checkbutton(n)               Tk Built-In Commands               checkbutton(n)



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NAME
       checkbutton - Create and manipulate checkbutton widgets

SYNOPSIS
       checkbutton pathName ?options?

STANDARD OPTIONS
       -activebackground     -disabledforeground  -padx
       -activeforeground     -font                -pady
       -anchor               -foreground          -relief
       -background           -highlightbackground -takefocus
       -bitmap               -highlightcolor      -text
       -borderwidth          -highlightthickness  -textvariable
       -compound             -image               -underline
       -cursor               -justify             -wraplength

       See the options manual entry for details on the standard options.

WIDGET-SPECIFIC OPTIONS
       Command-Line Name:-command
       Database Name:  command
       Database Class: Command

              Specifies a Tcl command to associate with the button.  This
              command is typically invoked when mouse button 1 is released
              over the button window.  The button's global variable (-variable
              option) will be updated before the command is invoked.

       Command-Line Name:-height
       Database Name:  height
       Database Class: Height

              Specifies a desired height for the button.  If an image or
              bitmap is being displayed in the button then the value is in
              screen units (i.e. any of the forms acceptable to Tk_GetPixels);
              for text it is in lines of text.  If this option is not
              specified, the button's desired height is computed from the size
              of the image or bitmap or text being displayed in it.

       Command-Line Name:-indicatoron
       Database Name:  indicatorOn
       Database Class: IndicatorOn

              Specifies whether or not the indicator should be drawn.  Must be
              a proper boolean value.  If false, the -relief option is ignored
              and the widget's relief is always sunken if the widget is
              selected and raised otherwise.

       Command-Line Name:-offrelief
       Database Name:  offRelief
       Database Class: OffRelief

              Specifies the relief for the checkbutton when the indicator is
              not drawn and the checkbutton is off.  The default value is
              "raised".  By setting this option to "flat" and setting
              -indicatoron to false and -overrelief to "raised", the effect is
              achieved of having a flat button that raises on mouse-over and
              which is depressed when activated.  This is the behavior
              typically exhibited by the Bold, Italic, and Underline
              checkbuttons on the toolbar of a word-processor, for example.

       Command-Line Name:-offvalue
       Database Name:  offValue
       Database Class: Value

              Specifies value to store in the button's associated variable
              whenever this button is deselected.  Defaults to "0".

       Command-Line Name:-onvalue
       Database Name:  onValue
       Database Class: Value

              Specifies value to store in the button's associated variable
              whenever this button is selected.  Defaults to "1".

       Command-Line Name:-overrelief
       Database Name:  overRelief
       Database Class: OverRelief

              Specifies an alternative relief for the checkbutton, to be used
              when the mouse cursor is over the widget.  This option can be
              used to make toolbar buttons, by configuring -relief flat
              -overrelief raised.  If the value of this option is the empty
              string, then no alternative relief is used when the mouse cursor
              is over the checkbutton.  The empty string is the default value.

       Command-Line Name:-selectcolor
       Database Name:  selectColor
       Database Class: Background

              Specifies a background color to use when the button is selected.
              If indicatorOn is true then the color is used as the background
              for the indicator regardless of the select state.  If
              indicatorOn is false, this color is used as the background for
              the entire widget, in place of background or activeBackground,
              whenever the widget is selected.  If specified as an empty
              string then no special color is used for displaying when the
              widget is selected.

       Command-Line Name:-selectimage
       Database Name:  selectImage
       Database Class: SelectImage

              Specifies an image to display (in place of the -image option)
              when the checkbutton is selected.  This option is ignored unless
              the -image option has been specified.

       Command-Line Name:-state
       Database Name:  state
       Database Class: State

              Specifies one of three states for the checkbutton:  normal,
              active, or disabled.  In normal state the checkbutton is
              displayed using the -foreground and -background options.  The
              active state is typically used when the pointer is over the
              checkbutton.  In active state the checkbutton is displayed using
              the -activeforeground and -activebackground options.  Disabled
              state means that the checkbutton should be insensitive:  the
              default bindings will refuse to activate the widget and will
              ignore mouse button presses.  In this state the
              -disabledforeground and -background options determine how the
              checkbutton is displayed.

       Command-Line Name:-tristateimage
       Database Name:  tristateImage
       Database Class: TristateImage

              Specifies an image to display (in place of the -image option)
              when the checkbutton is in tri-state mode.  This option is
              ignored unless the -image option has been specified.

       Command-Line Name:-tristatevalue
       Database Name:  tristateValue
       Database Class: Value

              Specifies the value that causes the checkbutton to display the
              multi-value selection, also known as the tri-state mode.
              Defaults to "".

       Command-Line Name:-variable
       Database Name:  variable
       Database Class: Variable

              Specifies the name of a global variable to set to indicate
              whether or not this button is selected.  Defaults to the name of
              the button within its parent (i.e. the last element of the
              button window's path name).

       Command-Line Name:-width
       Database Name:  width
       Database Class: Width

              Specifies a desired width for the button.  If an image or bitmap
              is being displayed in the button then the value is in screen
              units (i.e. any of the forms acceptable to Tk_GetPixels); for
              text it is in characters.  If this option is not specified, the
              button's desired width is computed from the size of the image or
              bitmap or text being displayed in it.
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DESCRIPTION
       The checkbutton command creates a new window (given by the pathName
       argument) and makes it into a checkbutton widget.  Additional options,
       described above, may be specified on the command line or in the option
       database to configure aspects of the checkbutton such as its colors,
       font, text, and initial relief.  The checkbutton command returns its
       pathName argument.  At the time this command is invoked, there must not
       exist a window named pathName, but pathName's parent must exist.

       A checkbutton is a widget that displays a textual string, bitmap or
       image and a square called an indicator.  If text is displayed, it must
       all be in a single font, but it can occupy multiple lines on the screen
       (if it contains newlines or if wrapping occurs because of the
       -wraplength option) and one of the characters may optionally be
       underlined using the -underline option.  A checkbutton has all of the
       behavior of a simple button, including the following: it can display
       itself in either of three different ways, according to the -state
       option; it can be made to appear raised, sunken, or flat; it can be
       made to flash; and it invokes a Tcl command whenever mouse button 1 is
       clicked over the checkbutton.

       In addition, checkbuttons can be selected.  If a checkbutton is
       selected then the indicator is normally drawn with a selected
       appearance, and a Tcl variable associated with the checkbutton is set
       to a particular value (normally 1).  The indicator is drawn with a
       check mark inside.  If the checkbutton is not selected, then the
       indicator is drawn with a deselected appearance, and the associated
       variable is set to a different value (typically 0).  The indicator is
       drawn without a check mark inside.  In the special case where the
       variable (if specified) has a value that matches the tristatevalue, the
       indicator is drawn with a tri-state appearance and is in the tri-state
       mode indicating mixed or multiple values.  (This is used when the check
       box represents the state of multiple items.)  The indicator is drawn in
       a platform dependent manner.  Under Unix and Windows, the background
       interior of the box is "grayed".  Under Mac, the indicator is drawn
       with a dash mark inside.  By default, the name of the variable
       associated with a checkbutton is the same as the name used to create
       the checkbutton.  The variable name, and the "on", "off" and "tristate"
       values stored in it, may be modified with options on the command line
       or in the option database.  Configuration options may also be used to
       modify the way the indicator is displayed (or whether it is displayed
       at all).  By default a checkbutton is configured to select and deselect
       itself on alternate button clicks.  In addition, each checkbutton
       monitors its associated variable and automatically selects and
       deselects itself when the variables value changes to and from the
       button's "on", "off" and "tristate" values.

WIDGET COMMAND
       The checkbutton command creates a new Tcl command whose name is
       pathName.  This command may be used to invoke various operations on the
       widget.  It has the following general form:
              pathName option ?arg arg ...?
       Option and the args determine the exact behavior of the command.  The
       following commands are possible for checkbutton widgets:

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

       pathName configure ?option? ?value option value ...?
              Query or modify the configuration options of the widget.  If no
              option is specified, returns a list describing all of the
              available options for pathName (see Tk_ConfigureInfo 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
              corresponding 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
              checkbutton command.

       pathName deselect
              Deselects the checkbutton and sets the associated variable to
              its "off" value.

       pathName flash
              Flashes the checkbutton.  This is accomplished by redisplaying
              the checkbutton several times, alternating between active and
              normal colors.  At the end of the flash the checkbutton is left
              in the same normal/active state as when the command was invoked.
              This command is ignored if the checkbutton's state is disabled.

       pathName invoke
              Does just what would have happened if the user invoked the
              checkbutton with the mouse: toggle the selection state of the
              button and invoke the Tcl command associated with the
              checkbutton, if there is one.  The return value is the return
              value from the Tcl command, or an empty string if there is no
              command associated with the checkbutton.  This command is
              ignored if the checkbutton's state is disabled.

       pathName select
              Selects the checkbutton and sets the associated variable to its
              "on" value.

       pathName toggle
              Toggles the selection state of the button, redisplaying it and
              modifying its associated variable to reflect the new state.

BINDINGS
       Tk automatically creates class bindings for checkbuttons that give them
       the following default behavior:

       [1]    On Unix systems, a checkbutton activates whenever the mouse
              passes over it and deactivates whenever the mouse leaves the
              checkbutton.  On Mac and Windows systems, when mouse button 1 is
              pressed over a checkbutton, the button activates whenever the
              mouse pointer is inside the button, and deactivates whenever the
              mouse pointer leaves the button.

       [2]    When mouse button 1 is pressed over a checkbutton, it is invoked
              (its selection state toggles and the command associated with the
              button is invoked, if there is one).

       [3]    When a checkbutton has the input focus, the space key causes the
              checkbutton to be invoked.  Under Windows, there are additional
              key bindings; plus (+) and equal (=) select the button, and
              minus (-) deselects the button.

       If the checkbutton's state is disabled then none of the above actions
       occur:  the checkbutton is completely non-responsive.

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

EXAMPLE
       This example shows a group of uncoupled checkbuttons.

              labelframe .lbl -text "Steps:"
              checkbutton .c1 -text Lights  -variable lights
              checkbutton .c2 -text Cameras -variable cameras
              checkbutton .c3 -text Action! -variable action
              pack .c1 .c2 .c3 -in .lbl
              pack .lbl

SEE ALSO
       button(n), options(n), radiobutton(n), ttk::checkbutton(n)

KEYWORDS
       checkbutton, widget



Tk                                    4.4                       checkbutton(n)
