NAME
       canvas - Create and manipulate canvas widgets

SYNOPSIS
       canvas pathName ?options?

STANDARD OPTIONS
       background      insertBorderWidth              reliefxScrollCommand
       borderWidth     insertOffTime  selectBackgroundyScrollCommand
       cursor          insertOnTime   selectBorderWidth
       insertBackground               insertWidth     selectForeground

       See  the ``options'' manual entry for details on the stan-
       dard options.

WIDGET-SPECIFIC OPTIONS
       Name:           closeEnough
       Class:          CloseEnough
       Command-Line Switch:-closeenough

              Specifies a  floating-point  value  indicating  how
              close the mouse cursor must be to an item before it
              is considered to be ``inside'' the item.   Defaults
              to 1.0.

       Name:           confine
       Class:          Confine
       Command-Line Switch:-confine

              Specifies a boolean value that indicates whether or
              not it should be allowable to set the canvas's view
              outside  the  region  defined  by  the scrollRegion
              argument.  Defaults to true, which means  that  the
              view  will be constrained within the scroll region.

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

              Specifies a desired window height that  the  canvas
              widget  should  request  from its geometry manager.
              The value may be specified  in  any  of  the  forms
              described in the COORDINATES section below.

       Name:           scrollIncrement
       Class:          ScrollIncrement
       Command-Line Switch:-scrollincrement

              Specifies  a  distance  used  as  increment  during
              scrolling:  when one of the  arrow  buttons  on  an
              associated  scrollbar  is pressed, the picture will
              shift by this distance.  The distance may be speci-
              fied  in  any of the forms described in the COORDI-
              NATES section below.
       Name:           scrollRegion
       Class:          ScrollRegion
       Command-Line Switch:-scrollregion

              Specifies a list with four  coordinates  describing
              the  left,  top, right, and bottom coordinates of a
              rectangular  region.   This  region  is  used   for
              scrolling  purposes  and  is  considered  to be the
              boundary of the information in the canvas.  Each of
              the  coordinates  may  be  specified  in any of the
              forms given in the COORDINATES section below.

       Name:           width
       Class:          width
       Command-Line Switch:-width

              Specifies a desired window width  that  the  canvas
              widget  should  request  from its geometry manager.
              The value may be specified  in  any  of  the  forms
              described in the COORDINATES section below.


INTRODUCTION
       The  canvas  command  creates  a  new window (given by the
       pathName argument) and makes  it  into  a  canvas  widget.
       Additional  options,  described above, may be specified on
       the command line or in the option  database  to  configure
       aspects  of  the canvas such as its colors and 3-D relief.
       The canvas command returns its pathName argument.  At  the
       time  this command is invoked, there must not exist a win-
       dow named pathName, but pathName's parent must exist.

       Canvas widgets implement structured  graphics.   A  canvas
       displays  any  number  of  items, which may be things like
       rectangles, circles, lines, and text.  Items may be manip-
       ulated  (e.g.  moved  or  re-colored)  and commands may be
       associated with items in much the same way that  the  bind
       command allows commands to be bound to widgets.  For exam-
       ple, a particular command may be associated with the <But-
       ton-1>  event so that the command is invoked whenever but-
       ton 1 is pressed with the mouse cursor over an item.  This
       means that items in a canvas can have behaviors defined by
       the Tcl scripts bound to them.


DISPLAY LIST
       The items in a canvas are ordered for purposes of display,
       with  the  first  item in the display list being displayed
       first, followed by the next item in the list, and  so  on.
       Items  later  in  the  display list obscure those that are
       earlier in the display list and are sometimes referred  to
       as  being ``on top'' of earlier items.  When a new item is
       created it is placed at the end of the  display  list,  on
       top  of  everything  else.  Widget commands may be used to
       re-arrange the order of the display list.


ITEM IDS AND TAGS
       Items in a canvas widget may be named  in  either  of  two
       ways: by id or by tag.  Each item has a unique identifying
       number which is assigned to that item when it is  created.
       The  id  of an item never changes and id numbers are never
       re-used within the lifetime of a canvas widget.

       Each item may also have any number of tags associated with
       it.  A tag is just a string of characters, and it may take
       any form except that of an integer.  For example, ``x123''
       is  OK  but ``123'' isn't.  The same tag may be associated
       with many different items.  This is commonly done to group
       items  in  various  interesting  ways;   for  example, all
       selected items might be given the tag ``selected''.

       The tag all is implicitly associated with  every  item  in
       the  canvas;   it  may be used to invoke operations on all
       the items in the canvas.

       The tag current is managed automatically by Tk; it applies
       to the current item, which is the topmost item whose drawn
       area covers the position of  the  mouse  cursor.   If  the
       mouse  is not in the canvas widget or is not over an item,
       then no item has the current tag.

       When specifying items in canvas widget  commands,  if  the
       specifier is an integer then it is assumed to refer to the
       single item with that id.  If  the  specifier  is  not  an
       integer,  then  it is assumed to refer to all of the items
       in the canvas that have a tag matching the specifier.  The
       symbol  tagOrId is used below to indicate that an argument
       specifies either an id that selects a single item or a tag
       that  selects  zero  or  more items.  Some widget commands
       only operate on a single item at a time;   if  tagOrId  is
       specified  in  a  way  that names multiple items, then the
       normal behavior is for the command to use the first  (low-
       est)  of  these items in the display list that is suitable
       for the command.  Exceptions are noted in the widget  com-
       mand descriptions below.


COORDINATES
       All  coordinates  related to canvases are stored as float-
       ing-point numbers.  Coordinates and distances  are  speci-
       fied  in  screen  units,  which are floating-point numbers
       optionally followed by one of several letters.  If no let-
       ter  is  supplied  then the distance is in pixels.  If the
       letter is m then the distance is  in  millimeters  on  the
       screen;  if it is c then the distance is in centimeters; i
       means inches, and p means  printers  points  (1/72  inch).
       Larger  y-coordinates refer to points lower on the screen;
       larger x-coordinates refer to points farther to the right.


TRANSFORMATIONS
       Normally  the origin of the canvas coordinate system is at
       the upper-left corner of the window containing the canvas.
       It  is possible to adjust the origin of the canvas coordi-
       nate system relative to the origin of the window using the
       xview  and  yview widget commands;  this is typically used
       for scrolling.  Canvases do not support scaling  or  rota-
       tion  of the canvas coordinate system relative to the win-
       dow coordinate system.

       Indidividual items may be moved  or  scaled  using  widget
       commands described below, but they may not be rotated.


INDICES
       Text  items support the notion of an index for identifying
       particular positions within the item.   Indices  are  used
       for  commands  such as inserting text, deleting a range of
       characters, and setting the insertion cursor position.  An
       index  may  be  specified  in any of a number of ways, and
       different types of items may support different  forms  for
       specifying  indices.   Text  items  support  the following
       forms for an index;  if you define new types of  text-like
       items,  it  would be advisable to support as many of these
       forms as practical.  Note that it is possible to refer  to
       the  character  just  after the last one in the text item;
       this is necessary for such tasks as inserting new text  at
       the end of the item.

       number    A  decimal  number  giving  the  position of the
                 desired  character  within  the  text  item.   0
                 refers  to  the  first  character, 1 to the next
                 character, and so on.  A number less than  0  is
                 treated as if it were zero, and a number greater
                 than the length of the text item is  treated  as
                 if it were equal to the length of the text item.

       end       Refers to the character just after the last  one
                 in the item (same as the number of characters in
                 the item).

       insert    Refers to the character just  before  which  the
                 insertion cursor is drawn in this item.

       sel.first Refers  to  the  first selected character in the
                 item.  If the selection isn't in this item  then
                 this form is illegal.

       sel.last  Refers  to  the  last  selected character in the
                 item.  If the selection isn't in this item  then
                 this form is illegal.
       @x,y      Refers  to the character at the point given by x
                 and y, where x and y are specified in the  coor-
                 dinate  system  of  the  canvas.  If x and y lie
                 outside the  coordinates  covered  by  the  text
                 item, then they refer to the first or last char-
                 acter in the line that is closest to  the  given
                 point.


WIDGET COMMAND
       The canvas 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 widget commands are possible for
       canvas widgets:

       pathName addtag tag searchSpec ?arg arg ...?
              For each item that meets the constraints  specified
              by  searchSpec and the args, add tag to the list of
              tags associated with the item if it  isn't  already
              present on that list.  It is possible that no items
              will satisfy the constraints  given  by  searchSpec
              and  args, in which case the command has no effect.
              This command returns an  empty  string  as  result.
              SearchSpec  and arg's may take any of the following
              forms:

              above tagOrId
                     Selects the item just after (above) the  one
                     given  by  tagOrId  in the display list.  If
                     tagOrId denotes more than one item, then the
                     last (topmost) of these items in the display
                     list is used.

              all    Selects all the items in the canvas.

              below tagOrId
                     Selects the item just before (below) the one
                     given  by  tagOrId  in the display list.  If
                     tagOrId denotes more than one item, then the
                     first (lowest) of these items in the display
                     list is used.

              closest x y ?halo? ?start?
                     Selects the item closest to the point  given
                     by x and y.  If more than one item is at the
                     same closest distance (e.g. two items  over-
                     lap  the  point), then the top-most of these
                     items (the last one in the display list)  is
                     used.  If halo is specified, then it must be
                     a non-negative value.  Any item closer  than
                     halo  to  the point is considered to overlap
                     it.  The start argument may be used to  step
                     circularly  through  all  the closest items.
                     If start is  specified,  it  names  an  item
                     using a tag or id (if by tag, it selects the
                     first item in  the  display  list  with  the
                     given  tag).   Instead of selecting the top-
                     most closest item, this form will select the
                     topmost  closest item that is below start in
                     the display list;  if no such  item  exists,
                     then  the  selection behaves as if the start
                     argument had not been specified.

              enclosed x1 y1 x2 y2
                     Selects all the  items  completely  enclosed
                     within  the  rectangular region given by x1,
                     y1, x2, and y2.  X1 must be no greater  then
                     x2 and y1 must be no greater than y2.

              overlapping x1 y1 x2 y2
                     Selects  all  the  items that overlap or are
                     enclosed within the rectangular region given
                     by  x1,  y1,  x2,  and  y2.   X1  must be no
                     greater then x2 and y1 must  be  no  greater
                     than y2.

              withtag tagOrId
                     Selects all the items given by tagOrId.

       pathName bbox tagOrId ?tagOrId tagOrId ...?
              Returns a list with four elements giving an approx-
              imate bounding box for all the items named  by  the
              tagOrId  arguments.   The list has the form ``x1 y1
              x2 y2'' such that the drawn areas of all the  named
              elements are within the region bounded by x1 on the
              left, x2 on the right, y1 on the top, and y2 on the
              bottom.   The  return  value  may  overestimate the
              actual bounding box by a few pixels.  If  no  items
              match  any  of  the tagOrId arguments then an empty
              string is returned.

       pathName bind tagOrId ?sequence? ?command?
              This command associates command with all the  items
              given  by  tagOrId  such  that  whenever  the event
              sequence given by sequence occurs for  one  of  the
              items  the  command  will  be invoked.  This widget
              command is similar to the bind command except  that
              it operates on items in a canvas rather than entire
              widgets.  See the bind manual  entry  for  complete
              details on the syntax of sequence and the substitu-
              tions performed on command before invoking it.   If
              all  arguments  are specified then a new binding is
              created, replacing any  existing  binding  for  the
              same  sequence  and tagOrId (if the first character
              of command is ``+'' then command augments an exist-
              ing  binding  rather  than  replacing it).  In this
              case the return value is an empty string.  If  com-
              mand  is  omitted then the command returns the com-
              mand associated with tagOrId and sequence (an error
              occurs  if there is no such binding).  If both com-
              mand and sequence  are  omitted  then  the  command
              returns a list of all the sequences for which bind-
              ings have been defined for tagOrId.

              The only events for which bindings may be specified
              are  those  related to the mouse and keyboard, such
              as Enter, Leave, ButtonPress, Motion, and KeyPress.
              The handling of events in canvases uses the current
              item defined in ITEM IDS AND TAGS above.  Enter and
              Leave  events  trigger  for an item when it becomes
              the current item or ceases to be the current  item;
              note that these events are different than Enter and
              Leave events for windows.  Mouse-related events are
              directed  to  the  current item, if any.  Keyboard-
              related events are directed to the focus  item,  if
              any (see the focus widget command below for more on
              this).

              It is possible for multiple commands to be bound to
              a  single event sequence for a single object.  This
              occurs, for example, if one command  is  associated
              with  the  item's id and another is associated with
              one of the item's  tags.   When  this  occurs,  the
              first  matching binding is used.  A binding for the
              item's id has highest  priority,  followed  by  the
              oldest  tag for the item and proceeding through all
              of the item's tags up  through  the  most-recently-
              added one.  If a binding is associated with the tag
              all, the binding will have lower priority than  all
              other bindings associated with the item.

       pathName canvasx screenx ?gridspacing?
              Given  a  screen  x-coordinate screenx this command
              returns the canvas x-coordinate that  is  displayed
              at  that  location.   If  gridspacing is specified,
              then the canvas coordinate is rounded to the  near-
              est multiple of gridspacing units.

       pathName canvasy screeny ?gridspacing?
              Given  a  screen  y-coordinate screeny this command
              returns the canvas y-coordinate that  is  displayed
              at  that  location.   If  gridspacing is specified,
              then the canvas coordinate is rounded to the  near-
              est multiple of gridspacing units.

       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 identi-
              cal 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 canvas command.

       pathName coords tagOrId ?x0 y0 ...?
              Query or modify  the  coordinates  that  define  an
              item.   If  no coordinates are specified, this com-
              mand returns a list whose elements are the  coordi-
              nates of the item named by tagOrId.  If coordinates
              are specified, then they replace the current  coor-
              dinates  for  the named item.  If tagOrId refers to
              multiple items, then the first one in  the  display
              list is used.

       pathName create type x y ?x y ...? ?option value ...?
              Create  a  new  item in pathName of type type.  The
              exact format of the arguments after type depends on
              type,  but  usually they consist of the coordinates
              for one or more points, followed by  specifications
              for zero or more item options.  See the subsections
              on individual item types below for more on the syn-
              tax  of  this command.  This command returns the id
              for the new item.

       pathName dchars tagOrId first ?last?
              For each item given by tagOrId, delete the  charac-
              ters  in  the range given by first and last, inclu-
              sive.  If some of the items given by tagOrId  don't
              support  text  operations,  then  they are ignored.
              First and last are indices of characters within the
              item(s)  as described in INDICES above.  If last is
              omitted,  it  defaults  to  first.   This   command
              returns an empty string.

       pathName delete ?tagOrId tagOrId ...?
              Delete each of the items given by each tagOrId, and
              return an empty string.

       pathName dtag tagOrId ?tagToDelete?
              For each of the items given by tagOrId, delete  the
              tag  given  by  tagToDelete  from the list of those
              associated with the item.  If an item doesn't  have
              the  tag tagToDelete then the item is unaffected by
              the command.  If tagToDelete  is  omitted  then  it
              defaults to tagOrId.  This command returns an empty
              string.

       pathName find searchCommand ?arg arg ...?
              This command returns a list consisting of  all  the
              items   that  meet  the  constraints  specified  by
              searchCommand and arg's.   SearchCommand  and  args
              have  any  of the forms accepted by the addtag com-
              mand.

       pathName focus ?tagOrId?
              Set the keyboard focus for the canvas widget to the
              item  given  by tagOrId.  If tagOrId refers to sev-
              eral items, then the focus is set to the first such
              item  in  the display list that supports the inser-
              tion cursor.   If  tagOrId  doesn't  refer  to  any
              items,  or  if  none  of them support the insertion
              cursor, then the focus isn't changed.   If  tagOrId
              is an empty string, then the focus item is reset so
              that no item has the  focus.   If  tagOrId  is  not
              specified  then  the command returns the id for the
              item that currently has  the  focus,  or  an  empty
              string if no item has the focus.

              Once  the  focus  has been set to an item, the item
              will display the insertion cursor and all  keyboard
              events  will  be  directed to that item.  The focus
              item within a canvas and the focus  window  on  the
              screen  (set  with  the  focus command) are totally
              independent: a given item doesn't actually have the
              input focus unless (a) its canvas is the focus win-
              dow and (b) the item is the focus item  within  the
              canvas.   In  most  cases it is advisable to follow
              the focus widget command with the focus command  to
              set  the  focus  window to the canvas (if it wasn't
              there already).

       pathName gettags tagOrId
              Return a list whose elements are the  tags  associ-
              ated  with  the  item given by tagOrId.  If tagOrId
              refers to more than one item,  then  the  tags  are
              returned  from  the  first such item in the display
              list.  If tagOrId doesn't refer to any items, or if
              the  item contains no tags, then an empty string is
              returned.

       pathName icursor tagOrId index
              Set the position of the insertion  cursor  for  the
              item(s) given by tagOrId to just before the charac-
              ter whose position is given by index.  If  some  or
              all  of the items given by tagOrId don't support an
              insertion cursor then this command has no effect on
              them.   See  INDICES above for a description of the
              legal forms for index.  Note:  the insertion cursor
              is only displayed in an item if that item currently
              has the keyboard  focus  (see  the  widget  command
              focus,  below),  but the cursor position may be set
              even when the item doesn't have  the  focus.   This
              command returns an empty string.

       pathName index tagOrId index
              This  command  returns  a decimal string giving the
              numerical index  within  tagOrId  corresponding  to
              index.   Index  gives  a textual description of the
              desired position as  described  in  INDICES  above.
              The return value is guaranteed to lie between 0 and
              the number of characters within  the  item,  inclu-
              sive.   If  tagOrId  refers to multiple items, then
              the index is processed in the first of these  items
              that  supports indexing operations (in display list
              order).

       pathName insert tagOrId beforeThis string
              For each of the items given by tagOrId, if the item
              supports  text  insertion  then  string is inserted
              into the item's  text  just  before  the  character
              whose  index  is beforeThis.  See INDICES above for
              information about the forms allowed for beforeThis.
              This command returns an empty string.

       pathName  itemconfigure  tagOrId  ?option?  ?value?
              ?option value ...?
              This  command  is  similar  to the configure widget
              command  except  that  it  modifies   item-specific
              options  for  the items given by tagOrId instead of
              modifying options for the  overall  canvas  widget.
              If  no option is specified, returns a list describ-
              ing all of the available options for the first item
              given by tagOrId (see Tk_ConfigureInfo for informa-
              tion 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 each of the items given
              by tagOrId;  in this case the  command  returns  an
              empty  string.  The options and values are the same
              as those permissible in the create  widget  command
              when  the  item(s)  were  created; see the sections
              describing individual item types below for  details
              on the legal options.

       pathName lower tagOrId ?belowThis?
              Move  all  of  the  items given by tagOrId to a new
              position in the display list just before  the  item
              given by belowThis.  If tagOrId refers to more than
              one item then all are moved but the relative  order
              of  the moved items will not be changed.  BelowThis
              is a tag or id;  if it refers to more than one item
              then  the first (lowest) of these items in the dis-
              play list is used as the destination  location  for
              the  moved  items.   This  command returns an empty
              string.

       pathName move tagOrId xAmount yAmount
              Move each of the items given by tagOrId in the can-
              vas  coordinate  space  by adding xAmount to the x-
              coordinate of each point associated with  the  item
              and yAmount to the y-coordinate of each point asso-
              ciated with the  item.   This  command  returns  an
              empty string.

       pathName postscript ?option value option value ...?
              Generate  a  Postscript  representation for part or
              all of the canvas.  If the -file option  is  speci-
              fied  then  the Postscript is written to a file and
              an  empty  string  is  returned;    otherwise   the
              Postscript  is  returned  as the result of the com-
              mand.  The Postscript is  created  in  Encapsulated
              Postscript  form  using version 3.0 of the Document
              Structuring Conventions.  The option-value argument
              pairs provide additional information to control the
              generation of Postscript.   The  following  options
              are supported:

              -colormap varName
                     VarName  must  be the name of a global array
                     variable that specifies a color  mapping  to
                     use in the Postscript.  Each element of var-
                     Name must consist of Postscript code to  set
                     a particular color value (e.g. ``1.0 1.0 0.0
                     setrgbcolor'').    When   outputting   color
                     information  in the Postscript, Tk checks to
                     see if there is an element of  varName  with
                     the  same name as the color.  If so, Tk uses
                     the value of the element as  the  Postscript
                     command  to  set  the color.  If this option
                     hasn't been specified, or if there isn't  an
                     entry  in varName for a given color, then Tk
                     uses the red, green,  and  blue  intensities
                     from the X color.

              -colormode mode
                     Specifies  how  to output color information.
                     Mode must be either color  (for  full  color
                     output),  gray  (convert all colors to their
                     gray-scale equivalents) or mono (convert all
                     colors to black or white).
              -file fileName
                     Specifies  the  name of the file in which to
                     write the Postscript.  If this option  isn't
                     specified then the Postscript is returned as
                     the result of the command instead  of  being
                     written to a file.

              -fontmap varName
                     VarName  must  be the name of a global array
                     variable that specifies a  font  mapping  to
                     use in the Postscript.  Each element of var-
                     Name must consist of a  Tcl  list  with  two
                     elements,  which are the name and point size
                     of  a  Postscript  font.   When   outputting
                     Postscript  commands  for a particular font,
                     Tk checks to see if varName contains an ele-
                     ment  with  the  same  name as the font.  If
                     there is such  an  element,  then  the  font
                     information  contained  in  that  element is
                     used  in  the  Postscript.    Otherwise   Tk
                     attempts  to  guess  what Postscript font to
                     use.  Tk's guesses generally only  work  for
                     well-known fonts such as Times and Helvetica
                     and Courier, and only if  the  X  font  name
                     does  not  omit  any  dashes  up through the
                     point       size.        For        example,
                     -*-Courier-Bold-R-Normal--*-120-*  will work
                     but  *Courier-Bold-R-Normal*120*  will  not;
                     Tk needs the dashes to parse the font name).

              -height size
                     Specifies the height of the area of the can-
                     vas to print.  Defaults to the height of the
                     canvas window.

              -pageanchor anchor
                     Specifies which point of  the  printed  area
                     should  be appear over the positioning point
                     on the page (which is given  by  the  -pagex
                     and  -pagey options).  For example, -pagean-
                     chor n means that  the  top  center  of  the
                     printed  area should be over the positioning
                     point.  Defaults to center.

              -pageheight size
                     Specifies  that  the  Postscript  should  be
                     scaled  in  both x and y so that the printed
                     area is size high on  the  Postscript  page.
                     Size  consists  of  a  floating-point number
                     followed by c for centimeters, i for inches,
                     m  for  millimeters,  or  p  or  nothing for
                     printer's points (1/72 inch).   Defaults  to
                     the  height  of  the  printed  area  on  the
                     screen.  If both -pageheight and  -pagewidth
                     are specified then the scale factor from the
                     later option is used (non-uniform scaling is
                     not implemented).

              -pagewidth size
                     Specifies  that  the  Postscript  should  be
                     scaled in both x and y so that  the  printed
                     area  is  size  wide on the Postscript page.
                     Size has the same form as  for  -pageheight.
                     Defaults to the width of the printed area on
                     the  screen.   If   both   -pageheight   and
                     -pagewidth are specified then the scale fac-
                     tor from the  later  option  is  used  (non-
                     uniform scaling is not implemented).

              -pagex position
                     Position gives the x-coordinate of the posi-
                     tioning point on the Postscript page,  using
                     any  of  the  forms allowed for -pageheight.
                     Used in  conjunction  with  the  -pagey  and
                     -pageanchor  options  to determine where the
                     printed area appears on the Postscript page.
                     Defaults to the center of the page.

              -pagey position
                     Position gives the y-coordinate of the posi-
                     tioning point on the Postscript page,  using
                     any  of  the  forms allowed for -pageheight.
                     Used in  conjunction  with  the  -pagex  and
                     -pageanchor  options  to determine where the
                     printed area appears on the Postscript page.
                     Defaults to the center of the page.

              -rotate boolean
                     Boolean  specifies  whether the printed area
                     is to be rotated 90 degrees.  In non-rotated
                     output  the  x-axis of the printed area runs
                     along  the  short  dimension  of  the   page
                     (``portrait''  orientation); in rotated out-
                     put the x-axis runs along the long dimension
                     of  the  page  (``landscape''  orientation).
                     Defaults to non-rotated.

              -width size
                     Specifies the width of the area of the  can-
                     vas  to print.  Defaults to the width of the
                     canvas window.

              -x position
                     Specifies the x-coordinate of the left  edge
                     of  the  area  of  the  canvas that is to be
                     printed, in canvas coordinates,  not  window
                     coordinates.   Defaults to the coordinate of
                     the left edge of the window.
              -y position
                     Specifies the y-coordinate of the  top  edge
                     of  the  area  of  the  canvas that is to be
                     printed, in canvas coordinates,  not  window
                     coordinates.   Defaults to the coordinate of
                     the top edge of the window.

       pathName raise tagOrId ?aboveThis?
              Move all of the items given by  tagOrId  to  a  new
              position  in  the  display list just after the item
              given by aboveThis.  If tagOrId refers to more than
              one  item then all are moved but the relative order
              of the moved items will not be changed.   AboveThis
              is a tag or id;  if it refers to more than one item
              then the last (topmost) of these items in the  dis-
              play  list  is used as the destination location for
              the moved items.  This  command  returns  an  empty
              string.

       pathName scale tagOrId xOrigin yOrigin xScale yScale
              Rescale all of the items given by tagOrId in canvas
              coordinate space.  XOrigin and yOrigin identify the
              origin  for  the  scaling  operation and xScale and
              yScale identify the scale factors  for  x-  and  y-
              coordinates,  respectively  (a  scale factor of 1.0
              implies no change to that coordinate).  For each of
              the  points defining each item, the x-coordinate is
              adjusted to change the distance from xOrigin  by  a
              factor  of xScale.  Similarly, each y-coordinate is
              adjusted to change the distance from yOrigin  by  a
              factor  of  yScale.   This command returns an empty
              string.

       pathName scan option args
              This command is used to implement scanning on  can-
              vases.  It has two forms, depending on option:

              pathName scan mark x y
                     Records  x  and  y  and the canvas's current
                     view;  used in conjunction with  later  scan
                     dragto  commands.  Typically this command is
                     associated with a mouse button press in  the
                     widget  and  x  and y are the coordinates of
                     the mouse.  It returns an empty string.

              pathName scan dragto x y.
                     This command computes the difference between
                     its  x  and y arguments (which are typically
                     mouse coordinates) and the x and y arguments
                     to  the  last scan mark command for the wid-
                     get.  It then adjusts the view by  10  times
                     the difference in coordinates.  This command
                     is typically associated  with  mouse  motion
                     events  in the widget, to produce the effect
                     of dragging the canvas at high speed through
                     its  window.   The  return value is an empty
                     string.

       pathName select option ?tagOrId arg?
              Manipulates the selection in one of  several  ways,
              depending  on  option.  The command may take any of
              the forms described below.  In all of the  descrip-
              tions  below,  tagOrId  must  refer to an item that
              supports indexing and selection;  if it  refers  to
              multiple  items  then  the first of these that sup-
              ports indexing and the selection  is  used.   Index
              gives  a  textual  description of a position within
              tagOrId, as described in INDICES above.

              pathName select adjust tagOrId index
                     Locate the end of the selection  in  tagOrId
                     nearest to the character given by index, and
                     adjust that end of the selection  to  be  at
                     index  (i.e.  including but not going beyond
                     index).  The other end of the  selection  is
                     made  the  anchor point for future select to
                     commands.  If the selection isn't  currently
                     in  tagOrId  then  this  command behaves the
                     same  as  the  select  to  widget   command.
                     Returns an empty string.

              pathName select clear
                     Clear the selection if it is in this widget.
                     If the selection isn't in this  widget  then
                     the command has no effect.  Returns an empty
                     string.

              pathName select from tagOrId index
                     Set the selection anchor point for the  wid-
                     get to be just before the character given by
                     index in the item given  by  tagOrId.   This
                     command  doesn't  change  the selection;  it
                     just sets the fixed end of the selection for
                     future select to commands.  Returns an empty
                     string.

              pathName select item
                     Returns the id of the selected item, if  the
                     selection  is in an item in this canvas.  If
                     the selection is not in this canvas then  an
                     empty string is returned.

              pathName select to tagOrId index
                     Set  the selection to consist of those char-
                     acters  of  tagOrId  between  the  selection
                     anchor  point  and index.  The new selection
                     will include the character given  by  index;
                     it  will  include the character given by the
                     anchor point only if index is  greater  than
                     or  equal  to  the anchor point.  The anchor
                     point  is  determined  by  the  most  recent
                     select  adjust  or  select  from command for
                     this widget.  If the selection anchor  point
                     for  the  widget isn't currently in tagOrId,
                     then it is set to the same  character  given
                     by index.  Returns an empty string.

       pathName type tagOrId
              Returns the type of the item given by tagOrId, such
              as rectangle or text.  If tagOrId  refers  to  more
              than  one  item, then the type of the first item in
              the display list is returned.  If  tagOrId  doesn't
              refer  to  any items at all then an empty string is
              returned.

       pathName xview index
              Change the view in the canvas so  that  the  canvas
              position given by index appears at the left edge of
              the window.  This  command  is  typically  used  by
              scrollbars  to  scroll the canvas.  Index counts in
              units  of  scroll  increments  (the  value  of  the
              scrollIncrement  option):  a value of 0 corresponds
              to the left edge of the scroll region  (as  defined
              by  the  scrollRegion  option),  a value of 1 means
              one scroll unit to the right of this,  and  so  on.
              The return value is an empty string.

       pathName yview index
              Change  the  view  in the canvas so that the canvas
              position given by index appears at the top edge  of
              the  window.   This  command  is  typically used by
              scrollbars to scroll the canvas.  Index  counts  in
              units  of  scroll  increments  (the  value  of  the
              scrollIncrement option):  a value of 0  corresponds
              to the top edge of the scroll region (as defined by
              the scrollRegion option),  a value of 1  means  one
              scroll  unit  below  this,  and  so on.  The return
              value is an empty string.


OVERVIEW OF ITEM TYPES
       The sections below describe the  various  types  of  items
       supported by canvas widgets.  Each item type is character-
       ized by two things: first, the form of the create  command
       used  to  create instances of the type;  and second, a set
       of configuration options for items of that type, which may
       be  used  in the create and itemconfigure widget commands.
       Most items don't support indexing or selection or the com-
       mands  related  to  them, such as index and insert.  Where
       items do support these facilities, it is noted  explicitly
       in  the  descriptions  below  (at present, only text items
       provide this support).
ARC ITEMS
       Items of type arc appear  on  the  display  as  arc-shaped
       regions.   An arc is a section of an oval delimited by two
       angles (specified by the -start and -extent  options)  and
       displayed  in one of several ways (specified by the -style
       option).  Arcs are created with  widget  commands  of  the
       following form:

              pathName create arc x1 y1 x2 y2 ?option value option value ...?
       The  arguments  x1, y1, x2, and y2 give the coordinates of
       two diagonally opposite corners of  a  rectangular  region
       enclosing  the oval that defines the arc.  After the coor-
       dinates there may be any  number  of  option-value  pairs,
       each  of  which  sets one of the configuration options for
       the item.  These same option-value pairs may  be  used  in
       itemconfigure widget commands to change the item's config-
       uration.  The following options are supported for arcs:

       -extent degrees
              Specifies the size of the angular range occupied by
              the  arc.   The  arc's  range  extends  for degrees
              degrees counter-clockwise from the  starting  angle
              given  by  the -start option.  Degrees may be nega-
              tive.

       -fill color
              Fill the region of the arc with color.   Color  may
              have  any of the forms accepted by Tk_GetColor.  If
              color is an empty string (the default),  then  then
              the arc will not be filled.

       -outline color
              Color  specifies  a  color  to  use for drawing the
              arc's outline;   it  may  have  any  of  the  forms
              accepted  by  Tk_GetColor.  This option defaults to
              black.  If the arc's style is arc then this  option
              is  ignored  (the  section  of  perimeter is filled
              using the -fill option).  If color is specified  as
              an  empty  string  then no outline is drawn for the
              arc.

       -start degrees
              Specifies the beginning of the angular range  occu-
              pied  by  the  arc.   Degrees  is given in units of
              degrees   measured   counter-clockwise   from   the
              3-o'clock  position;   it may be either positive or
              negative.

       -stipple bitmap
              Indicates that the arc should be filled in a  stip-
              ple  pattern;  bitmap specifies the stipple pattern
              to  use,  in  any  of   the   forms   accepted   by
              Tk_GetBitmap.   If  the  -fill  option  hasn't been
              specified then  this  option  has  no  effect.   If
              bitmap is an empty string (the default), then fill-
              ing is done in a solid fashion.

       -style type
              Specifies how to draw the arc.  If type is pieslice
              (the default) then the arc's region is defined by a
              section of the oval's perimeter plus two line  seg-
              ments,  one between the center of the oval and each
              end of the perimeter section.   If  type  is  chord
              then  the  arc's  region is defined by a section of
              the oval's perimeter plus  a  single  line  segment
              connecting the two end points of the perimeter sec-
              tion.  If type is arc then the  arc's  region  con-
              sists of a section of the perimeter alone.  In this
              last case there is no outline for the arc  and  the
              -outline option is ignored.

       -tags tagList
              Specifies  a  set  of  tags  to  apply to the item.
              TagList consists of a  list  of  tag  names,  which
              replace  any  existing  tags for the item.  TagList
              may be an empty list.

       -width outlineWidth
              Specifies the width of  the  outline  to  be  drawn
              around  the  arc's  region,  in  any  of  the forms
              described in the COORDINATES section above.  If the
              -outline  option  has  been  specified  as an empty
              string then this option has no effect.   Wide  out-
              lines  will  be  drawn centered on the edges of the
              arc's region.  This option defaults to 1.0.


BITMAP ITEMS
       Items of type bitmap appear on the display as images  with
       two  colors,  foreground and background.  Bitmaps are cre-
       ated with widget commands of the following form:

              pathName create bitmap x y ?option value option value ...?
       The arguments x and y specify the coordinates of  a  point
       used  to  position  the  bitmap  on  the  display (see the
       -anchor option below for more information on  how  bitmaps
       are  displayed).   After  the coordinates there may be any
       number of option-value pairs, each of which  sets  one  of
       the  configuration  options  for  the  item.   These  same
       option-value pairs may be  used  in  itemconfigure  widget
       commands  to change the item's configuration.  The follow-
       ing options are supported for bitmaps:

       -anchor anchorPos
              AnchorPos tells how to position the bitmap relative
              to the positioning point for the item;  it may have
              any of the forms  accepted  by  Tk_GetAnchor.   For
              example,  if anchorPos is center then the bitmap is
              centered on the point;  if anchorPos is n then  the
              bitmap  will  be drawn so that its top center point
              is at the positioning point.  This option  defaults
              to center.

       -background color
              Specifies  a  color  to  use for each of the bitmap
              pixels whose value is 0.  Color may have any of the
              forms  accepted  by  Tk_GetColor.   If  this option
              isn't specified, or if it is specified as an  empty
              string, then the background color for the canvas is
              used.

       -bitmap bitmap
              Specifies  the  bitmap  to  display  in  the  item.
              Bitmap  may  have  any  of  the  forms  accepted by
              Tk_GetBitmap.

       -foreground color
              Specifies a color to use for  each  of  the  bitmap
              pixels whose value is 1.  Color may have any of the
              forms  accepted  by  Tk_GetColor  and  defaults  to
              black.

       -tags tagList
              Specifies  a  set  of  tags  to  apply to the item.
              TagList consists of a  list  of  tag  names,  which
              replace  any  existing  tags for the item.  TagList
              may be an empty list.


LINE ITEMS
       Items of type line appear on the display as  one  or  more
       connected line segments or curves.  Lines are created with
       widget commands of the following form:

              pathName create line x1 y1... xn yn ?option value option value ...?
       The arguments x1 through yn give  the  coordinates  for  a
       series  of  two  or  more points that describe a series of
       connected line segments.  After the coordinates there  may
       be  any  number  of option-value pairs, each of which sets
       one of the configuration options for the item.  These same
       option-value  pairs  may  be  used in itemconfigure widget
       commands to change the item's configuration.  The  follow-
       ing options are supported for lines:

       -arrow where
              Indicates whether or not arrowheads are to be drawn
              at one or both ends of the line.  Where  must  have
              one  of  the values none (for no arrowheads), first
              (for an arrowhead at the first point of the  line),
              last  (for  an  arrowhead  at the last point of the
              line), or both (for arrowheads at both ends).  This
              option defaults to none.
       -arrowshape shape
              This  option indicates how to draw arrowheads.  The
              shape argument must be a list with three  elements,
              each  specifying  a  distance  in  any of the forms
              described in the COORDINATES  section  above.   The
              first  element of the list gives the distance along
              the line from the neck of the arrowhead to its tip.
              The  second  element  gives  the distance along the
              line from the trailing points of the  arrowhead  to
              the  tip,  and the third element gives the distance
              from the outside edge of the line to  the  trailing
              points.   If  this  option  isn't specified then Tk
              picks a ``reasonable'' shape.

       -capstyle style
              Specifies the ways in which caps are to be drawn at
              the  endpoints  of the line.  Style may have any of
              the forms accepted by  Tk_GetCapStyle  (butt,  pro-
              jecting, or round).  If this option isn't specified
              then it defaults to  butt.   Where  arrowheads  are
              drawn the cap style is ignored.

       -fill color
              Color  specifies  a  color  to  use for drawing the
              line; it may have any of the  forms  acceptable  to
              Tk_GetColor.   It  may  also be an empty string, in
              which case the  line  will  be  transparent.   This
              option defaults to black.

       -joinstyle style
              Specifies  the ways in which joints are to be drawn
              at the vertices of the line.  Style may have any of
              the forms accepted by Tk_GetCapStyle (bevel, miter,
              or round).  If this option isn't specified then  it
              defaults  to  miter.  If the line only contains two
              points then this option is irrelevant.

       -smooth boolean
              Boolean must have one  of  the  forms  accepted  by
              Tk_GetBoolean.   It  indicates  whether  or not the
              line should be drawn as a curve.  If so,  the  line
              is  rendered as a set of Bezier splines: one spline
              is drawn for the first and  second  line  segments,
              one for the second and third, and so on.  Straight-
              line segments can be generated within  a  curve  by
              duplicating the end-points of the desired line seg-
              ment.

       -splinesteps number
              Specifies the  degree  of  smoothness  desired  for
              curves:  each spline will be approximated with num-
              ber line segments.  This option is  ignored  unless
              the -smooth option is true.
       -stipple bitmap
              Indicates that the line should be filled in a stip-
              ple pattern; bitmap specifies the  stipple  pattern
              to   use,   in   any   of  the  forms  accepted  by
              Tk_GetBitmap.  If bitmap is an  empty  string  (the
              default),  then filling is done in a solid fashion.

       -tags tagList
              Specifies a set of  tags  to  apply  to  the  item.
              TagList  consists  of  a  list  of tag names, which
              replace any existing tags for  the  item.   TagList
              may be an empty list.

       -width lineWidth
              LineWidth  specifies  the width of the line, in any
              of the forms described in the  COORDINATES  section
              above.   Wide  lines  will be drawn centered on the
              path specified by the points.  If this option isn't
              specified then it defaults to 1.0.


OVAL ITEMS
       Items  of  type oval appear as circular or oval regions on
       the display.  Each oval may have an outline,  a  fill,  or
       both.   Ovals are created with widget commands of the fol-
       lowing form:

              pathName create oval x1 y1 x2 y2 ?option value option value ...?
       The arguments x1, y1, x2, and y2 give the  coordinates  of
       two  diagonally  opposite  corners of a rectangular region
       enclosing the oval.  The oval will  include  the  top  and
       left  edges of the rectangle not the lower or right edges.
       If the region is square then the resulting oval is  circu-
       lar;  otherwise it is elongated in shape.  After the coor-
       dinates there may be any  number  of  option-value  pairs,
       each  of  which  sets one of the configuration options for
       the item.  These same option-value pairs may  be  used  in
       itemconfigure widget commands to change the item's config-
       uration.  The following options are supported for ovals:

       -fill color
              Fill the area of the oval with  color.   Color  may
              have  any of the forms accepted by Tk_GetColor.  If
              color is an empty string (the default),  then  then
              the oval will not be filled.

       -outline color
              Color  specifies  a  color  to  use for drawing the
              oval's outline;  it  may  have  any  of  the  forms
              accepted  by  Tk_GetColor.  This option defaults to
              black.  If color is an empty string then no outline
              will be drawn for the oval.
       -stipple bitmap
              Indicates that the oval should be filled in a stip-
              ple pattern; bitmap specifies the  stipple  pattern
              to   use,   in   any   of  the  forms  accepted  by
              Tk_GetBitmap.  If  the  -fill  option  hasn't  been
              specified  then  this  option  has  no  effect.  If
              bitmap is an empty string (the default), then fill-
              ing is done in a solid fashion.

       -tags tagList
              Specifies  a  set  of  tags  to  apply to the item.
              TagList consists of a  list  of  tag  names,  which
              replace  any  existing  tags for the item.  TagList
              may be an empty list.

       -width outlineWidth
              outlineWidth specifies the width of the outline  to
              be  drawn  around  the  oval,  in  any of the forms
              described in the COORDINATES section above.  If the
              -outline  option  hasn't  been  specified then this
              option has no effect.  Wide outlines are drawn cen-
              tered  on  the oval path defined by x1, y1, x2, and
              y2.  This option defaults to 1.0.


POLYGON ITEMS
       Items of type polygon appear as polygonal or curved filled
       regions  on the display.  Polygons are created with widget
       commands of the following form:

              pathName create polygon x1 y1 ... xn yn ?option value option value ...?
       The arguments x1 through yn specify  the  coordinates  for
       three  or  more  points that define a closed polygon.  The
       first and last points may be the same;  whether  they  are
       or  not,  Tk  will  draw  the polygon as a closed polygon.
       After the coordinates there may be any number  of  option-
       value  pairs,  each of which sets one of the configuration
       options for the item.  These same option-value  pairs  may
       be  used  in  itemconfigure  widget commands to change the
       item's configuration.  The following options are supported
       for polygons:

       -fill color
              Color specifies a color to use for filling the area
              of the polygon;  it  may  have  any  of  the  forms
              acceptable  to  Tk_GetColor.   If color is an empty
              string then the polygon will be transparent.   This
              option defaults to black.

       -smooth boolean
              Boolean  must  have  one  of  the forms accepted by
              Tk_GetBoolean It indicates whether or not the poly-
              gon  should  be  drawn with a curved perimeter.  If
              so, the outline of the polygon  becomes  a  set  of
              Bezier splines, one spline for the first and second
              line segments, one for the second and third, and so
              on.   Straight-line  segments can be generated in a
              smoothed polygon by duplicating the  end-points  of
              the desired line segment.

       -splinesteps number
              Specifies  the  degree  of  smoothness  desired for
              curves:  each spline will be approximated with num-
              ber  line  segments.  This option is ignored unless
              the -smooth option is true.

       -stipple bitmap
              Indicates that the polygon should be  filled  in  a
              stipple  pattern; bitmap specifies the stipple pat-
              tern to use,  in  any  of  the  forms  accepted  by
              Tk_GetBitmap.   If  bitmap  is an empty string (the
              default), then filling is done in a solid  fashion.

       -tags tagList
              Specifies  a  set  of  tags  to  apply to the item.
              TagList consists of a  list  of  tag  names,  which
              replace  any  existing  tags for the item.  TagList
              may be an empty list.


RECTANGLE ITEMS
       Items of type rectangle appear as rectangular  regions  on
       the  display.  Each rectangle may have an outline, a fill,
       or both.  Rectangles are created with widget  commands  of
       the following form:

              pathName create rectangle x1 y1 x2 y2 ?option value option value ...?
       The  arguments  x1, y1, x2, and y2 give the coordinates of
       two diagonally opposite  corners  of  the  rectangle  (the
       rectangle  will  include  its upper and left edges but not
       its lower or right edges).  After  the  coordinates  there
       may  be  any  number  of option-value pairs, each of which
       sets one of the configuration options for the item.  These
       same  option-value pairs may be used in itemconfigure wid-
       get commands to change the item's configuration.  The fol-
       lowing options are supported for rectangles:

       -fill color
              Fill  the  area  of the rectangle with color, which
              may be specified in any of the  forms  accepted  by
              Tk_GetColor.   If  color  is  an  empty string (the
              default), then  then  the  rectangle  will  not  be
              filled.

       -outline color
              Draw an outline around the edge of the rectangle in
              color.  Color may have any of the forms accepted by
              Tk_GetColor.   This  option  defaults to black.  If
              color is an empty string then no  outline  will  be
              drawn for the rectangle.

       -stipple bitmap
              Indicates  that the rectangle should be filled in a
              stipple pattern; bitmap specifies the stipple  pat-
              tern  to  use,  in  any  of  the  forms accepted by
              Tk_GetBitmap.  If  the  -fill  option  hasn't  been
              specified  then  this  option  has  no  effect.  If
              bitmap is an empty string (the default), then fill-
              ing is done in a solid fashion.

       -tags tagList
              Specifies  a  set  of  tags  to  apply to the item.
              TagList consists of a  list  of  tag  names,  which
              replace  any  existing  tags for the item.  TagList
              may be an empty list.

       -width outlineWidth
              OutlineWidth specifies the width of the outline  to
              be  drawn around the rectangle, in any of the forms
              described in the COORDINATES section above.  If the
              -outline  option  hasn't  been  specified then this
              option has no effect.  Wide outlines are drawn cen-
              tered  on  the  rectangular path defined by x1, y1,
              x2, and y2.  This option defaults to 1.0.


TEXT ITEMS
       A text item displays a string of characters on the  screen
       in  one  or  more  lines.  Text items support indexing and
       selection, along with the  following  text-related  canvas
       widget  commands:   dchars, focus, icursor, index, insert,
       select.  Text items are created with  widget  commands  of
       the following form:

              pathName create text x y ?option value option value ...?
       The  arguments  x and y specify the coordinates of a point
       used to position the text on the display (see the  options
       below  for  more  information  on  how text is displayed).
       After the coordinates there may be any number  of  option-
       value  pairs,  each of which sets one of the configuration
       options for the item.  These same option-value  pairs  may
       be  used  in  itemconfigure  widget commands to change the
       item's configuration.  The following options are supported
       for text items:

       -anchor anchorPos
              AnchorPos  tells  how to position the text relative
              to the positioning point for the text;  it may have
              any  of  the  forms  accepted by Tk_GetAnchor.  For
              example, if anchorPos is center then  the  text  is
              centered  on the point;  if anchorPos is n then the
              text will be drawn such that the top  center  point
              of the rectangular region occupied by the text will
              be at the positioning point.  This option  defaults
              to center.

       -fill color
              Color specifies a color to use for filling the text
              characters; it may have any of the  forms  accepted
              by  Tk_GetColor.   If  this  option isn't specified
              then it defaults to black.

       -font fontName
              Specifies the font to use for the text item.  Font-
              Name    may    be    any   string   acceptable   to
              Tk_GetFontStruct.  If this option isn't  specified,
              it defaults to a system-dependent font.

       -justify how
              Specifies how to justify the text within its bound-
              ing region.  How must be one of  the  values  left,
              right,  or center.  This option will only matter if
              the text is displayed as multiple  lines.   If  the
              option is omitted, it defaults to left.

       -stipple bitmap
              Indicates  that the text should be drawn in a stip-
              pled pattern rather than  solid;  bitmap  specifies
              the  stipple  pattern  to  use, in any of the forms
              accepted by Tk_GetBitmap.  If bitmap  is  an  empty
              string  (the  default)  then the text is drawn in a
              solid fashion.

       -tags tagList
              Specifies a set of  tags  to  apply  to  the  item.
              TagList  consists  of  a  list  of tag names, which
              replace any existing tags for  the  item.   TagList
              may be an empty list.

       -text string
              String  specifies the characters to be displayed in
              the  text  item.   Newline  characters  cause  line
              breaks.   The  characters  in  the item may also be
              changed with the insert and delete widget commands.
              This option defaults to an empty string.

       -width lineLength
              Specifies  a  maximum  line length for the text, in
              any of the forms described in the COORDINATES  sec-
              tion  abov.   If  this option is zero (the default)
              the text is broken into lines only at newline char-
              acters.   However,  if this option is non-zero then
              any line that would be longer  than  lineLength  is
              broken  just  before  a space character to make the
              line shorter than lineLength;  the space  character
              is treated as if it were a newline character.
WINDOW ITEMS
       Items  of type window cause a particular window to be dis-
       played at a given position on the  canvas.   Window  items
       are created with widget commands of the following form:

              pathName create window x y ?option value option value ...?
       The  arguments  x and y specify the coordinates of a point
       used to position  the  window  on  the  display  (see  the
       -anchor  option  below for more information on how bitmaps
       are displayed).  After the coordinates there  may  be  any
       number  of  option-value  pairs, each of which sets one of
       the  configuration  options  for  the  item.   These  same
       option-value  pairs  may  be  used in itemconfigure widget
       commands to change the item's configuration.  The  follow-
       ing options are supported for window items:

       -anchor anchorPos
              AnchorPos tells how to position the window relative
              to the positioning point for the item;  it may have
              any  of  the  forms  accepted by Tk_GetAnchor.  For
              example, if anchorPos is center then the window  is
              centered  on the point;  if anchorPos is n then the
              window will be drawn so that its top  center  point
              is  at the positioning point.  This option defaults
              to center.

       -height pixels
              Specifies the height to assign to the  item's  win-
              dow.  Pixels may have any of the forms described in
              the COORDINATES  section  above.   If  this  option
              isn't  specified, or if it is specified as an empty
              string, then the window is given whatever height it
              requests internally.

       -tags tagList
              Specifies  a  set  of  tags  to  apply to the item.
              TagList consists of a  list  of  tag  names,  which
              replace  any  existing  tags for the item.  TagList
              may be an empty list.

       -width pixels
              Specifies the width to assign to the item's window.
              Pixels  may  have any of the forms described in the
              COORDINATES section above.  If  this  option  isn't
              specified,  or  if  it  is  specified  as  an empty
              string, then the window is given whatever width  it
              requests internally.

       -window pathName
              Specifies  the  window to associate with this item.
              The window specified by pathName must either  be  a
              child  of  the  canvas  widget  or  a child of some
              ancestor of the canvas widget.   PathName  may  not
              refer to a top-level window.
APPLICATION-DEFINED ITEM TYPES
       It  is  possible for individual applications to define new
       item types for canvas widgets using C  code.   The  inter-
       faces for this mechanism are not presently documented, and
       it's possible they may change, but you should be  able  to
       see  how  they  work by examining the code for some of the
       existing item types.


BINDINGS
       In the current implementation, new canvases are not  given
       any default behavior:  you'll have to execute explicit Tcl
       commands to give the canvas its behavior.


CREDITS
       Tk's canvas widget is a blatant ripoff of ideas from  Joel
       Bartlett's  ezd program.  Ezd provides structured graphics
       in a Scheme environment and preceded canvases by a year or
       two.   Its  simple  mechanisms  for  placing and animating
       graphical objects inspired the functions of canvases.


KEYWORDS
       canvas, widget
