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<h1 ALIGN=
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</h1>
<center><IMG SRC=EntryField.gif
ALT=
"" WIDTH=
313 HEIGHT=
177></center>
<dt> <h3>Name
</h3></dt><dd>
entry widget with validation
<dt> <h3>Inherits
</h3></dt><dd>
<a href=
"MegaWidget.html">Pmw.MegaWidget
</a><br>
<dt> <h3>Description
</h3></dt><dd>
An entry field contains an entry widget with optional validation of
various kinds. Built-in validation may be used, such as
<strong>integer
</strong>,
<strong>real
</strong>,
<strong>time
</strong> or
<strong>date
</strong>, or an external validation
function may be supplied. If valid text is entered, it will be
displayed with the normal background. If invalid text is entered,
it is not displayed and the previously displayed text is restored.
If partially valid text is entered, it will be displayed with a
background color to indicate it is in error. An example of
partially valid
<strong>real
</strong> text is
<strong>'-.'
</strong>, which may be the first two
charactes of the valid string
<strong>'-
.5'
</strong>. Some validators, such as
<strong>date
</strong>, have a relaxed interpretation of partial validity, which
allows the user flexibility in how they enter the text.
</p><p> Validation is performed
<em>early
</em>, at each keystroke or other event
which modifies the text. However, if partially valid text is
permitted, the validity of the entered text can be checked just
before it is to be used, which is a form of
<em>late
</em> validation.
</p><p> Minimum and maximum values may be specified. Some validators also
accept other specifications, such as date and time formats and
<dt> <h3>Validation function return values
</h3></dt><dd>
Validation is performed by a function which takes as its first
argument the entered text and returns one of three standard
values, indicating whether the text is valid:
</p><dl><dt><strong>Pmw.OK
</strong></dt><dd>The text is valid.
<p></p>
<dt><strong>Pmw.ERROR
</strong></dt><dd>The text is invalid and is not acceptable for
display. In this case the entry will be restored to its
<dt><strong>Pmw.PARTIAL
</strong></dt><dd>The text is partially valid and is acceptable
for display. In this case the text will be displayed
using the
<strong>errorbackground
</strong> color.
<p></p><dt> <h3>Options
</h3></dt><dd>
Options for this megawidget and its base
classes are described below.
<p></p><a name=option.command
></a>
This specifies a function to call whenever the
<strong><Return
></strong> key is
pressed or
<code>invoke()
</code> is called. The default is
<strong>None
</strong>.
</p><a name=option.errorbackground
></a>
<dl><dt> <strong>errorbackground
Specifies the background color to use when displaying invalid or
partially valid text. The default is
<strong>'pink'
</strong>.
</p><a name=option.extravalidators
></a>
<dl><dt> <strong>extravalidators
This is a dictionary of extra validators. The keys are the names
of validators which may be used in a future call to the
<strong>validate
</strong> option. Each value in the dictionary is a tuple of
(
<em>validate_function
</em>,
<em>stringtovalue_function
</em>).
</p><p> The
<em>validate_function
</em> is used to implement the validation and
the
<em>stringtovalue_function
</em> is used to convert the entry input
into a value which can be compared with the minimum and maximum
limits. These functions are as described for the
<strong>validate
</strong><p> If either of these is not given as a function, it is assumed to be
the name of one of the other extra validators or one of the
standard validators. The alias search is performed when the
<strong>validate
</strong> option is configured, not when the
<strong>extravalidators
</strong>
option is configured or when the
<strong>validate
</strong> function is called.
</p><p> If the name of one of the extra validators is the same as one of
the standard validators, the extra validator takes precedence. The default is
<strong>{}
</strong>.
</p><a name=option.invalidcommand
></a>
<dl><dt> <strong>invalidcommand
This is executed when invalid text is entered and the text is
restored to its previous value (that is, when the
<strong>validate
</strong> function returns
<strong>Pmw.ERROR
</strong>). It is also called if an attempt is
made to set invalid text in a call to
<code>setentry()
</code>. The default
is
<strong>self.bell
</strong>.
</p><a name=option.labelmargin
></a>
<dl><dt> <strong>labelmargin
Initialisation option. If the
<strong>labelpos
</strong> option is not
<strong>None
</strong>, this specifies the
distance between the
<strong>label
</strong> component and the rest of the
megawidget. The default is
<strong>0</strong>.
</p><a name=option.labelpos
></a>
<dl><dt> <strong>labelpos
Initialisation option. Specifies where to place the
<strong>label
</strong> component. If not
<strong>None
</strong>, it should be a concatenation of one or two of the
letters
<strong>'n'
</strong>,
<strong>'s'
</strong>,
<strong>'e'
</strong> and
<strong>'w'
</strong>. The first letter
specifies on which side of the megawidget to place the label.
If a second letter is specified, it indicates where on that
side to place the label. For example, if
<strong>labelpos
</strong> is
<strong>'w'
</strong>,
the label is placed in the center of the left hand side; if
it is
<strong>'wn'
</strong>, the label is placed at the top of the left
hand side; if it is
<strong>'ws'
</strong>, the label is placed at the
bottom of the left hand side.
</p><p> If
<strong>None
</strong>, a label component is not created. The default is
<strong>None
</strong>.
</p>
<a name=option.modifiedcommand
></a>
<dl><dt> <strong>modifiedcommand
This is called whenever the text of the entry has been changed
due to user action or by a call to
<code>setentry()
</code>. The default is
<strong>None
</strong>.
</p><a name=option.sticky
></a>
Initialisation option. The default is
<strong>'ew'
</strong>.
</p><a name=option.validate
></a>
<dl><dt> <strong>validate
Specifies what kind of validation should be performed on the entry
<p> The most general way to specify the
<strong>validate
</strong> option is as a
dictionary. The kind of validation is specified by the
<strong>'validator'
</strong> dictionary field, which may be the name of one of
the standard validators described below, the name of a validator
supplied by the
<strong>extravalidators
</strong> option, a function or
<strong>None
</strong>.
The default is
<strong>None
</strong>.
</p><p> Any other dictionary fields specify other restrictions on the
entered values. For all validators, the following fields may be
<dl><dt><strong>'min'
</strong></dt><dd>Specifies the minimum acceptable value, or
<strong>None
</strong> if no
minimum checking should be performed. The default is
<strong>None
</strong>.
<p></p><dt><strong>'max'
</strong></dt><dd>Specifies the maximum acceptable value, or
<strong>None
</strong> if no
maximum checking should be performed. The default is
<strong>None
</strong>.
<p></p><dt><strong>'minstrict'
</strong></dt><dd>If true, then minimum checking is strictly enforced.
Otherwise, the entry input may be less than
<strong>min
</strong>, but will be
displayed using the
<strong>errorbackground
</strong> color. The default is true.
<p></p><dt><strong>'maxstrict'
</strong></dt><dd>If true, then maximum checking is strictly enforced.
Otherwise, the entry input may be more than
<strong>max
</strong>, but will be
displayed using the
<strong>errorbackground
</strong> color. The default is true.
<p></p><p> If the dictionary contains a
<strong>'stringtovalue'
</strong> field, it overrides
the normal
<em>stringtovalue
</em> function for the validator. The
<em>stringtovalue
</em> function is described below.
</p>
<p> Other fields in the dictionary (apart from the core fields
mentioned above) are passed on to the
<em>validator
</em> and
<em>stringtovalue
</em> functions as keyword arguments.
</p>
<p> If
<strong>validate
</strong> is not a dictionary, then it is equivalent to
specifying it as a dictionary with a single
<strong>'validator'
</strong> field.
For example,
<code>validate = 'real'
</code> is equivalent to /validate =
{'validator' : 'real'}/ and specifies real numbers without any
minimum or maximum limits and using
<strong>'.'
</strong> as the decimal point
<p> The standard validators accepted in the
<strong>'validator'
</strong> field are:
</p>
<dl><dt><strong>'numeric'
</strong></dt><dd>An integer greater than or equal to
0. Digits
<dt><strong>'integer'
</strong></dt><dd>Any integer (negative,
0 or positive) as accepted
by
<code>string.atol()
</code>.
<p></p><dt><strong>'hexadecimal'
</strong></dt><dd>Hex number (with optional leading
<strong>'
0x'
</strong>), as accepted
by
<code>string.atol(text,
16)
</code>.
<p></p><dt><strong>'real'
</strong></dt><dd>A number, with or without a decimal point and optional
exponent (e or E), as accepted by
<code>string.atof()
</code>. This
validator accepts a
<strong>'separator'
</strong> argument, which specifies
the character used to represent the decimal point. The
default
<strong>'separator'
</strong> is
<strong>'.'
</strong>.
<p></p><dt><strong>'alphabetic'
</strong></dt><dd>Consisting of the letters
<strong>'a-z'
</strong> and
<strong>'A-Z'
</strong>.
In this case,
<strong>'min'
</strong> and
<strong>'max'
</strong> specify limits on the length
<dt><strong>'alphanumeric'
</strong></dt><dd>Consisting of the letters
<strong>'a-z'
</strong>,
<strong>'A-Z'
</strong> and
<strong>'
0-
9'
</strong>.
In this case,
<strong>'min'
</strong> and
<strong>'max'
</strong> specify limits on the length
<dt><strong>'time'
</strong></dt><dd>Hours, minutes and seconds, in the format
<strong>'HH:MM:SS'
</strong>, as accepted by
<code>Pmw.timestringtoseconds()
</code>.
This validator accepts a
<strong>'separator'
</strong> argument, which
specifies the character used to separate the three fields.
The default separator is
<strong>':'
</strong>. The time may be negative.
<p></p><dt><strong>'date'
</strong></dt><dd>Day, month and year, as accepted by
<code>Pmw.datestringtojdn()
</code>. This validator accepts a
<strong>'separator'
</strong> argument, which specifies the character used to
separate the three fields. The default is
<strong>':'
</strong>. This
validator also accepts a
<strong>'format'
</strong> argument, which is passed to
<code>Pmw.datestringtojdn()
</code> to specify the desired ordering of the
fields. The default is
<strong>'ymd'
</strong>.
<p></p><p> If
<strong>'validator'
</strong> is a function, then it will be called whenever
the contents of the entry may have changed due to user action or
by a call to
<code>setentry()
</code>. The function is called with at least
one argument, the first one being the new text as modified by the
user or
<code>setentry()
</code>. The other arguments are keyword arguments
made up of the non-core fields of the
<strong>validate
</strong> dictionary.
</p><p> The
<em>validator
</em> function should return
<strong>Pmw.OK
</strong>,
<strong>Pmw.ERROR
</strong> or
<strong>Pmw.PARTIAL
</strong> as described above. It should not perform minimum
and maximum checking. This is done after the call, if it returns
<strong>Pmw.OK
</strong>.
</p>
<p> The
<strong>'stringtovalue'
</strong> field in the dictionary may be specified as
the name of one of the standard validators, the name of a
validator supplied by the
<strong>extravalidators
</strong> option, a function or
<strong>None
</strong>.
</p>
<p> The
<em>stringtovalue
</em> function is used to convert the entry input
into a value which can then be compared with any minimum or
maximum values specified for the validator. If the
<strong>'min'
</strong> or
<strong>'max'
</strong> fields are specified as strings, they are converted using
the
<em>stringtovalue
</em> function. The
<em>stringtovalue
</em> function is
called with the same arguments as the
<em>validator
</em> function. The
<em>stringtovalue
</em> function for the standard number validators
convert the string to a number. Those for the standard alpha
validators return the length of the string. Those for the
standard
<strong>'time'
</strong> and
<strong>'date'
</strong> validators return the number of
seconds and the Julian Day Number, respectively. See
<code>Pmw.stringtoreal()
</code>,
<code>Pmw.timestringtoseconds()
</code> and
<code>Pmw.datestringtojdn()
</code>.
</p>
<p> If the validator has been specified as a function and no
<strong>'stringtovalue'
</strong> field is given, then it defaults to the standard
python
<code>len()
</code> function.
</p><p> If
<strong>'validator'
</strong> is
<strong>None
</strong>, no validation is performed. However,
minimum and maximum checking may be performed, according to the
<em>stringtovalue
</em> function. For example, to limit the entry text to
a maximum of five characters:
</p><dl><dd><pre> Pmw.EntryField(validate = {'max' :
5})
</pre></dd></dl>
<p> The validator functions for each of the standard validators can
<dl><dd><pre> Pmw.numericvalidator
Pmw.alphanumericvalidator
Pmw.datevalidator
</pre></dd></dl><p> Whenever the
<strong>validate
</strong> option is configured, the text currently
displayed in the entry widget is revalidated. If it is not valid,
the
<strong>errorbackground
</strong> color is set and the
<strong>invalidcommand
</strong> function is called. However, the displayed text is not modified.
</p><p> The default for
<strong>validate
</strong> is
<strong>None
</strong>.
</p>
<a name=option.value
></a>
Initialisation option. Specifies the initial contents of the entry.
If this text is invalid, it will be displayed with the
<strong>errorbackground
</strong> color and the
<strong>invalidcommand
</strong> function will be called.
If both
<strong>value
</strong> and
<strong>entry_textvariable
</strong> options are specified in
the constructor,
<strong>value
</strong> will take precedence. The default is
<strong>''
</strong>.
</p><dt> <h3>Components
</h3></dt><dd>
Components created by this megawidget and its base
classes are described below.
<p></p><a name=component.entry
></a>
The widget where the user may enter text. Long text may be
scrolled horizontally by dragging with the middle mouse button. By default, this component is a Tkinter.Entry.
</p><a name=component.hull
></a>
This acts as the body for the entire megawidget. Other components
are created as children of the hull to further specialise this
class. By default, this component is a Tkinter.Frame.
</p><a name=component.label
></a>
If the
<strong>labelpos
</strong> option is not
<strong>None
</strong>, this component is
created as a text label for the megawidget. See the
<strong>labelpos
</strong> option for details. Note that to set, for example,
the
<strong>text
</strong> option of the label, you need to use the
<strong>label_text
</strong> component option. By default, this component is a Tkinter.Label.
</p><dt> <h3>Methods
</h3></dt><dd>
Only methods specific to this megawidget are described below.
For a description of its inherited methods, see the
manual for its base class
<strong><a href=
"MegaWidget.html#methods">Pmw.MegaWidget
</a></strong>.
In addition, methods from the
<strong>Tkinter.Entry
</strong> class
are forwarded by this megawidget to the
<strong>entry
</strong> component.
<a name=method.checkentry
></a>
<dl><dt> <strong>checkentry
</strong>()
</dt><dd>
Check the validity of the current contents of the entry widget
If the text is not valid, set the background to
<strong>errorbackground
</strong> and
call the
<strong>invalidcommand
</strong> function. If there is a variable
specified by the
<strong>entry_textvariable
</strong> option, this method should be
called after the
<code>set()
</code> method of the variable is called. If this
is not done in this case, the entry widget background will not be
<a name=method.clear
></a>
<dl><dt> <strong>clear
</strong>()
</dt><dd>
Remove all text from the entry widget. Equivalent to
<code>setentry('')
</code>.
</p><a name=method.getvalue
></a>
<dl><dt> <strong>getvalue
</strong>()
</dt><dd>
Return the text displayed by the entry.
</p><a name=method.invoke
></a>
<dl><dt> <strong>invoke
</strong>()
</dt><dd>
Invoke the command specified by the
<strong>command
</strong> option as if the
<strong><Return
></strong> key had been pressed and return the result.
</p>
<a name=method.setentry
></a>
<dl><dt> <strong>setentry
</strong>(
<em>text
</em>)
</dt><dd>
Same as
<code>setvalue()
</code> method.
</p><a name=method.setvalue
></a>
<dl><dt> <strong>setvalue
</strong>(
<em>text
</em>)
</dt><dd>
Set the contents of the entry widget to
<em>text
</em> and carry out
validation as if the text had been entered by the user. If the
text is invalid, the entry widget will not be changed and the
<strong>invalidcommand
</strong> function will be called. Return the validity
<a name=method.valid
></a>
<dl><dt> <strong>valid
</strong>()
</dt><dd>
Return true if the contents of the entry widget are valid.
</p><dt> <h3>Example
</h3></dt><dd>
The image at the top of this manual is a snapshot
of the window (or part of the window) produced
by the following code.
<p></p> def __init__(self, parent):
# Create and pack the EntryFields.
self._any = Pmw.EntryField(parent,
self._real = Pmw.EntryField(parent,
label_text = 'Real (
10.0 to
99.0):',
validate = {'validator' : 'real',
'min' :
10, 'max' :
99, 'minstrict' :
0},
modifiedcommand = self.changed)
self._odd = Pmw.EntryField(parent,
label_text = 'Odd length:',
validate = self.custom_validate,
self._date = Pmw.EntryField(parent,
label_text = 'Date (in
2000):',
validate = {'validator' : 'date',
'min' : '
2000/
1/
1', 'max' : '
2000/
12/
31',
'minstrict' :
0, 'maxstrict' :
0,
now = time.localtime(time.time())
self._date2 = Pmw.EntryField(parent,
label_text = 'Date (d.m.y):',
value = '%d.%d.%d' % (now[
2], now[
1], now[
0]),
validate = {'validator' : 'date',
'format' : 'dmy', 'separator' : '.'},
self._time = Pmw.EntryField(parent,
label_text = 'Time (
24hr clock):',
validate = {'validator' : 'time',
'min' : '
00:
00:
00', 'max' : '
23:
59:
59',
'minstrict' :
0, 'maxstrict' :
0},
self._comma = Pmw.EntryField(parent,
label_text = 'Real (with comma):',
validate = {'validator' : 'real', 'separator' : ','},
entries = (self._any, self._real, self._odd, self._date, self._date2,
entry.pack(fill='x', expand=
1, padx=
10, pady=
5)
self._any.component('entry').focus_set()
print 'Text changed, value is', self._real.getvalue()
print 'Return pressed, value is', self._any.getvalue()
# This implements a custom validation routine. It simply checks
# if the string is of odd length.
def custom_validate(self, text):
<center><P ALIGN=
"CENTER">
<IMG SRC = blue_line.gif ALT =
"" WIDTH=
320 HEIGHT=
5>
<center><P ALIGN=
"CENTER">
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<a href=
"index.html">Home
</a> <br>Manual page last reviewed:
22 May
1998
projects / OpenSPARC-T2-DV / blob