options(3)
NAME
Tk::options - Standard options supported by widgets and
their manipulation
SYNOPSIS
$value = $widget->cget('-option'); $widget->configure(-option=>value ?,-option=>value ...?); @list = $widget->configure('-option'); @lol = $widget->configure;
DESCRIPTION
All widgets, and images have a standard mechanism for set
ting and querying attibutes or options. The mechanism is
based on two methods configure and cget. The behaviour of
these methods is as follows:
- $widget->configure(-option=>value ?,-option=>value ...?);
- Sets the values of -option to value for each -option=>value pair. The internal new method does an implicit configure in this form with options passed in at widget create time.
- $widget->configure('-option')
- In array context returns a list of five or two ele
ments. If -option is an alias for another options it return a list consisting of the alias option and the
name for the option is is an alias for, e.g., "('-bg',
'background')". If -option is not an alias the
returned list has the following five elements: - Option Name
The value of -option, e.g., -background.
- Name The option's name in the option database,
- e.g., "background".
- Class The option's class value in the option
- database, e.g., "Background".
- Default The default value for the option if not speci
- fied or in the option database, e.g., "grey".
- Value The current value (as returned by cget), e.g.,
- "white".
- $widget->configure
- Returns a list of lists for all the options supported
by $widget. Each sub-list is in the form returned by configure('-option'). (This mechanism is used by the Tk::Derived class to determine the options available from base class.) - $widget->cget('-option')
- Returns the current value of -option for $widget.
- cget('-option') is clumsy with the need for '' due to
perl's parsing rules. Something more subtle using tie
might look better. - The following paragraphs describe the common configuration
options supported by widgets in the Tk toolkit. Every
widget does not necessarily support every option (see the
the documentation entries for individual widgets for a
list of the standard options supported by that widget),
but if a widget does support an option with one of the
names listed below, then the option has exactly the effect
described below. - In the descriptions below, ``Name'' refers to the option's
name in the option database. ``Class'' refers to the
option's class value in the option database. ``Switch''
refers to the switch used in widget-creation and configure widget methods to set this value. For example, if an
option's configure option is -foreground and there exists a widget $widget, then the call:
$widget->configure(-foreground=>'black')- may be used to specify the value black for the option in
the widget $widget. Configure options may be abbreviated, as long as the abbreviation is unambiguous (abbreviation
is deprecated in perl/Tk). - Creation options: Widget Name and Class
- The Name and -class options can only be specified when a
widget is created, and cannot be changed with configure.
These options determine the widget's identity and how Tk
applies resource values from the option database (see
Tk::option) and so they cannot be assigned by the options
database. - Name: name
Switch: Name - Specifies the path element for the widget. Names gen
erally begin with a lowercase letter. - Each widget has a unique pathname that follows the
hierarchy from the MainWindow to the widget itself.
Since the widget's PathName is used to assign options
from the options database, it is important to specify
a distinctive Name for any widget that will have nondefault options. See Tk::option for details. - Name: class
Switch: -class - Specifies a class for the window. Classes generally
begin with an uppercase letter. - This class will be used when querying the option
database for the window's other options (see
Tk::options), and it will also be used later for other
purposes such as bindings. One typically assigns a
class to a TopLevel or Frame so that the class will apply to all of that widget's children. - Reconfigurable options
- These options can be set at widget creation or changed
later via configure. - Name: activeBackground
Class: Foreground
Switch: -activebackground - Specifies background color to use when drawing active
elements. An element (a widget or portion of a wid
get) is active if the mouse cursor is positioned over
the element and pressing a mouse button will cause
some action to occur. If strict Motif compliance has
been requested by setting the $Tk::strictMotif vari able, this option will normally be ignored; the nor
mal background color will be used instead. For some
elements on Windows and Macintosh systems, the active
color will only be used while mouse button 1 is
pressed over the element. - Name: activeBorderWidth
Class: BorderWidth
Switch: -activeborderwidth - Specifies a non-negative value indicating the width of
the 3-D border drawn around active elements. See
above for definition of active elements. The value
may have any of the forms acceptable to Tk_GetPixels. This option is typically only available in widgets
displaying more than one element at a time (e.g. menus
but not buttons). - Name: activeForeground
Class: Background
Switch: -activeforeground - Specifies foreground color to use when drawing active
elements. See above for definition of active ele
ments. - Name: activetile
Class: Tile
Switch: -activetile - Specifies image used to display inside active elements
of the widget. See above for definition of active
elements. - Name: anchor
Class: Anchor
Switch: -anchor - Specifies how the information in a widget (e.g. text
or a bitmap) is to be displayed in the widget. Must
be one of the values n, ne, e, se, s, sw, w, nw, or center. For example, nw means display the information such that its top-left corner is at the top-left cor
ner of the widget. - Name: background
Class: Background
Switch: -background
Alias: -bg - Specifies the normal background color to use when dis
playing the widget. - Name: bitmap
Class: Bitmap
Switch: -bitmap - Specifies a bitmap to display in the widget, in any of
the forms acceptable to Tk_GetBitmap. The exact way in which the bitmap is displayed may be affected by
other options such as -anchor or -justify. Typically, if this option is specified then it overrides other
options that specify a textual value to display in the
widget; the -bitmap option may be reset to an empty
string to re-enable a text display. In widgets that
support both -bitmap and -image options, -image will usually override -bitmap. - Name: borderWidth
Class: BorderWidth
Switch: -borderwidth
Alias: -bd - Specifies a non-negative value indicating the width of
the 3-D border to draw around the outside of the wid
get (if such a border is being drawn; the relief
option typically determines this). The value may also
be used when drawing 3-D effects in the interior of
the widget. The value may have any of the forms
acceptable to Tk_GetPixels. - Name: cursor
Class: Cursor
Switch: -cursor - Specifies the mouse cursor to be used for the widget.
The value may have any of the forms acceptable to
Tk_GetCursor. - Name: dash
Class: Dash
Switch: -dash - The value may have any of the forms accepted by
Tk_GetDash, such as 4, [6,4], ., -, -., or -... - Name: dashoffset
Class: Dashoffset
Switch: -dashoffset - Specifies the offset in the dash list where the draw
ing starts. - Name: disabledForeground
Class: DisabledForeground
Switch: -disabledforeground - Specifies foreground color to use when drawing a dis
abled element. If the option is specified as an empty
string (which is typically the case on monochrome dis
plays), disabled elements are drawn with the normal
foreground color but they are dimmed by drawing them
with a stippled fill pattern. - Name: disabledtile
Class: Tile
Switch: -disabledtile - Specifies image to use when drawing a disabled ele
ment. - Name: exportSelection
Class: ExportSelection
Switch: -exportselection - Specifies whether or not a selection in the widget
should also be the X selection. The value may have
any of the forms accepted by Tcl_GetBoolean, such as true, false, 0, 1, yes, or no. If the selection is exported, then selecting in the widget deselects the
current X selection, selecting outside the widget des
elects any widget selection, and the widget will
respond to selection retrieval requests when it has a
selection. The default is usually for widgets to
export selections. - Name: font
Class: Font
Switch: -font - Specifies the font to use when drawing text inside the
widget. - Name: foreground
Class: Foreground
Switch: -foreground
Alias: -fg - Specifies the normal foreground color to use when dis
playing the widget. - Name: highlightBackground
Class: HighlightBackground
Switch: -highlightbackground - Specifies the color to display in the traversal high
light region when the widget does not have the input
focus. - Name: highlightColor
Class: HighlightColor
Switch: -highlightcolor - Specifies the color to use for the traversal highlight
rectangle that is drawn around the widget when it has
the input focus. - Name: highlightThickness
Class: HighlightThickness
Switch: -highlightthickness - Specifies a non-negative value indicating the width of
the highlight rectangle to draw around the outside of
the widget when it has the input focus. The value may
have any of the forms acceptable to Tk_GetPixels. If the value is zero, no focus highlight is drawn around
the widget. - Name: image
Class: Image
Switch: -image - Specifies an image to display in the widget, which
must have been created with an image create. (See
Tk::Image for details of image creation.) Typically,
if the -image option is specified then it overrides
other options that specify a bitmap or textual value
to display in the widget; the -image option may be
reset to an empty string to re-enable a bitmap or text
display. - Name: insertBackground
Class: Foreground
Switch: -insertbackground - Specifies the color to use as background in the area
covered by the insertion cursor. This color will nor
mally override either the normal background for the
widget (or the selection background if the insertion
cursor happens to fall in the selection). - Name: insertBorderWidth
Class: BorderWidth
Switch: -insertborderwidth - Specifies a non-negative value indicating the width of
the 3-D border to draw around the insertion cursor.
The value may have any of the forms acceptable to
Tk_GetPixels. - Name: insertOffTime
Class: OffTime
Switch: -insertofftime - Specifies a non-negative integer value indicating the
number of milliseconds the insertion cursor should
remain ``off'' in each blink cycle. If this option is
zero then the cursor doesn't blink: it is on all the
time. - Name: insertOnTime
Class: OnTime
Switch: -insertontime - Specifies a non-negative integer value indicating the
number of milliseconds the insertion cursor should
remain ``on'' in each blink cycle. - Name: insertWidth
Class: InsertWidth
Switch: -insertwidth - Specifies a value indicating the total width of the
insertion cursor. The value may have any of the forms
acceptable to Tk_GetPixels. If a border has been specified for the insertion cursor (using the insert
BorderWidth option), the border will be drawn inside the width specified by the insertWidth option. - Name: jump
Class: Jump
Switch: -jump - For widgets with a slider that can be dragged to
adjust a value, such as scrollbars, this option deter
mines when notifications are made about changes in the
value. The option's value must be a boolean of the
form accepted by Tcl_GetBoolean. If the value is false, updates are made continuously as the slider is
dragged. If the value is true, updates are delayed
until the mouse button is released to end the drag;
at that point a single notification is made (the value
``jumps'' rather than changing smoothly). - Name: justify
Class: Justify
Switch: -justify - When there are multiple lines of text displayed in a
widget, this option determines how the lines line up
with each other. Must be one of left, center, or right. Left means that the lines' left edges all line up, center means that the lines' centers are aligned,
and right means that the lines' right edges line up. - Name: offset
Class: Offset
Switch: -offset - Specifies the offset of tiles (see also -tile option).
It can have two different formats -offset x,y or -off set side, where side can be n, ne, e, se, s, sw, w, nw, or center. In the first case the origin is the origin of the toplevel of the current window. For the
canvas itself and canvas objects the origin is the
canvas origin, but putting # in front of the coordi
nate pair indicates using the toplevel origin in
stead. For canvas objects, the -offset option is used for stippling as well. For the line and polygon can
vas items you can also specify an index as argument,
which connects the stipple or tile origin to one of
the coordinate points of the line/polygon. - Name: orient
Class: Orient
Switch: -orient - For widgets that can lay themselves out with either a
horizontal or vertical orientation, such as scroll
bars, this option specifies which orientation should
be used. Must be either horizontal or vertical or an abbreviation of one of these. - Name: padX
Class: Pad
Switch: -padx - Specifies a non-negative value indicating how much
extra space to request for the widget in the X-direc
tion. The value may have any of the forms acceptable
to Tk_GetPixels. When computing how large a window it needs, the widget will add this amount to the width it
would normally need (as determined by the width of the
things displayed in the widget); if the geometry man
ager can satisfy this request, the widget will end up
with extra internal space to the left and/or right of
what it displays inside. Most widgets only use this
option for padding text: if they are displaying a
bitmap or image, then they usually ignore padding
options. - Name: padY
Class: Pad
Switch: -pady - Specifies a non-negative value indicating how much
extra space to request for the widget in the Y-direc
tion. The value may have any of the forms acceptable
to Tk_GetPixels. When computing how large a window it needs, the widget will add this amount to the height
it would normally need (as determined by the height of
the things displayed in the widget); if the geometry
manager can satisfy this request, the widget will end
up with extra internal space above and/or below what
it displays inside. Most widgets only use this option
for padding text: if they are displaying a bitmap or
image, then they usually ignore padding options. - Name: relief
Class: Relief
Switch: -relief - Specifies the 3-D effect desired for the widget.
Acceptable values are raised, sunken, flat, ridge, solid, and groove. The value indicates how the inte rior of the widget should appear relative to its exte
rior; for example, raised means the interior of the
widget should appear to protrude from the screen, rel
ative to the exterior of the widget. - Name: repeatDelay
Class: RepeatDelay
Switch: -repeatdelay - Specifies the number of milliseconds a button or key
must be held down before it begins to auto-repeat.
Used, for example, on the up- and down-arrows in
scrollbars. - Name: repeatInterval
Class: RepeatInterval
Switch: -repeatinterval - Used in conjunction with repeatDelay: once autorepeat begins, this option determines the number of
milliseconds between auto-repeats. - Name: selectBackground
Class: Foreground
Switch: -selectbackground - Specifies the background color to use when displaying
selected items. - Name: selectBorderWidth
Class: BorderWidth
Switch: -selectborderwidth - Specifies a non-negative value indicating the width of
the 3-D border to draw around selected items. The
value may have any of the forms acceptable to Tk_Get
Pixels. - Name: selectForeground
Class: Background
Switch: -selectforeground - Specifies the foreground color to use when displaying
selected items. - Name: setGrid
Class: SetGrid
Switch: -setgrid - Specifies a boolean value that determines whether this
widget controls the resizing grid for its top-level
window. This option is typically used in text wid
gets, where the information in the widget has a natu
ral size (the size of a character) and it makes sense
for the window's dimensions to be integral numbers of
these units. These natural window sizes form a grid.
If the setGrid option is set to true then the widget will communicate with the window manager so that when
the user interactively resizes the top-level window
that contains the widget, the dimensions of the window
will be displayed to the user in grid units and the
window size will be constrained to integral numbers of
grid units. See "GRIDDED GEOMETRY MANAGEMENT" in
Tk::Wm for more details. - Name: takeFocus
Class: TakeFocus
Switch: -takefocus - Determines whether the window accepts the focus during
keyboard traversal (e.g., Tab and Shift-Tab). Before
setting the focus to a window, the traversal scripts
consult the value of the takeFocus option. A value of 0 means that the window should be skipped entirely
during keyboard traversal. 1 means that the window
should receive the input focus as long as it is view
able (it and all of its ancestors are mapped). An
empty value for the option means that the traversal
scripts make the decision about whether or not to
focus on the window: the current algorithm is to skip
the window if it is disabled, if it has no key bind
ings, or if it is not viewable. If the value has any
other form, then the traversal scripts take the value,
append the name of the window to it (with a separator
space), and evaluate the resulting string as a Call
back. The script must return 0, 1, or an empty
string: a 0 or 1 value specifies whether the window
will receive the input focus, and an empty string
results in the default decision described above.
Note: this interpretation of the option is defined
entirely by the Callbacks that implement traversal:
the widget implementations ignore the option entirely,
so you can change its meaning if you redefine the key
board traversal scripts. - Name: text
Class: Text
Switch: -text - Specifies a string to be displayed inside the widget.
The way in which the string is displayed depends on
the particular widget and may be determined by other
options, such as anchor or justify. - Name: textVariable
Class: Variable
Switch: -textvariable - Specifies the name of a variable. The value of the
variable is a text string to be displayed inside the
widget; if the variable value changes then the widget
will automatically update itself to reflect the new
value. The way in which the string is displayed in
the widget depends on the particular widget and may be
determined by other options, such as anchor or jus tify. - Name: troughColor
Class: Background
Switch: -troughcolor - Specifies the color to use for the rectangular trough
areas in widgets such as scrollbars and scales. - Name: troughTile
Class: Tile
Switch: -troughtile - Specifies image used to display in the rectangular
trough areas in widgets such as scrollbars and scales. - Name: underline
Class: Underline
Switch: -underline - Specifies the integer index of a character to under
line in the widget. This option is used by the
default bindings to implement keyboard traversal for
menu buttons and menu entries. 0 corresponds to the
first character of the text displayed in the widget, 1
to the next character, and so on. - Name: wrapLength
Class: WrapLength
Switch: -wraplength - For widgets that can perform word-wrapping, this
option specifies the maximum line length. Lines that
would exceed this length are wrapped onto the next
line, so that no line is longer than the specified
length. The value may be specified in any of the
standard forms for screen distances. If this value is
less than or equal to 0 then no wrapping is done:
lines will break only at newline characters in the
text. - Name: xScrollCommand
Class: ScrollCommand
Switch: -xscrollcommand - Specifies a callback used to communicate with horizon
tal scrollbars. When the view in the widget's window
changes (or whenever anything else occurs that could
change the display in a scrollbar, such as a change in
the total size of the widget's contents), the widget
will make a callback passing two numeric arguments in
addition to any specified in the callback. Each of
the numbers is a fraction between 0 and 1, which indi
cates a position in the document. 0 indicates the
beginning of the document, 1 indicates the end, .333
indicates a position one third the way through the
document, and so on. The first fraction indicates the
first information in the document that is visible in
the window, and the second fraction indicates the
information just after the last portion that is visi
ble. Typically the xScrollCommand option consists of the scrollbar widget object and the method ``set''
i.e. [set => $sb]: this will cause the scrollbar to be updated whenever the view in the window changes. If
this option is not specified, then no command will be
executed. - Name: yScrollCommand
Class: ScrollCommand
Switch: -yscrollcommand - Specifies a calback used to communicate with vertical
scrollbars. This option is treated in the same way as
the xScrollCommand option, except that it is used for vertical scrollbars and is provided by widgets that
support vertical scrolling. See the description of
xScrollCommand for details on how this option is used.
SEE ALSO
Tk::option Tk::callbacks Tk::configspec Tk_GetPixels
KEYWORDS
- class, name, standard option, switch