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button(n)




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NAME

       button - Create and manipulate button widgets


SYNOPSIS

       button pathName ?options?


STANDARD OPTIONS

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

       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 com-
              mand is typically invoked when mouse button 1 is  released  over
              the button window.

       Command-Line Name:-default
       Database Name:  default
       Database Class: Default

              Specifies  one  of  three  states  for the default ring: normal, |
              active, or disabled.  In active state, the button is drawn  with |
              the  platform specific appearance for a default button.  In nor- |
              mal state, the  button  is  drawn  with  the  platform  specific |
              appearance  for  a  non-default  button, leaving enough space to |
              draw the default  button  appearance.   The  normal  and  active |
              states  will  result  in  buttons of the same size.  In disabled |
              state, the button is drawn with the non-default  button  appear- |
              ance without leaving space for the default appearance.  The dis- |
              abled state may result in  a  smaller  button  than  the  active |
              state.

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

              Specifies  a desired height for the button.  If an image or bit-
              map 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.                   |

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

              Specifies an alternative relief for the button, 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 |
              button.  The empty string is the default value.

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

              Specifies  one  of three states for the button:  normal, active,
              or disabled.  In normal state the button is displayed using  the
              foreground  and  background  options.  The active state is typi-
              cally used when the pointer is over the button.  In active state
              the  button  is displayed using the activeForeground and active-
              Background options.  Disabled state means that the button 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
              button is displayed.

       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 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  button  command  creates a new window (given by the pathName argu-
       ment) and makes it into a button widget.  Additional options, described
       above,  may  be specified on the command line or in the option database
       to configure aspects of the button such as its colors, font, text,  and
       initial  relief.  The button 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  button  is a widget that displays a textual string, bitmap or image.
       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  char-
       acters may optionally be underlined using the underline option.  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; and it
       can be made to flash.  When a user  invokes  the  button  (by  pressing
       mouse  button  1 with the cursor over the button), then the Tcl command
       specified in the -command option is invoked.


WIDGET COMMAND

       The button 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 button 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  but-
              ton 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 avail-
              able  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 button command.

       pathName flash
              Flash the button.  This is accomplished by redisplaying the but-
              ton several times, alternating between active and normal colors.
              At  the  end  of  the  flash the button is left in the same nor-
              mal/active state as when the command was invoked.  This  command
              is ignored if the button's state is disabled.

       pathName invoke
              Invoke  the  Tcl command associated with the button, 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
              button.  This command is ignored if the button's state  is  dis-
              abled.


DEFAULT BINDINGS

       Tk  automatically  creates  class  bindings  for buttons that give them
       default behavior:

       [1]    A button activates whenever the mouse passes over it and deacti-
              vates whenever the mouse leaves the button.  Under Windows, this |
              binding is only active when mouse button 1 has been pressed over |
              the button.

       [2]    A  button's  relief is changed to sunken whenever mouse button 1
              is pressed over the button, and the relief is  restored  to  its
              original value when button 1 is later released.

       [3]    If  mouse  button  1 is pressed over a button and later released
              over the button, the button is invoked.  However, if  the  mouse
              is  not over the button when button 1 is released, then no invo-
              cation occurs.

       [4]    When a button has the input focus, the space key causes the but-
              ton to be invoked.

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

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


KEYWORDS

       button, widget

Tk                                    4.4                            button(n)

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