entry(3)

NAME

Tk::Entry - Create and manipulate Entry widgets

SYNOPSIS

$entry = $parent->Entry(?options?);

STANDARD OPTIONS

-background -highlightbackground -inserton time -selectforeground -borderwidth -highlight color -insertwidth -takefocus -cursor -highlight thickness -justify -textvariable -exportselec tion -insertbackground -relief -xscrollcommand -font -insertborderwidth -selectbackground -fore ground -insertofftime -selectborderwidth

WIDGET-SPECIFIC OPTIONS

Name: invalidCommand
Class: InvalidCommand
Switch: -invalidcommand
Alias: -invcmd

Specifies a script to eval when validateCommand returns 0. Setting it to <undef> disables this fea
ture (the default). The best use of this option is to
set it to bell. See Validation below for more infor mation.

Name: show
Class: Show
Switch: -show

If this option is specified, then the true contents of
the entry are not displayed in the window. Instead,
each character in the entry's value will be displayed
as the first character in the value of this option,
such as ``*''. This is useful, for example, if the
entry is to be used to enter a password. If charac
ters in the entry are selected and copied elsewhere,
the information copied will be what is displayed, not
the true contents of the entry.

Name: state
Class: State
Switch: -state

Specifies one of two states for the entry: normal or
disabled. If the entry is disabled then the value may not be changed using widget methods and no insertion
cursor will be displayed, even if the input focus is
in the widget.

Name: validate
Class: Validate
Switch: -validate

Specifies the mode in which validation should operate:
none, focus, focusin, focusout, key, or all. It defaults to none. When you want validation, you must
explicitly state which mode you wish to use. See Val
idation below for more.

Name: validateCommand
Class: ValidateCommand
Switch: -validatecommand
Alias: -vcmd

Specifies a script to eval when you want to validate
the input into the entry widget. Setting it to
"undef" disables this feature (the default). This
command must return a valid boolean value. If it
returns 0 (or the valid boolean equivalent) then it
means you reject the new edition and it will not occur
and the invalidCommand will be evaluated if it is set. If it returns 1, then the new edition occurs. See
Validation below for more information.

Name: width
Class: Width
Switch: -width

Specifies an integer value indicating the desired
width of the entry window, in average-size characters
of the widget's font. If the value is less than or
equal to zero, the widget picks a size just large
enough to hold its current text.

DESCRIPTION

The Entry method creates a new window (given by the $entry
argument) and makes it into an entry widget. Additional
options, described above, may be specified on the command
line or in the option database to configure aspects of the
entry such as its colors, font, and relief. The entry
command returns its $entry argument. At the time this
command is invoked, there must not exist a window named
$entry, but $entry's parent must exist.

An entry is a widget that displays a one-line text string
and allows that string to be edited using methods
described below, which are typically bound to keystrokes
and mouse actions. When first created, an entry's string
is empty. A portion of the entry may be selected as
described below. If an entry is exporting its selection
(see the exportSelection option), then it will observe the standard X11 protocols for handling the selection; entry
selections are available as type STRING. Entries also
observe the standard Tk rules for dealing with the input
focus. When an entry has the input focus it displays an
insertion cursor to indicate where new characters will be inserted.

Entries are capable of displaying strings that are too
long to fit entirely within the widget's window. In this
case, only a portion of the string will be displayed;
methods described below may be used to change the view in
the window. Entries use the standard xScrollCommand mech anism for interacting with scrollbars (see the description
of the -xscrollcommand option for details). They also support scanning, as described below.

VALIDATION

Validation of entry widgets is derived from part of the
patch written by jhobbs@cs.uoregon.edu. This works by
setting the validateCommand option to a callback which will be evaluated according to the validate option as fol lows:

none

Default. This means no validation will occur.

focus

validateCommand will be called when the entry receives or loses focus.

focusin

validateCommand will be called when the entry receives focus.

focusout

validateCommand will be called when the entry loses focus.

key validateCommand will be called when the entry is

edited.

all validateCommand will be called for all above condi

tions.

The validateCommand and invalidCommand are called with the following arguments:

· The proposed value of the entry. If you are configuring
the entry widget to have a new textvariable, this will be
the value of that textvariable.
· The characters to be added (or deleted). This will be
"undef" if validation is due to focus, explcit call to
validate or if change is due to "-textvariable" changing.
· The current value of entry i.e. before the proposed
change.
· index of char string to be added/deleted, if any. -1
otherwise
· type of action. 1 == INSERT, 0 == DELETE, -1 if it's a
forced validation or textvariable validation

In general, the textVariable and validateCommand can be dangerous to mix. If you try set the textVariable to some thing that the validateCommand will not accept it will be set back to the value of the entry widget. Using the
textVariable for read-only purposes will never cause prob lems.

The validateCommand will turn itself off by setting vali date to none when an error occurs, for example when the validateCommand or invalidCommand encounters an error in its script while evaluating, or validateCommand does not return a valid boolean value.

With the perl/Tk version validate option is supposed to be "suspended" while executing the validateCommand or the invalidCommand. This is experimental but in theory either callback can "correct" the value of the widget, and over
ride the proposed change. (validateCommand should still return false to inhibit the change from happening when it
returns.)

WIDGET METHODS

The Entry method creates a widget object. This object
supports the configure and cget methods described in Tk::options which can be used to enquire and modify the
options described above. The widget also inherits all the
methods provided by the generic Tk::Widget class.

Many of the additional methods for entries take one or
more indices as arguments. An index specifies a particu
lar character in the entry's string, in any of the follow
ing ways:

number

Specifies the character as a numerical index, where 0
corresponds to the first character in the string.

anchor

Indicates the anchor point for the selection, which is
set with the selectionFrom and selectionAdjust meth ods.

end Indicates the character just after the last one in the

entry's string. This is equivalent to specifying a
numerical index equal to the length of the entry's
string.

insert

Indicates the character adjacent to and immediately
following the insertion cursor.

sel.first

Indicates the first character in the selection. It is
an error to use this form if the selection isn't in
the entry window.

sel.last

Indicates the character just after the last one in the
selection. It is an error to use this form if the
selection isn't in the entry window.

@number

In this form, number is treated as an x-coordinate in
the entry's window; the character spanning that
x-coordinate is used. For example, ``@0'' indicates
the left-most character in the window.

Abbreviations may be used for any of the forms above, e.g.
``e'' or ``sel.f''. In general, out-of-range indices are
automatically rounded to the nearest legal value.

The following additional methods are available for entry
widgets:

$entry->bbox(index)

Returns a list of four numbers describing the bounding
box of the character given by index. The first two
elements of the list give the x and y coordinates of
the upper-left corner of the screen area covered by
the character (in pixels relative to the widget) and
the last two elements give the width and height of the
character, in pixels. The bounding box may refer to a
region outside the visible area of the window.

$entry->delete(first, ?last?)

Returns the current value of the configuration option
given by option. Option may have any of the values accepted by the entry command.

$entry->configure(?option?, ?value, option, value, ...?)

Query or modify the configuration options of the wid
get. If no option is specified, returns a list
describing all of the available options for $entry
(see Tk::configure for information on the format of
this list). If option is specified with no value, then the command returns a list describing the one
named option (this list will be identical to the cor
responding sublist of the value returned if no option
is specified). If one or more option-value pairs are specified, then the command modifies the given widget
option(s) to have the given value(s); in this case
the command returns an empty string. Option may have
any of the values accepted by the entry command.

$entry->delete(first, ?last?)

Delete one or more elements of the entry. First is
the index of the first character to delete, and last
is the index of the character just after the last one
to delete. If last isn't specified it defaults to
first+1, i.e. a single character is deleted. This
method returns an empty string.

$entry->get

Returns the entry's string.

$entry->icursor(index)

Arrange for the insertion cursor to be displayed just
before the character given by index. Returns an empty
string.

$entry->index(index)

Returns the numerical index corresponding to index.

$entry->insert(index, string)

Insert the characters of string just before the char
acter indicated by index. Returns an empty string.

$entry->scan(option, args)
$entry->scanOption(args)

This method is used to implement scanning on entries.
It has two forms, depending on Option:

$entry->scanMark(x)

Records x and the current view in the entry
widget; used in conjunction with later scan
Dragto methods. Typically this method is
associated with a mouse button press in the
widget. It returns an empty string.

$entry->scanDragto(x)

This method computes the difference between
its x argument and the x argument to the last
scanMark method for the widget. It then
adjusts the view left or right by 10 times the
difference in x-coordinates. This method is
typically associated with mouse motion events
in the widget, to produce the effect of drag
ging the entry at high speed through the wid
get. The return value is an empty string.

$entry->selection(option, arg) $entry->selectionOption(arg)

This method is used to adjust the selection within an
entry. It has several forms, depending on Option:

$entry->selectionAdjust(index)

Locate the end of the selection nearest to the
character given by index, and adjust that end
of the selection to be at index (i.e including
but not going beyond index). The other end of
the selection is made the anchor point for
future selectionTo methods. If the selection isn't currently in the entry, then a new
selection is created to include the characters
between index and the most recent selection
anchor point, inclusive. Returns an empty
string.

$entry->selectionClear

Clear the selection if it is currently in this
widget. If the selection isn't in this widget
then the method has no effect. Returns an
empty string.

$entry->selectionFrom(index)

Set the selection anchor point to just before
the character given by index. Doesn't change
the selection. Returns an empty string.

$entry->selectionPresent

Returns 1 if there is are characters selected
in the entry, 0 if nothing is selected.

$entry->selectionRange(start, end)

Sets the selection to include the characters
starting with the one indexed by start and
ending with the one just before end. If end
refers to the same character as start or an
earlier one, then the entry's selection is
cleared.

$entry->selectionTo(index)

If index is before the anchor point, set the
selection to the characters from index up to
but not including the anchor point. If index
is the same as the anchor point, do nothing.
If index is after the anchor point, set the
selection to the characters from the anchor
point up to but not including index. The
anchor point is determined by the most recent
selectionFrom or selectionAdjust method in this widget. If the selection isn't in this
widget then a new selection is created using
the most recent anchor point specified for the
widget. Returns an empty string.

$entry->validate

This command is used to force an evaluation of the
validateCommand independent of the conditions speci fied by the validate option. It returns 0 or 1.

$entry->xview(args)

This command is used to query and change the horizon
tal position of the text in the widget's window. It
can take any of the following forms:

$entry->xview

Returns a list containing two elements. Each
element is a real fraction between 0 and 1;
together they describe the horizontal span
that is visible in the window. For example,
if the first element is .2 and the second ele
ment is .7, 20% of the entry's text is offscreen to the left, the middle 50% is visible
in the window, and 30% of the text is offscreen to the right. These are the same val
ues passed to scrollbars via the -xscrollcom mand option.

$entry->xview(index)

Adjusts the view in the window so that the
character given by index is displayed at the
left edge of the window.

$entry->xviewMoveto(fraction)

Adjusts the view in the window so that the
character fraction of the way through the text appears at the left edge of the window. Frac_
tion must be a fraction between 0 and 1.

$entry->xviewScroll(number, what)

This method shifts the view in the window left
or right according to number and what. Number must be an integer. What must be either units or pages or an abbreviation of one of these.
If what is units, the view adjusts left or right by number average-width characters on
the display; if it is pages then the view
adjusts by number screenfuls. If number is negative then characters farther to the left
become visible; if it is positive then char
acters farther to the right become visible.

DEFAULT BINDINGS

Tk automatically creates class bindings for entries that
give them the following default behavior. In the descrip
tions below, ``word'' refers to a contiguous group of let
ters, digits, or ``_'' characters, or any single character
other than these.

[1] Clicking mouse button 1 positions the insertion cursor

just before the character underneath the mouse cursor,
sets the input focus to this widget, and clears any
selection in the widget. Dragging with mouse button 1
strokes out a selection between the insertion cursor
and the character under the mouse.

[2] Double-clicking with mouse button 1 selects the word

under the mouse and positions the insertion cursor at
the beginning of the word. Dragging after a double
click will stroke out a selection consisting of whole
words.

[3] Triple-clicking with mouse button 1 selects all of the

text in the entry and positions the insertion cursor
before the first character.

[4] The ends of the selection can be adjusted by dragging

with mouse button 1 while the Shift key is down; this
will adjust the end of the selection that was nearest
to the mouse cursor when button 1 was pressed. If the
button is double-clicked before dragging then the
selection will be adjusted in units of whole words.

[5] Clicking mouse button 1 with the Control key down will

position the insertion cursor in the entry without
affecting the selection.

[6] If any normal printing characters are typed in an

entry, they are inserted at the point of the insertion
cursor.

[7] The view in the entry can be adjusted by dragging with

mouse button 2. If mouse button 2 is clicked without
moving the mouse, the selection is copied into the
entry at the position of the mouse cursor.

[8] If the mouse is dragged out of the entry on the left

or right sides while button 1 is pressed, the entry
will automatically scroll to make more text visible
(if there is more text off-screen on the side where
the mouse left the window).

[9] The Left and Right keys move the insertion cursor one

character to the left or right; they also clear any
selection in the entry and set the selection anchor.
If Left or Right is typed with the Shift key down,
then the insertion cursor moves and the selection is
extended to include the new character. Control-Left
and Control-Right move the insertion cursor by words,
and Control-Shift-Left and Control-Shift-Right move
the insertion cursor by words and also extend the
selection. Control-b and Control-f behave the same as
Left and Right, respectively. Meta-b and Meta-f
behave the same as Control-Left and Control-Right,
respectively.

[10]

The Home key, or Control-a, will move the insertion
cursor to the beginning of the entry and clear any
selection in the entry. Shift-Home moves the inser
tion cursor to the beginning of the entry and also
extends the selection to that point.

[11]

The End key, or Control-e, will move the insertion
cursor to the end of the entry and clear any selection
in the entry. Shift-End moves the cursor to the end
and extends the selection to that point.

[12]

The Select key and Control-Space set the selection
anchor to the position of the insertion cursor. They
don't affect the current selection. Shift-Select and
Control-Shift-Space adjust the selection to the cur
rent position of the insertion cursor, selecting from
the anchor to the insertion cursor if there was not
any selection previously.

[13]

Control-/ selects all the text in the entry.

[14]

Control- clears any selection in the entry.

[15]

The F16 key (labelled Copy on many Sun workstations)
or Meta-w copies the selection in the widget to the
clipboard, if there is a selection.

[16]

The F20 key (labelled Cut on many Sun workstations) or
Control-w copies the selection in the widget to the
clipboard and deletes the selection. If there is no
selection in the widget then these keys have no
effect.

[17]

The F18 key (labelled Paste on many Sun workstations)
or Control-y inserts the contents of the clipboard at
the position of the insertion cursor.

[18]

The Delete key deletes the selection, if there is one
in the entry. If there is no selection, it deletes
the character to the right of the insertion cursor.

[19]

The BackSpace key and Control-h delete the selection,
if there is one in the entry. If there is no selec
tion, it deletes the character to the left of the
insertion cursor.

[20]

Control-d deletes the character to the right of the
insertion cursor.

[21]

Meta-d deletes the word to the right of the insertion
cursor.

[22]

Control-k deletes all the characters to the right of
the insertion cursor.

[23]

Control-t reverses the order of the two characters to
the right of the insertion cursor.

If the entry is disabled using the -state option, then the entry's view can still be adjusted and text in the
entry can still be selected, but no insertion cursor
will be displayed and no text modifications will take
place.

The behavior of entries can be changed by defining new
bindings for individual widgets or by redefining the
class bindings.

KEYWORDS

entry, widget

perl v5.8.0 1999-12-04 ENTRY(1)