================================
``grail.widgets.gminmax`` module
================================
.. include:: ../../version.h
.. include:: ref.h


.. contents:: Table of Contents
   :backlinks: top

-----------
Description
-----------

The :c:`GMinMax` widget is useful for asking users for a minimum and
maximum integer range. The widget has error checking to ensure that the
maximum value is always greater than the minimum value. You may also
attach :c:`IntegerRTV` variables to both the minimum and maximum value
fields to provide instant update of your local data when the user
updates this widget.

-------
Example
-------

The following example creates a window that will have two
:c:`IntegerRTV` objects associated with it. When the window is closed,
the contents of the :c:`IntegerRTV` objects will be printed out.

.. Python::

    from grail.widgets import *
    from grail.rtv import IntegerRTV

    root = gwidgetinit()
    root.title("GMinMax Example")

    minrtv = IntegerRTV(name='__gminmax_test_min')
    maxrtv = IntegerRTV(name='__gminmax_test_max')
    mm = GMinMax(root, group_text="Example min/max entry",
                 rtv_min=minrtv, rtv_max=maxrtv,
                 min=0, max=10)
    mm.pack()
    root.mainloop()

    print "minimum: %d." % (minrtv.get())
    print "maximum: %d." % (maxrtv.get())

The above script will create a window that will appear as follows,
 
.. figure:: figure-gminmax-example.gif
   :alt: Screen shot of the GMinMax widget.

   Example of the :c:`GMinMax` widget.


--------------
GMinMax Widget
--------------

The :c:`GMinMax` widget inherits from,
  * :c:`gwidget.GWidget` (grail.widgets.gwidget_)
  * :c:`objsignal.Emitter` (grail.objsignal_)

class :dc:`GMinMax([parent, **keywords])`
    Widget used to collect minimum-maximum data via spinners.
    
    Arguments:
       :a:`parent` : :c:`Tkinter.Frame` 
         Parent widget, widget we insert into.

       :a:`keywords` 
         Variable keyword list defined below.

    Keywords:
      :a:`min` : integer
        Smallest valid value (default is :d:`-sys.maxint`).
      :a:`max` : integer
        Largest valid value (default is :d:`sys.maxint`).
      :a:`rtv_min` : :c:`IntegerRTV`
        Attaches a grail.rtv_ variable with the minimum value box.
      :a:`rtv_max` : :c:`IntegerRTV`
        Attaches a grail.rtv_ variable with the maximum value box.

    Components:
      minlabel_text
        Label for the minimum entry.
      maxlabel_text 
        Label for the maximum entry.
      minspinner
        Spinner for the minimum entry.
      maxspinner 
        Spinner for the maximum entry.
   
    Signals:
      :d:`const.sigON_MIN_CHANGE`
        Emitted when the minimum entry changes.
      :d:`const.sigON_MAX_CHANGE` 
        Emitted when the maximum entry changes.
  
    :df:`destroy()`
        Cleans up listner's and destroys the widget.
    
    :df:`disable()`
        Set the :c:`GMinMax` widget to ignore user events.
    
    :df:`enable()`
        Set the :c:`GMinMax` widget to respond to user events.
    
    :df:`updatevars()`
        Force all vars to synchronize with the user's input.