# --------------------------------------------------------------------------- #
# FLOATSPIN Control wxPython IMPLEMENTATION
# Python Code By:
#
# Andrea Gavana, @ 16 Nov 2005
# Latest Revision: 03 Jan 2014, 23.00 GMT
#
# Modifications for DisplayCAL:
# - Select text on focus
# - Always accept "," (comma) as decimal point
# - Only call SyncSpinToText if TextCtrl value has actually changed
# - Set value to min/max if not in range
# - Use a different method for tab traversal because the original code didn't
#   work under wxGTK
# - If CMD or CTRL are held, don't block keycodes that are not allowed (fixes
#   copy/paste/select all keyboard shortcuts not working)
# - Do default action if return key is pressed (currently only works if the
#   default item is a button)
# - Fix children not reflecting enbled state under wxMac
#
# TODO List/Caveats
#
# 1. Ay Idea?
#
# For All Kind Of Problems, Requests Of Enhancements And Bug Reports, Please
# Write To Me At:
#
# andrea.gavana@gmail.com
# andrea.gavana@maerskoil.com
#
# Or, Obviously, To The wxPython Mailing List!!!
#
#
# End Of Comments
# --------------------------------------------------------------------------- #


"""
:class:`FloatSpin` implements a floating point :class:`SpinCtrl`.


Description
===========

:class:`FloatSpin` implements a floating point :class:`SpinCtrl`. It is built using a custom
:class:`PyControl`, composed by a :class:`TextCtrl` and a :class:`SpinButton`. In order to
correctly handle floating points numbers without rounding errors or non-exact
floating point representations, :class:`FloatSpin` uses the great :class:`FixedPoint` class
from Tim Peters.

What you can do:

- Set the number of representative digits for your floating point numbers;
- Set the floating point format (``%f``, ``%F``, ``%e``, ``%E``, ``%g``, ``%G``);
- Set the increment of every ``EVT_FLOATSPIN`` event;
- Set minimum, maximum values for :class:`FloatSpin` as well as its range;
- Change font and colour for the underline :class:`TextCtrl`.


Usage
=====

Usage example::

    import wx
    import wx.lib.agw.floatspin as FS

    class MyFrame(wx.Frame):

        def __init__(self, parent):
        
            wx.Frame.__init__(self, parent, -1, "FloatSpin Demo")

            panel = wx.Panel(self)
            
            floatspin = FS.FloatSpin(panel, -1, pos=(50, 50), min_val=0, max_val=1,
                                     increment=0.01, value=0.1, agwStyle=FS.FS_LEFT)
            floatspin.SetFormat("%f")
            floatspin.SetDigits(2)

            
    # our normal wxApp-derived class, as usual

    app = wx.App(0)

    frame = MyFrame(None)
    app.SetTopWindow(frame)
    frame.Show()

    app.MainLoop()



Events
======

:class:`FloatSpin` catches 3 different types of events:

1) Spin events: events generated by spinning up/down the spinbutton;
2) Char events: playing with up/down arrows of the keyboard increase/decrease
   the value of :class:`FloatSpin`;
3) Mouse wheel event: using the wheel will change the value of :class:`FloatSpin`.

In addition, there are some other functionalities:

- It remembers the initial value as a default value, call meth:~FloatSpin.SetToDefaultValue`, or
  press ``Esc`` to return to it;
- ``Shift`` + arrow = 2 * increment        (or ``Shift`` + mouse wheel);
- ``Ctrl``  + arrow = 10 * increment       (or ``Ctrl`` + mouse wheel);
- ``Alt``   + arrow = 100 * increment      (or ``Alt`` + mouse wheel);
- Combinations of ``Shift``, ``Ctrl``, ``Alt`` increment the :class:`FloatSpin` value by the
  product of the factors;
- ``PgUp`` & ``PgDn`` = 10 * increment * the product of the ``Shift``, ``Ctrl``, ``Alt``
  factors;
- ``Space`` sets the control's value to it's last valid state.


Window Styles
=============

This class supports the following window styles:

=============== =========== ==================================================
Window Styles   Hex Value   Description
=============== =========== ==================================================
``FS_READONLY``         0x1 Sets :class:`FloatSpin` as read-only control.
``FS_LEFT``             0x2 Horizontally align the underlying :class:`TextCtrl` on the left.
``FS_CENTRE``           0x4 Horizontally align the underlying :class:`TextCtrl` on center.
``FS_RIGHT``            0x8 Horizontally align the underlying :class:`TextCtrl` on the right.
=============== =========== ==================================================


Events Processing
=================

This class processes the following events:

================= ==================================================
Event Name        Description
================= ==================================================
``EVT_FLOATSPIN`` Emitted when the user changes the value of :class:`FloatSpin`, either with the mouse or with the keyboard.
================= ==================================================


License And Version
===================

:class:`FloatSpin` control is distributed under the wxPython license.

Latest revision: Andrea Gavana @ 03 Jan 2014, 23.00 GMT

Version 0.9


Backward Incompatibilities
==========================

Modifications to allow `min_val` or `max_val` to be ``None`` done by:

James Bigler,
SCI Institute, University of Utah,
March 14, 2007

:note: Note that the changes I made will break backward compatibility,
 because I changed the contructor's parameters from `min` / `max` to
 `min_val` / `max_val` to be consistent with the other functions and to
 eliminate any potential confusion with the built in `min` and `max`
 functions.

You specify open ranges like this (you can equally do this in the
constructor)::

    SetRange(min_val=1, max_val=None)     # [1,  ]
    SetRange(min_val=None, max_val=0)     # [ , 0]

or no range::

    SetRange(min_val=None, max_val=None)  # [ , ]

"""

def Property(func):
    return property(**func())


#----------------------------------------------------------------------
# Beginning Of FLOATSPIN wxPython Code
#----------------------------------------------------------------------

import wx
import locale
from math import ceil, floor

# Set The Styles For The Underline wx.TextCtrl
FS_READONLY = 1
""" Sets :class:`FloatSpin` as read-only control. """
FS_LEFT = 2
""" Horizontally align the underlying :class:`TextCtrl` on the left. """
FS_CENTRE = 4
""" Horizontally align the underlying :class:`TextCtrl` on center. """
FS_RIGHT = 8
""" Horizontally align the underlying :class:`TextCtrl` on the right. """

# Define The FloatSpin Event
wxEVT_FLOATSPIN = wx.NewEventType()

#-----------------------------------#
#        FloatSpinEvent
#-----------------------------------#

EVT_FLOATSPIN = wx.PyEventBinder(wxEVT_FLOATSPIN, 1)
""" Emitted when the user changes the value of :class:`FloatSpin`, either with the mouse or""" \
""" with the keyboard. """

# ---------------------------------------------------------------------------- #
# Class FloatSpinEvent
# ---------------------------------------------------------------------------- #

class FloatSpinEvent(wx.PyCommandEvent):
    """ This event will be sent when a ``EVT_FLOATSPIN`` event is mapped in the parent. """

    def __init__(self, eventType, eventId=1, nSel=-1, nOldSel=-1):
        """
        Default class constructor.

        :param `eventType`: the event type;
        :param `eventId`: the event identifier;
        :param `nSel`: the current selection;
        :param `nOldSel`: the old selection.
        """

        wx.PyCommandEvent.__init__(self, eventType, eventId)
        self._eventType = eventType


    def SetPosition(self, pos):
        """
        Sets event position.

        :param `pos`: an integer specyfing the event position.
        """

        self._position = pos


    def GetPosition(self):
        """ Returns event position. """

        return self._position


#----------------------------------------------------------------------------
# FloatTextCtrl
#----------------------------------------------------------------------------


class FloatTextCtrl(wx.TextCtrl):
    """
    A class which holds a :class:`TextCtrl`, one of the two building blocks
    of :class:`FloatSpin`.
    """
    
    def __init__(self, parent, id=wx.ID_ANY, value="", pos=wx.DefaultPosition,
                 size=wx.DefaultSize, style=wx.TE_NOHIDESEL | wx.TE_PROCESS_ENTER,
                 validator=wx.DefaultValidator,
                 name=wx.TextCtrlNameStr):
        """
        Default class constructor.
        Used internally. Do not call directly this class in your code!

        :param `parent`: the :class:`FloatTextCtrl` parent;
        :param `id`: an identifier for the control: a value of -1 is taken to mean a default;
        :param `value`: default text value;
        :param `pos`: the control position. A value of (-1, -1) indicates a default position,
         chosen by either the windowing system or wxPython, depending on platform;
        :param `size`: the control size. A value of (-1, -1) indicates a default size,
         chosen by either the windowing system or wxPython, depending on platform;
        :param `style`: the window style;
        :param `validator`: the window validator;
        :param `name`: the window name.
        
        """

        wx.TextCtrl.__init__(self, parent, id, value, pos, size, style, validator, name)

        self._parent = parent
        self._selection = (-1, -1)
        self._value = value
        self.Bind(wx.EVT_WINDOW_DESTROY, self.OnDestroy)
        self.Bind(wx.EVT_KEY_DOWN, self.OnKeyDown)
        self.Bind(wx.EVT_SET_FOCUS, self.OnFocus)
        self.Bind(wx.EVT_KILL_FOCUS, self.OnKillFocus)


    def OnDestroy(self, event):
        """
        Handles the ``wx.EVT_WINDOW_DESTROY`` event for :class:`FloatTextCtrl`.

        :param `event`: a :class:`WindowDestroyEvent` event to be processed.

        :note: This method tries to correctly handle the control destruction under MSW.
        """

        if self._parent:
            self._parent._textctrl = None
            self._parent = None


    def OnKeyDown(self, event):
        """
        Handles the ``wx.EVT_KEYDOWN`` event for :class:`FloatTextCtrl`.

        :param `event`: a :class:`KeyEvent` event to be processed.
        """

        if self._parent:
            self._parent.OnKeyDown(event)


    def OnFocus(self, event):
        self._value = self.Value
        self.RestoreSelection()
        event.Skip()


    def OnKillFocus(self, event):
        """
        Handles the ``wx.EVT_KILL_FOCUS`` event for :class:`FloatTextCtrl`.

        :param `event`: a :class:`FocusEvent` event to be processed.

        :note: This method synchronizes the :class:`SpinButton` and the :class:`TextCtrl`
         when focus is lost.
         """

        self._selection = self.GetSelection()
        if self._parent and self.Value != self._value:
            self._parent.SyncSpinToText(True)
        self.SetSelection(0, 0)

        event.Skip()

    def RestoreSelection(self):
        """
        Restores the selection under Mac OS X, selects all under other platforms
        (consistent with default wx.TextCtrl behaviour)
        
        """

        if "__WXMAC__" in wx.PlatformInfo and self._selection != (-1, -1):
            self.SetSelection(*self._selection)
        else:
            self.SelectAll()


#---------------------------------------------------------------------------- #
# FloatSpin
# This Is The Main Class Implementation
# ---------------------------------------------------------------------------- #

class FloatSpin(wx.PyControl):
    """
    :class:`FloatSpin` implements a floating point :class:`SpinCtrl`. It is built using a custom
    :class:`PyControl`, composed by a :class:`TextCtrl` and a :class:`SpinButton`. In order to
    correctly handle floating points numbers without rounding errors or non-exact
    floating point representations, :class:`FloatSpin` uses the great :class:`FixedPoint` class
    from Tim Peters.
    """

    _spinwidth = 0

    def __init__(self, parent, id=wx.ID_ANY, pos=wx.DefaultPosition,
                 size=(95,-1), style=0, value=0.0, min_val=None, max_val=None,
                 increment=1.0, digits=-1, agwStyle=FS_LEFT,
                 name="FloatSpin"):
        """
        Default class constructor.

        :param `parent`: the :class:`FloatSpin` parent;
        :param `id`: an identifier for the control: a value of -1 is taken to mean a default;
        :param `pos`: the control position. A value of (-1, -1) indicates a default position,
         chosen by either the windowing system or wxPython, depending on platform;
        :param `size`: the control size. A value of (-1, -1) indicates a default size,
         chosen by either the windowing system or wxPython, depending on platform;
        :param `style`: the window style;
        :param `value`: is the current value for :class:`FloatSpin`;
        :param `min_val`: the minimum value, ignored if ``None``;
        :param `max_val`: the maximum value, ignored if ``None``;
        :param `increment`: the increment for every :class:`FloatSpinEvent` event;
        :param `digits`: number of representative digits for your floating point numbers;
        :param `agwStyle`: one of the following bits:

         =============== =========== ==================================================
         Window Styles   Hex Value   Description
         =============== =========== ==================================================
         ``FS_READONLY``         0x1 Sets :class:`FloatSpin` as read-only control.
         ``FS_LEFT``             0x2 Horizontally align the underlying :class:`TextCtrl` on the left.
         ``FS_CENTRE``           0x4 Horizontally align the underlying :class:`TextCtrl` on center.
         ``FS_RIGHT``            0x8 Horizontally align the underlying :class:`TextCtrl` on the right.
         =============== =========== ==================================================

        :param `name`: the window name.

        """

        wx.PyControl.__init__(self, parent, id, pos, size, style|wx.NO_BORDER|
                              wx.NO_FULL_REPAINT_ON_RESIZE | wx.CLIP_CHILDREN,
                              wx.DefaultValidator, name)

        # Don't call SetRange here, because it will try to modify
        # self._value whose value doesn't exist yet.
        self.SetRangeDontClampValue(min_val, max_val)
        self._value = self.ClampValue(FixedPoint(str(value), 20))
        self._defaultvalue = self._value
        self._increment = FixedPoint(str(increment), 20)
        self._spinmodifier = FixedPoint(str(1.0), 20)
        self._digits = digits
        self._snapticks = False
        self._spinbutton = None
        self._ignore_spin_event = False
        self._textctrl = None
        self._spinctrl_bestsize = wx.Size(-999, -999)
        self._enabled = True

        # start Philip Semanchuk addition
        # The textbox & spin button are drawn slightly differently 
        # depending on the platform. The difference is most pronounced
        # under OS X.
        if "__WXMAC__" in wx.PlatformInfo:
            self._gap = 8
            self._spin_top = 3
            self._text_left = 4
            self._text_top = 4
        elif "__WXMSW__" in wx.PlatformInfo:
            self._gap = 1
            self._spin_top = 0
            self._text_left = 0
            self._text_top = 0
        else:
            # GTK
            if "gtk3" in wx.PlatformInfo:
                self._gap = 1
            else:
                self._gap = -1
            self._spin_top = 0
            self._text_left = 0
            self._text_top = 0
        # end Philip Semanchuk addition

        self.SetLabel(name)
        self.SetForegroundColour(parent.GetForegroundColour())

        width = size[0]
        height = size[1]
        best_size = self.DoGetBestSize()

        if width == -1:
            width = best_size.GetWidth()
        if height == -1:
            height = best_size.GetHeight()

        self._validkeycode = [43, 44, 45, 46, 69, 101]
        self._validkeycode.extend(range(48, 58))
        self._validkeycode.extend([wx.WXK_BACK, wx.WXK_DELETE, wx.WXK_LEFT,
                                   wx.WXK_RIGHT,
                                   wx.WXK_NUMPAD0, wx.WXK_NUMPAD1,
                                   wx.WXK_NUMPAD2, wx.WXK_NUMPAD3,
                                   wx.WXK_NUMPAD4, wx.WXK_NUMPAD5,
                                   wx.WXK_NUMPAD6, wx.WXK_NUMPAD7,
                                   wx.WXK_NUMPAD8, wx.WXK_NUMPAD9,
                                   wx.WXK_NUMPAD_ADD, wx.WXK_NUMPAD_DECIMAL,
                                   wx.WXK_NUMPAD_SEPARATOR,
                                   wx.WXK_NUMPAD_SUBTRACT])

        self._spinbutton = wx.SpinButton(self, wx.ID_ANY, wx.DefaultPosition,
                                         size=(-1, height),
                                         style=wx.SP_ARROW_KEYS | wx.SP_VERTICAL |
                                         wx.SP_WRAP)
        self._spinbutton.SetRange(-2 ** 32 / 2.0, 2 ** 32 / 2.0 - 1)
        self._spinbutton.AcceptsFocusFromKeyboard = lambda: False
        if "gtk3" in wx.PlatformInfo:
            if not FloatSpin._spinwidth:
                spin = wx.SpinCtrl(self, -1)
                text = wx.TextCtrl(self, -1)
                FloatSpin._spinwidth = spin.Size[0] - text.Size[0] + 11
                spin.Destroy()
                text.Destroy()
            self._spinbutton.MaxSize = FloatSpin._spinwidth, height

        txtstyle = wx.TE_NOHIDESEL | wx.TE_PROCESS_ENTER

        if agwStyle & FS_RIGHT:
            txtstyle = txtstyle | wx.TE_RIGHT
        elif agwStyle & FS_CENTRE:
            txtstyle = txtstyle | wx.TE_CENTER

        if agwStyle & FS_READONLY:
            txtstyle = txtstyle | wx.TE_READONLY

        self._textctrl = FloatTextCtrl(self, wx.ID_ANY, "", wx.DefaultPosition,
                                       (width-self._spinbutton.GetSize().GetWidth(), height),
                                       txtstyle)

        # start Philip Semanchuk addition
        # Setting the textctrl's size in the ctor also sets its min size. 
        # But the textctrl is entirely controlled by the parent floatspin 
        # control and should accept whatever size its parent dictates, so
        # here we tell it to forget its min size.
        self._textctrl.SetMinSize(wx.DefaultSize)
        # Setting the spin buttons's size in the ctor also sets its min size. 
        # Under OS X that results in a rendering artifact because spin buttons
        # are a little shorter than textboxes. 
        # Setting the min size to the default allows OS X to draw the spin
        # button correctly. However, Windows and KDE take the call to
        # SetMinSize() as a cue to size the spin button taller than the
        # textbox, so we avoid the call there.
        if "__WXMAC__" in wx.PlatformInfo:
            self._spinbutton.SetMinSize(wx.DefaultSize)
        # end Philip Semanchuk addition

        self._mainsizer = wx.BoxSizer(wx.HORIZONTAL)
        # Ensure the spin button is shown, and the text widget takes
        # all remaining free space
        self._mainsizer.Add(self._textctrl, 1)
        if "gtk3" in wx.PlatformInfo:
            self._mainsizer.Add((self._gap, 1), 0)
        self._mainsizer.Add(self._spinbutton, 0)
        self.SetSizer(self._mainsizer)
        self._mainsizer.Layout()

        self.SetFormat()

        if not (agwStyle & FS_READONLY):
            self.Bind(wx.EVT_SPIN_UP, self.OnSpinUp)
            self.Bind(wx.EVT_SPIN_DOWN, self.OnSpinDown)
            self._spinbutton.Bind(wx.EVT_LEFT_DOWN, self.OnSpinMouseDown)
            self._spinbutton.Bind(wx.EVT_LEFT_UP, self.OnSpinMouseUp)
            
        self._textctrl.Bind(wx.EVT_TEXT_ENTER, self.OnTextEnter)
        self._textctrl.Bind(wx.EVT_MOUSEWHEEL, self.OnMouseWheel)
        self._spinbutton.Bind(wx.EVT_MOUSEWHEEL, self.OnMouseWheel)

        self.Bind(wx.EVT_SET_FOCUS, self.OnFocus)

        if not "gtk3" in wx.PlatformInfo:
            self.Bind(wx.EVT_SIZE, self.OnSize)

        if hasattr(self, "SetBestSize"):
            # Not Phoenix
            # start Philip Semanchuk move
            self.SetBestSize((width, height))
            # end Philip Semanchuk move


    def OnDestroy(self, event):
        """
        Handles the ``wx.EVT_WINDOW_DESTROY`` event for :class:`FloatSpin`.

        :param `event`: a :class:`WindowDestroyEvent` event to be processed.

        :note: This method tries to correctly handle the control destruction under MSW.
        """

        # Null This Since MSW Sends KILL_FOCUS On Deletion
        if self._textctrl:
            self._textctrl._parent = None
            self._textctrl.Destroy()
            self._textctrl = None

        self._spinbutton.Destroy()
        self._spinbutton = None


    def DoGetBestSize(self):
        """
        Gets the size which best suits the window: for a control, it would be the
        minimal size which doesn't truncate the control, for a panel - the same
        size as it would have after a call to `Fit()`.
        
        :note: Overridden from :class:`PyControl`.
        """

        if self._spinctrl_bestsize.x == -999:

            spin = wx.SpinCtrl(self, -1)
            self._spinctrl_bestsize = spin.GetBestSize()

            # oops something went wrong, set to reasonable value
            if self._spinctrl_bestsize.GetWidth() < 20:
                self._spinctrl_bestsize.SetWidth(95)
            if self._spinctrl_bestsize.GetHeight() < 10:
                self._spinctrl_bestsize.SetHeight(22)

            spin.Destroy()

        return self._spinctrl_bestsize


    def DoSendEvent(self):
        """ Send the event to the parent. """

        event = wx.CommandEvent(wx.wxEVT_COMMAND_SPINCTRL_UPDATED, self.GetId())
        event.SetEventObject(self)
        event.SetInt(int(self._value + 0.5))

        if self._textctrl:
            event.SetString(self._textctrl.GetValue())

        self.GetEventHandler().ProcessEvent(event)

        eventOut = FloatSpinEvent(wxEVT_FLOATSPIN, self.GetId())
        eventOut.SetPosition(int(self._value + 0.5))
        eventOut.SetEventObject(self)
        self.GetEventHandler().ProcessEvent(eventOut)


    def Disable(self):
        self.Enable(False)


    def Enable(self, enable=True):
        """ Enable the child controls. This is needed under wxMac """

        wx.PyControl.Enable(self, enable)
        self._enabled = enable
        
        if self._textctrl:
            self._textctrl.Enable(enable)
        self._spinbutton.Enable(enable)


    @Property
    def Enabled():
        def fget(self):
            return self._enabled

        def fset(self, enable=True):
            self.Enable(enable)

        return locals()


    def IsEnabled(self):
        return self._enabled


    def OnSpinMouseDown(self, event):
        """
        Handles the ``wx.EVT_LEFT_DOWN`` event for :class:`FloatSpin`.

        :param `event`: a :class:`MouseEvent` event to be processed.

        :note: This method works on the underlying :class:`SpinButton`.
        """

        modifier = FixedPoint(str(1.0), 20)
        if event.ShiftDown():
            modifier = modifier*2.0
        if event.ControlDown():
            modifier = modifier*10.0
        if event.AltDown():
            modifier = modifier*100.0

        self._spinmodifier = modifier

        self._ignore_spin_event = False
        event.Skip()


    def OnSpinMouseUp(self, event):
        """
        Handles the ``wx.EVT_LEFT_UP`` event for :class:`FloatSpin`.

        :param `event`: a :class:`MouseEvent` event to be processed.

        :note: This method works on the underlying :class:`SpinButton`.
        """

        if self._textctrl:
            if "__WXMSW__" in wx.PlatformInfo:
                self._textctrl.SetFocus()
                self._textctrl.SelectAll()
            elif not "__WXMAC__" in wx.PlatformInfo:
                self._textctrl.SetFocus()
                self._textctrl.SetSelection(0, 0)

        self._ignore_spin_event = False
        event.Skip()


    def OnSpinUp(self, event):
        """
        Handles the ``wx.EVT_SPIN_UP`` event for :class:`FloatSpin`.

        :param `event`: a :class:`SpinEvent` event to be processed.
        """

        if self._ignore_spin_event:
            self._ignore_spin_event = False
            return

        if self._textctrl and self._textctrl.IsModified():
            self.SyncSpinToText(False)

        if self.InRange(self._value + self._increment*self._spinmodifier):

            self._value = self._value + self._increment*self._spinmodifier
        elif self._max is not None:
            self._value = self._max
        self.SetValue(self._value)
        if "__WXMAC__" in wx.PlatformInfo:
            self._textctrl.SelectAll()
        self.DoSendEvent()


    def OnSpinDown(self, event):
        """
        Handles the ``wx.EVT_SPIN_DOWN`` event for :class:`FloatSpin`.

        :param `event`: a :class:`SpinEvent` event to be processed.
        """

        if self._ignore_spin_event:
            self._ignore_spin_event = False
            return

        if self._textctrl and self._textctrl.IsModified():
            self.SyncSpinToText(False)

        if self.InRange(self._value - self._increment*self._spinmodifier):

            self._value = self._value - self._increment*self._spinmodifier
        elif self._min is not None:
            self._value = self._min
        self.SetValue(self._value)
        if "__WXMAC__" in wx.PlatformInfo:
            self._textctrl.SelectAll()
        self.DoSendEvent()


    def OnTextEnter(self, event):
        """
        Handles the ``wx.EVT_TEXT_ENTER`` event for :class:`FloatSpin`.

        :param `event`: a :class:`KeyEvent` event to be processed.

        :note: This method works on the underlying :class:`TextCtrl`.
        """

        self.SyncSpinToText(True)
        event.Skip()


    def OnKeyDown(self, event):
        """
        Handles the ``wx.EVT_KEYDOWN`` event for :class:`FloatSpin`.

        :param `event`: a :class:`KeyEvent` event to be processed.

        :note: This method works on the underlying :class:`TextCtrl`.
        """

        modifier = FixedPoint(str(1.0), 20)
        if event.ShiftDown():
            modifier = modifier*2.0
        if event.ControlDown():
            modifier = modifier*10.0
        if event.AltDown():
            modifier = modifier*100.0

        keycode = event.GetKeyCode()

        if keycode == wx.WXK_UP:

            if self._textctrl and self._textctrl.IsModified():
                self.SyncSpinToText(False)

            self.SetValue(self._value + self._increment*modifier)
            self.DoSendEvent()

        elif keycode == wx.WXK_DOWN:

            if self._textctrl and self._textctrl.IsModified():
                self.SyncSpinToText(False)

            self.SetValue(self._value - self._increment*modifier)
            self.DoSendEvent()

        elif keycode == wx.WXK_PAGEUP:

            if self._textctrl and self._textctrl.IsModified():
                self.SyncSpinToText(False)

            self.SetValue(self._value + 10.0*self._increment*modifier)
            self.DoSendEvent()

        elif keycode == wx.WXK_PAGEDOWN:

            if self._textctrl and self._textctrl.IsModified():
                self.SyncSpinToText(False)

            self.SetValue(self._value - 10.0*self._increment*modifier)
            self.DoSendEvent()

        elif keycode == wx.WXK_SPACE:

            self.SetValue(self._value)
            if self._textctrl:
                self._textctrl.SelectAll()
            event.Skip(False)

        elif keycode == wx.WXK_ESCAPE:

            self.SetToDefaultValue()
            if self._textctrl:
                self._textctrl.SelectAll()
            self.DoSendEvent()

        elif keycode == wx.WXK_TAB:

            # The original event code doesn't work under wxGTK
            focus_next_keyboard_focusable_control(event.EventObject)

        elif keycode in (wx.WXK_RETURN, wx.WXK_NUMPAD_ENTER):

            default = self.TopLevelParent.DefaultItem
            if (default and default.Enabled and default.IsShownOnScreen() and
                isinstance(default, wx.Button)):
                default.ProcessEvent(wx.PyCommandEvent(wx.EVT_BUTTON.typeId,
                                                       default.GetId()))

        else:
            if (not event.CmdDown() and not event.ControlDown() and
                keycode not in self._validkeycode):
                return

            event.Skip()


    def OnMouseWheel(self, event):
        """
        Handles the ``wx.EVT_MOUSEWHEEL`` event for :class:`FloatSpin`.

        :param `event`: a :class:`MouseEvent` event to be processed.
        """

        modifier = FixedPoint(str(1.0), 20)
        if event.ShiftDown():
            modifier = modifier*2.0
        if event.ControlDown():
            modifier = modifier*10.0
        if event.AltDown():
            modifier = modifier*100.0

        if self._textctrl and self._textctrl.IsModified():
            self.SyncSpinToText(False)

        if event.GetWheelRotation() > 0:
            self.SetValue(self._value + self._increment*modifier)

        else:

            self.SetValue(self._value - self._increment*modifier)

        if self._textctrl:
            if "__WXMAC__" in wx.PlatformInfo:
                self._textctrl.SelectAll()
            else:
                self._textctrl.SetFocus()
                self._textctrl.SetSelection(0, 0)

        self.DoSendEvent()


    def OnSize(self, event):
        """
        Handles the ``wx.EVT_SIZE`` event for :class:`FloatSpin`.

        :param `event`: a :class:`SizeEvent` event to be processed.

        :note: This method resizes the text control and reposition the spin button when
         resized.
        """
        # start Philip Semanchuk addition
        event_width = event.GetSize().width
        
        self._textctrl.SetPosition((self._text_left, self._text_top))
        
        text_width, text_height = self._textctrl.Size
        
        spin_width, _ = self._spinbutton.Size
        
        text_width = event_width - (spin_width + self._gap + self._text_left)

        self._textctrl.SetSize(wx.Size(text_width, event.GetSize().height))
        
        # The spin button is always snug against the right edge of the 
        # control.
        self._spinbutton.SetPosition((event_width - spin_width, self._spin_top))
        
        event.Skip()
        # end Philip Semanchuk addition


    def ReplaceDoubleZero(self, strs):
        """
        Replaces the (somewhat) python ugly `+e000` with `+e00`.

        :param `strs`: a string (possibly) containing a `+e00` substring.
        """

        if self._textformat not in ["%g", "%e", "%E", "%G"]:
            return strs

        if strs.find("e+00") >= 0:
            strs = strs.replace("e+00", "e+0")
        elif strs.find("e-00") >= 0:
            strs = strs.replace("e-00", "e-0")
        elif strs.find("E+00") >= 0:
            strs = strs.replace("E+00", "E+0")
        elif strs.find("E-00") >= 0:
            strs = strs.replace("E-00", "E-0")

        return strs


    def SetValue(self, value):
        """
        Sets the :class:`FloatSpin` value.

        :param `value`: the new value.
        """        
        if not self._textctrl or not self.InRange(value):
            return

        if self._snapticks and self._increment != 0.0:

            finite, snap_value = self.IsFinite(value)

            if not finite: # FIXME What To Do About A Failure?

                if (snap_value - floor(snap_value) < ceil(snap_value) - snap_value):
                    value = self._defaultvalue + floor(snap_value)*self._increment
                else:
                    value = self._defaultvalue + ceil(snap_value)*self._increment

        decimal = locale.localeconv()["decimal_point"]
        strs = ("%100." + str(self._digits) + self._textformat[1])%value
        strs = strs.replace(".", decimal)
        strs = strs.replace(",", ".")
        strs = strs.strip()
        strs = self.ReplaceDoubleZero(strs)

        # Sync spinbutton so that events generated by it match up with the
        # actual spin direction.
        # This fixes an issue under GTK and Mac OS X where the EVT_SPIN event
        # generated by pressing the spin up/down buttons is dependent on the
        # spin button value (e.g. if the down button is pressed when the button
        # value is at its minimum, there will always be a EVT_SPIN_UP generated
        # under GTK, and no event at all under Mac OS X).
        min_val = self._min if self._min is not None else self._spinbutton.Min
        max_val = self._max if self._max is not None else self._spinbutton.Max
        # Scale the value to the spinbutton range
        spinvalue = int(round(((value - min_val) / float(max_val - min_val)) *
                              self._spinbutton.Max))
        # Setting the spin button value causes a EVT_SPIN event to be generated
        # under GTK, which we need to ignore
        self._ignore_spin_event = True
        self._spinbutton.SetValue(spinvalue)

        if value != self._value or strs != self._textctrl.GetValue():

            self._textctrl.SetValue(strs)
            self._textctrl.DiscardEdits()
            self._value = value


    def GetValue(self):
        """ Returns the :class:`FloatSpin` value. """

        return float(self._value)


    def SetRangeDontClampValue(self, min_val, max_val):
        """
        Sets the allowed range.

        :param `min_val`: the minimum value for :class:`FloatSpin`. If it is ``None`` it is
         ignored;
        :param `max_val`: the maximum value for :class:`FloatSpin`. If it is ``None`` it is
         ignored.

        :note: This method doesn't modify the current value.
        """

        if (min_val != None):
            self._min = FixedPoint(str(min_val), 20)
        else:
            self._min = None
        if (max_val != None):
            self._max = FixedPoint(str(max_val), 20)
        else:
            self._max = None


    def SetRange(self, min_val, max_val):
        """
        Sets the allowed range.

        :param `min_val`: the minimum value for :class:`FloatSpin`. If it is ``None`` it is
         ignored;
        :param `max_val`: the maximum value for :class:`FloatSpin`. If it is ``None`` it is
         ignored.

        :note: This method doesn't modify the current value.

        :note: You specify open ranges like this (you can equally do this in the
         constructor)::

             SetRange(min_val=1, max_val=None)
             SetRange(min_val=None, max_val=0)


         or no range::

             SetRange(min_val=None, max_val=None)
        
        """

        self.SetRangeDontClampValue(min_val, max_val)

        value = self.ClampValue(self._value)
        if (value != self._value):
            self.SetValue(value)


    def ClampValue(self, var):
        """
        Clamps `var` between `_min` and `_max` depending if the range has
        been specified.

        :param `var`: the value to be clamped.
        
        :return: A clamped copy of `var`.
        """

        if (self._min != None):
            if (var < self._min):
                var = self._min
                return var

        if (self._max != None):
            if (var > self._max):
                var = self._max
                
        return var


    def SetIncrement(self, increment):
        """
        Sets the increment for every ``EVT_FLOATSPIN`` event.

        :param `increment`: a floating point number specifying the :class:`FloatSpin` increment.
        """

        if increment < 1./10.0**self._digits:
            raise Exception("\nERROR: Increment Should Be Greater Or Equal To 1/(10**digits).")

        self._increment = FixedPoint(str(increment), 20)
        self.SetValue(self._value)


    def GetIncrement(self):
        """ Returns the increment for every ``EVT_FLOATSPIN`` event. """

        return self._increment


    def SetDigits(self, digits=-1):
        """
        Sets the number of digits to show.

        :param `digits`: the number of digits to show. If `digits` < 0, :class:`FloatSpin`
         tries to calculate the best number of digits based on input values passed
         in the constructor.
        """

        if digits < 0:
            incr = str(self._increment)
            if incr.find(".") < 0:
                digits = 0
            else:
                digits = len(incr[incr.find(".")+1:])

        self._digits = digits

        self.SetValue(self._value)


    def GetDigits(self):
        """ Returns the number of digits shown. """

        return self._digits


    def SetFormat(self, fmt="%f"):
        """
        Set the string format to use.

        :param `fmt`: the new string format to use. One of the following strings:

         ====== =================================
         Format Description
         ====== =================================         
         'e'    Floating point exponential format (lowercase)
         'E'    Floating point exponential format (uppercase)
         'f'    Floating point decimal format
         'F'    Floating point decimal format
         'g'    Floating point format. Uses lowercase exponential format if exponent is less than -4 or not less than precision, decimal format otherwise
         'G'    Floating point format. Uses uppercase exponential format if exponent is less than -4 or not less than precision, decimal format otherwise
         ====== =================================         

        """

        if fmt not in ["%f", "%g", "%e", "%E", "%F", "%G"]:
            raise Exception('\nERROR: Bad Float Number Format: ' + repr(fmt) + '. It Should Be ' \
                            'One Of "%f", "%g", "%e", "%E", "%F", "%G"')

        self._textformat = fmt

        if self._digits < 0:
            self.SetDigits()
        else:
            self.SetValue(self._value)


    def GetFormat(self):
        """
        Returns the string format in use.

        :see: :meth:`~FloatSpin.SetFormat` for a list of valid string formats.
        """

        return self._textformat


    def SetDefaultValue(self, defaultvalue):
        """
        Sets the :class:`FloatSpin` default value.

        :param `defaultvalue`: a floating point value representing the new default
         value for :class:`FloatSpin`.
        """

        if self.InRange(defaultvalue):
            self._defaultvalue = FixedPoint(str(defaultvalue), 20)


    def GetDefaultValue(self):
        """ Returns the :class:`FloatSpin` default value. """

        return self._defaultvalue


    def IsDefaultValue(self):
        """ Returns whether the current value is the default value or not. """

        return self._value == self._defaultvalue


    def SetToDefaultValue(self):
        """ Sets :class:`FloatSpin` value to its default value. """

        self.SetValue(self._defaultvalue)


    def SetSnapToTicks(self, forceticks=True):
        """
        Force the value to always be divisible by the increment. Initially ``False``.

        :param `forceticks`: ``True`` to force the snap to ticks option, ``False`` otherwise.
        
        :note: This uses the default value as the basis, you will get strange results
         for very large differences between the current value and default value
         when the increment is very small.
        """

        if self._snapticks != forceticks:

            self._snapticks = forceticks
            self.SetValue(self._value)


    def GetSnapToTicks(self):
        """ Returns whether the snap to ticks option is active or not. """

        return self._snapticks


    def OnFocus(self, event):
        """
        Handles the ``wx.EVT_SET_FOCUS`` event for :class:`FloatSpin`.

        :param `event`: a :class:`FocusEvent` event to be processed.
        """

        if self._textctrl:
            self._textctrl.SetFocus()

        event.Skip()


    def SyncSpinToText(self, send_event=True, force_valid=True):
        """
        Synchronize the underlying :class:`TextCtrl` with :class:`SpinButton`.

        :param `send_event`: ``True`` to send a ``EVT_FLOATSPIN`` event, ``False``
         otherwise;
        :param `force_valid`: ``True`` to force a valid value (i.e. inside the
         provided range), ``False`` otherwise.
        """

        if not self._textctrl:
            return

        curr = self._textctrl.GetValue()
        curr = curr.strip()
        decimal = locale.localeconv()["decimal_point"]
        curr = curr.replace(decimal, ".")
        curr = curr.replace(",", ".")

        if curr:
            try:
                curro = float(curr)
                curr = FixedPoint(curr, 20)
            except:
                self.SetValue(self._value)
                return

            if force_valid or not self.HasRange() or self.InRange(curr):

                if force_valid and self.HasRange():

                    curr = self.ClampValue(curr)

                if self._value != curr:
                    self.SetValue(curr)

                    if send_event:
                        self.DoSendEvent()

        elif force_valid:

            # textctrl is out of sync, discard and reset
            self.SetValue(self.GetValue())


    def SetFont(self, font=None):
        """
        Sets the underlying :class:`TextCtrl` font.

        :param `font`: a valid instance of :class:`Font`.
        """

        if font is None:
            font = wx.SystemSettings_GetFont(wx.SYS_DEFAULT_GUI_FONT)

        if not self._textctrl:
            return False

        return self._textctrl.SetFont(font)


    def GetFont(self):
        """ Returns the underlying :class:`TextCtrl` font. """

        if not self._textctrl:
            return self.GetFont()

        return self._textctrl.GetFont()


    def GetMin(self):
        """
        Returns the minimum value for :class:`FloatSpin`. It can be a
        number or ``None`` if no minimum is present.
        """

        return self._min


    def GetMax(self):
        """
        Returns the maximum value for :class:`FloatSpin`. It can be a
        number or ``None`` if no minimum is present.
        """

        return self._max


    def HasRange(self):
        """ Returns whether :class:`FloatSpin` range has been set or not. """

        return (self._min != None) or (self._max != None)


    def InRange(self, value):
        """
        Returns whether a value is inside :class:`FloatSpin` range.

        :param `value`: the value to test.
        """

        if (not self.HasRange()):
            return True
        if (self._min != None):
            if (value < self._min):
                return False
        if (self._max != None):
            if (value > self._max):
                return False
        return True


    def GetTextCtrl(self):
        """ Returns the underlying :class:`TextCtrl`. """

        return self._textctrl


    def IsFinite(self, value):
        """
        Tries to determine if a value is finite or infinite/NaN.

        :param `value`: the value to test.
        """

        try:
            snap_value = (value - self._defaultvalue)/self._increment
            finite = True
        except:
            finite = False
            snap_value = None

        return finite, snap_value


if wx.VERSION >= (3, ):

    # Use wx.SpinCtrlDouble

    EVT_FLOATSPIN = wx.EVT_SPINCTRLDOUBLE

    class FloatSpin(wx.SpinCtrlDouble):

        _spinwidth = 0

        def __init__(self, parent, id=wx.ID_ANY, pos=wx.DefaultPosition,
                     size=(95,-1), style=wx.SP_ARROW_KEYS | wx.ALIGN_RIGHT,
                     value=0.0, min_val=None, max_val=None,
                     increment=1.0, digits=-1, agwStyle=FS_LEFT,
                     name="FloatSpin"):
            if "gtk3" in wx.PlatformInfo:
                if not FloatSpin._spinwidth:
                    spin = wx.SpinCtrl(parent, -1)
                    text = wx.TextCtrl(parent, -1)
                    FloatSpin._spinwidth = spin.Size[0] - text.Size[0] + 11
                    spin.Destroy()
                    text.Destroy()
                size = size[0] + FloatSpin._spinwidth, size[1]

            if agwStyle & FS_RIGHT:
                style = style | wx.TE_RIGHT
            elif agwStyle & FS_CENTRE:
                style = style | wx.TE_CENTER

            if agwStyle & FS_READONLY:
                style = style | wx.TE_READONLY

            wx.SpinCtrlDouble.__init__(self, parent, id, str(value), pos, size,
                                       style, min_val or 0, max_val or 100,
                                       value, increment, name)
            if digits > -1:
                self.SetDigits(digits)



# Class FixedPoint, version 0.0.4.
# Released to the public domain 28-Mar-2001,
# by Tim Peters (tim.one@home.com).

# Provided as-is; use at your own risk; no warranty; no promises; enjoy!


# 28-Mar-01 ver 0.0,4
#     Use repr() instead of str() inside __str__, because str(long) changed
#     since this was first written (used to produce trailing "L", doesn't
#     now).
#
# 09-May-99 ver 0,0,3
#     Repaired __sub__(FixedPoint, string); was blowing up.
#     Much more careful conversion of float (now best possible).
#     Implemented exact % and divmod.
#
# 14-Oct-98 ver 0,0,2
#     Added int, long, frac.  Beefed up docs.  Removed DECIMAL_POINT
#     and MINUS_SIGN globals to discourage bloating this class instead
#     of writing formatting wrapper classes (or subclasses)
#
# 11-Oct-98 ver 0,0,1
#     posted to c.l.py

__version__ = 0, 0, 4

# The default value for the number of decimal digits carried after the
# decimal point.  This only has effect at compile-time.
DEFAULT_PRECISION = 2
""" The default value for the number of decimal digits carried after the decimal point.  This only has effect at compile-time. """

class FixedPoint(object):
    """
    FixedPoint objects support decimal arithmetic with a fixed number of
    digits (called the object's precision) after the decimal point.  The
    number of digits before the decimal point is variable & unbounded.

    The precision is user-settable on a per-object basis when a FixedPoint
    is constructed, and may vary across FixedPoint objects.  The precision
    may also be changed after construction via `FixedPoint.set_precision(p)`.
    Note that if the precision of a FixedPoint is reduced via :meth:`FixedPoint.set_precision() <FixedPoint.set_precision>`,
    information may be lost to rounding.

    Example::    

        >>> x = FixedPoint("5.55")  # precision defaults to 2
        >>> print x
        5.55
        >>> x.set_precision(1)      # round to one fraction digit
        >>> print x
        5.6
        >>> print FixedPoint("5.55", 1)  # same thing setting to 1 in constructor
        5.6
        >>> repr(x) #  returns constructor string that reproduces object exactly
        "FixedPoint('5.6', 1)"
        >>>


    When :class:`FixedPoint` objects of different precision are combined via + - * /,
    the result is computed to the larger of the inputs' precisions, which also
    becomes the precision of the resulting :class:`FixedPoint` object. Example::

        >>> print FixedPoint("3.42") + FixedPoint("100.005", 3)
        103.425
        >>>


    When a :class:`FixedPoint` is combined with other numeric types (ints, floats,
    strings representing a number) via + - * /, then similarly the computation
    is carried out using -- and the result inherits -- the :class:`FixedPoint`'s
    precision. Example::

        >>> print FixedPoint(1) / 7
        0.14
        >>> print FixedPoint(1, 30) / 7
        0.142857142857142857142857142857
        >>>


    The string produced by `str(x)` (implictly invoked by `print`) always
    contains at least one digit before the decimal point, followed by a
    decimal point, followed by exactly `x.get_precision()` digits.  If `x` is
    negative, `str(x)[0] == "-"`.

    The :class:`FixedPoint` constructor can be passed an int, long, string, float,
    :class:`FixedPoint`, or any object convertible to a float via `float()` or to a
    long via `long()`. Passing a precision is optional; if specified, the
    precision must be a non-negative int. There is no inherent limit on
    the size of the precision, but if very very large you'll probably run
    out of memory.

    Note that conversion of floats to :class:`FixedPoint` can be surprising, and
    should be avoided whenever possible. Conversion from string is exact
    (up to final rounding to the requested precision), so is greatly
    preferred. Example::

        >>> print FixedPoint(1.1e30)
        1099999999999999993725589651456.00
        >>> print FixedPoint("1.1e30")
        1100000000000000000000000000000.00
        >>>


    """

    # the exact value is self.n / 10**self.p;
    # self.n is a long; self.p is an int

    def __init__(self, value=0, precision=DEFAULT_PRECISION):
        """
        Default class constructor.

        :param `value`: the initial value;
        :param `precision`: must be an int >= 0, and defaults to ``DEFAULT_PRECISION``.
        """
        
        self.n = self.p = 0
        self.set_precision(precision)
        p = self.p

        if isinstance(value, type("42.3e5")):
            n, exp = _string2exact(value)
            # exact value is n*10**exp = n*10**(exp+p)/10**p
            effective_exp = exp + p
            if effective_exp > 0:
                n = n * _tento(effective_exp)
            elif effective_exp < 0:
                n = _roundquotient(n, _tento(-effective_exp))
            self.n = n
            return

        if isinstance(value, type(42)) or isinstance(value, type(42L)):
            self.n = long(value) * _tento(p)
            return

        if isinstance(value, FixedPoint):
            temp = value.copy()
            temp.set_precision(p)
            self.n, self.p = temp.n, temp.p
            return

        if isinstance(value, type(42.0)):
            # XXX ignoring infinities and NaNs and overflows for now
            import math
            f, e = math.frexp(abs(value))
            assert f == 0 or 0.5 <= f < 1.0
            # |value| = f * 2**e exactly

            # Suck up CHUNK bits at a time; 28 is enough so that we suck
            # up all bits in 2 iterations for all known binary double-
            # precision formats, and small enough to fit in an int.
            CHUNK = 28
            top = 0L
            # invariant: |value| = (top + f) * 2**e exactly
            while f:
                f = math.ldexp(f, CHUNK)
                digit = int(f)
                assert digit >> CHUNK == 0
                top = (top << CHUNK) | digit
                f = f - digit
                assert 0.0 <= f < 1.0
                e = e - CHUNK

            # now |value| = top * 2**e exactly
            # want n such that n / 10**p = top * 2**e, or
            # n = top * 10**p * 2**e
            top = top * _tento(p)
            if e >= 0:
                n = top << e
            else:
                n = _roundquotient(top, 1L << -e)
            if value < 0:
                n = -n
            self.n = n
            return

        if isinstance(value, type(42-42j)):
            raise TypeError("can't convert complex to FixedPoint: " +
                            `value`)

        # can we coerce to a float?
        yes = 1
        try:
            asfloat = float(value)
        except:
            yes = 0
        if yes:
            self.__init__(asfloat, p)
            return

        # similarly for long
        yes = 1
        try:
            aslong = long(value)
        except:
            yes = 0
        if yes:
            self.__init__(aslong, p)
            return

        raise TypeError("can't convert to FixedPoint: " + `value`)


    def get_precision(self):
        """
        Return the precision of this :class:`FixedPoint`.

        :note: The precision is the number of decimal digits carried after
         the decimal point, and is an int >= 0.
        """

        return self.p


    def set_precision(self, precision=DEFAULT_PRECISION):
        """
        Change the precision carried by this :class:`FixedPoint` to `precision`.

        :param `precision`: must be an int >= 0, and defaults to
         ``DEFAULT_PRECISION``.

        :note: If `precision` is less than this :class:`FixedPoint`'s current precision,
         information may be lost to rounding.
        """

        try:
            p = int(precision)
        except:
            raise TypeError("precision not convertable to int: " +
                            `precision`)
        if p < 0:
            raise ValueError("precision must be >= 0: " + `precision`)

        if p > self.p:
            self.n = self.n * _tento(p - self.p)
        elif p < self.p:
            self.n = _roundquotient(self.n, _tento(self.p - p))
        self.p = p


    def __str__(self):
        
        n, p = self.n, self.p
        i, f = divmod(abs(n), _tento(p))
        if p:
            frac = repr(f)[:-1]
            frac = "0" * (p - len(frac)) + frac
        else:
            frac = ""
        return "-"[:n<0] + \
               repr(i)[:-1] + \
               "." + frac


    def __repr__(self):

        return "FixedPoint" + `(str(self), self.p)`


    def copy(self):
        """ Create a copy of the current :class:`FixedPoint`. """
        
        return _mkFP(self.n, self.p)

    __copy__ = __deepcopy__ = copy


    def __cmp__(self, other):
        
        if (other is None):
            return 1
        xn, yn, p = _norm(self, other)
        return cmp(xn, yn)


    def __hash__(self):
        # caution!  == values must have equal hashes, and a FixedPoint
        # is essentially a rational in unnormalized form.  There's
        # really no choice here but to normalize it, so hash is
        # potentially expensive.
        n, p = self.__reduce()

        # Obscurity: if the value is an exact integer, p will be 0 now,
        # so the hash expression reduces to hash(n).  So FixedPoints
        # that happen to be exact integers hash to the same things as
        # their int or long equivalents.  This is Good.  But if a
        # FixedPoint happens to have a value exactly representable as
        # a float, their hashes may differ.  This is a teensy bit Bad.
        return hash(n) ^ hash(p)

    def __nonzero__(self):
        return self.n != 0

    def __neg__(self):
        return _mkFP(-self.n, self.p)

    def __abs__(self):
        if self.n >= 0:
            return self.copy()
        else:
            return -self

    def __add__(self, other):
        n1, n2, p = _norm(self, other)
        # n1/10**p + n2/10**p = (n1+n2)/10**p
        return _mkFP(n1 + n2, p)

    __radd__ = __add__

    def __sub__(self, other):
        if not isinstance(other, FixedPoint):
            other = FixedPoint(other, self.p)
        return self.__add__(-other)

    def __rsub__(self, other):
        return (-self) + other

    def __mul__(self, other):
        n1, n2, p = _norm(self, other)
        # n1/10**p * n2/10**p = (n1*n2/10**p)/10**p
        return _mkFP(_roundquotient(n1 * n2, _tento(p)), p)

    __rmul__ = __mul__

    def __div__(self, other):
        n1, n2, p = _norm(self, other)
        if n2 == 0:
            raise ZeroDivisionError("FixedPoint division")
        if n2 < 0:
            n1, n2 = -n1, -n2
        # n1/10**p / (n2/10**p) = n1/n2 = (n1*10**p/n2)/10**p
        return _mkFP(_roundquotient(n1 * _tento(p), n2), p)

    def __rdiv__(self, other):
        n1, n2, p = _norm(self, other)
        return _mkFP(n2, p) / self

    def __divmod__(self, other):
        n1, n2, p = _norm(self, other)
        if n2 == 0:
            raise ZeroDivisionError("FixedPoint modulo")
        # floor((n1/10**p)/(n2*10**p)) = floor(n1/n2)
        q = n1 / n2
        # n1/10**p - q * n2/10**p = (n1 - q * n2)/10**p
        return q, _mkFP(n1 - q * n2, p)

    def __rdivmod__(self, other):
        n1, n2, p = _norm(self, other)
        return divmod(_mkFP(n2, p), self)

    def __mod__(self, other):
        return self.__divmod__(other)[1]

    def __rmod__(self, other):
        n1, n2, p = _norm(self, other)
        return _mkFP(n2, p).__mod__(self)

    # caution! float can lose precision
    def __float__(self):
        n, p = self.__reduce()
        return float(n) / float(_tento(p))

    # XXX should this round instead?
    # XXX note e.g. long(-1.9) == -1L and long(1.9) == 1L in Python
    # XXX note that __int__ inherits whatever __long__ does,
    # XXX and .frac() is affected too
    def __long__(self):
        answer = abs(self.n) / _tento(self.p)
        if self.n < 0:
            answer = -answer
        return answer

    def __int__(self):
        return int(self.__long__())

    def frac(self):
        """
        Returns fractional portion as a :class:`FixedPoint`.

        :note: In :class:`FixedPoint`,
        
         this equality holds true::
        
                x = x.frac() + long(x)

            
        """
        return self - long(self)

    # return n, p s.t. self == n/10**p and n % 10 != 0
    def __reduce(self):
        n, p = self.n, self.p
        if n == 0:
            p = 0
        while p and n % 10 == 0:
            p = p - 1
            n = n / 10
        return n, p

# return 10L**n

def _tento(n, cache={}):
    try:
        return cache[n]
    except KeyError:
        answer = cache[n] = 10L ** n
        return answer

# return xn, yn, p s.t.
# p = max(x.p, y.p)
# x = xn / 10**p
# y = yn / 10**p
#
# x must be FixedPoint to begin with; if y is not FixedPoint,
# it inherits its precision from x.
#
# Note that this is called a lot, so default-arg tricks are helpful.

def _norm(x, y, isinstance=isinstance, FixedPoint=FixedPoint,
                _tento=_tento):
    assert isinstance(x, FixedPoint)
    if not isinstance(y, FixedPoint):
        y = FixedPoint(y, x.p)
    xn, yn = x.n, y.n
    xp, yp = x.p, y.p
    if xp > yp:
        yn = yn * _tento(xp - yp)
        p = xp
    elif xp < yp:
        xn = xn * _tento(yp - xp)
        p = yp
    else:
        p = xp  # same as yp
    return xn, yn, p

def _mkFP(n, p, FixedPoint=FixedPoint):
    f = FixedPoint()
    f.n = n
    f.p = p
    return f

# divide x by y, rounding to int via nearest-even
# y must be > 0
# XXX which rounding modes are useful?

def _roundquotient(x, y):
    assert y > 0
    n, leftover = divmod(x, y)
    c = cmp(leftover << 1, y)
    # c < 0 <-> leftover < y/2, etc
    if c > 0 or (c == 0 and (n & 1) == 1):
        n = n + 1
    return n

# crud for parsing strings
import re

# There's an optional sign at the start, and an optional exponent
# at the end.  The exponent has an optional sign and at least one
# digit.  In between, must have either at least one digit followed
# by an optional fraction, or a decimal point followed by at least
# one digit.  Yuck.

_parser = re.compile(r"""
    \s*
    (?P<sign>[-+])?
    (
        (?P<int>\d+) (\. (?P<frac>\d*))?
    |
        \. (?P<onlyfrac>\d+)
    )
    ([eE](?P<exp>[-+]? \d+))?
    \s* $
""", re.VERBOSE).match

del re

# return n, p s.t. float string value == n * 10**p exactly

def _string2exact(s):
    m = _parser(s)
    if m is None:
        raise ValueError("can't parse as number: " + `s`)

    exp = m.group('exp')
    if exp is None:
        exp = 0
    else:
        exp = int(exp)

    intpart = m.group('int')
    if intpart is None:
        intpart = "0"
        fracpart = m.group('onlyfrac')
    else:
        fracpart = m.group('frac')
        if fracpart is None or fracpart == "":
            fracpart = "0"
    assert intpart
    assert fracpart

    i, f = long(intpart), long(fracpart)
    nfrac = len(fracpart)
    i = i * _tento(nfrac) + f
    exp = exp - nfrac

    if m.group('sign') == "-":
        i = -i

    return i, exp

def get_all_keyboard_focusable_children(parent):
    """
    Get all keyboard focusable children of parent
    
    """

    children = []
    try:
        iter(parent.Children)
        # Under Mac OS X panels may have non-iterator children
    except:
        pass
    else:
        for child in parent.Children:
            if child.Enabled and child.IsShownOnScreen():
                if child.AcceptsFocusFromKeyboard():
                    if not isinstance(child, wx.RadioButton) or child.Value:
                        children.append(child)
                if child.Children:
                    children.extend(get_all_keyboard_focusable_children(child))
    return children

def focus_next_keyboard_focusable_control(control):
    """
    Focus the next control in tab order that can gain focus.
    
    If the shift key is held down, tab order is reversed.
    
    """

    # Find the last panel in the hierarchy of parents
    parent = control.Parent
    focusparent = None
    while parent:
        if isinstance(parent, (wx.Panel, wx.PyPanel)):
            focusparent = parent
        parent = parent.Parent
    if focusparent:
        children = get_all_keyboard_focusable_children(focusparent)
        if wx.GetKeyState(wx.WXK_SHIFT):
            children = list(reversed(children))
        for i, child in enumerate(children):
            if child is control:
                for next in children[i + 1:] + children[:i]:
                    if next is not child.Parent:
                        next.SetFocus()
                        break
                break
