The gtk_widget_set_uposition()
function is used to set the position of any widget.
The gtk_widget_set_usize() function
is used to set the size of a widget. In order to use all the
features that are provided by this function when it acts on a
window, you may want to use the
gtk_window_set_policy function. The
definition of these functions are:
| void gtk_widget_set_usize (GtkWidget *widget,
                           gint width,
                           gint height);
void gtk_window_set_policy (GtkWindow *window,
                            gint allow_shrink,
                            gint allow_grow,
                            gint auto_shrink); | 
auto_shrink will automatically shrink
the window when the requested size of the child widgets goes
below the current size of the
window. allow_shrink will give the user the
authorisation to make the window smaller that it should
normally be. allow_grow gives the user
the ability to make the window bigger. The default
values for these parameters are:
| allow_shrink = FALSE
allow_grow   = TRUE
auto_shrink  = FALSE | 
The gtk_widget_set_usize() functions
is not the easiest way to set a window size since you cannot
decrease this window size with another call to this function
unless you call it twice, as in:
|      gtk_widget_set_usize(your_widget, -1, -1);
     gtk_widget_set_usize(your_widget, new_x_size, new_y_size); | 
Another way to set the size of and/or move a window is to use
the gdk_window_move_resize() function which
uses to work fine both to grow or to shrink the window:
|      gdk_window_move_resize(window->window, 
                            x_pos, y_pos, 
                            x_size, y_size); |