canvas man page on OpenServer

Man page or keyword search:  
man Server   5388 pages
apropos Keyword Search (all sections)
Output format
OpenServer logo
[printable version]

canvas(n)		     Tk Built-In Commands		     canvas(n)

______________________________________________________________________________

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 parenthesized 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.

       Note that the default origin of the canvas's visible area is coincident
       with  the  origin for the whole window as that makes bindings using the
       mouse position easier to work with; you only need to  use  the  canvasx
       and  canvasy  widget  commands  if you adjust the origin of the visible
       area.  However, this also means that any focus ring (as	controlled  by
       the -highlightthickness option) and window border (as controlled by the
       -borderwidth option) must be taken into account before you get  to  the
       visible area of the canvas.

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	 indices  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 subtracting 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 a 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 transpar-
       ent.

       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 is
       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 Post-
	      script  is created in Encapsulated Postscript form using version
	      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 canvas 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 Post-
		     script, Tk checks to see if there is an element  of  var-
		     Name 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	 Post-
		     script  page.   Size  consists of a floating-point number
		     followed by c for centimeters, i for inches, m  for  mil-
		     limeters,	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	 Post-
		     script  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 factor from -pagewidth  is used (non-uniform	 scal-
		     ing 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 poly-
       gons 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 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.  Note that stipples are not
	      well supported on platforms that do not use X11 as their drawing
	      API.

       -stipple bitmap

       -activestipple bitmap

       -disabledstipple bitmap
	      This option specifies stipple patterns that should  be  used  to
	      fill 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.  Note that	 stip-
	      ples  are not well supported on platforms that do not use X11 as
	      their drawing API.

       -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 smoothMethod
	      smoothMethod  must  have	one  of the forms accepted by Tcl_Get-
	      Boolean or a line smoothing method.  Only bezier is supported in
	      the  core, but more can be added at runtime.  If a boolean false
	      value or empty string is given,  no  smoothing  is  applied.   A
	      boolean  truth  value  assume  bezier  smoothing.	  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  Tcl_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.

SEE ALSO
       bind(n), font(n), image(n), scrollbar(n)

KEYWORDS
       canvas, widget

Tk				      8.3			     canvas(n)
[top]
                             _         _         _ 
                            | |       | |       | |     
                            | |       | |       | |     
                         __ | | __ __ | | __ __ | | __  
                         \ \| |/ / \ \| |/ / \ \| |/ /  
                          \ \ / /   \ \ / /   \ \ / /   
                           \   /     \   /     \   /    
                            \_/       \_/       \_/ 
More information is available in HTML format for server OpenServer

List of man pages available for OpenServer

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net