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``grail.widgets.garrow`` module
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.. include:: ../../version.h
.. include:: ref.h

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



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

Contains the GArrow widget commonly used in the GComboBox and GSpinner
widgets.

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

The following example illustrates how the :c:`GArrow` widget is used to help create a simplified version of the :c:`GSpinner` widget.

 .. Python::

    from grail.rtv import IntegerRTV
    from grail.widgets import GTextEntry
    
    var = IntegerRTV(name="__garrow_test")
   
    # event handlers
    def _onup():
        var.set(var.get() + 1)
    def _ondown():
        var.set(var.get() - 1)
  

    root = Tkinter.Tk()
    up = GArrow(root, height=7, width=14, direction='up')
    down = GArrow(root, height=7, width=14, direction='down')
    objsignal.listen(down, const.sigON_CLICK, None, _ondown)
    objsignal.listen(up, const.sigON_CLICK, None, _onup)
    te = GTextEntry(root, rtv=var)

    te.grid(row=0, column=0, rowspan=2, sticky=Tkinter.NSEW)
    up.grid(row=0, column=1, sticky=Tkinter.NSEW)
    down.grid(row=1, column=1, sticky=Tkinter.NSEW)
    root.mainloop()

-------------
GArrow Widget
-------------

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

class :dc:`GArrow([parent, **kws])` 
    Draws a simple arrow on a canvas widget. This widget attempts to
    encapsulate all the logic necessary for drawing an arrow button.
    
    Examples of an arrow button are on the spinners and comboboxes.
    
    Keywords:
      Inherits all the :c:`Tkinter.Canvas` keywords. The most important of
      :c:`Tkinter.Canvas` keywords are :a:`height` and :a:`width`.

      Additional keywords are as follows,

      :a:`direction`
	 The direction the arrow points, either :d:`const.strUP`,
	 :d:`const.strDOWN`, :d:`const.strLEFT`, :d:`const.strRIGHT`.

      :a:`fg`, :a:`foreground`  
	 Specifies the color of the arrow.  Defaults to
	 :d:`const.colorENABLED_FOREGROUND`.  

    Signal:
      :d:`const.sigON_CLICK`
        Generated whenever the arrow button is clicked by the user.

    Components:
      None.
       

    :df:`bindarrow()`
        *Internal usage only*. Binds the arrow to the windows events.
    
    :df:`disable()`
        Set the arrow to ignore user events.
    
    :df:`enable()`
        Allow the arrow to respond to user events.
    
    :df:`invoke()`
        Causes the arrow to perform an a button down then up event.
    
    :df:`unbindarrow()`
        *Internal usage only*. Unbinds the arrows to the windows events.
    
    :df:`updatevars()`
        No RTVs on this widget; always returns 1.