Module wx.lib.masked.maskededit

contains MaskedEditMixin class that drives all the other masked controls.

====================
Masked Edit Overview
====================

masked.TextCtrl:
    is a sublassed text control that can carefully control the user's input
    based on a mask string you provide.

    General usage example::

        control = masked.TextCtrl( win, -1, '', mask = '(###) ###-####')

    The example above will create a text control that allows only numbers to be
    entered and then only in the positions indicated in the mask by the # sign.

masked.ComboBox:
    is a similar subclass of wxComboBox that allows the same sort of masking,
    but also can do auto-complete of values, and can require the value typed
    to be in the list of choices to be colored appropriately.

masked.Ctrl:
    is actually a factory function for several types of masked edit controls:

    =================   ==================================================
    masked.TextCtrl     standard masked edit text box
    masked.ComboBox     adds combobox capabilities
    masked.IpAddrCtrl   adds special semantics for IP address entry
    masked.TimeCtrl     special subclass handling lots of types as values
    masked.NumCtrl      special subclass handling numeric values
    =================   ==================================================

    It works by looking for a *controlType* parameter in the keyword
    arguments of the control, to determine what kind of instance to return.
    If not specified as a keyword argument, the default control type returned
    will be masked.TextCtrl.

    Each of the above classes has its own set of arguments, but masked.Ctrl
    provides a single "unified" interface for masked controls.

What follows is a description of how to configure the generic masked.TextCtrl
and masked.ComboBox;  masked.NumCtrl and masked.TimeCtrl have their own demo 
pages and interface descriptions.

=========================

Initialization Parameters
-------------------------
mask
    Allowed mask characters and function:

    =========  ==========================================================
    Character   Function
    =========  ==========================================================
        #       Allow numeric only (0-9)
        N       Allow letters and numbers (0-9)
        A       Allow uppercase letters only
        a       Allow lowercase letters only
        C       Allow any letter, upper or lower
        X       Allow string.letters, string.punctuation, string.digits
        &       Allow string.punctuation only (doesn't include all unicode symbols)
        \*       Allow any visible character
        |       explicit field boundary (takes no space in the control; allows mix
                of adjacent mask characters to be treated as separate fields,
                eg: '&|###' means "field 0 = '&', field 1 = '###'", but there's
                no fixed characters in between.
    =========  ==========================================================


    These controls define these sets of characters using string.letters,
    string.uppercase, etc.  These sets are affected by the system locale
    setting, so in order to have the masked controls accept characters
    that are specific to your users' language, your application should
    set the locale.
    For example, to allow international characters to be used in the
    above masks, you can place the following in your code as part of
    your application's initialization code::

      import locale
      locale.setlocale(locale.LC_ALL, '')

    The controls now also support (by popular demand) all "visible" characters,
    by use of the * mask character, including unicode characters above
    the standard ANSI keycode range.
    Note:  As string.punctuation doesn't typically include all unicode
    symbols, you will have to use includechars to get some of these into 
    otherwise restricted positions in your control, such as those specified
    with &.

  Using these mask characters, a variety of template masks can be built. See
  the demo for some other common examples include date+time, social security
  number, etc.  If any of these characters are needed as template rather
  than mask characters, they can be escaped with \, ie. \N means "literal N".
  (use \ for literal backslash, as in: r'CCC\NNN'.)


  *Note:*
      Masks containing only # characters and one optional decimal point
      character are handled specially, as "numeric" controls.  Such
      controls have special handling for typing the '-' key, handling
      the "decimal point" character as truncating the integer portion,
      optionally allowing grouping characters and so forth.
      There are several parameters and format codes that only make sense
      when combined with such masks, eg. groupChar, decimalChar, and so
      forth (see below).  These allow you to construct reasonable
      numeric entry controls.

  *Note:*
      Changing the mask for a control deletes any previous field classes
      (and any associated validation or formatting constraints) for them.

useFixedWidthFont
  By default, masked edit controls use a fixed width font, so that
  the mask characters are fixed within the control, regardless of
  subsequent modifications to the value.  Set to False if having
  the control font be the same as other controls is required. (This is
  a control-level parameter.)

defaultEncoding
  (Applies to unicode systems only) By default, the default unicode encoding
  used is latin1, or iso-8859-1.  If necessary, you can set this control-level
  parameter to govern the codec used to decode your keyboard inputs.
  (This is a control-level parameter.)

formatcodes
  These other properties can be passed to the class when instantiating it:
    Formatcodes are specified as a string of single character formatting
    codes that modify  behavior of the control::
    
            _  Allow spaces
            !  Force upper
            ^  Force lower
            R  Right-align field(s)
            r  Right-insert in field(s) (implies R)
            <  Stay in field until explicit navigation out of it

            >  Allow insert/delete within partially filled fields (as
               opposed to the default "overwrite" mode for fixed-width
               masked edit controls.)  This allows single-field controls
               or each field within a multi-field control to optionally
               behave more like standard text controls.
               (See EMAIL or phone number autoformat examples.)

               *Note: This also governs whether backspace/delete operations
               shift contents of field to right of cursor, or just blank the
               erased section.

               Also, when combined with 'r', this indicates that the field
               or control allows right insert anywhere within the current
               non-empty value in the field.  (Otherwise right-insert behavior
               is only performed to when the entire right-insertable field is
               selected or the cursor is at the right edge of the field.*


            ,  Allow grouping character in integer fields of numeric controls
               and auto-group/regroup digits (if the result fits) when leaving
               such a field.  (If specified, .SetValue() will attempt to
               auto-group as well.)
               ',' is also the default grouping character.  To change the
               grouping character and/or decimal character, use the groupChar
               and decimalChar parameters, respectively.
               Note: typing the "decimal point" character in such fields will
               clip the value to that left of the cursor for integer
               fields of controls with "integer" or "floating point" masks.
               If the ',' format code is specified, this will also cause the
               resulting digits to be regrouped properly, using the current
               grouping character.
            -  Prepend and reserve leading space for sign to mask and allow
               signed values (negative #s shown in red by default.) Can be
               used with argument useParensForNegatives (see below.)
            0  integer fields get leading zeros
            D  Date[/time] field
            T  Time field
            F  Auto-Fit: the control calulates its size from
               the length of the template mask
            V  validate entered chars against validRegex before allowing them
               to be entered vs. being allowed by basic mask and then having
               the resulting value just colored as invalid.
               (See USSTATE autoformat demo for how this can be used.)
            S  select entire field when navigating to new field

fillChar

defaultValue
  These controls have two options for the initial state of the control.
  If a blank control with just the non-editable characters showing
  is desired, simply leave the constructor variable fillChar as its
  default (' ').  If you want some other character there, simply
  change the fillChar to that value.  Note: changing the control's fillChar
  will implicitly reset all of the fields' fillChars to this value.

  If you need different default characters in each mask position,
  you can specify a defaultValue parameter in the constructor, or
  set them for each field individually.
  This value must satisfy the non-editable characters of the mask,
  but need not conform to the replaceable characters.

groupChar

decimalChar
  These parameters govern what character is used to group numbers
  and is used to indicate the decimal point for numeric format controls.
  The default groupChar is ',', the default decimalChar is '.'
  By changing these, you can customize the presentation of numbers
  for your location.

  Eg::

        formatcodes = ',', groupChar='''                  allows  12'345.34
        formatcodes = ',', groupChar='.', decimalChar=','  allows  12.345,34

  (These are control-level parameters.)

shiftDecimalChar
  The default "shiftDecimalChar" (used for "backwards-tabbing" until
  shift-tab is fixed in wxPython) is '>' (for QUERTY keyboards.) for
  other keyboards, you may want to customize this, eg '?' for shift ',' on
  AZERTY keyboards, ':' or ';' for other European keyboards, etc.
  (This is a control-level parameter.)

useParensForNegatives=False
  This option can be used with signed numeric format controls to
  indicate signs via () rather than '-'.
  (This is a control-level parameter.)

autoSelect=False
  This option can be used to have a field or the control try to
  auto-complete on each keystroke if choices have been specified.

autoCompleteKeycodes=[]
  By default, DownArrow, PageUp and PageDown will auto-complete a
  partially entered field.  Shift-DownArrow, Shift-UpArrow, PageUp
  and PageDown will also auto-complete, but if the field already
  contains a matched value, these keys will cycle through the list
  of choices forward or backward as appropriate.  Shift-Up and
  Shift-Down also take you to the next/previous field after any
  auto-complete action.

  Additional auto-complete keys can be specified via this parameter.
  Any keys so specified will act like PageDown.
  (This is a control-level parameter.)



Validating User Input
=====================
There are a variety of initialization parameters that are used to validate
user input.  These parameters can apply to the control as a whole, and/or
to individual fields:

        =====================  ==================================================================
        excludeChars           A string of characters to exclude even if otherwise allowed
        includeChars           A string of characters to allow even if otherwise disallowed
        validRegex             Use a regular expression to validate the contents of the text box
        validRange             Pass a rangeas list (low,high) to limit numeric fields/values
        choices                A list of strings that are allowed choices for the control.
        choiceRequired         value must be member of choices list
        compareNoCase          Perform case-insensitive matching when validating against list
                               *Note: for masked.ComboBox, this defaults to True.*
        emptyInvalid           Boolean indicating whether an empty value should be considered 
                               invalid

        validFunc              A function to call of the form: bool = func(candidate_value)
                               which will return True if the candidate_value satisfies some
                               external criteria for the control in addition to the the
                               other validation, or False if not.  (This validation is
                               applied last in the chain of validations.)

        validRequired          Boolean indicating whether or not keys that are allowed by the
                               mask, but result in an invalid value are allowed to be entered
                               into the control.  Setting this to True implies that a valid
                               default value is set for the control.

        retainFieldValidation  False by default; if True, this allows individual fields to
                               retain their own validation constraints independently of any
                               subsequent changes to the control's overall parameters.
                               (This is a control-level parameter.)

        validator              Validators are not normally needed for masked controls, because
                               of the nature of the validation and control of input.  However,
                               you can supply one to provide data transfer routines for the
                               controls.
        raiseOnInvalidPaste    False by default; normally a bad paste simply is ignored with a bell;
                               if True, this will cause a ValueError exception to be thrown,
                               with the .value attribute of the exception containing the bad value.
        =====================  ==================================================================


Coloring Behavior
=================
  The following parameters have been provided to allow you to change the default
  coloring behavior of the control.   These can be set at construction, or via
  the .SetCtrlParameters() function.  Pass a color as string e.g. 'Yellow':

        ========================  =======================================================================
        emptyBackgroundColour      Control Background color when identified as empty. Default=White
        invalidBackgroundColour    Control Background color when identified as Not valid. Default=Yellow
        validBackgroundColour      Control Background color when identified as Valid. Default=white
        ========================  =======================================================================


  The following parameters control the default foreground color coloring behavior of the
  control. Pass a color as string e.g. 'Yellow':

        ========================  ======================================================================
        foregroundColour           Control foreground color when value is not negative.  Default=Black
        signedForegroundColour     Control foreground color when value is negative. Default=Red
        ========================  ======================================================================


Fields
======
  Each part of the mask that allows user input is considered a field.  The fields
  are represented by their own class instances.  You can specify field-specific
  constraints by constructing or accessing the field instances for the control
  and then specifying those constraints via parameters.

fields
  This parameter allows you to specify Field instances containing
  constraints for the individual fields of a control, eg: local
  choice lists, validation rules, functions, regexps, etc.
  It can be either an ordered list or a dictionary.  If a list,
  the fields will be applied as fields 0, 1, 2, etc.
  If a dictionary, it should be keyed by field index.
  the values should be a instances of maskededit.Field.

  Any field not represented by the list or dictionary will be
  implicitly created by the control.

  Eg::

    fields = [ Field(formatcodes='_r'), Field('choices=['a', 'b', 'c']) ]
    
  Or::

    fields = {
               1: ( Field(formatcodes='_R', choices=['a', 'b', 'c']),
               3: ( Field(choices=['01', '02', '03'], choiceRequired=True)
             }

  The following parameters are available for individual fields, with the
  same semantics as for the whole control but applied to the field in question:

    ==============  =============================================================================
    fillChar        if set for a field, it will override the control's fillChar for that field
    groupChar       if set for a field, it will override the control's default
    defaultValue    sets field-specific default value; overrides any default from control
    compareNoCase   overrides control's settings
    emptyInvalid    determines whether field is required to be filled at all times
    validRequired   if set, requires field to contain valid value
    ==============  =============================================================================

  If any of the above parameters are subsequently specified for the control as a
  whole, that new value will be propagated to each field, unless the
  retainFieldValidation control-level parameter is set.

    ==============  ==============================
    formatcodes      Augments control's settings
    excludeChars         '       '        '
    includeChars         '       '        '
    validRegex           '       '        '
    validRange           '       '        '
    choices              '       '        '
    choiceRequired       '       '        '
    validFunc            '       '        '
    ==============  ==============================



Control Class Functions
=======================
.GetPlainValue(value=None)
                    Returns the value specified (or the control's text value
                    not specified) without the formatting text.
                    In the example above, might return phone no='3522640075',
                    whereas control.GetValue() would return '(352) 264-0075'
.ClearValue()
                    Returns the control's value to its default, and places the
                    cursor at the beginning of the control.
.SetValue()
                    Does "smart replacement" of passed value into the control, as does
                    the .Paste() method.  As with other text entry controls, the
                    .SetValue() text replacement begins at left-edge of the control,
                    with missing mask characters inserted as appropriate.
                    .SetValue will also adjust integer, float or date mask entry values,
                    adding commas, auto-completing years, etc. as appropriate.
                    For "right-aligned" numeric controls, it will also now automatically
                    right-adjust any value whose length is less than the width of the
                    control before attempting to set the value.
                    If a value does not follow the format of the control's mask, or will
                    not fit into the control, a ValueError exception will be raised.

                    Eg::

                      mask = '(###) ###-####'
                          .SetValue('1234567890')           => '(123) 456-7890'
                          .SetValue('(123)4567890')         => '(123) 456-7890'
                          .SetValue('(123)456-7890')        => '(123) 456-7890'
                          .SetValue('123/4567-890')         => illegal paste; ValueError

                      mask = '#{6}.#{2}', formatcodes = '_,-',
                          .SetValue('111')                  => ' 111   .  '
                          .SetValue(' %9.2f' % -111.12345 ) => '   -111.12'
                          .SetValue(' %9.2f' % 1234.00 )    => '  1,234.00'
                          .SetValue(' %9.2f' % -1234567.12345 ) => insufficient room; ValueError

                      mask = '#{6}.#{2}', formatcodes = '_,-R'  # will right-adjust value for right-aligned control
                          .SetValue('111')                  => padded value misalignment ValueError: "       111" will not fit
                          .SetValue('%.2f' % 111 )          => '    111.00'
                          .SetValue('%.2f' % -111.12345 )   => '   -111.12'


.IsValid(value=None)
                    Returns True if the value specified (or the value of the control
                    if not specified) passes validation tests
.IsEmpty(value=None)
                    Returns True if the value specified (or the value of the control
                    if not specified) is equal to an "empty value," ie. all
                    editable characters == the fillChar for their respective fields.
.IsDefault(value=None)
                    Returns True if the value specified (or the value of the control
                    if not specified) is equal to the initial value of the control.

.Refresh()
                    Recolors the control as appropriate to its current settings.

.SetCtrlParameters(\*\*kwargs)
                    This function allows you to set up and/or change the control parameters
                    after construction; it takes a list of key/value pairs as arguments,
                    where the keys can be any of the mask-specific parameters in the constructor.

                    Eg::

                        ctl = masked.TextCtrl( self, -1 )
                        ctl.SetCtrlParameters( mask='###-####',
                                               defaultValue='555-1212',
                                               formatcodes='F')

.GetCtrlParameter(parametername)
                    This function allows you to retrieve the current value of a parameter
                    from the control.

  *Note:* Each of the control parameters can also be set using its
      own Set and Get function.  These functions follow a regular form:
      All of the parameter names start with lower case; for their
      corresponding Set/Get function, the parameter name is capitalized.

    Eg::

          ctl.SetMask('###-####')
          ctl.SetDefaultValue('555-1212')
          ctl.GetChoiceRequired()
          ctl.GetFormatcodes()

  *Note:* After any change in parameters, the choices for the
      control are reevaluated to ensure that they are still legal.  If you
      have large choice lists, it is therefore more efficient to set parameters
      before setting the choices available.

.SetFieldParameters(field_index, \*\*kwargs)
                    This function allows you to specify change individual field
                    parameters after construction. (Indices are 0-based.)

.GetFieldParameter(field_index, parametername)
                    Allows the retrieval of field parameters after construction


The control detects certain common constructions. In order to use the signed feature
(negative numbers and coloring), the mask has to be all numbers with optionally one
decimal point. Without a decimal (e.g. '######', the control will treat it as an integer
value. With a decimal (e.g. '###.##'), the control will act as a floating point control
(i.e. press decimal to 'tab' to the decimal position). Pressing decimal in the
integer control truncates the value.  However, for a true numeric control,
masked.NumCtrl provides all this, and true numeric input/output support as well.


Check your controls by calling each control's .IsValid() function and the
.IsEmpty() function to determine which controls have been a) filled in and
b) filled in properly.


Regular expression validations can be used flexibly and creatively.
Take a look at the demo; the zip-code validation succeeds as long as the
first five numerals are entered. the last four are optional, but if
any are entered, there must be 4 to be valid.

masked.Ctrl Configuration
=========================
masked.Ctrl works by looking for a special *controlType*
parameter in the variable arguments of the control, to determine
what kind of instance to return.
controlType can be one of::

    controlTypes.TEXT
    controlTypes.COMBO
    controlTypes.IPADDR
    controlTypes.TIME
    controlTypes.NUMBER

These constants are also available individually, ie, you can
use either of the following::

    from wxPython.wx.lib.masked import MaskedCtrl, controlTypes
    from wxPython.wx.lib.masked import MaskedCtrl, COMBO, TEXT, NUMBER, IPADDR

If not specified as a keyword argument, the default controlType is
controlTypes.TEXT.