checkbutton

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

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

WIDGET-SPECIFIC OPTIONS
       [-command 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.
       [-height 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 isn't specified, the
       button's desired height is computed from the size of the image or
       bitmap or text being displayed in it.  [-indicatoron 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.  [-offvalue offValue] Specifies value to store in the
       button's associated variable whenever this button is deselected.
       Defaults to ``0''.  [-onvalue onValue] Specifies value to store in the
       button's associated variable whenever this button is selected.
       Defaults to ``1''.  [-selectcolor selectColor] Specifies a background
       color to use when the button is selected.  If indicatorOn is true then
       the color applies to the indicator.  Under Windows, this 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.
       [-selectimage 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.  [-state 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.  [-variable variable] Specifies name of 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).  [-width 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 isn't
       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).  Under Unix, the indicator is drawn │
       with a sunken relief and a special color.  Under Windows, 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).  Under   │
       Unix, the indicator is drawn with a raised relief and no special color. │
       Under Windows, the indicator is drawn without a check 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'' and ``off'' 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'' value.


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.


KEYWORDS
       checkbutton, widget



Tk                                    4.4                       checkbutton(n)