[Ruby-GNOME2 Project Website] create - tut-gtk2-treev-spbttr (ruby-gnome2-doc-cvs) - Ruby-GNOME2

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REMOTE_ADDR = 74.15.84.244
REMOTE_HOST = 
        URL = http://ruby-gnome2.sourceforge.jp/hiki.cgi?tut-gtk2-treev-spbttr
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TITLE       = tut-gtk2-treev-spbttr
KEYWORD     = 
= The Tree View Widget
{{link "tut-gtk2-treev-pxbr", "tut-gtk2-treev", "tut-gtk", "tut-gtk2-treev-cbbr"}}

== Spin Button Renderers

In session about "Numeric/Text Data Entry" we have learnt about the Gtk::SpinButton. While Gtk::CellRendererText can display numbers, a better option is to use Gtk::CellRendererSpin. Instead of displaying a Gtk::Entry when the content is to be edited, a Gtk::CellRendererSpin is used.

{{image_left("treev-crs-01.png")}}
Just like with the pixbuf renderer example there is a problem with the spin button renderers, you can see this from the image on the the left, where we would expect spin buttons in the Count column. Obviously there is again a problem in GTK+. As of Ruby 1.8.6 and Ruby-GNOME2 rel.: 2-0.17.0-rc1, {{image_right("dialog-warning.png")}} most of the methods in Gtk::CellRendererSpinf class do not work as expected. It also looks that this is a combined C GTK+ as well as Ruby GTK+ problem. I have compiled the C example from Andrew Klause's book, and it exhibits exactly the same problems as my Ruby translation. You may check it out by clicking on ((<pixbuf-spin.c|tut-gtk2-treev-treev-spin-cgtk-01>))

{{br}}

((*pixbuf-spin.rb*))

{{br}}

 #!/usr/bin/env ruby
 require 'gtk2'

 # Add three columns to the GtkTreeView. All three of the
 # columns will be displayed as text, although one is a boolean
 # value and another is an integer.
 def setup_tree_view(treeview)

   renderer = Gtk::CellRendererToggle.new
   column = Gtk::TreeViewColumn.new("Buy", renderer, "active" => $buy_index)

   renderer.activatable = true
   renderer.signal_connect('toggled') do |w, path|
     iter = treeview.model.get_iter(path)
     iter[$buy_index] = !iter[$buy_index] if (iter)
   end
   treeview.append_column(column)

 # Create spin button cell renderer
                         # value, min, max,   step, pg-incr, pg-size
   adj = Gtk::Adjustment.new(0.0, 0.0, 100.0, 1.0,  2.0,     2.0)
   renderer = Gtk::CellRendererSpin.new
   renderer.adjustment = adj
   renderer.signal_connect('edited') do |w, path, new_text|
     iter = treeview.model.get_iter(path)
     iter[$qty_index] = new_text
   end
   column = Gtk::TreeViewColumn.new("Count", renderer, "text" => $qty_index)
   treeview.append_column(column) 

   renderer = Gtk::CellRendererText.new
   column = Gtk::TreeViewColumn.new("Product", renderer, "text" => $prod_index)
   treeview.append_column(column)
 end

 window = Gtk::Window.new(Gtk::Window::TOPLEVEL)
 window.resizable = true
 window.title = "Grocery List"
 window.border_width = 10
 window.signal_connect('delete_event') { Gtk.main_quit }
 window.set_size_request(275, 200)

 class GroceryItem
   attr_accessor :product_type, :buy, :quantity, :product
   def initialize(t,b,q,p)
     @product_type, @buy, @quantity, @product = t, b, q, p
   end
 end
 $buy_index = 0; $qty_index = 1; $prod_index = 2
 $p_category = 0; $p_child = 1

 list = Array.new
 list[0] = GroceryItem.new($p_category, true,  0, "Cleaning Supplies")
 list[1] = GroceryItem.new($p_child,    true,  1, "Paper Towels")
 list[2] = GroceryItem.new($p_child,    true,  3, "Toilet Paper")
 list[3] = GroceryItem.new($p_category, true,  0, "Food")
 list[4] = GroceryItem.new($p_child,    true,  2, "Bread")
 list[5] = GroceryItem.new($p_child,    false, 1, "Butter")
 list[6] = GroceryItem.new($p_child,    true,  1, "Milk")
 list[7] = GroceryItem.new($p_child,    false, 3, "Chips")
 list[8] = GroceryItem.new($p_child,    true,  4, "Soda")

 treeview = Gtk::TreeView.new
 setup_tree_view(treeview)

 # Create a new tree model with three columns, as Boolean, 
 # integer and string.
 store = Gtk::TreeStore.new(TrueClass, Integer, String)

 # Avoid creation of iterators on every iterration, since they
 # need to provide state information for all iterations. Hence:
 # establish closure variables for iterators parent and child.
 parent = child = nil

 # Add all of the products to the GtkListStore.
 list.each_with_index do |e, i|

   # If the product type is a category, count the quantity
   # of all of the products in the category that are going
   # to be bought.
   if (e.product_type == $p_category)
     j = i + 1

     # Calculate how many products will be bought in
     # the category.
     while j < list.size && list[j].product_type != $p_category
       list[i].quantity += list[j].quantity if list[j].buy
       j += 1
     end

     # Add the category as a new root (parent) row (element).
     parent = store.append(nil)
     # store.set_value(parent, $buy_index, list[i].buy) # <= same as below
     parent[$buy_index]  = list[i].buy
     parent[$qty_index]  = list[i].quantity
     parent[$prod_index] = list[i].product

   # Otherwise, add the product as a child row of the category.
   else
     child = store.append(parent)
     # store.set_value(child, $buy_index, list[i].buy) # <= same as below
     child[$buy_index]  = list[i].buy
     child[$qty_index]  = list[i].quantity
     child[$prod_index] = list[i].product
   end
 end

 # Add the tree model to the tree view
 treeview.model = store
 treeview.expand_all

 scrolled_win = Gtk::ScrolledWindow.new
 scrolled_win.add(treeview)
 scrolled_win.set_policy(Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC)
 window.add(scrolled_win)
 window.show_all
 Gtk.main

Ruby-GNOME2

[ruby-gnome2-doc-cvs] [Ruby-GNOME2 Project Website] create - tut-gtk2-treev-spbttr