How to register get_size etc when extends Gtk::CellRenderer in ruby

Ruby
1

Hi, all

When i extends Gtk::CellRenderer from the gems of
gtk2 | RubyGems.org | your community gem host （MS Windows), i got some error messages as
followed:
Gtk-CRITICAL **:gtk_cell_renderer_get_size: assertion
GTK_CELL_RENDERER_GET_CLASS (cell)->get_size != NULL' failed Gtk-CRITICAL **:gtk_cell_renderer_render: assertion GTK_CELL_RENDERER_GET_CLASS (cell)->render != NULL’ failed

I think they must caused by the methods such as
gtk_cell_renderer_get_size of GTK+:
g_return_if_fail (GTK_IS_CELL_RENDERER (cell));
g_return_if_fail (GTK_CELL_RENDERER_GET_CLASS (cell)->get_size != NULL);

Maybe that means my custom cell renderer(Here as CellRendererRow, for
different cell renderer per row in the same column)'s get_size cann’t be
recognized by GTK+.

I know i have use the 'type_register ’ to register the CellRendererRow
to GTK+, but has there some way to register the methods such as
get_size, or we only need to name the method as do_get_size like
Python/GTK, but how to name the method in Ruby?

The followed is my source code(CellRendererRow.rb):

begin
require ‘rubygems’
rescue LoadError
end

require ‘gtk2’
require ‘glib2’

class CellRendererRow < Gtk::CellRenderer
type_register

install_property(GLib::Param::String.new(
“cell_type”,
“cell_type”,
“The type of the cell renderer”,
“”,
GLib::Param::READABLE|GLib::Param::WRITABLE))

install_property(GLib::Param::String.new(
“cell_value”,
“cell_value”,
“The value of the cell renderer”,
“”,
GLib::Param::READABLE|GLib::Param::WRITABLE))

PIXBUF = “1”
PROGRESS = “2”
SPIN = “3”
TEXT = “4”
TOGGLE = “5”

attr_reader :cell_type, :cell_value

def initialize(treeview)
super()
@treeview = treeview
@comb_renderers = Hash.new
@pixbuf = Gtk::CellRendererPixbuf.new
@spin = Gtk::CellRendererSpin.new
@text = Gtk::CellRendererText.new
@toggle = Gtk::CellRendererToggle.new
end

def cell_type= (s)
puts "cell type is: " + s
@cell_type = s
end

def cell_value= (s)
puts "cell value is: " + s

@s = s
case cell_type
  when  PIXBUF
    @pixbuf.pixbuf = s
  when  SPIN
    @spin.adjustment = s
  when  TEXT
    @text.text = s
  when  TOGGLE
    @toggle.active = s
  else
    cellrenderer = @comb_renderers.fetch(cell_type, @text)
    cellrenderer.text = s
end

end

def renderer
cellrenderer = case cell_type
when PIXBUF
@pixbuf
when SPIN
@spin
when TEXT
@text
when TOGGLE
@toggle
else @comb_renderers.fetch(cell_type, @text)
end
end

def get_size(widget, cell_area)
cellrenderer = renderer
puts cellrenderer.class
cellrenderer.get_size(widget, cell_area)
end

def render(window, widget, background_area, cell_area, expose_area,
flags)
cellrenderer = renderer
puts cellrenderer.class
cellrenderer.render(window, widget, background_area, cell_area,
expose_area, flags)
end

end