gtk_window_set_policy()

[Havoc Pennington <hp redhat com>]

Hi,

Bug http://bugzilla.gnome.org/show_bug.cgi?id=7357 suggests
deprecating gtk_window_set_policy() in favor of a
gtk_window_set_user_resizeable().

More rationale appended, from the docs.

Any objections to this?

Havoc

<!-- ##### FUNCTION gtk_window_set_policy ##### -->
<para>
Changes how a toplevel window deals with its size request and user resize
attempts. There are really only two reasonable ways to call this function:
<orderedlist>
<listitem>
<para>
<literal>gtk_window_set_policy(GTK_WINDOW(window), FALSE, TRUE, FALSE)</literal> 
means that the window is user-resizable.
</para>
</listitem>
<listitem>
<para>
<literal>gtk_window_set_policy(GTK_WINDOW(window), FALSE, FALSE, TRUE)</literal> 
means that the window's size is program-controlled, and should simply match 
the current size request of the window's children.
</para>
</listitem>
</orderedlist>
The first policy is the default, that is, by default windows are designed to 
be resized by users.
</para>

<para>
The basic ugly truth of this function is that it should be simply:
<programlisting>
 void gtk_window_set_user_resizeable(GtkWidget* window, gboolean setting);
</programlisting>
So, pretend it is like that, and only use the two policies mentioned above.
GTK+ 1.4 may replace gtk_window_set_policy() with a nicer function like
gtk_window_set_user_resizeable().
</para>

<para>
If set to TRUE, the @allow_grow parameter allows the user to expand the window
beyond the size request of its child widgets. If @allow_grow is TRUE, be sure to
check that your child widgets work properly as the window is resized.
</para>

<para>
A toplevel window will always change size to ensure its child widgets receive
their requested size. This means that if you add child widgets, the toplevel
window will expand to contain them. However, normally the toplevel will not
shrink to fit the size request of its children if it's too large; the
@auto_shrink parameter causes the window to shrink when child widgets have too
much space. @auto_shrink is normally used with the second of the two window
policies mentioned above.  That is, set @auto_shrink to TRUE if you want the
window to have a fixed, always-optimal size determined by your program.
</para>

<para>
Note that @auto_shrink doesn't do anything if @allow_shrink and @allow_grow are
both set to FALSE.
</para>

<para>
Neither of the two suggested window policies set the @allow_shrink paramter to
TRUE.  If @allow_shrink is TRUE, the user can shrink the window so that its
children do not receive their full size request; this is basically a bad thing,
because most widgets will look wrong if this happens. Furthermore GTK+ has a
tendency to re-expand the window if size is recalculated for any reason. The
upshot is that @allow_shrink should always be set to FALSE.
</para>

<para>
Sometimes when you think you want to use @allow_shrink, the real problem is that
some specific child widget is requesting too much space, so the user can't
shrink the window sufficiently. Perhaps you are calling gtk_widget_set_usize()
on a child widget, and forcing its size request to be too large. Instead of
setting the child's usize, consider using gtk_window_set_default_size() so that
the child gets a larger allocation than it requests.
</para>

@window: the window
@allow_shrink: whether the user can shrink the window below its size request
@allow_grow: whether the user can grow the window larger than its size request
@auto_shrink: whether the window automatically snaps back to its size request if
it's larger