NAME
       scrollbar - Create and manipulate scrollbar widgets

SYNOPSIS
       scrollbar pathName ?options?

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

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

WIDGET-SPECIFIC OPTIONS
       Command-Line Name:-activerelief
       Database Name:  activeRelief
       Database Class: ActiveRelief

              Specifies the relief to  use  when  displaying  the
              element  that  is  active,  if any.  Elements other
              than the active element are always displayed with a
              raised relief.

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

              Specifies  the prefix of a Tcl command to invoke to
              change the view in the widget associated  with  the
              scrollbar.   When  a user requests a view change by
              manipulating  the  scrollbar,  a  Tcl  command   is
              invoked.   The  actual  command  consists  of  this
              option  followed  by  additional   information   as
              described  later.   This option almost always has a
              value such as .t xview or .t yview,  consisting  of
              the  name  of  a  widget  and  either xview (if the
              scrollbar is for  horizontal  scrolling)  or  yview
              (for  vertical  scrolling).  All scrollable widgets
              have xview and yview commands that take exactly the
              additional  arguments  appended by the scrollbar as
              described in SCROLLING COMMANDS below.

       Command-Line Name:-elementborderwidth
       Database Name:  elementBorderWidth
       Database Class: BorderWidth

              Specifies the width of  borders  drawn  around  the
              internal  elements of the scrollbar (the two arrows
              and the slider).  The value may  have  any  of  the
              forms acceptable to Tk_GetPixels.  If this value is
              less than zero, the value of the borderWidth option
              is used in its place.

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

              Specifies  the  desired  narrow  dimension  of  the
              scrollbar window, not including 3-D border, if any.
              For  vertical scrollbars this will be the width and
              for horizontal scrollbars this will be the  height.
              The  value  may have any of the forms acceptable to
              Tk_GetPixels.


DESCRIPTION
       The scrollbar command creates a new window (given  by  the
       pathName  argument)  and makes it into a scrollbar widget.
       Additional options, described above, may be  specified  on
       the  command  line  or in the option database to configure
       aspects of the scrollbar such as its colors,  orientation,
       and  relief.   The  scrollbar 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 scrollbar is a widget that displays two arrows,  one  at
       each  end  of  the  scrollbar,  and a slider in the middle
       portion of the scrollbar.  It provides  information  about
       what  is  visible in an associated window that displays an
       document of some sort (such as a file being  edited  or  a
       drawing).   The  position  and size of the slider indicate
       which portion of the document is visible in the associated
       window.    For  example,  if  the  slider  in  a  vertical
       scrollbar covers the top third of the area between the two
       arrows,  it  means that the associated window displays the
       top third of its document.

       Scrollbars  can  be  used  to  adjust  the  view  in   the
       associated  window by clicking or dragging with the mouse.
       See the BINDINGS section below for details.


ELEMENTS
       A scrollbar displays five elements, which are referred  to
       in the widget commands for the scrollbar:

       arrow1    The top or left arrow in the scrollbar.

       trough1   The region between the slider and arrow1.

       slider    The  rectangle that indicates what is visible in
                 the associated widget.

       trough2   The region between the slider and arrow2.

       arrow2    The bottom or right arrow in the scrollbar.


WIDGET COMMAND
       The scrollbar 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
       scrollbar widgets:

       pathName activate ?element?
              Marks  the  element indicated by element as active,
              which causes it to be displayed as specified by the
              activeBackground  and  activeRelief  options.   The
              only element values understood by this command  are
              arrow1,  slider,  or arrow2.  If any other value is
              specified then no element of the scrollbar will  be
              active.   If  element is not specified, the command
              returns the name of the element that  is  currently
              active, or an empty string if no element is active.

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

       pathName delta deltaX deltaY
              Returns  a  real  number  indicating the fractional
              change in the scrollbar setting that corresponds to
              a given change in slider position.  For example, if
              the scrollbar is horizontal, the  result  indicates
              how  much the scrollbar setting must change to move
              the slider deltaX pixels to the  right  (deltaY  is
              ignored   in  this  case).   If  the  scrollbar  is
              vertical,  the  result  indicates  how   much   the
              scrollbar  setting  must  change to move the slider
              deltaY pixels down.  The arguments and  the  result
              may be zero or negative.

       pathName fraction x y
              Returns  a  real  number between 0 and 1 indicating
              where the point given by x and y lies in the trough
              area  of the scrollbar.  The value 0 corresponds to
              the  top  or  left  of  the  trough,  the  value  1
              corresponds to the bottom or right, 0.5 corresponds
              to the middle, and so on.  X and y  must  be  pixel
              coordinates relative to the scrollbar widget.  If x
              and y refer to a  point  outside  the  trough,  the
              closest point in the trough is used.

       pathName get
              Returns  the  scrollbar  settings  in the form of a
              list whose elements are the arguments to  the  most
              recent set widget command.

       pathName identify x y
              Returns  the  name  of  the element under the point
              given by x and y (such  as  arrow1),  or  an  empty
              string  if the point does not lie in any element of
              the scrollbar.  X and y must be  pixel  coordinates
              relative to the scrollbar widget.

       pathName set first last
              This   command   is   invoked  by  the  scrollbar's
              associated widget to tell the scrollbar  about  the
              current  view in the widget.  The command takes two
              arguments, each of which is a real fraction between
              0  and  1.  The fractions describe the range of the
              document that is visible in the associated  widget.
              For  example,  if  first is 0.2 and last is 0.4, it
              means that the first part of the  document  visible
              in  the  window  is  20%  of  the  way  through the
              document, and the last visible part is 40%  of  the
              way through.


SCROLLING COMMANDS
       When the user interacts with the scrollbar, for example by
       dragging the slider, the scrollbar notifies the associated
       widget  that it must change its view.  The scrollbar makes
       the notification by evaluating  a  Tcl  command  generated
       from  the  scrollbar's  -command  option.  The command may
       take any of the following forms.  In each case, prefix  is
       the  contents  of the -command option, which usually has a
       form like .t yview

       prefix moveto fraction
              Fraction is a real number between  0  and  1.   The
              widget  should  adjust  its  view so that the point
              given by fraction appears at the beginning  of  the
              widget.    If  fraction  is  0  it  refers  to  the
              beginning of the document.  1.0 refers to  the  end
              of  the document, 0.333 refers to a point one-third
              of the way through the document, and so on.

       prefix scroll number units
              The widget should adjust its view by number  units.
              The  units  are defined in whatever way makes sense
              for the widget, such as characters or  lines  in  a
              text  widget.   Number is either 1, which means one
              unit should scroll off  the  top  or  left  of  the
              window,  or  -1,  which  means that one unit should
              scroll off the bottom or right of the window.

       prefix scroll number pages
              The widget should adjust its view by number  pages.
              It  is  up to the widget to define the meaning of a
              page;  typically it is slightly less than what fits
              in  the  window,  so that there is a slight overlap
              between the old and new views.  Number is either 1,
              which means the next page should become visible, or
              -1, which  means  that  the  previous  page  should
              become visible.


OLD COMMAND SYNTAX
       In  versions  of  Tk  before  4.0,  the set and get widget
       commands used  a  different  form.   This  form  is  still
       supported   for   backward   compatibility,   but   it  is
       deprecated.  In the old command  syntax,  the  set  widget
       command has the following form:

       pathName set totalUnits windowUnits firstUnit lastUnit
              In  this  form  the  arguments  are  all  integers.
              TotalUnits gives the total size of the object being
              displayed in the associated widget.  The meaning of
              one unit depends on  the  associated  widget;   for
              example,  in  a  text  editor  widget  units  might
              correspond to lines of text.  WindowUnits indicates
              the  total  number  of  units  that  can fit in the
              associated  window  at  one  time.   FirstUnit  and
              lastUnit  give  the  indices  of the first and last
              units currently visible in  the  associated  window
              (zero corresponds to the first unit of the object).

       Under the old syntax the get widget command returns a list
       of   four   integers,   consisting   of   the  totalUnits,
       windowUnits, firstUnit, and lastUnit values from the  last
       set widget command.

       The commands generated by scrollbars also have a different
       form when the old syntax is being used:

       prefix unit
              Unit is  an  integer  that  indicates  what  should
              appear  at  the  top  or  left  of  the  associated
              widget's window.  It has the same  meaning  as  the
              firstUnit  and lastUnit arguments to the set widget
              command.

       The most recent set widget command determines  whether  or
       not  to  use  the  old  syntax.   If  it is given two real
       arguments then the new syntax will be used in the  future,
       and  if  it  is  given four integer arguments then the old
       syntax will be used.


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


       [1]    Pressing button 1 over arrow1 causes  the  view  in
              the  associated  widget  to  shift up (left) by one
              unit so that the  document  appears  to  move  down
              (right)  one unit.  If the button is held down, the
              action auto-repeats.

       [2]    Pressing button 1 over trough1 causes the  view  in
              the  associated  widget  to  shift up (left) by one
              screenful so that the document appears to move down
              (right) one screenful.  If the button is held down,
              the action auto-repeats.

       [3]    Pressing button 1  over  the  slider  and  dragging
              causes  the  view  to drag with the slider.  If the
              jump option is true, then  the  view  doesn't  drag
              along  with  the  slider;  it changes only when the
              mouse button is released.

       [4]    Pressing button 1 over trough2 causes the  view  in
              the  associated widget to shift down (right) by one
              screenful so that the document appears to  move  up
              (left)  one screenful.  If the button is held down,
              the action auto-repeats.

       [5]    Pressing button 1 over arrow2 causes  the  view  in
              the  associated widget to shift down (right) by one
              unit so that the document appears to move up (left)
              one  unit.   If the button is held down, the action
              auto-repeats.

       [6]    If button 2 is  pressed  over  the  trough  or  the
              slider, it sets the view to correspond to the mouse
              position;  dragging the mouse with  button  2  down
              causes  the view to drag with the mouse.  If button
              2 is pressed over one of the arrows, it causes  the
              same behavior as pressing button 1.

       [7]    If  button  1 is pressed with the Control key down,
              then if the mouse is over  arrow1  or  trough1  the
              view   changes  to  the  very  top  (left)  of  the
              document;  if the mouse is over arrow2  or  trough2
              the  view changes to the very bottom (right) of the
              document;  if the mouse is anywhere else  then  the
              button press has no effect.

       [8]    In  vertical  scrollbars  the Up and Down keys have
              the same behavior as mouse clicks over  arrow1  and
              arrow2,  respectively.   In  horizontal  scrollbars
              these keys have no effect.

       [9]    In vertical scrollbars Control-Up and  Control-Down
              have the same behavior as mouse clicks over trough1
              and   trough2,   respectively.     In    horizontal
              scrollbars these keys have no effect.

       [10]   In  horizontal scrollbars the Up and Down keys have
              the same behavior as mouse clicks over  arrow1  and
              arrow2, respectively.  In vertical scrollbars these
              keys have no effect.

       [11]   In horizontal scrollbars  Control-Up  and  Control-
              Down  have  the  same behavior as mouse clicks over
              trough1 and  trough2,  respectively.   In  vertical
              scrollbars these keys have no effect.

       [12]   The  Prior  and Next keys have the same behavior as
              mouse   clicks   over    trough1    and    trough2,
              respectively.

       [13]   The  Home  key  adjusts  the  view to the top (left
              edge) of the document.

       [14]   The End key adjusts the view to the  bottom  (right
              edge) of the document.


KEYWORDS
