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







checkbutton - Create and manipulate checkbutton widgets








checkbutton pathName ?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.








[-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 is not 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.
    [-offrelief 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.
    [-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”.
    [-overrelief 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.
    [-selectcolor selectColor] 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.
    [-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. [-tristateimage
    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.
    [-tristatevalue tristateValue]
    Specifies the value that causes the checkbutton to display the multi-value
    selection, also known as the tri-state mode. Defaults to “”.
    [-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 is not specified, the button's desired width is
    computed from the size of the image or bitmap or text being displayed in
  it.










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.








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:


  

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

  

  
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.

  

  
Deselects the checkbutton and sets the associated variable to its
      “off” value.

  

  
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.

  

  
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.

  

  
Selects the checkbutton and sets the associated variable to its
      “on” value.

  

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










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.








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










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








checkbutton, widget







  

    4.4
    Tk