasis>only</emphasis>, and there is
no <literal>GDK_WINDOW_PIXMAP</literal>. You can use the
<function>GDK_IS_PIXMAP()</function> macro to see if you have a pixmap, if
you need to know that.
</para>
</listitem>
<listitem>
<para>
<structname>GtkStyle</structname> and <structname>GtkRcStyle</structname> are
now subclasses of <structname>GObject</structname> as well. This
requires fairly extensive changes to theme engines, but
shouldn't affect most other code.
</para>
</listitem>
<listitem>
<para>
<structfield>xthickness</structfield> and <structfield>ythickness</structfield> have moved from
<structname>GtkStyleClass</structname> to <structname>GtkStyle</structname>
(from class to instance). This gives themes a bit more flexibility
and is generally more of the Right Thing. You can trivially fix
your code with <literal>s/style->klass->xthickness/style->xthickness/g</literal> and
same for <literal>ythickness</literal>.
</para>
</listitem>
<listitem>
<para>
Some <structname>GtkStyle</structname> <function>draw_*</function> methods
have been removed (cross, oval, ramp)
and others have been added (expander, layout). This will require
changes to theme engines.
</para>
</listitem>
<listitem>
<para>
If you were using private GDK types, they have been rearranged
significantly. You shouldn't use private types. ;-)
</para>
</listitem>
<listitem>
<para>
The visual for a widget, and also the default visual is now derived
from the colormap for the widget and the default colormap.
<function>gtk_widget_set_visual()</function>,
<function>gtk_widget_set_default_visual()</function>,
<function>gtk_widget_push_visual()</function> and
<function>gtk_widget_pop_visual()</function> now do
nothing. Since the visual always had to match that of the colormap,
it is safe to simply delete all references to these functions.
</para>
</listitem>
<listitem>
<para>
A number of functions in GDK have been renamed for consistency and
clarity. #defines to provide backwards compatibility have been
included, but can be disabled by defining <literal>GDK_DISABLE_DEPRECATED</literal>.
<informaltable>
<tgroup cols="2">
<thead>
<row><entry>Old function</entry><entry>Defined As</entry></row>
</thead>
<tbody>
<row><entry><function>gdk_draw_pixmap</function></entry><entry><function>gdk_draw_drawable</function></entry></row>
<row><entry><function>gdk_draw_bitmap</function></entry><entry><function>gdk_draw_drawable</function></entry></row>
<row><entry><function>gdk_window_get_size</function></entry><entry><function>gdk_drawable_get_size</function></entry></row>
<row><entry><function>gdk_window_get_type</function></entry><entry><function>gdk_window_get_window_type</function></entry></row>
<row><entry><function>gdk_window_get_colormap</function></entry><entry><function>gdk_drawable_get_colormap</function></entry></row>
<row><entry><function>gdk_window_set_colormap</function></entry><entry><function>gdk_drawable_set_colormap</function></entry></row>
<row><entry><function>gdk_window_get_visual</function></entry><entry><function>gdk_drawable_get_visual</function></entry></row>
<row><entry><function>gdk_window_ref</function></entry><entry><function>gdk_drawable_ref</function></entry></row>
<row><entry><function>gdk_window_unref</function></entry><entry><function>gdk_drawable_unref</function></entry></row>
<row><entry><function>gdk_bitmap_ref</function></entry><entry><function>gdk_drawable_ref</function></entry></row>
<row><entry><function>gdk_bitmap_unref</function></entry><entry><function>gdk_drawable_unref</function></entry></row>
<row><entry><function>gdk_pixmap_ref</function></entry><entry><function>gdk_drawable_ref</function></entry></row>
<row><entry><function>gdk_pixmap_unref</function></entry><entry><function>gdk_drawable_unref</function></entry></row>
<row><entry><function>gdk_gc_destroy</function></entry><entry><function>gdk_gc_unref</function></entry></row>
<row><entry><function>gdk_image_destroy</function></entry><entry><function>gdk_image_unref</function></entry></row>
<row><entry><function>gdk_cursor_destroy</function></entry><entry><function>gdk_cursor_unref</function></entry></row>
<row><entry><function>gdk_window_copy_area(drawable,gc,x,y,source_drawable,source_x,source_y,width,height)</function></entry><entry><function>gdk_draw_pixmap(drawable,gc,source_drawable,source_x,source_y,x,y,width,height)</function></entry></row>
<row><entry><function>gdk_rgb_get_cmap</function></entry><entry><function>gdk_rgb_get_colormap</function></entry></row>
</tbody>
</tgroup>
</informaltable>
(Note that <function>g_object_ref()</function> and
<function>g_object_unref()</function> may be used for all of the above ref
and unref functions.)
<function>gtk_widget_popup()</function> was removed, it was only usable
for <structname>GtkWindow</structname>s, and there the same effect can be
achieved by <function>gtk_window_move()</function> and
<function>gtk_widget_show()</function>.
</para>
</listitem>
<listitem>
<para>
<function>gdk_pixmap_foreign_new()</function> no longer calls
<function>XFreePixmap()</function> on the pixmap when the
<structname>GdkPixmap</structname> is finalized. This change corresponds
to the behavior of <function>gdk_window_foreign_new()</function>, and fixes
a lot of problems with code where the pixmap wasn't supposed to be freed.
If <function>XFreePixmap()</function> is needed, it can be done using the
destroy-notification facilities of <function>g_object_set_data()</function>.
</para>
</listitem>
<listitem>
<para>
<structname>GtkProgress</structname>/<structname>GtkProgressBar</structname>
had serious problems in GTK+ 1.2.
<itemizedlist>
<listitem>
<para>
Only 3 or 4 functions are really needed for 95% of progress interfaces;
<structname>GtkProgress</structname>/<structname>GtkProgressBar</structname>
had about 25 functions, and didn't even include these 3 or 4.
</para>
</listitem>
<listitem>
<para>
In activity mode, the API involves setting the adjustment
to any random value, just to have the side effect of
calling the progress bar update function - the adjustment
is totally ignored in activity mode.
</para>
</listitem>
<listitem>
<para>
You set the activity step as a pixel value, which means to
set the activity step you basically need to connect to
size_allocate.
</para>
</listitem>
<listitem>
<para>
There are <function>ctree_set_expander_style()</function>-functions, to
randomly change look-and-feel for no good reason.
</para>
</listitem>
<listitem>
<para>
The split between <structname>GtkProgress</structname> and
<structname>GtkProgressBar</structname> makes no sense to me whatsoever.
</para>
</listitem>
</itemizedlist>
This was a big wart on GTK+ and made people waste lots of time,
both learning and using the interface.
So, we have added what we feel is the correct API, and marked all the
rest deprecated. However, the changes are 100% backward-compatible and
should break no existing code.
The following 5 functions are the new programming interface and you
should consider changing your code to use them:
<programlisting>
void gtk_progress_bar_pulse (GtkProgressBar *pbar);
void gtk_progress_bar_set_text (GtkProgressBar *pbar,
const gchar *text);
void gtk_progress_bar_set_fraction (GtkProgressBar *pbar,
gfloat fraction);
void gtk_progress_bar_set_pulse_step (GtkProgressBar *pbar,
gfloat fraction);
void gtk_progress_bar_set_orientation (GtkProgressBar *pbar,
GtkProgressBarOrientation orientation);
</programlisting>
</para>
</listitem>
<listitem>
<para>
The <structname>GtkNotebookPage</structname> structure has been removed from
the public header files;
this was never meant to be a public structure, and all functionality that
could be done by accessing the struct fields of this structure should be
accessible otherwise.
</para>
</listitem>
<listitem>
<para>
Negative values of the <parameter>position</parameter> parameter to
<function>gtk_notebook_reorder_child()</function> now cause the page to be appended, not
inserted at the beginning. (This gives consistency with
<function>gtk_box_reorder_child()</function>, <function>gtk_menu_reorder_child()</function>.)
</para>
</listitem>
<listitem>
<para>
<function>GtkMenuPositionFunc</function> has a new parameter
<literal>push_in</literal> which controls how menus placed outside the
screen is handled. If this is set to <literal>TRUE</literal> and
part of the menu is outside the screen then GTK+ pushes it into the visible
area. Otherwise the menu is cut of at the end of the visible screen area.
</para>
<para>
Regardless of what happens to the size of the menu, the result is always
that the items are placed in the same place as if the menu was placed
outside the screen, using menu scrolling if necessary.
</para>
</listitem>
<listitem>
<para>
The "draw" signal and virtual method on <structname>GtkWidget</structname>
has been removed.
All drawing should now occur by invalidating a region of the widget
(call <function>gdk_window_invalidate_rect()</function> or
<function>gtk_widget_queue_draw()</function> for example to invalidate
a region). GTK+ merges all invalid regions, and sends expose events to
the widget in an idle handler for the invalid regions.
<function>gtk_widget_draw()</function> is deprecated but still works; it
adds the passed-in area to the invalid region and immediately sends
expose events for the current invalid region.
Most widgets will work fine if you just delete their "draw"
implementation, since they will already have working expose_event
implementations. The draw method was rarely called in practice
anyway.
</para>
</listitem>
<listitem>
<para>
The <structname>GdkExposeEvent</structname> has a new <structfield>region</structfield>
field. This can be used instead of the <structfield>area</structfield> field if you
want a more exact representation of the area to update.
</para>
</listitem>
<listitem>
<para>
Sending synthetic exposes using <function>gtk_widget_event()</function> is no
longer allowed. If you just need an expose call you should use
<function>gdk_window_invalidate_rect()</function> or
<function>gdk_window_invalidate_region()</function> instead. For the case
of container widgets that need to propagate expose events to
<literal>NO_WINDOW</literal> children you can either use
<function>gtk_container_propagate_expose()</function>, or chain to the
default container expose handler.
</para>
</listitem>
<listitem>
<para>
The draw_default and draw_focus methods/signals on
<structname>GtkWidget</structname> are gone; simply draw things in your
expose handler. <function>gtk_widget_draw_focus()</function> and
<function>gtk_widget_draw_default()</function> wrapper
functions are also gone; just queue a draw on the widget,
or the part affected by the focus/default anyway.
Also, <structname>GtkWidget</structname> now has default implementations for
focus_in_event and focus_out_event. These set/unset
<literal>GTK_HAS_FOCUS</literal>, and queue a draw. So if your focus in/out
handler just does that, you can delete it.
</para>
</listitem>
<listitem>
<para>
<structname>GtkText</structname> and <structname>GtkTree</structname> are
buggy and broken. We don't recommend using them, and changing old code to
avoid them is a good idea. The recommended alternatives are
<structname>GtkTextView</structname> and <structname>GtkTreeView</structname>.
The broken widgets are not declared in the headers by default; to use
them, define the symbol <literal>GTK_ENABLE_BROKEN</literal> during
compilation. In some future release, these widgets will be removed from GTK+.
</para>
</listitem>
<listitem>
<para>
<structname>GdkColorContext</structname> is gone; you probably weren't using
it anyway. Use <structname>GdkColormap</structname> and the
<function>gdk_rgb_*</function> functions instead.
</para>
</listitem>
<listitem>
<para>
<structname>GtkMenuBar</structname> now draws the <structfield>GtkContainer::border_width</structfield>
space outside the frame, not inside the frame.
</para>
</listitem>
<listitem>
<para>
In GTK+ 1.2, if an event handler returned <literal>TRUE</literal> it prevented
propagation of that event to parent widgets. That is, the
event signal would not be emitted on parent widgets. In
GTK+ 2.0, if an event handler returns <literal>TRUE</literal>, the current
signal emission on the current widget is immediately stopped. That is,
other callbacks connected to the signal will not be invoked.
</para>
</listitem>
<listitem>
<para>
<function>gtk_toolbar_new()</function> no longer has arguments. This function
was broken because the default <literal>GtkToolbarStyle</literal> (icons,
text, both) is now a user preference, which is overridden when you call
<function>gtk_toolbar_set_style()</function>. The constructor forced everyone
to override the preference, which was undesirable. So to port
your app, decide if you want to force the toolbar style
or conform to the user's global defaults; if you want to force
it, call <function>gtk_toolbar_set_style()</function>.
</para>
<para>
The orientation arg was removed from <function>gtk_toolbar_new()</function>
as well, just because it wasn't very useful and we were breaking the function
anyway so had an opportunity to lose it. Call
<function>gtk_toolbar_set_orientation()</function> to set toolbar orientation.
</para>
</listitem>
<listitem>
<para>
<structname>GtkRange</structname>/<structname>GtkScrollbar</structname>/<structname>GtkScale</structname> were rewritten; this means that most
theme engines won't draw them properly, and any custom subclasses of
these widgets will need a rewrite (though if you could figure out
how to subclass the old version of <structname>GtkRange</structname>, you
have our respect). Also, <literal>GtkTroughType</literal> is gone.
</para>
<para>
Here are some notable changes:
<itemizedlist>
<listitem>
<para>
<literal>stepper_size</literal> style property is the height for
vertical ranges, width for horizontal; the other dimension matches
the trough size.
</para>
</listitem>
<listitem>
<para>
Added the ability to do NeXT-style steppers (and several other styles
that don't make any sense).
</para>
</listitem>
<listitem>
<para>
Added <literal>min_slider_length</literal>,
<literal>fixed_slider_length</literal> properties to
<structname>GtkScrollbar</structname>.
</para>
</listitem>
<listitem>
<para>
Cleaned some private (or at least useless) functions out of
<filename>gtkscale.h</filename>, e.g.
<function>gtk_scale_value_width</function>.
</para>
</listitem>
<listitem>
<para>
Moved bindings from subclasses to <structname>GtkScale</structname>,
even arrow keys, since blind users don't know scale orientation.
</para>
</listitem>
<listitem>
<para>
Changed <literal>move_slider</literal> action signal to use new
<structname>GtkScrollType</structname>, remove
<structname>GtkTroughType</structname> argument.
</para>
</listitem>
<listitem>
<para>
Digits rounds the values a range will input to the given
number of decimals, but will not try to force adjustment
values set by other controllers. That is, we no longer
modify <literal>adjustment->value</literal> inside a
<literal>value_changed</literal> handler.
</para>
</listitem>
<listitem>
<para>
Added getters for <structname>GtkScale</structname> setters.
</para>
</listitem>
<listitem>
<para>
Middle-click begins a slider drag.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
The GtkContainer::focus signal/virtual function and
<function>gtk_container_focus()</function> call were replaced by
GtkWidget::focus and <function>gtk_widget_child_focus()</function>.
The semantics are the same, so you should be able to just
replace <literal>container_class->focus = mywidget_focus</literal> with
<literal>widget_class->focus = mywidget_focus</literal> and replace
<function>gtk_container_focus()</function> calls with
<function>gtk_widget_child_focus()</function> calls.
</para>
<para>
The purpose of this change was to allow non-containers to have
focusable elements.
</para>
</listitem>
<listitem>
<para>
<function>gtk_rc_set_image_loader()</function> and
<function>gtk_rc_load_image()</function> have been removed, now
that GTK+ includes decent image loading capabilities itself.
</para>
</listitem>
<listitem>
<para>
An extra <structname>GtkSettings</structname> argument has been added to
<function>gtk_rc_find_pixmap_in_path()</function>. This function is only
actually useful from a theme engine during parsing, at which point the
<structname>GtkSettings</structname> is provided.
</para>
</listitem>
<listitem>
<para>
The child argument facility in <filename>gtkcontainer.c</filename> has been
converted to a child property facility using
<structname>GParamSpec</structname> and other facilities
for <structname>GObject</structname>.
</para>
</listitem>
<listitem>
<para>
The <function>set_child_arg()</function> and <function>get_child_arg()</function>
virtual methods have been replaced with <function>set_child_property()</function>/<function>get_child_property()</function>, which
work similar to GObject->set_property/get_property.
</para>
</listitem>
<listitem>
<para>
Other removed <structname>GtkContainer</structname> functions with the replacements:
<informaltable>
<tgroup cols="2">
<thead>
<row><entry>Old function</entry><entry>Replacement</entry></row>
</thead>
<tbody>
<row><entry><function>gtk_container_add_child_arg_type</function></entry><entry><function>gtk_container_class_install_child_property</function></entry></row>
<row><entry><function>gtk_container_query_child_args</function></entry><entry><function>gtk_container_class_list_child_properties</function></entry></row>
<row><entry><function>gtk_container_child_getv</function></entry><entry><function>gtk_container_child_set_property</function></entry></row>
<row><entry><function>gtk_container_child_setv</function></entry><entry><function>gtk_container_child_get_property</function></entry></row>
<row><entry><function>gtk_container_add_with_args</function></entry><entry><function>gtk_container_add_with_properties</function></entry></row>
<row><entry><function>gtk_container_addv</function></entry><entry><function>gtk_container_add</function>/<function>gtk_container_child_set_property</function></entry></row>
</tbody>
</tgroup>
</informaltable>
</para>
</listitem>
<listitem>
<para>
<function>gdk_image_get()</function> (or rather its replacement,
<function>gdk_drawable_get_image()</function>) now handles errors properly
by returning <literal>NULL</literal>, previously it would crash. Also, a
window being offscreen is no longer considered an error; instead, the area
contains undefined contents for the offscreen areas. In most cases, code
using <function>gdk_image_get()</function> should really be ported to
<function>gdk_pixbuf_get_from_drawable()</function>.
</para>
</listitem>
<listitem>
<para>
<function>gtk_widget_set_usize()</function> has been renamed to
<function>gtk_widget_set_size_request()</function>, however the old name
still exists unless you define <literal>GTK_DISABLE_DEPRECATED</literal>.
</para>
</listitem>
<listitem>
<para>
<function>gtk_widget_set_uposition()</function> is deprecated; use
<function>gtk_window_move()</function>,
<function>gtk_fixed_put()</function>, or <function>gtk_layout_put()</function>
instead.
</para>
</listitem>
<listitem>
<para>
<function>gtk_window_set_policy()</function> is deprecated. To get the effect of
"allow_shrink", call
<literal>gtk_widget_set_size_request (window, 0, 0)</literal>. To get the
effect of "allow_grow", call
<literal>gtk_window_set_resizable (window, TRUE)</literal>. You didn't want
the effect of "auto_shrink", it made no sense. But maybe if you were using
it you want to use <literal>gtk_window_resize (window, 1, 1)</literal> to
snap a window back to its minimum size (the 1, 1 will be rounded up to the
minimum window size).
</para>
</listitem>
<listitem>
<para>
The core GTK+ now takes care of handling mapping, unmapping and
realizing the child widgets of containers in
<function>gtk_widget_set_parent()</function>. In most cases, this allows
container implementations to be simplified by removing the code in
<function>add()</function> methods to map and realize children. However,
there are a couple of things to watch out for here:
</para>
</listitem>
<listitem>
<para>
If the parent is realized before the <function>add()</function> happens,
<function>gtk_widget_set_parent_window()</function> must be called before
<function>gtk_widget_set_parent()</function>, since
<function>gtk_widget_set_parent()</function> will realize the child.
</para>
</listitem>
<listitem>
<para>
If a container depended on its children not being mapped
unless it did so itself (for example, <structname>GtkNotebook</structname>
only mapped the current page), then the new function
<function>gtk_widget_set_child_visible()</function> must be called to keep
widgets that should not be mapped not mapped.
</para>
<para>
As part of this change, most containers also will no longer need custom
implementations of the <function>map()</function> and
<function>unmap()</function> virtual functions. The only cases where this
is necessary are:
<itemizedlist>
<listitem>
<para>
For <literal>!NO_WINDOW</literal> widgets, if you create children of
<literal>widget->window</literal>
and don't map them in <function>realize()</function> then you must map them
in <function>map()</function>. [ In almost all cases, you can simply map the
windows in <function>realize()</function>. ]
</para>
</listitem>
<listitem>
<para>
For <literal>NO_WINDOW</literal> widgets, if you create windows in your
<function>realize()</function> method, you must map then in
<function>map()</function> and unmap them in <function>unmap()</function>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
<function>gtk_widget_set_default_style()</function>,
<function>gtk_widget_push_style()</function>,
and <function>gtk_widget_pop_style()</function> have been removed, since they
did not work properly with themes and there were better
alternatives for modifying the appearance of widgets.
You should generally use <function>gtk_widget_modify_*()</function>
instead.
</para>
</listitem>
<listitem>
<para>
<function>gtk_image_new()</function> now takes no arguments and creates an
empty <structname>GtkImage</structname> widget. To create a
<structname>GtkImage</structname> widget from a
<structname>GdkImage</structname> (the least
common usage of <structname>GdkImage</structname>), use
<function>gtk_image_new_from_image()</function>.
</para>
</listitem>
<listitem>
<para>
<literal>GTK_SELECTION_EXTENDED</literal> is now deprecated, and neither the
<structname>GtkList</structname>/<structname>GtkTree</structname> nor the
<structname>GtkCList</structname>/<structname>GtkCTree</structname> support
<literal>GTK_SELECTION_EXTENDED</literal> anymore. However, the old extended
behavior replaces <literal>MULTIPLE</literal> behavior.
</para>
</listitem>
<listitem>
<para>
The following variables are no longer exported from GDK. (Other variables
are also no longer exported; the following are the ones found used
externally in a large sample of GTK+ code.)
<informaltable>
<tgroup cols="2">
<thead>
<row><entry>Variable</entry><entry>Replacement</entry></row>
</thead>
<tbody>
<row><entry><literal>gdk_null_window_warnings</literal></entry><entry>None - did nothing in GTK+ 1.2</entry></row>
<row><entry><literal>gdk_leader_window</literal></entry><entry>None - private variable</entry></row>
<row><entry><literal>gdk_screen</literal></entry><entry><function>gdk_x11_get_default_screen ()</function></entry></row>
<row><entry><literal>gdk_root_window</literal></entry><entry><function>gdk_x11_get_default_root_xwindow ()</function></entry></row>
<row><entry><literal>gdk_root_parent</literal></entry><entry><function>gdk_get_default_root_window ()</function></entry></row>
<row><entry><literal>gdk_error_code</literal></entry><entry><function>gdk_error_trap_push ()/pop ()</function></entry></row>
<row><entry><literal>gdk_error_warnings</literal></entry><entry><function>gdk_error_trap_push ()/pop ()</function></entry></row>
<row><entry><literal>gdk_display_name</literal></entry><entry><function>gdk_get_display ()</function></entry></row>
<row><entry><literal>gdk_wm_delete_window</literal></entry><entry><literal>gdk_atom_intern ("WM_DELETE_WINDOW", FALSE)</literal></entry></row>
<row><entry><literal>gdk_wm_take_focus</literal></entry><entry><literal>gdk_atom_intern ("WM_TAKE_FOCUS", FALSE)</literal></entry></row>
<row><entry><literal>gdk_wm_protocols</literal></entry><entry><literal>gdk_atom_intern ("WM_PROTOCOLS", FALSE)</literal></entry></row>
</tbody>
</tgroup>
</informaltable>
</para>
</listitem>
<listitem>
<para>
The handling of colormaps and widgets has been changed:
<itemizedlist>
<listitem>
<para>
The default colormap for widgets is now the <structname>GdkRGB</structname>
colormap, not the system default colormap. If you try to use resources
created for a widget (e.g., <literal>widget->style</literal>) with
a window using the system colormap, errors will result on some machines.
</para>
</listitem>
<listitem>
<para>
<function>gtk_widget_push()</function>/<function>gtk_widget_pop_colormap()</function>
only cause the colormap to be explicitly set on toplevel widgets, not on
all widgets. The colormap for other widgets (when not set using
<function>gtk_widget_set_colormap()</function>), is determined by finding
the nearest ancestor with a colormap set on it explicitly, or if that
fails, the default colormap.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
The default selected day for <structname>GtkCalendar</structname> is now the
current day in the month, not the first day in the month. The current month
and year were already used.
</para>
</listitem>
<listitem>
<para>
GDK is no longer put into threaded mode automatically when
<function>g_thread_init()</function> has been called. In order to use the
global GDK thread mutex with <function>gdk_threads_enter()</function> and
<function>gdk_threads_leave()</function>, you must call
<function>gdk_threads_init()</function> explicitly.
If you aren't using GDK and GTK+ functions from multiple threads,
there is no reason to call <function>gdk_threads_init()</function>.
</para>
</listitem>
<listitem>
<para>
The <structname>GtkPreviewInfo</structname> struct has had its visual and
colormap fields removed. Also, <function>gtk_preview_get_cmap()</function>
and <function>gtk_preview_get_visual()</function> are deprecated, as
<structname>GdkRGB</structname> works on any colormap and visual. You no
longer need to
<literal>gtk_widget_push_cmap (gtk_preview_get_cmap ())</literal> in
your code.
</para>
</listitem>
<listitem>
<para>
The <structname>GtkBox</structname>, <structname>GtkTable</structname>, and
<structname>GtkAlignment</structname> widgets now call
<literal>gtk_widget_set_redraw_on_allocate (widget, FALSE);</literal> on
themselves. If you want to actually draw contents in a widget derived from
one of these widgets, you'll probably want to change this
in your <function>init()</function> function.
</para>
</listitem>
<listitem>
<para>
A number of widgets are now <literal>NO_WINDOW</literal> widgets (most
importantly <structname>GtkButton</structname>, but also
<structname>GtkRange</structname> and <structname>GtkNotebook</structname>)
This has a couple of effects:
<itemizedlist>
<listitem>
<para>
If you are deriving from one of these widgets, you need to
adapt your code appropriately -- for instance, drawing coordinates
start from <literal>widget->allocation.x, widget->allocation.y</literal>.
</para>
</listitem>
<listitem>
<para>
If you are embedding one of these widgets in a custom widget,
you must make sure you call <function>gtk_container_propagate_expose()</function>
correctly, as you must for any <literal>NO_WINDOW</literal> widgets.
</para>
</listitem>
</itemizedlist>
</para>
<para>
<structname>GtkFixed</structname> is a little special; it is now created by
default as a <literal>NO_WINDOW</literal> widget, but if you do
<programlisting>
gtk_fixed_set_has_window (fixed, TRUE);
</programlisting>
after creating a fixed widget, it will create a window and
handle it properly.
</para>
</listitem>
<listitem>
<para>
<structname>GtkLayout</structname> no longer has the <structfield>xoffset</structfield>,
<structfield>yoffset</structfield> fields, which used to store the difference between
world and window coordinates for <literal>layout->bin_window</literal>.
These coordinate systems are now always the same.
</para>
</listitem>
<listitem>
<para>
<function>gtk_paint_focus()</function>, <function>gtk_draw_focus()</function>
and <function>GtkStyle::draw_focus()</function>
have been changed a bit:
<itemizedlist>
<listitem>
<para>
A <literal>GtkStateType</literal> argument has been added to <function>gtk_paint_focus()</function>.
</para>
</listitem>
<listitem>
<para>
The default implementation of the <function>GtkStyle::draw_focus()</function>
virtual function now draws a focus rectangle whose width is
determined by the GtkWidget::focus-width style property.
</para>
</listitem>
<listitem>
<para>
The rectangle passed in is the bounding box, instead of
the rectangle used in the <function>gdk_draw_rectangle()</function> call,
so it is no longer necessary to subtract 1 from the width and height.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</refsect1>
</refentry>