NAME
       canvas - Create and manipulate canvas widgets

SYNOPSIS
       canvas pathName ?options?

STANDARD OPTIONS
       -background           -insertborderwidth   -selectborderwidth
       -borderwidth          -insertofftime       -selectforeground
       -cursor               -insertontime        -takefocus
       -highlightbackground  -insertwidth         -xscrollcommand
       -highlightcolor       -relief              -yscrollcommand
       -highlightthickness   -state
       -insertbackground     -selectbackground

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

WIDGET-SPECIFIC OPTIONS
       Command-Line Name:-closeenough
       Database Name:  closeEnough
       Database Class: 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.

       Command-Line Name:-confine
       Database Name:  confine
       Database Class: 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.

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

       Command-Line Name:-scrollregion
       Database Name:  scrollRegion
       Database Class: 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.

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

              Modifies  the default state of the canvas where state may be set
              to one  of:  normal,  disabled,  or  hidden.  Individual  canvas
              objects  all  have their own state option which may override the
              default state.  Many options can  take  separate  specifications
              such that the appearance of the item can be different in differ-
              ent situations. The options that start with active  control  the
              appearence  when  the mouse pointer is over it, while the option
              starting with disabled controls the appearence when the state is
              disabled.   Canvas  items  which  are disabled will not react to
              canvas bindings.

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

       Command-Line Name:-xscrollincrement
       Database Name:  xScrollIncrement
       Database Class: ScrollIncrement

              Specifies  an  increment for horizontal scrolling, in any of the
              usual forms permitted for screen distances.   If  the  value  of
              this  option  is  greater  than zero, the horizontal view in the
              window will be constrained so that the canvas  x  coordinate  at
              the  left  edge  of  the  window  is  always an even multiple of
              xScrollIncrement;  furthermore, the units for  scrolling  (e.g.,
              the change in view when the left and right arrows of a scrollbar
              are selected) will also be xScrollIncrement.  If  the  value  of
              this  option  is  less  than  or  equal to zero, then horizontal
              scrolling is unconstrained.

       Command-Line Name:-yscrollincrement
       Database Name:  yScrollIncrement
       Database Class: ScrollIncrement

              Specifies an increment for vertical scrolling,  in  any  of  the
              usual  forms  permitted  for  screen distances.  If the value of
              this option is greater than zero, the vertical view in the  win-
              dow  will  be constrained so that the canvas y coordinate at the
              top  edge  of  the  window  is  always  an  even   multiple   of
              yScrollIncrement;   furthermore,  the units for scrolling (e.g.,
              the change in view when the top and bottom arrows of a scrollbar
              are  selected)  will  also be yScrollIncrement.  If the value of
              this option is  less  than  or  equal  to  zero,  then  vertical
              scrolling is unconstrained.


INTRODUCTION
       The  canvas  command  creates a new window (given by the pathName argu-
       ment) 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 window 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 manipulated (e.g. moved or re-colored) and com-
       mands may be associated with items in much the same way that  the  bind
       command allows commands to be bound to widgets.  For example, a partic-
       ular command may be associated with the <Button-1> event  so  that  the
       command  is  invoked whenever button 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  every-
       thing else.  Widget commands may be used to re-arrange the order of the
       display list.

       Window items are an exception to the above rules.  The underlying  win-
       dow  systems require them always to be drawn on top of other items.  In
       addition, the stacking order of window items is not affected by any  of
       the  canvas  widget  commands; you must use the raise and lower Tk com-
       mands instead.


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 cur-
       rent item, which is the topmost item whose drawn area covers the  posi-
       tion  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.

       tagOrId may contain a logical expressions of tags by  using  operators:
       '&&', '||', '^' '!', and parenthezised subexpressions.  For example:
                    .c find withtag {(a&&!b)||(!a&&b)}
       or equivalently:
                    .c find withtag {a^b}
       will find only those items with either "a" or "b" tags, but not both.

       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  nor-
       mal  behavior  is  for  the  command to use the first (lowest) of these
       items in the display list that is suitable for the command.  Exceptions
       are noted in the widget command descriptions below.


COORDINATES
       All  coordinates  related to canvases are stored as floating-point num-
       bers.  Coordinates and distances are specified in screen  units,  which
       are  floating-point  numbers optionally followed by one of several let-
       ters.  If no letter 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.   Coordinates  can be specified either as an even number of
       parameters, or as a single list parameter containing an even number  of
       x and y coordinate values.


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 coordinate system relative to the ori-
       gin 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 window  coordinate
       system.

       Individual 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.   In  a similar fashion, line and polygon
       items support index for identifying, inserting and deleting subsets  of
       their  coordinates.  Indices are used for commands such as inserting or
       deleting a range of characters or coordinates, and setting  the  inser-
       tion  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  advis-
       able  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.  Lines and Polygons don't support the insertion cursor
       and  the  selection.  Their  indixes  are  supposed  to be even always,
       because coordinates always appear in pairs.

       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. If indexes are odd  for  lines
                 and  polygons, they will be automatically decremented by one.
                 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.  For  poly-
                 gons,  numbers  less than 0 or greater then the length of the
                 coordinate list will be adjusted by  adding  or  substracting
                 the  length  until the result is between zero and the length,
                 inclusive.

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

       insert    Refers to the character just before which the insertion  cur-
                 sor  is drawn in this item. Not valid for lines and polygons.

       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 or coordinate at the point given by x
                 and  y,  where x and y are specified in the coordinate system
                 of the canvas.  If x and y lie outside the  coordinates  cov-
                 ered  by  the text item, then they refer to the first or last
                 character in the line that is closest to the given point.


DASH PATTERNS
       Many items support the notion of an dash pattern for outlines.

       The first possible syntax is a list of integers.  Each  element  repre-
       sents the number of pixels of a line segment. Only the odd segments are
       drawn  using  the  "outline"  color.  The  other  segments  are   drawn
       transparant.

       The second possible syntax is a character list containing only 5 possi-
       ble characters [.,-_ ]. The space can be  used  to  enlarge  the  space
       between other line elements, and can not occur as the first position in
       the string. Some examples:
           -dash .= -dash {2 4}
           -dash -     = -dash {6 4}
           -dash -.    = -dash {6 4 2 4}
           -dash -..   = -dash {6 4 2 4 2 4}
           -dash {. }  = -dash {2 8}
           -dash ,= -dash {4 4}

       The main difference of this syntax with the  previous  is  that  it  it
       shape-conserving.  This  means that all values in the dash list will be
       multiplied by the line width before display. This assures that "." will
       always be displayed as a dot and "-" always as a dash regardless of the
       line width.

       On systems which support only a limited set of dash patterns, the  dash
       pattern  will  be  displayed as the closest dash pattern that is avail-
       able.  For example, on Windows only the first 4 of the  above  examples
       are  available.   The  last 2 examples will be displayed identically to
       the first one.


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 overlap 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 consid-
                     ered  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 topmost 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  argu-
                     ment 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 approximate 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 or if
              the matching items have empty bounding  boxes  (i.e.  they  have
              nothing to display) 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  substitutions  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 existing binding rather than replacing it).
              In this case the return value is an empty string.  If command is
              omitted  then  the  command  returns the command associated with
              tagOrId and sequence (an error occurs if there is no such  bind-
              ing).  If both command and sequence are omitted then the command
              returns a list of all the sequences for which bindings 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, Button-
              Press, Motion, and KeyPress) or virtual events.  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).
              If  a virtual event is used in a binding, that binding can trig-
              ger only if the virtual event is defined by an underlying mouse-
              related or keyboard-related event.

              It  is  possible  for  multiple  bindings  to match a particular
              event.  This could occur, for example, if one binding is associ-
              ated  with  the  item's id and another is associated with one of
              the item's tags.  When this occurs, all of the matching bindings
              are  invoked.   A binding associated with the all tag is invoked
              first, followed by one binding for each of the item's  tags  (in
              order), followed by a binding associated with the item's id.  If
              there are multiple matching bindings for a single tag, then only
              the  most  specific binding is invoked.  A continue command in a
              binding script terminates that script, and a break command  ter-
              minates  that  script  and  skips  any remaining scripts for the
              event, just as for the bind command.

              If bindings have been created for a canvas window using the bind
              command,  then  they are invoked in addition to bindings created
              for the canvas's items using the bind widget command.  The bind-
              ings  for  items  will be invoked before any of the bindings for
              the window as a whole.

       pathName canvasx screenx ?gridspacing?
              Given a window x-coordinate in the canvas screenx, this  command
              returns  the canvas x-coordinate that is displayed at that loca-
              tion.  If gridspacing is specified, then the  canvas  coordinate
              is rounded to the nearest multiple of gridspacing units.

       pathName canvasy screeny ?gridspacing?
              Given  a  window y-coordinate in the canvas screeny this command
              returns the canvas y-coordinate that is displayed at that  loca-
              tion.   If  gridspacing is specified, then the canvas coordinate
              is rounded to the nearest multiple of gridspacing units.

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

       pathName configure ?option? ?value? ?option value ...?
              Query or modify the configuration options of the widget.  If  no
              option is specified, returns a list describing all of the avail-
              able options for pathName (see Tk_ConfigureInfo for  information
              on  the  format  of  this list).  If option is specified with no
              value, then the command returns a list describing the one  named
              option (this list will be identical to the corresponding sublist
              of the value returned if no option is  specified).   If  one  or
              more option-value pairs are specified, then the command modifies
              the given widget option(s) to have the given value(s);  in  this
              case  the  command returns an empty string.  Option may have any
              of the values accepted by the canvas command.

       pathName coords tagOrId ?x0 y0 ...?

       pathName coords tagOrId ?coordList?
              Query or modify the coordinates that  define  an  item.   If  no
              coordinates  are  specified,  this  command returns a list whose
              elements are the coordinates of the item named by  tagOrId.   If
              coordinates are specified, then they replace the current coordi-
              nates 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 ...?

       pathName create type coordList ?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  con-
              sist  of  the  coordinates  for  one or more points, followed by
              specifications for zero or more item options.  See  the  subsec-
              tions  on  individual item types below for more on the syntax 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 characters, or  coor-
              dinates,  in  the  range given by first and last, inclusive.  If
              some of the items given by tagOrId don't support indexing opera-
              tions  then  they ignore dchars.  Text items interpret first and
              last as indices to a character, line and polygon items interpret
              them  indices  to  a  coordinate  (an  x,y  pair).   Indices are
              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  unaf-
              fected  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  command.  The items are returned in stacking order, with
              the lowest item first.

       pathName focus ?tagOrId?
              Set the keyboard focus for the canvas widget to the  item  given
              by  tagOrId.  If tagOrId refers to several items, then the focus
              is set to the first such item in the display list that  supports
              the insertion 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 cur-
              rently 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  indepen-
              dent:  a given item doesn't actually have the input focus unless
              (a) its canvas is the focus window 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 associated 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 dis-
              play 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 character 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 wid-
              get 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.   Text items interpret index as an index to a  character,
              line and polygon items interpret it as an index to a  coordinate
              (an  x,y pair).  The return value is guaranteed to lie between 0
              and the number of characters, or coordinates, within  the  item,
              inclusive.   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 or coordinate, insertion then string is inserted  into  the
              item's  text  just  before  the  character, or coordinate, whose
              index is beforeThis.  Text  items  interpret  beforethis  as  an
              index to a  character, line and polygon items interpret it as an
              index to a coordinate (an x,y pair).  For lines and polygons the
              string  must  be a valid coordinate sequence.  See INDICES above
              for information about the forms allowed  for  beforeThis.   This
              command returns an empty string.

       pathName itemcget tagOrId option
              Returns  the  current  value of the configuration option for the
              item given by tagOrId whose name is  option.   This  command  is
              similar  to  the cget widget command except that it applies to a
              particular item rather than the widget as a whole.   Option  may
              have  any  of  the  values accepted by the create widget command
              when the item was created.  If tagOrId is a tag that  refers  to
              more than one item, the first (lowest) such item is used.

       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 wid-
              get.  If no option is specified, returns a list  describing  all
              of  the  available  options  for the first item given by tagOrId
              (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 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  display  list  is
              used  as  the  destination  location for the moved items.  Note:
              this command has no effect on window items.  Window items always
              obscure other item types, and the stacking order of window items
              is determined by the raise and lower commands, not the raise and
              lower  widget  commands  for  canvases.  This command returns an
              empty string.

       pathName move tagOrId xAmount yAmount
              Move each of the items given by tagOrId in the canvas coordinate
              space  by adding xAmount to the x-coordinate of each point asso-
              ciated with the item and yAmount to  the  y-coordinate  of  each
              point  associated  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 can-
              vas.   If  the  -file option is specified then the Postscript is
              written to a file and an empty string  is  returned;   otherwise
              the Postscript is returned as the result of the command.  If the
              interpreter that owns the canvas is marked as safe,  the  opera-
              tion  will  fail  because  safe  interpreters are not allowed to
              write files.  If the -channel option is specified, the  argument
              denotes  the  name  of a channel already opened for writing. The
              Postscript is written to that channel, and the channel  is  left
              open  for  further  writing  at  the  end of the operation.  The
              Postscript is created in Encapsulated Postscript form using ver-
              sion  3.0  of  the  Document  Structuring Conventions.  Note: by
              default  Postscript  is  only  generated  for  information  that
              appears  in the canvas's window on the screen.  If the canvas is
              freshly created it may still have its initial size of 1x1  pixel
              so  nothing  will  appear in the Postscript.  To get around this
              problem either invoke the "update" command to wait for the  can-
              vas  window  to reach its final size, or else use the -width and
              -height options to specify the area of the canvas to print.  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 an array variable that speci-
                     fies a color mapping to use in the Postscript.  Each ele-
                     ment  of varName must consist of Postscript code to set a
                     particular  color  value  (e.g.  ``1.0  1.0  0.0  setrgb-
                     color'').   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 an array variable that speci-
                     fies  a font mapping to use in the Postscript.  Each ele-
                     ment of varName must consist of a Tcl list with two  ele-
                     ments,  which are the name and point size of a Postscript
                     font.  When outputting Postscript commands for a particu-
                     lar font, Tk checks to see if varName contains an element
                     with the same name as the font.  If there is such an ele-
                     ment, 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 gener-
                     ally 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 exam-
                     ple,   -*-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 canvas to print.
                     Defaults to the height of the canvas window.

              -pageanchor anchor
                     Specifies which point of the printed area of  the  canvas
                     should  appear  over  the  positioning  point on the page
                     (which is given by the -pagex and -pagey  options).   For
                     example,  -pageanchor  n means that the top center of the
                     area of the canvas being printed (as it  appears  in  the
                     canvas  window)  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  num-
                     ber  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 -pagewidth is used (non-uni-
                     form 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  -page-
                     height.  Defaults to the width of the printed area on the
                     screen.  If both -pageheight and -pagewidth are specified
                     then  the scale factor from -pagewidth  is used (non-uni-
                     form scaling is not implemented).

              -pagex position
                     Position gives the x-coordinate of the positioning  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 positioning 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 output the x-
                     axis runs along the long dimension of the  page  (``land-
                     scape'' orientation).  Defaults to non-rotated.

              -width size
                     Specifies  the  width of the area of the canvas 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 coordi-
                     nates, not window coordinates.  Defaults to  the  coordi-
                     nate 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 display list is used as the des-
              tination location for the moved items.  Note: this  command  has
              no  effect  on  window items.  Window items always obscure other
              item types, and the stacking order of window items is determined
              by  the raise and lower commands, not the raise and lower widget
              commands for canvases.  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 canvases.  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 ?gain?.
                     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
                     widget.  It then adjusts the view by gain times the  dif-
                     ference  in coordinates, where gain defaults to 10.  This
                     command is typically associated with mouse motion  events
                     in the widget, to produce the effect of dragging the can-
                     vas 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 descriptions below, tagOrId must refer to an item
              that supports indexing and selection;  if it refers to  multiple
              items  then  the  first  of these that supports indexing and the
              selection is used.  Index gives a textual description of a posi-
              tion 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 widget 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  characters  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 wid-
                     get.   If the selection anchor point for the widget isn't
                     currently in tagOrId, then it is set to the same  charac-
                     ter 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  ?args?
              This command is used to query and change the horizontal position
              of the information displayed in the  canvas's  window.   It  can
              take any of the following forms:

              pathName xview
                     Returns  a list containing two elements.  Each element is
                     a real fraction between 0 and 1;  together they  describe
                     the  horizontal  span that is visible in the window.  For
                     example, if the first element is .2 and the  second  ele-
                     ment  is  .6, 20% of the canvas's area (as defined by the
                     -scrollregion option) is off-screen to the left, the mid-
                     dle  40%  is visible in the window, and 40% of the canvas
                     is off-screen to the right.  These are  the  same  values
                     passed to scrollbars via the -xscrollcommand option.

              pathName xview moveto fraction
                     Adjusts  the  view  in the window so that fraction of the
                     total width of the canvas  is  off-screen  to  the  left.
                     Fraction must be a fraction between 0 and 1.

              pathName xview scroll number what
                     This  command shifts the view in the window left or right
                     according to number and what.  Number must be an integer.
                     What  must be either units or pages or an abbreviation of
                     one of these.  If what is units, the view adjusts left or
                     right  in  units of the xScrollIncrement option, if it is
                     greater than zero, or in units of one-tenth the  window's
                     width  otherwise.  If what is pages then the view adjusts
                     in units of nine-tenths the window's width.  If number is
                     negative  then  information  farther  to the left becomes
                     visible;  if it is positive then information  farther  to
                     the right becomes visible.

       pathName yview ?args?
              This  command  is used to query and change the vertical position
              of the information displayed in the  canvas's  window.   It  can
              take any of the following forms:

              pathName yview
                     Returns  a list containing two elements.  Each element is
                     a real fraction between 0 and 1;  together they  describe
                     the  vertical  span  that  is visible in the window.  For
                     example, if the first element is .6 and the  second  ele-
                     ment  is  1.0,  the  lowest  40% of the canvas's area (as
                     defined by the -scrollregion option) is  visible  in  the
                     window.   These  are the same values passed to scrollbars
                     via the -yscrollcommand option.

              pathName yview moveto fraction
                     Adjusts the view in the window so that  fraction  of  the
                     canvas's  area  is  off-screen to the top.  Fraction is a
                     fraction between 0 and 1.

              pathName yview scroll number what
                     This command adjusts the view in the window  up  or  down
                     according to number and what.  Number must be an integer.
                     What must be either units or pages.  If  what  is  units,
                     the view adjusts up or down in units of the yScrollIncre-
                     ment option, if it is greater than zero, or in  units  of
                     one-tenth  the  window's  height  otherwise.   If what is
                     pages then the view adjusts in units of  nine-tenths  the
                     window's  height.   If  number  is  negative  then higher
                     information becomes visible;   if  it  is  positive  then
                     lower information becomes visible.


OVERVIEW OF ITEM TYPES
       The  sections  below  describe  the various types of items supported by
       canvas widgets.  Each item type is characterized 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 commands  related
       to them, such as index and insert.  Where items do support these facil-
       ities, it is noted explicitly in the descriptions below.   At  present,
       text,  line  and  polygon  items  provide  this support.  For lines and
       polygons the indexing facility is used to manipulate the coordinates of
       the item.


COMMON ITEM OPTIONS
       Many  items share a common set of options.  These options are explained
       here, and then referred to be each widget type for brevity.


       -dash pattern

       -activedash pattern

       -disableddash pattern
              This option specifies  dash  patterns  for  the  normal,  active
              state,  and  disabled state of an item.  pattern may have any of
              the forms accepted by Tk_GetDash.  If the dash options are omit-
              ted  then  the  default is a solid outline.  See "DASH PATTERNS"
              for more information.

       -dashoffset offset
              The starting offset in pixels into the pattern provided  by  the
              -dash  option.  -dashoffset is ignored if there is no -dash pat-
              tern.  The offset may have any of the  forms  described  in  the
              COORDINATES section above.

       -fill color

       -activefill color

       -disabledfill color
              Specifies the color to be used to fill item's area.  in its nor-
              mal, active, and disabled states, Color  may  have  any  of  the
              forms accepted by Tk_GetColor.  If color is an empty string (the
              default), then then the item will not be filled.  For  the  line
              item,  it  specifies  the color of the line drawn.  For the text
              item, it specifies the foreground color of the text.

       -outline color

       -activeoutline color

       -disabledoutline color
              This option specifies the color that should be used to draw  the
              outline  of  the item in its normal, active and disabled states.
              Color may have any of the forms accepted by  Tk_GetColor.   This
              option  defaults  to  black.   If color is specified as an empty
              string then no outline is drawn for the item.

       -offset offset
              Specifies the offset of stipples.  The offset value  can  be  of
              the  form x,y or side, where side can be n, ne, e, se, s, sw, w,
              nw, or center. In the first case the origin is the origin of the
              toplevel  of the current window.  For the canvas itself and can-
              vas objects the origin is the canvas origin, but  putting  #  in
              front of the coordinate pair indicates using the toplevel origin
              instead. For canvas objects, the  -offset  option  is  used  for
              stippling  as  well.   For the line and polygon canvas items you
              can also specify an index as argument, which connects the  stip-
              ple  origin to one of the coordinate points of the line/polygon.

       -outlinestipple bitmap

       -activeoutlinestipple bitmap

       -disabledoutlinestipple bitmap
              This option specifies stipple patterns that should  be  used  to
              draw  the outline of the item in its normal, active and disabled
              states.  Indicates that the outline for the item should be drawn
              with  a stipple pattern; bitmap specifies the stipple pattern to
              use, in any of the forms accepted by Tk_GetBitmap.  If the -out-
              line  option  hasn't  been  specified  then  this  option has no
              effect.  If bitmap is an empty string (the  default),  then  the
              outline is drawn in a solid fashion.

       -stipple bitmap

       -activestipple bitmap

       -disabledstipple bitmap
              This  option  specifies  stipple patterns that should be used to
              fill the the item in its normal,  active  and  disabled  states.
              bitmap specifies the stipple pattern to use, in any of the forms
              accepted by Tk_GetBitmap.  If the -fill option hasn't been spec-
              ified  then  this  option  has no effect.  If bitmap is an empty
              string (the default), then filling is done in a  solid  fashion.
              For the text item, it affects the actual text.

       -state state
              This allows an item to override the canvas widget's global state
              option.  It takes the same values: normal, disabled or hidden.

       -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

       -activewidth outlineWidth

       -disabledwidth outlineWidth
              Specifies the width of the outline to be drawn around the item's
              region, in its normal, active and disabled states.  outlineWidth
              may be 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.  This option defaults  to
              1.0.   For  arcs,  wide  outlines  will be drawn centered on the
              edges of the arc's region.


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 (spec-
       ified  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 ...?
              pathName create arc coordList ?option value option value ...?
       The arguments x1, y1, x2, and y2 or coordList give the  coordinates  of
       two  diagonally  opposite corners of a rectangular region enclosing the
       oval that defines the arc.  After the coordinates there may be any num-
       ber  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 standard options are supported by arcs:
              -dash
              -activedash
              -disableddash
              -dashoffset
              -fill
              -activefill
              -disabledfill
              -offset
              -outline
              -activeoutline
              -disabledoutline
              -outlinestipple
              -activeoutlinestipple
              -disabledoutlinestipple
              -stipple
              -activestipple
              -disabledstipple
              -state
              -tags
              -width
              -activewidth
              -disabledwidth
       The following extra 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 negative.  If it is greater than 360 or less than -360,  then
              degrees modulo 360 is used as the extent.

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

       -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 segments, 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 section.  If type is  arc  then  the
              arc's  region  consists of a section of the perimeter alone.  In
              this last case the -fill option is ignored.


BITMAP ITEMS
       Items of type bitmap appear on the display as images with  two  colors,
       foreground and background.  Bitmaps are created with widget commands of
       the following form:
              pathName create bitmap x y ?option value option value ...?
              pathName create bitmap coordList ?option value option value ...?
       The arguments x and y or coordList 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 following standard options are supported by bitmaps:
              -state
              -tags
       The following extra options are supported for bitmaps:

       -anchor anchorPos
              AnchorPos tells how to position the bitmap relative to the posi-
              tioning  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

       -activebackground bitmap

       -disabledbackground bitmap
              Specifies  the  color to use for each of the bitmap's '0' valued
              pixels in its normal, active and  disabled  states.   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
              nothing  is  displayed where the bitmap pixels are 0;  this pro-
              duces a transparent effect.

       -bitmap bitmap

       -activebitmap bitmap

       -disabledbitmap bitmap
              Specifies the bitmaps to display in  the  item  in  its  normal,
              active  and  disabled  states.  Bitmap may have any of the forms
              accepted by Tk_GetBitmap.

       -foreground color

       -activeforeground bitmap

       -disabledforeground bitmap
              Specifies the color to use for each of the bitmap's  '1'  valued
              pixels  in  its  normal,  active and disabled states.  Color may
              have any of the forms accepted by Tk_GetColor  and  defaults  to
              black.


IMAGE ITEMS
       Items of type image are used to display images on a canvas.  Images are
       created with widget commands of the following form:
              pathName create image x y ?option value option value ...?
              pathName create image coordList ?option value option value ...?
       The arguments x and y or coordList specify the coordinates of  a  point
       used to position the image on the display (see the -anchor option below
       for more information).  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 standard options are supported by images:
              -state
              -tags
       The following extra options are supported for images:

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

       -image name

       -activeimage name

       -disabledimage name
              Specifies the name of the images to display in the  item  in  is
              normal,  active  and disabled states.  This image must have been
              created previously with the image create command.


LINE ITEMS
       Items of type line appear on the display as one or more connected  line
       segments  or curves.  Line items support coordinate indexing operations
       using the canvas widget commands: dchars,  index,  insert.   Lines  are
       created with widget commands of the following form:
              pathName create line x1 y1... xn yn ?option value option value ...?
              pathName create line coordList ?option value option value ...?
       The  arguments  x1  through  yn or coordList 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 itemconfig-
       ure widget commands to change the item's configuration.
       The following standard options are supported by lines:
              -dash
              -activedash
              -disableddash
              -dashoffset
              -fill
              -activefill
              -disabledfill
              -stipple
              -activestipple
              -disabledstipple
              -state
              -tags
              -width
              -activewidth
              -disabledwidth
       The following extra 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 argu-
              ment must be a list with three elements, each specifying a  dis-
              tance  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 ``rea-
              sonable'' shape.

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

       -joinstyle style
              Specifies the ways in which joints are to be drawn at  the  ver-
              tices  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 parabolic  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 segment.

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


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 following form:
              pathName create oval x1 y1 x2 y2 ?option value option value ...?
              pathName create oval coordList ?option value option value ...?
       The arguments x1, y1, x2, and y2 or coordList 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 result-
       ing oval is circular; otherwise it is elongated in  shape.   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 standard options are supported by ovals:
              -dash
              -activedash
              -disableddash
              -dashoffset
              -fill
              -activefill
              -disabledfill
              -offset
              -outline
              -activeoutline
              -disabledoutline
              -outlinestipple
              -activeoutlinestipple
              -disabledoutlinestipple
              -stipple
              -activestipple
              -disabledstipple
              -state
              -tags
              -width
              -activewidth
              -disabledwidth


POLYGON ITEMS
       Items of type polygon appear as polygonal or curved filled  regions  on
       the  display.   Polygon  items  support  coordinate indexing operations
       using the canvas widget commands: dchars, index, insert.  Polygons  are
       created with widget commands of the following form:
              pathName create polygon x1 y1 ... xn yn ?option value option value ...?
              pathName create polygon coordList ?option value option value ...?
       The  arguments  x1  through yn or coordList specify the coordinates for
       three or more points that define a polygon.  The first point should not
       be repeated as the last to close the shape; Tk will automatically close
       the periphery between the first and last points.  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 standard options are supported by polygons:
              -dash
              -activedash
              -disableddash
              -dashoffset
              -fill
              -activefill
              -disabledfill
              -offset
              -outline
              -activeoutline
              -disabledoutline
              -outlinestipple
              -activeoutlinestipple
              -disabledoutlinestipple
              -stipple
              -activestipple
              -disabledstipple
              -state
              -tags
              -width
              -activewidth
              -disabledwidth
       The following extra options are supported for polygons:

       -joinstyle style
              Specifies the ways in which joints are to be drawn at  the  ver-
              tices  of the outline.  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.

       -smooth boolean
              Boolean  must have one of the forms accepted by Tk_GetBoolean It
              indicates whether or not the polygon  should  be  drawn  with  a
              curved  perimeter.   If so, the outline of the polygon becomes a
              set of parabolic 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  number  line  segments.   This
              option is ignored unless the -smooth option is true.

       Polygon  items are different from other items such as rectangles, ovals
       and arcs in that interior points are  considered  to  be  ``inside''  a
       polygon  (e.g.  for  purposes  of the find closest and find overlapping
       widget commands) even if it is not filled.  For most other item  types,
       an  interior point is considered to be inside the item only if the item
       is filled or if it has neither a fill nor an  outline.   If  you  would
       like an unfilled polygon whose interior points are not considered to be
       inside the polygon, use a line item instead.


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 ...?
              pathName create rectangle coordList ?option value option value ...?
       The arguments x1, y1, x2, and y2 or coordList 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 widget com-
       mands to change the item's configuration.
       The following standard options are supported by rectangles:
              -dash
              -activedash
              -disableddash
              -dashoffset
              -fill
              -activefill
              -disabledfill
              -offset
              -outline
              -activeoutline
              -disabledoutline
              -outlinestipple
              -activeoutlinestipple
              -disabledoutlinestipple
              -stipple
              -activestipple
              -disabledstipple
              -state
              -tags
              -width
              -activewidth
              -disabledwidth


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 ...?
              pathName create text coordList ?option value option value ...?
       The arguments x and y or coordList 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 standard options are supported by text items:
              -fill
              -activefill
              -disabledfill
              -stipple
              -activestipple
              -disabledstipple
              -state
              -tags
       The following extra options are supported for text items:

       -anchor anchorPos
              AnchorPos tells how to position the text relative to  the  posi-
              tioning  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 position-
              ing point.  This option defaults to center.

       -font fontName
              Specifies the font to use for the text item.   FontName  may  be
              any string acceptable to Tk_GetFont.  If this option isn't spec-
              ified, it defaults to a system-dependent font.

       -justify how
              Specifies how to justify the text within  its  bounding  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.

       -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  section  above.  If this
              option is zero (the default) the text is broken into lines  only
              at newline characters.  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 line-
              Length;  the space character is treated as if it were a  newline
              character.


WINDOW ITEMS
       Items  of  type  window  cause a particular window to be displayed 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 ...?
              pathName create window coordList ?option value option value ...?
       The  arguments  x and y or coordList 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 following standard options are supported by window items:
              -state
              -tags
       The following extra options are supported for window items:

       -anchor anchorPos
              AnchorPos tells how to position the window relative to the posi-
              tioning 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 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 height it
              requests internally.

       -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 wid-
              get or a child of some ancestor of the canvas widget.   PathName
              may not refer to a top-level window.

       Note:   due to restrictions in the ways that windows are managed, it is
       not possible to draw other graphical items (such as lines  and  images)
       on  top  of  window  items.  A window item always obscures any graphics
       that overlap it, regardless of their order in the display list.


APPLICATION-DEFINED ITEM TYPES
       It is possible for individual applications to define new item types for
       canvas  widgets using C code.  See the documentation for Tk_CreateItem-
       Type.


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 can-
       vases.


KEYWORDS
