From: Hidetoshi NAGAI <nagai@...>
Date: 2009-07-01T19:54:18+09:00
Subject: [RFC] Are these widgets worth adding as standard libraries of Ruby/Tk?

Hi, 

I'm planning to upgrade some Ruby/Tk samples to standard widgets of
Ruby/Tk. I want comments of yours about making each of widgets as a
standard library.

Ruby's source archive includes Ruby/Tk sample scripts.
Some of them are only demonstration, but some of the others are
usable as widget class libraries.
The following sample script includes the classes which are candidates
for upgrading (Probably, class names are modified and bug-fixed 
when upgrade).

* editable_listbox.rb
    class Editable_Listbox
       A listbox widget, but you can edit the text of each item with
       your keyboard.
       For example, when double-crick on an item of the listbox, 
       a entry box is shown on the item to edit the text of the item.
       Of course, the result of editing is reflected on the listbox.


* scrollframe.rb
    class TkScrollFrame
       A frame widget, but it has a scrollable view window to see a
       part of the frame. 
       For example, please remember a toolbar with many buttons, and
       the toolbar is very long than the window size.
       Then, you may want to scroll the toolbar buttons.
       TkScrollFrame can do that easily.


* tkalignbox.rb
    It may be a little difficult to keep same width/height of widgets
    (e.g. buttons with differnt length of text and different height of
    font) even if the window size is changed.
    The followings are kinds of Frame widget to make it easy.
       class Tk::HBox
       class Tk::HLBox
       class Tk::HRBox
       class Tk::VBox
       class Tk::VTBox
       class Tk::VBBox
    For example, Tk::HLBox.new(parent).add(b1, b2, b3, b4, ...) adds 
    buttons b1, b2, b3, b4, ... from left to right on the HLBox frame 
    widget, and gives and keeps same width/height on the buttons.
    A HLBox frame widget is a widget. So, of course, you can pack it
    as same as other widgets.


* tkballoonhelp.rb
    class TkBalloonHelp
       Add a balloonhelp tip on its parent widget.
       Of course, you can contoll its message, on-mouse interval
       before showing the balloonhelp, and so on.
       You can add a hook-method at showing. It means you can also 
       show a different message for each line of a listbox.


* tkcombobox.rb
    class TkAutoScrollListbox
       A listbox widget, but has up/down autoscroll tabs when has items
       out of display range. (Mouse on the tab and don't move mouse,
       then scroll listbox automatically.)

    class TkCombobox
       A combobox widget, but its select-listbox has autoscroll tabs.


* tktextframe.rb
    Based on TkTextFrame class, design Tk::ScrollbarComposite module.
    The module help to add scrollbars to a scrollable widget. 
    For example, define
    ---------------------------------------
      class ScrListbox < Tk::Listbox
        include Tk::ScrollbarComposite
        DEFALUT_HSCROLL = false
        def create_component(keys={})
          Tk::Listbox.new(@frame, keys)
        end
        private :create_component
      end
    ---------------------------------------
    then, you can treat listbox widgets with Y scrollbar, 
    by calling ScrListbox.new().pack() and so on.


-- 
Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)