NAME
       scale - Create and manipulate scale widgets

SYNOPSIS
       scale pathName ?options?

STANDARD OPTIONS
       -activebackground     -foreground          -relief
       -background           -highlightbackground -repeatdelay
       -borderwidth          -highlightcolor      -repeatinterval
       -cursor               -highlightthickness  -takefocus
       -font                 -orient              -troughcolor

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

WIDGET-SPECIFIC OPTIONS
       Command-Line Name:-bigincrement
       Database Name:  bigIncrement
       Database Class: BigIncrement

              Some interactions with the scale cause its value to
              change by ``large'' increments;  this option speci-
              fies the size of the large increments.   If  speci-
              fied as 0, the large increments default to 1/10 the
              range of the scale.

       Command-Line Name:-command
       Database Name:  command
       Database Class: Command

              Specifies the prefix of a  Tcl  command  to  invoke
              whenever  the scale's value is changed via a widget
              command.   The  actual  command  consists  of  this
              option  followed by a space and a real number indi-
              cating the new value of the scale.

       Command-Line Name:-digits
       Database Name:  digits
       Database Class: Digits

              An integer specifying how many  significant  digits
              should be retained when converting the value of the
              scale to a string.  If the number is less  than  or
              equal  to  zero,  then the scale picks the smallest
              value that guarantees that  every  possible  slider
              position prints as a different string.

       Command-Line Name:-from
       Database Name:  from
       Database Class: From

              A  real  value corresponding to the left or top end
              of the scale.
       Command-Line Name:-label
       Database Name:  label
       Database Class: Label

              A string to display as a label for the scale.   For
              vertical  scales the label is displayed just to the
              right of the top end of the scale.  For  horizontal
              scales  the  label is displayed just above the left
              end of the scale.  If the option is specified as an
              empty string, no label is displayed.

       Command-Line Name:-length
       Database Name:  length
       Database Class: Length

              Specifies  the  desired long dimension of the scale
              in screen units (i.e. any of the  forms  acceptable
              to  Tk_GetPixels).  For vertical scales this is the
              scale's height;  for horizontal scales  it  is  the
              scale's width.

       Command-Line Name:-resolution
       Database Name:  resolution
       Database Class: Resolution

              A  real  value  specifying  the  resolution for the
              scale.  If this value is greater than zero then the
              scale's  value  will  always  be rounded to an even
              multiple of this value, as will tick marks and  the
              endpoints  of the scale.  If the value is less than
              zero then no rounding occurs.  Defaults to 1 (i.e.,
              the value will be integral).

       Command-Line Name:-showvalue
       Database Name:  showValue
       Database Class: ShowValue

              Specifies a boolean value indicating whether or not
              the current value of the scale is to be  displayed.

       Command-Line Name:-sliderlength
       Database Name:  sliderLength
       Database Class: SliderLength

              Specfies the size of the slider, measured in screen
              units along the slider's long dimension.  The value
              may  be specified in any of the forms acceptable to
              Tk_GetPixels.

       Command-Line Name:-sliderrelief
       Database Name:  sliderRelief
       Database Class: SliderRelief

              Specifies  the  relief  to  use  when  drawing  the
              slider, such as raised or sunken.

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

              Specifies  one of three states for the scale:  nor-
              mal, active, or disabled.  If the scale is disabled
              then  the  value  may  not be changed and the scale
              won't activate.  If the scale is active, the slider
              is  displayed  using  the  color  specified  by the
              activeBackground option.

       Command-Line Name:-tickinterval
       Database Name:  tickInterval
       Database Class: TickInterval

              Must be  a  real  value.   Determines  the  spacing
              between  numerical tick marks displayed below or to
              the left of the slider.  If 0, no tick  marks  will
              be displayed.

       Command-Line Name:-to
       Database Name:  to
       Database Class: To

              Specifies  a  real value corresponding to the right
              or bottom end of the  scale.   This  value  may  be
              either less than or greater than the from option.

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

              Specifies  the name of a global variable to link to
              the scale.  Whenever  the  value  of  the  variable
              changes,  the  scale  will  update  to reflect this
              value.  Whenever the scale is manipulated  interac-
              tively,  the  variable  will be modified to reflect
              the scale's new value.

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

              Specifies  the  desired  narrow  dimension  of  the
              trough  in  screen  units  (i.e.  any  of the forms
              acceptable to Tk_GetPixels).  For  vertical  scales
              this  is the trough's width;  for horizontal scales
              this is the trough's height.


DESCRIPTION
       The scale command creates  a  new  window  (given  by  the
       pathName  argument)  and  makes  it  into  a scale widget.
       Additional options, described above, may be  specified  on
       the  command  line  or in the option database to configure
       aspects of the scale such as its colors, orientation,  and
       relief.   The scale 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 scale is a widget that displays a rectangular trough and
       a small slider.  The trough corresponds to a range of real
       values  (determined  by  the  from,  to,  and   resolution
       options), and the position of the slider selects a partic-
       ular real value.  The slider's  position  (and  hence  the
       scale's  value) may be adjusted with the mouse or keyboard
       as described in the BINDINGS section below.  Whenever  the
       scale's  value is changed, a Tcl command is invoked (using
       the command option) to notify other interested widgets  of
       the  change.   In  addition, the value of the scale can be
       linked to a Tcl variable (using the variable  option),  so
       that changes in either are reflected in the other.

       Three  annotations  may be displayed in a scale widget:  a
       label appearing at the top right of the widget  (top  left
       for  horizontal  scales),  a  number displayed just to the
       left of the slider (just above the slider  for  horizontal
       scales),  and a collection of numerical tick marks just to
       the left of the current value (just below the  trough  for
       horizontal  scales).   Each of these three annotations may
       be enabled or disabled using the configuration options.


WIDGET COMMAND
       The scale 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  scale
       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 scale 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 path-
              Name (see Tk_ConfigureInfo for information  on  the
              format  of this list).  If option is specified with
              no value, then the command returns a list  describ-
              ing  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 scale command.

       pathName coords ?value?
              Returns a list whose elements are the x and y coor-
              dinates  of  the  point along the centerline of the
              trough that corresponds  to  value.   If  value  is
              omitted then the scale's current value is used.

       pathName get ?x y?
              If  x  and y are omitted, returns the current value
              of the scale.  If x and y are specified, they  give
              pixel  coordinates  within the widget;  the command
              returns the scale value corresponding to the  given
              pixel.  Only one of x or y is used:  for horizontal
              scales y is ignored, and for vertical scales  x  is
              ignored.

       pathName identify x y
              Returns  a string indicating what part of the scale
              lies under the coordinates given by  x  and  y.   A
              return value of slider means that the point is over
              the slider;  trough1 means that the point  is  over
              the  portion of the slider above  or to the left of
              the slider; and trough2 means  that  the  point  is
              over  the  portion  of  the  slider below or to the
              right of the slider.  If the point isn't  over  one
              of these elements, an empty string is returned.

       pathName set value
              This command is invoked to change the current value
              of the scale, and hence the position at  which  the
              slider is displayed.  Value gives the new value for
              the scale.  The command has no effect if the  scale
              is disabled.


BINDINGS
       Tk  automatically  creates  class bindings for scales that
       give them  the  following  default  behavior.   Where  the
       behavior  is different for vertical and horizontal scales,
       the horizontal behavior is described in parentheses.

       [1]    If button 1 is pressed in the trough,  the  scale's
              value  will  be  incremented  or decremented by the
              value of the resolution option so that  the  slider
              moves  in the direction of the cursor.  If the but-
              ton is held down, the action auto-repeats.
       [2]    If button 1 is pressed over the slider, the  slider
              can be dragged with the mouse.

       [3]    If  button 1 is pressed in the trough with the Con-
              trol key down, the slider moves all the way to  the
              end  of  its  range,  in  the direction towards the
              mouse cursor.

       [4]    If button 2 is pressed, the scale's value is set to
              the  mouse  position.  If the mouse is dragged with
              button 2 down, the scale's value changes  with  the
              drag.

       [5]    The  Up  and Left keys move the slider up (left) by
              the value of the resolution option.

       [6]    The Down  and  Right  keys  move  the  slider  down
              (right) by the value of the resolution option.

       [7]    Control-Up  and  Control-Left  move  the  slider up
              (left) by the value of the bigIncrement option.

       [8]    Control-Down and Control-Right move the slider down
              (right) by the value of the bigIncrement option.

       [9]    Home  moves the slider to the top (left) end of its
              range.

       [10]   End moves the slider to the bottom (right)  end  of
              its range.

       If  the scale is disabled using the state option then none
       of the above bindings have any effect.

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


KEYWORDS
       scale, slider, trough, widget
