


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


NAME
       text - Create and manipulate text widgets

SYNOPSIS
       (text                       widget-name                      ?options?)
       :background    :highlightbackground     :insertontime  :selectborder-
       width    :borderwidth   :highlightcolor     :insertwidth   :selectfore-
       ground                 :cursor   :highlightthickness :padx     :setgrid
       :exportselection    :insertbackground   :pady     :takefocus
       :font     :insertborderwidth  :relief   :xscrollcommand
       :foreground    :insertofftime :selectbackground   :yscrollcommand

WIDGET-SPECIFIC OPTIONS
       Specifies  the desired height for the window, in units of characters in
       the font given by the :font option.  Must be at  least  one.   Requests
       additional  space  above each text line in the widget, using any of the
       standard forms for screen distances.  If a line wraps, this option only
       applies to the first line on the display.  This option may be overriden
       with :spacing1 options in tags.  For lines  that  wrap  (so  that  they
       cover  more  than  one line on the display) this option specifies addi-
       tional space to provide between the display lines that represent a sin-
       gle  line  of  text.   The value may have any of the standard forms for
       screen distances.  This option may be overriden with :spacing2  options
       in tags.  Requests additional space below each text line in the widget,
       using any of the standard forms for screen distances.  If a line wraps,
       this  option only applies to the last line on the display.  This option
       may be overriden with :spacing3 options in tags.  Specifies one of  two
       states for the text:  normal or disabled.  If the text is disabled then
       characters may not be inserted or deleted and no insertion cursor  will
       be  displayed,  even  if the input focus is in the widget.  Specifies a
       set of tab stops for the window.  The option's value consists of a list
       of  screen distances giving the positions of the tab stops.  Each posi-
       tion may optionally be followed in the next list element by one of  the
       keywords  left,  right, center, or numeric, which specifies how to jus-
       tify text relative to the tab stop.  Left is the default; it causes the
       text following the tab character to be positioned with its left edge at
       the tab position.  Right means that the right edge of the text  follow-
       ing  the  tab  character  is positioned at the tab position, and center
       means that the text is centered at the  tab  position.   Numeric  means
       that  the  decimal point in the text is positioned at the tab position;
       if there is no decimal point then the least significant  digit  of  the
       number is positioned just to the left of the tab position;  if there is
       no number in the text then the text is right-justified at the tab posi-
       tion.   For  example,  :tabs  `(2c left 4c 6c center) creates three tab
       stops at two-centimeter intervals;  the first two use  left  justifica-
       tion and the third uses center justification.  If the list of tab stops
       does not have enough elements to cover all of the tabs in a text  line,
       then Tk extrapolates new tab stops using the spacing and alignment from
       the last tab stop in the list.  The value of the  tabs  option  may  be
       overridden  by :tabs options in tags.  If no :tabs option is specified,
       or if it is specified as an empty  list,  then  Tk  uses  default  tabs
       spaced  every  eight  (average size) characters.  Specifies the desired
       width for the window in units of characters in the font  given  by  the
       :font  option.  If the font doesn't have a uniform width then the width



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


       of the character ``0'' is used in translating from character  units  to
       screen  units.   Specifies how to handle lines in the text that are too
       long to be displayed in a single line of the text's window.  The  value
       must be none or char or word.  A wrap mode of none means that each line
       of text appears as exactly one line on the  screen;   extra  characters
       that  don't  fit  on  the screen are not displayed.  In the other modes
       each line of text will be broken up into several screen lines if neces-
       sary  to  keep  all the characters visible.  In char mode a screen line
       break may occur after any character; in word mode  a  line  break  will
       only be made at word boundaries.


DESCRIPTION
       The text procedure creates a new window (given by the widget-name argu-
       ment) and makes it into a text widget.  Additional  options,  described
       above, may be specified on the procedure line or in the option database
       to configure aspects of the text such as its default  background  color
       and  relief.   The text procedure returns the path name of the new win-
       dow.

       A text widget displays one or more lines of text and allows  that  text
       to be edited.  Text widgets support four different kinds of annotations
       on the text, called tags, marks, embedded windows or  embedded  images.
       Tags  allow different portions of the text to be displayed with differ-
       ent fonts and colors.  In addition, STk procedures  can  be  associated
       with  tags  so that scripts are invoked when particular actions such as
       keystrokes and mouse button presses occur in particular ranges  of  the
       text.  See TAGS below for more details.

       The  second  form  of  annotation consists of marks, which are floating
       markers in the text.  Marks are used to keep track of various interest-
       ing  positions  in  the text as it is edited.  See MARKS below for more
       details.

       The third form of annotation allows arbitrary windows to be embedded in
       a text widget.  See EMBEDDED WINDOWS below for more details.

       The fourth form of annotation allows Tk images to be embedded in a text
       widget.  See EMBEDDED IMAGES below for more details.


INDICES
       Many of the widget procedures for texts take one  or  more  indices  as
       arguments.   An  index  is a string used to indicate a particular place
       within a text, such as a place to insert characters or one endpoint  of
       a range of characters to delete.  Indices have the syntax base modifier
       modifier modifier ...  Where base gives a starting point and the  modi-
       fiers  adjust  the  index from the starting point (e.g. move forward or
       backward one character).  Every index must contain a base, but the mod-
       ifiers are optional.

       The base for an index must have one of the following forms:

       line.char



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


       (line . char)
                   Indicates  char'th  character on line line.  Lines are num-
                   bered from 1 for consistency with other UNIX programs  that
                   use  this  numbering scheme.  Within a line, characters are
                   numbered from 0.

       @x,y        Indicates the character that covers the pixel whose x and y
                   coordinates within the text's window are x and y.

       end         Indicates the end of the text (the character just after the
                   last newline).

       mark        Indicates the character just after the mark whose  name  is
                   mark.

       tag.first   Indicates  the  first  character  in the text that has been
                   tagged with tag.  This form generates an error if no  char-
                   acters are currently tagged with tag.

       tag.last    Indicates the character just after the last one in the text
                   that has been tagged with  tag.   This  form  generates  an
                   error if no characters are currently tagged with tag.

       widget-name Indicates the position of the embedded window whose name is
                   widget-name.  This form generates an error if there  is  no
                   embedded window by the given name.

       imageName   Indicates  the position of the embedded image whose name is
                   imageName.  This form generates an error  if  there  is  no
                   embedded image by the given name.

       If  the  base  could  match more than one of the above forms, such as a
       mark and imageName both having the same value, then the form earlier in
       the  above  list takes precedence.  If modifiers follow the base index,
       each one of them must have one of the  forms  listed  below.   Keywords
       such  as  chars and wordend may be abbreviated as long as the abbrevia-
       tion is unambiguous.

       + count chars
              Adjust the index forward by count characters,  moving  to  later
              lines  in  the text if necessary.  If there are fewer than count
              characters in the text after the current  index,  then  set  the
              index  to the last character in the text.  Spaces on either side
              of count are optional.

       : count chars
              Adjust the index backward by count characters, moving to earlier
              lines  in  the text if necessary.  If there are fewer than count
              characters in the text before the current index,  then  set  the
              index to the first character in the text.  Spaces on either side
              of count are optional.

       + count lines
              Adjust the index forward by  count  lines,  retaining  the  same



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


              character  position  within  the  line.  If there are fewer than
              count lines after the line containing the  current  index,  then
              set  the  index  to  refer to the same character position on the
              last line of the text.  Then, if the line is not long enough  to
              contain  a character at the indicated character position, adjust
              the character position to refer to the  last  character  of  the
              line  (the  newline).   Spaces  on  either  side  of  count  are
              optional.

       - count lines
              Adjust the index backward by count  lines,  retaining  the  same
              character  position  within  the  line.  If there are fewer than
              count lines before the line containing the current  index,  then
              set  the  index  to  refer to the same character position on the
              first line of the text.  Then, if the line is not long enough to
              contain  a character at the indicated character position, adjust
              the character position to refer to the  last  character  of  the
              line  (the  newline).   Spaces  on  either  side  of  count  are
              optional.

       linestart
              Adjust the index to refer to the first character on the line.

       lineend
              Adjust the index to refer to the last character on the line (the
              newline).

       wordstart
              Adjust  the  index  to  refer to the first character of the word
              containing the current index.  A word consists of any number  of
              adjacent characters that are letters, digits, or underscores, or
              a single character that is not one of these.

       wordend
              Adjust the index to refer to the character just after  the  last
              one  of  the  word containing the current index.  If the current
              index refers to the last character of the text then  it  is  not
              modified.

       If  more than one modifier is present then they are applied in left-to-
       right order.  For example, the index ``end - 1 chars''  refers  to  the
       next-to-last  character  in  the  text  and  ``insert wordstart - 1 c''
       refers to the character just before the first one in the word  contain-
       ing the insertion cursor.

TAGS
       The first form of annotation in text widgets is a tag.  A tag is a tex-
       tual string that is associated with some of the characters in  a  text.
       Tags may contain arbitrary characters, but it is probably best to avoid
       using the the characters `` '' (space), +, or :: these characters  have
       special  meaning  in  indices, so tags containing them can't be used as
       indices.  There may be any number of tags associated with characters in
       a  text.   Each tag may refer to a single character, a range of charac-
       ters, or several ranges of characters.   An  individual  character  may



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


       have any number of tags associated with it.

       A  priority  order  is  defined  among  tags, and this order is used in
       implementing some of the tag-related functions described below.  When a
       tag  is  defined (by associating it with characters or setting its dis-
       play options or binding procedures to  it),  it  is  given  a  priority
       higher  than any existing tag.  The priority order of tags may be rede-
       fined using the ``widget-name  'tag  'raise''  and  ``widget-name  'tag
       'lower'' widget procedures.

       Tags serve three purposes in text widgets.  First, they control the way
       information is displayed on the screen.   By  default,  characters  are
       displayed as determined by the background, font, and foreground options
       for the text widget.  However, display options may be  associated  with
       individual  tags  using the ``widget-name tag configure'' widget proce-
       dure.  If a character has been tagged, then the display options associ-
       ated  with  the  tag override the default display style.  The following
       options are currently supported for tags:

       :background color
              Color specifies the background color to use for characters asso-
              ciated  with  the tag.  It may have any of the forms accepted by
              Tk_GetColor.

       :bgstipple bitmap
              Bitmap specifies a bitmap that is used as a stipple pattern  for
              the  background.   It  may  have  any  of  the forms accepted by
              Tk_GetBitmap.  If bitmap hasn't been  specified,  or  if  it  is
              specified as an empty string, then a solid fill will be used for
              the background.

       :borderwidth pixels
              Pixels specifies the width of a 3-D border to  draw  around  the
              background.  It may have any of the forms accepted by Tk_GetPix-
              els.  This option is used in conjunction with the :relief option
              to give a 3-D appearance to the background for characters; it is
              ignored unless the :background option has been set for the  tag.

       :fgstipple bitmap
              Bitmap specifies a bitmap that is used as a stipple pattern when
              drawing text and other foreground  information  such  as  under-
              lines.   It  may have any of the forms accepted by Tk_GetBitmap.
              If bitmap hasn't been specified, or if it  is  specified  as  an
              empty string, then a solid fill will be used.

       :font fontName
              FontName  is  the  name of a font to use for drawing characters.
              It may have any of the forms accepted by Tk_GetFontStruct.

       :foreground color
              Color specifies the color to use when  drawing  text  and  other
              foreground  information  such as underlines.  It may have any of
              the forms accepted by Tk_GetColor.




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


       :justify justify
              If the first character of a display line has  a  tag  for  which
              this  option  has been specified, then justify determines how to
              justify the line.  It must be one of left, right, or center.  If
              a  line  wraps, then the justification for each line on the dis-
              play is determined by the first character of that display  line.

       :lmargin1 pixels
              If  the  first character of a text line has a tag for which this
              option has been specified, then pixels specifies  how  much  the
              line  should be indented from the left edge of the window.  Pix-
              els may have any of the standard forms for screen distances.  If
              a line of text wraps, this option only applies to the first line
              on the display;  the :lmargin2 option controls  the  indentation
              for subsequent lines.

       :lmargin2 pixels
              If  the  first  character  of a display line has a tag for which
              this option has been specified, and if the display line  is  not
              the  first  for its text line (i.e., the text line has wrapped),
              then pixels specifies how much the line should be indented  from
              the  left  edge of the window.  Pixels may have any of the stan-
              dard forms for screen distances.  This option is only used  when
              wrapping is enabled, and it only applies to the second and later
              display lines for a text line.

       :offset pixels
              Pixels specifies an amount by which the text's  baseline  should
              be  offset  vertically from the baseline of the overall line, in
              pixels.  For example, a positive offset can be used  for  super-
              scripts  and a negative offset can be used for subscripts.  Pix-
              els may have any of the standard forms for screen distances.

       :overstrike boolean
              Specifies whether or not to draw a horizontal rule  through  the
              middle  of  characters.   Boolean  may  have  any  of  the forms
              accepted by Tk_GetBoolean.

       :relief relief
              Relief specifies the 3-D relief to use for drawing  backgrounds,
              in  any  of  the forms accepted by Tk_GetRelief.  This option is
              used in conjunction with the :borderwidth option to give  a  3-D
              appearance  to  the  background  for  characters;  it is ignored
              unless the :background option has been set for the tag.

       :rmargin pixels
              If the first character of a display line has  a  tag  for  which
              this option has been specified, then pixels specifies how wide a
              margin to leave between the end of the line and the  right  edge
              of  the  window.   Pixels may have any of the standard forms for
              screen distances.  This option is only  used  when  wrapping  is
              enabled.   If  a text line wraps, the right margin for each line
              on the display is determined by the first character of that dis-
              play line.



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


       :spacing1 pixels
              Pixels  specifies how much additional space should be left above
              each text line, using any of the standard forms for screen  dis-
              tances.   If a line wraps, this option only applies to the first
              line on the display.

       :spacing2 pixels
              For lines that wrap, this option specifies how  much  additional
              space to leave between the display lines for a single text line.
              Pixels may have any of the standard forms for screen  distances.

       :spacing3 pixels
              Pixels  specifies how much additional space should be left below
              each text line, using any of the standard forms for screen  dis-
              tances.   If  a line wraps, this option only applies to the last
              line on the display.

       :tabs tabList
              TabList specifies a set of tab stops in the same form as for the
              :tabs option for the text widget.  This option only applies to a
              display line if it applies to the first character on  that  dis-
              play  line.   If this option is specified as an empty string, it
              cancels the option, leaving it  unspecified  for  the  tag  (the
              default).  If the option is specified as a non-empty string that
              is an empty list, such as :tags " ", then  it  requests  default
              8-character tabs as described for the tags widget option.

       :underline boolean
              Boolean specifies whether or not to draw an underline underneath
              characters.  It may have any of the forms  accepted  by  Tk_Get-
              Boolean.

       :wrap mode
              Mode  specifies  how  to  handle  lines  that are wider than the
              text's window.  It has the same legal values as the :wrap option
              for  the  text widget:  none, char, or word.  If this tag option
              is specified, it overrides the :wrap option for the text widget.

       If  a  character has several tags associated with it, and if their dis-
       play options conflict, then the options of the highest priority tag are
       used.   If a particular display option hasn't been specified for a par-
       ticular tag, or if it is specified as an empty string, then that option
       will  never  be used;  the next-highest-priority tag's option will used
       instead.  If no tag specifies a particular  display  option,  then  the
       default style for the widget will be used.

       The second purpose for tags is event bindings.  You can associate bind-
       ings with a tag in much the same way you can associate bindings with  a
       widget  class:   whenever  particular X events occur on characters with
       the given tag, a given STk procedure will be  executed.   Tag  bindings
       can  be  used  to  give  behaviors to ranges of characters; among other
       things, this allows hypertext-like features  to  be  implemented.   For
       details, see the description of the tag bind widget procedure below.




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


       The third use for tags is in managing the selection.  See THE SELECTION
       below.


MARKS
       The second form of annotation in text widgets is  a  mark.   Marks  are
       used  for  remembering particular places in a text.  They are something
       like tags, in that they have names and they  refer  to  places  in  the
       file, but a mark isn't associated with particular characters.  Instead,
       a mark is associated with the gap between two characters.  Only a  sin-
       gle  position  may be associated with a mark at any given time.  If the
       characters around a mark are deleted the mark will  still  remain;   it
       will just have new neighbor characters.  In contrast, if the characters
       containing a tag are deleted then the tag will no longer have an  asso-
       ciation with characters in the file.  Marks may be manipulated with the
       ``widget-name mark'' widget procedure, and their current locations  may
       be  determined by using the mark name as an index in widget procedures.

       Each mark also has a gravity, which is either left or right.  The grav-
       ity for a mark specifies what happens to the mark when text is inserted
       at the point of the mark.  If a mark has left gravity, then the mark is
       treated  as  if  it  were attached to the character on its left, so the
       mark will remain to the left of any text inserted at the mark position.
       If  the  mark has right gravity, new text inserted at the mark position
       will appear to the right of the mark.  The gravity for a mark  defaults
       to right.

       The  name  space  for  marks is different from that for tags:  the same
       name may be used for both a mark and a tag, but they will refer to dif-
       ferent things.

       Two marks have special significance.  First, the mark insert is associ-
       ated with the insertion cursor, as described under THE INSERTION CURSOR
       below.  Second, the mark current is associated with the character clos-
       est to the mouse and is adjusted automatically to track the mouse posi-
       tion and any changes to the text in the widget (one exception:  current
       is not updated in response to mouse motions if a mouse button is  down;
       the  update  will  be  deferred  until  all  mouse  buttons  have  been
       released).  Neither of these special marks may be deleted.


EMBEDDED WINDOWS
       The third form of annotation in text widgets  is  an  embedded  window.
       Each  embedded  window  annotation causes a window to be displayed at a
       particular point in  the text.  There may be  any  number  of  embedded
       windows  in  a  text  widget, and any widget may be used as an embedded
       window (subject to the  usual  rules  for  geometry  management,  which
       require  the  text  window to be the parent of the embedded window or a
       descendant of its parent).   The  embedded  window's  position  on  the
       screen will be updated as the text is modified or scrolled, and it will
       be mapped and unmapped as it moves into and out of the visible area  of
       the  text  widget.  Each embedded window occupies one character's worth
       of index space in the text widget, and it may be referred to either  by
       the  name  of  its  embedded  window or by its position in the widget's



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


       index space.  If the range of text containing the  embedded  window  is
       deleted then the window is destroyed.

       When  an embedded window is added to a text widget with the window cre-
       ate widget procedure, several configuration options may  be  associated
       with  it.  These options may be  modified later with the window config-
       ure widget procedure.  The following options are currently supported:

       :align where
              If the window is not as tall as the line in  which  it  is  dis-
              played,  this option determines where the window is displayed in
              the line.  Where must have one of the values top (align the  top
              of the window with the top of the line), center (center the win-
              dow within the range of the line), bottom (align the  bottom  of
              the  window  with  the  bottom  of the line's area), or baseline
              (align the bottom of the window with the baseline of the  line).

       :create procedure
              Specifies  a  STk  procedure that may be evaluated to create the
              window for the annotation.  If no :window option has been speci-
              fied  for  the annotation this script will be evaluated when the
              annotation is about to be displayed on the screen.  Script  must
              create a window for the annotation and return that window as its
              result.  If the annotation's window should ever be deleted, pro-
              cedure  will  be evaluated again the next time the annotation is
              displayed.

       :padx pixels
              Pixels specifies the amount of extra space to leave on each side
              of  the  embedded  window.   It  may have any of the usual forms
              defined for a screen distance.

       :pady pixels
              Pixels specifies the amount of extra space to leave on  the  top
              and  on  the  bottom of the embedded window.  It may have any of
              the usual forms defined for a screen distance.

       :stretch boolean
              If the requested height of the embedded window is less than  the
              height  of the line in which it is displayed, this option can be
              used to specify whether the window should  be  stretched  verti-
              cally  to fill its line.  If the :pady option has been specified
              as well, then the requested padding will be retained even if the
              window is stretched.

       :window widget-name
              Specifies the window to display in the annotation.


EMBEDDED IMAGES
       The  final  form  of  annotation  in text widgets is an embedded image.
       Each embedded image annotation causes an image to  be  displayed  at  a
       particular  point  in   the  text.  There may be any number of embedded
       images in a text widget, and a particular  image  may  be  embedded  in



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


       multiple places in the same text widget.  The embedded image's position
       on the screen will be updated as the  text  is  modified  or  scrolled.
       Each  embedded  image  occupies one character's worth of index space in
       the text widget, and it may be referred to either by  its  position  in
       the  widget's index space, or the name it is assigned when the image is
       inserted into the text widget widh image create.  If the range of  text
       containing the embedded image is deleted then that copy of the image is
       removed from the screen.

       When an embedded image is added to a text widget with the image  create
       widget  command,  a  name  unique  to  this  instance  of  the image is
       returned.  This name may then be used to refer to this image  instance.
       The  name  is  taken  to  be  the  value of the :name option (described
       below).  If the :name option is not provided, the :image name  is  used
       instead.   If  the imageName is already in use in the text widget, then
       #nn is added to the end of the imageName,  where  nn  is  an  arbitrary
       integer.   This  insures  the  imageName  is unique.  Once this name is
       assigned to this instance of the image, it does not change, even though
       the :image or :name values can be changed with image configure.

       When  an embedded image is added to a text widget with the image create
       widget command, several configuration options may  be  associated  with
       it.   These options may be modified later with the image configure wid-
       get command.  The following options are currently supported:

       :align where
              If the image is not as tall as the line  in  which  it  is  dis-
              played,  this  option determines where the image is displayed in
              the line.  Where must have one of the values top (align the  top
              of the image with the top of the line), center (center the image
              within the range of the line), bottom (align the bottom  of  the
              image  with  the  bottom of the line's area), or baseline (align
              the bottom of the image with the baseline of the line).

       :image image
              Specifies the name of the Tk image to display in the annotation.
              If image is not a valid Tk image, then an error is returned.

       :name ImageName
              Specifies  the  name  by which this image instance may be refer-
              enced in the text widget. If ImageName is not supplied, then the
              name  of  the  Tk  image  is  used instead.  If the imageName is
              already in use, #nn is appended  to  the  end  of  the  name  as
              described above.

       :padx pixels
              Pixels specifies the amount of extra space to leave on each side
              of the embedded image.  It may  have  any  of  the  usual  forms
              defined for a screen distance.

       :pady pixels
              Pixels  specifies  the amount of extra space to leave on the top
              and on the bottom of the embedded image.  It may have any of the
              usual forms defined for a screen distance.



STk                            3.1                             10





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


THE SELECTION
       Selection  support  is  implemented  via  tags.  If the exportSelection
       option for the text widget is true then the sel tag will be  associated
       with the selection:

       [1]    Whenever  characters  are  tagged  with sel the text widget will
              claim ownership of the selection.

       [2]    Attempts to retrieve the selection will be serviced by the  text
              widget, returning all the characters with the sel tag.

       [3]    If  the  selection  is claimed away by another application or by
              another window within this application, then the sel tag will be
              removed from all characters in the text.

       The sel tag is automatically defined when a text widget is created, and
       it may not be deleted with the ``widget-name 'tag 'delete'' widget pro-
       cedure.   Furthermore,  the  selectBackground,  selectBorderWidth,  and
       selectForeground options for the text widget are  tied  to  the  :back-
       ground, :borderwidth, and :foreground options for the sel tag:  changes
       in either will automatically be reflected in the other.


THE INSERTION CURSOR
       The mark named insert has special significance in text widgets.  It  is
       defined  automatically  when a text widget is created and it may not be
       unset with the ``widget-name mark unset'' widget procedure.  The insert
       mark represents the position of the insertion cursor, and the insertion
       cursor will automatically be drawn at this point whenever the text wid-
       get has the input focus.


WIDGET PROCEDURE
       The  text  procedure creates a new STk procedure whose name is the same
       as the path name of the text's window.  This procedure may be  used  to
       invoke  various operations on the widget.  It has the following general
       form: (widget-name option ?arg arg ...?)  PathName is the name  of  the
       procedure,  which  is  the same as the text widget's path name.  Option
       and the args determine the exact behavior of the procedure.   The  fol-
       lowing procedures are possible for text widgets:

       (widget-name 'bbox index)
              Returns  a  list  of four elements describing the screen area of
              the character given by index.  The first  two  elements  of  the
              list  give  the  x and y coordinates of the upper-left corner of
              the area occupied by the character, and the  last  two  elements
              give the width and height of the area.  If the character is only
              partially visible on the screen, then the return value  reflects
              just  the  visible part.  If the character is not visible on the
              screen then the return value is an empty list.

       (widget-name 'cget option)
              Returns the current value of the configuration option  given  by
              option.   Option may have any of the values accepted by the text



STk                            3.1                             11





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


              procedure.

       (widget-name 'compare index1 op index2)
              Compares the indices given by index1 and index2 according to the
              relational  operator given by op, and returns 1 if the relation-
              ship is satisfied and 0 if it isn't.  Op  must  be  one  of  the
              operators  <,  <=,  ==,  >=,  >,  or  !=.  If op is == then 1 is
              returned if the two indices refer to the same character,  if  op
              is < then 1 is returned if index1 refers to an earlier character
              in the text than index2, and so on.

       (widget-name '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 widget-name (see Tk_ConfigureInfo for  informa-
              tion  on  the format of this list).  If option is specified with
              no value, then the procedure 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 procedure
              modifies the given widget option(s) to have the given  value(s);
              in  this case the procedure returns an empty string.  Option may
              have any of the values accepted by the text procedure.

       (widget-name 'debug )

       (widget-name 'debug boolean)
              If boolean is specified, then it must have one of  the  true  or
              false values accepted by Tcl_GetBoolean.  If the value is a true
              one then internal consistency checks will be turned on in the B-
              tree  code associated with text widgets.  If boolean has a false
              value then the debugging checks will be turned off.   In  either
              case  the  procedure returns an empty string.  If boolean is not
              specified then the procedure  returns  on  or  off  to  indicate
              whether or not debugging is turned on.  There is a single debug-
              ging switch shared by all text widgets:  turning debugging on or
              off  in any widget turns it on or off for all widgets.  For wid-
              gets with large amounts of  text,  the  consistency  checks  may
              cause a noticeable slow-down.

       (widget-name 'delete index1 )

       (widget-name 'delete index1 index2)
              Delete  a range of characters from the text.  If both index1 and
              index2 are specified, then delete all  the  characters  starting
              with  the  one  given  by index1 and stopping just before index2
              (i.e. the character  at  index2  is  not  deleted).   If  index2
              doesn't specify a position later in the text than index1 then no
              characters are deleted.  If index2 isn't specified then the sin-
              gle  character  at  index1  is  deleted.  It is not allowable to
              delete characters in a way that would leave the text  without  a
              newline  as  the last character.  The procedure returns an empty
              string.




STk                            3.1                             12





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


       (widget-name 'dlineinfo index)
              Returns a list with five elements describing the  area  occupied
              by the display line containing index.  The first two elements of
              the list give the x and y coordinates of the  upper-left  corner
              of  the area occupied by the line, the third and fourth elements
              give the width and height of the area,  and  the  fifth  element
              gives  the  position of the baseline for the line, measured down
              from the top of the area.  All of this information  is  measured
              in  pixels.   If  the  current  wrap  mode  is none and the line
              extends beyond the boundaries of the window, the  area  returned
              reflects  the  entire  area  of the line, including the portions
              that are out of the window.  If the line  is  shorter  than  the
              full  width  of  the window then the area returned reflects just
              the portion of the line  that  is  occupied  by  characters  and
              embedded  windows.   If the display line containing index is not
              visible on the screen then the return value is an empty list.

       (widget-name 'dump ?switches? index1 ?index2?)
              Return the contents of the text widget from index1  up  to,  but
              not  including  index2, including the text and information about
              marks, tags, and embedded windows.  If index2 is not  specified,
              then  it defaults to one character past index1.  The information
              is returned in the following format:

              key1 value1 index1 key2 value2 index2 ...

              The possible key values are text, mark, tagon, tagoff, and  win-
              dow.   The corresponding value is the text, mark name, tag name,
              or window name.  The index information is the index of the start
              of  the  text, the mark, the tag transition, or the window.  One
              or more of the following switches (or abbreviations thereof) may
              be specified to control the dump:

              :all   Return information about all elements: text, marks, tags,
                     and windows.  This is the default.

              :command closure
                     Instead of returning the information as the result of the
                     dump operation, invoke the closure on each element of the
                     text widget within the  range.   The  command  must  have
                     three arguments:  key, value, and index.

              :mark  Include information about marks in the dump results.

              :tag   Include  information  about  tag  transitions in the dump
                     results. Tag information is returned as tagon and  tagoff
                     elements that indicate the begin and end of each range of
                     each tag, respectively.

              :text  Include information about text in the dump results.   The
                     value  is  the  text up to the next element or the end of
                     range indicated by index2.  A text element does not  span
                     newlines.   A  multi-line  block of text that contains no
                     marks or tag transitions will still be dumped as a set of



STk                            3.1                             13





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


                     text  seqments that each end with a newline.  The newline
                     is part of the value.

              :window
                     Include information about embedded windows  in  the  dump
                     results.   The  value  of  a  window  is its Tk pathname,
                     unless the window has not been  created  yet.   (It  must
                     have  a  create script.)  In this case an empty string is
                     returned, and you must query  the  window  by  its  index
                     position to get more information.

       (widget-name 'get index1 )

       (widget-name 'get index1 index2)
              Return  a  range  of characters from the text.  The return value
              will be all the characters in the text  starting  with  the  one
              whose index is index1 and ending just before the one whose index
              is index2 (the character at index2 will not  be  returned).   If
              index2  is  omitted  then  the  single  character  at  index1 is
              returned.  If there are no characters  in  the  specified  range
              (e.g.  index1 is past the end of the file or index2 is less than
              or equal to index1) then an empty string is  returned.   If  the
              specified  range contains embedded windows, no information about
              them is included in the returned string.


       (widget-name 'image option ?arg arg ...?)
              This command is used to manipulate embedded images.  The  behav-
              ior  of  the command depends on the option argument that follows
              the tag argument.  The following forms of the command  are  cur-
              rently supported:

              (widget-name 'image 'cget index option)
                     Returns the value of a configuration option for an embed-
                     ded image.  Index  identifies  the  embedded  image,  and
                     option specifies a particular configuration option, which
                     must be one of the ones listed in  the  section  EMBEDDED
                     IMAGES.

              (widget-name 'image 'configure index ?option value ...?)
                     Query or modify the configuration options for an embedded
                     image.   If  no  option  is  specified,  returns  a  list
                     describing  all of the available options for the embedded
                     image at index (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 corre-
                     sponding sublist of the value returned if  no  option  is
                     specified).  If one or more option-value pairs are speci-
                     fied, then the command modifies the  given  option(s)  to
                     have  the  given  value(s);   in  this  case  the command
                     returns an empty string.  See EMBEDDED IMAGES for  infor-
                     mation on the options that are supported.




STk                            3.1                             14





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


              (Widget-name 'image 'create index ?option value ...?)
                     This  command  creates a new image annotation, which will
                     appear in the text at the position given by  index.   Any
                     number  of option-value pairs may be specified to config-
                     ure the annotation.  Returns a unique identifier that may
                     be used as an index to refer to this image.  See EMBEDDED
                     IMAGES for information on the options that are supported,
                     and a description of the identifier returned.

              (Widget-name 'image 'names)
                     Returns  a list whose elements are the names of all image
                     instances currently embedded in window.

       (widget-name 'index index)
              Returns the position corresponding to index in the form (line  .
              char)  where  line  is the line number and char is the character
              number.  Index may have any of the forms described under INDICES
              above.

       (widget-name 'insert index chars ?tagList chars tagList ...?)
              Inserts  all of the chars arguments just before the character at
              index.  If index refers to the end of the  text  (the  character
              after  the  last  newline)  then  the  new text is inserted just
              before the last newline instead.  If there  is  a  single  chars
              argument and no tagList, then the new text will receive any tags
              that are present on both the character before and the  character
              after  the  insertion  point; if a tag is present on only one of
              these characters then it will not be applied to  the  new  text.
              If tagList is specified then it consists of a list of tag names;
              the new characters will receive all of the tags in this list and
              no  others,  regardless of the tags present around the insertion
              point.  If multiple chars-tagList argument  pairs  are  present,
              they produce the same effect as if a separate insert widget pro-
              cedure had been issued  for  each  pair,  in  order.   The  last
              tagList argument may be omitted.

       (widget-name 'mark option ?arg arg ...?)
              This  procedure is used to manipulate marks.  The exact behavior
              of the procedure depends on the option argument that follows the
              mark  argument.   The  following forms of the procedure are cur-
              rently supported:

              (widget-name 'mark 'gravity markName)

              (widget-name 'mark 'gravity markName direction)
                     If direction is not specified, returns left or  right  to
                     indicate  which  of  its  adjacent characters markName is
                     attached to.  If direction is specified, it must be  left
                     or  right;  the  gravity  of markName is set to the given
                     value.

              (widget-name 'mark 'names)
                     Returns a list whose elements are the names  of  all  the
                     marks that are currently set.



STk                            3.1                             15





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


              (widget-name 'mark 'next index)
                     Returns  the name of the next mark at or after index.  If
                     index is specified in numerical form, then the search for
                     the next mark begins at that index.  If index is the name
                     of a mark, then the search for the next mark begins imme-
                     diately after that mark.  This can still return a mark at
                     the same position if there are multiple marks at the same
                     index.  These semantics mean that the mark next operation
                     can be used to step through all the marks in a text  wid-
                     get in the same order as the mark information returned by
                     the dump operation.  If a mark has been set to  the  spe-
                     cial  end  index,  then  it  appears to be after end with
                     respect to the mark next operation.   An  empty  list  is
                     returned if there are no marks after index.

              (widget-name 'mark 'previous index)
                     Returns  the  name  of  the  mark at or before index.  If
                     index is specified in numerical form, then the search for
                     the  previous  mark begins with the character just before
                     that index.  If index is the name of  a  mark,  then  the
                     search  for  the next mark begins immediately before that
                     mark.  This can still return a mark at the same  position
                     if  there  are  multiple  marks at the same index.  These
                     semantics mean that the mark previous  operation  can  be
                     used  to  step  through all the marks in a text widget in
                     the reverse order as the mark information returned by the
                     dump  operation.   An empty list is returned if there are
                     no marks before index.

              (widget-name 'mark 'set markName index)
                     Sets the mark named markName to a  position  just  before
                     the  character  at index.  If markName already exists, it
                     is moved from its old position; if it  doesn't  exist,  a
                     new  mark  is  created.   This procedure returns an empty
                     string.

              (widget-name 'mark 'unset markName ?markName markName ...?)
                     Remove the mark corresponding to  each  of  the  markName
                     arguments.   The  removed  marks  will  not  be usable in
                     indices and will not  be  returned  by  future  calls  to
                     ``widget-name  mark  names''.   This procedure returns an
                     empty string.

       (widget-name 'scan option args)
              This procedure is used to implement scanning on texts.   It  has
              two forms, depending on option:

              (widget-name 'scan 'mark x y)
                     Records  x and y and the current view in the text window,
                     for use in conjunction with later scan dragto procedures.
                     Typically  this procedure is associated with a mouse but-
                     ton press in the widget.  It returns an empty string.





STk                            3.1                             16





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


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

       (widget-name search ?switches? pattern index ?stopIndex?)
              Searches  the  text in widget-name starting at index for a range
              of characters that matches pattern.  If a match  is  found,  the
              index of the first character in the match is returned as result;
              otherwise an empty string is returned.  One or more of the  fol-
              lowing  switches  (or abbreviations thereof) may be specified to
              control the search:

              :forwards
                     The search will proceed forward through the text, finding
                     the  first  matching range starting at or after the posi-
                     tion given by index.  This is the default.

              :backwards
                     The search will proceed backward through the text,  find-
                     ing the matching range closest to index whose first char-
                     acter is before index.

              :exact Use exact matching:  the characters in the matching range
                     must  be  identical  to  those  in  pattern.  This is the
                     default.

              :regexp
                     Treat pattern  as  a  regular  expression  and  match  it
                     against  the text using the rules for regular expressions
                     (see the regexp procedure for details).

              :nocase
                     Ignore case differences between the pattern and the text.

              :count varName
                     The  argument  following :count gives the name of a vari-
                     able; if a match is found, the number  of  characters  in
                     the matching range will be stored in the variable.

              :environment env
                     The  argument following :environment gives the definition
                     environment of the variable counting  matches  (i.e.  the
                     one  given to the  :count option).  :- This switch has no
                     effect except to terminate the list of switches: the next
                     argument  will  be  treated  as pattern even if it starts
                     with :.

              The matching range must be entirely  within  a  single  line  of



STk                            3.1                             17





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


              text.   For regular expression matching the newlines are removed
              from the ends of the lines before matching:  use the  $  feature
              in  regular  expressions  to match the end of a line.  For exact
              matching the newlines are retained.  If stopIndex is  specified,
              the  search  stops at that index: for forward searches, no match
              at  or  after  stopIndex  will  be  considered;   for   backward
              searches,  no  match  earlier in the text than stopIndex will be
              considered.  If stopIndex is omitted, the entire  text  will  be
              searched:  when the beginning or end of the text is reached, the
              search continues at the other end until the starting location is
              reached  again;   if stopIndex is specified, no wrap-around will
              occur.

       (widget-name 'see index)
              Adjusts the view in the window so that the  character  given  by
              index  is  completely visible.  If index is already visible then
              the procedure does nothing.  If index is a short distance out of
              view,  the  procedure adjusts the view just enough to make index
              visible at the edge of the window.  If index is far out of view,
              then the procedure centers index in the window.

       (widget-name 'tag option ?arg arg ...?)
              This  procedure  is used to manipulate tags.  The exact behavior
              of the procedure depends on the option argument that follows the
              tag  argument.   The  following  forms of the procedure are cur-
              rently supported:

              (widget-name 'tag 'add tagName index1 ?index2 index1 index2
              ...?)
                     Associate  the  tag  tagName  with  all of the characters
                     starting with index1 and ending just before  index2  (the
                     character  at  index2  isn't tagged).  A single procedure
                     may contain any number of index1-index2  pairs.   If  the
                     last  index2  is  omitted  then  the  single character at
                     index1 is tagged.  If there  are  no  characters  in  the
                     specified  range (e.g. index1 is past the end of the file
                     or index2 is less than or equal to index1) then the  pro-
                     cedure has no effect.

              (widget-name 'tag 'bind tagName)

              (widget-name 'tag 'bind tagName sequence)

              (widget-name 'tag 'bind tagName sequence script)
                     This  procedure  associates  script with the tag given by
                     tagName.  Whenever the event sequence given  by  sequence
                     occurs for a character that has been tagged with tagName,
                     the script will be invoked.   This  widget  procedure  is
                     similar  to the bind procedure except that it operates on
                     characters in a text rather than entire widgets.  See the
                     bind  manual  entry for complete details on the syntax of
                     sequence and the substitutions performed on script before
                     invoking  it.   If all arguments are specified then a new
                     binding is created, replacing any  existing  binding  for



STk                            3.1                             18





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


                     the  same  sequence and tagName.  In this case the return
                     value is an empty string.  If script is omitted then  the
                     procedure  returns the script associated with tagName and
                     sequence (an error occurs if there is no  such  binding).
                     If  both  script and sequence are omitted then the proce-
                     dure returns a list of all the sequences for which  bind-
                     ings have been defined for tagName.

                     The  only  events for which bindings may be specified are
                     those related to the mouse and keyboard (such  as  Enter,
                     Leave,  ButtonPress,  Motion,  and  KeyPress)  or virtual
                     events.  Event bindings for a text widget use the current
                     mark  described  under MARKS above.  An Enter event trig-
                     gers for a tag when the tag first becomes present on  the
                     current  character,  and a Leave event triggers for a tag
                     when it ceases to be present on  the  current  character.
                     Enter and Leave events can happen either because the cur-
                     rent mark moved or because the character at that position
                     changed.  Note that these events are different than Enter
                     and Leave events for windows.  Mouse and keyboard  events
                     are  directed  to  the  current  character.  If a virtual
                     event is used in a binding, that binding can trigger only
                     if  the  virtual event is defined by an underlying mouse-
                     related or keyboard-related event.

                     It is possible for the current character to have multiple
                     tags,  and  for each of them to have a binding for a par-
                     ticular event sequence.  When this occurs, one binding is
                     invoked  for  each  tag, in order from lowest-priority to
                     highest priority.  If there are multiple  matching  bind-
                     ings  for a single tag, then the most specific binding is
                     chosen (see the manual entry for the bind  procedure  for
                     details).   continue  and break procedures within binding
                     scripts are processed in the same  way  as  for  bindings
                     created with the bind procedure.

                     If  bindings  are created for the widget as a whole using
                     the bind procedure, then those bindings  will  supplement
                     the  tag  bindings.   The  tag  bindings  will be invoked
                     first, followed by bindings for the window as a whole.

              (widget-name 'tag 'cget tagName option)
                     This procedure returns the current value  of  the  option
                     named  option  associated  with the tag given by tagName.
                     Option may have any of the values  accepted  by  the  tag
                     configure widget procedure.

              (widget-name 'tag 'configure tagName ?option? ?value? ?option
              value ...?)
                     This procedure is similar to the configure widget  proce-
                     dure  except that it modifies options associated with the
                     tag given by tagName instead of modifying options for the
                     overall text widget.  If no option is specified, the pro-
                     cedure returns a list describing  all  of  the  available



STk                            3.1                             19





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


                     options for tagName (see Tk_ConfigureInfo for information
                     on the format of this list).  If option is specified with
                     no  value,  then  the procedure 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   procedure  modifies  the  given
                     option(s) to have the given value(s) in tagName; in  this
                     case the procedure returns an empty list.  See TAGS above
                     for details on the options available for tags.

              (widget-name 'tag 'delete tagName ?tagName ...?)
                     Deletes all tag information for each of the tagName argu-
                     ments.   The  procedure removes the tags from all charac-
                     ters in the file and also deletes any  other  information
                     associated  with  the  tags, such as bindings and display
                     information.  The procedure returns an empty list.

              (widget-name'tag 'lower tagName )

              (widget-name'tag 'lower tagName  belowThis)
                     Changes the priority of tag tagName so that  it  is  just
                     lower  in  priority than the tag whose name is belowThis.
                     If belowThis  is  omitted,  then  tagName's  priority  is
                     changed to make it lowest priority of all tags.

              (widget-name 'tag 'names )

              (widget-name 'tag 'names  index)
                     Returns  a  list  whose elements are the names of all the
                     tags that are active at the character position  given  by
                     index.   If  index is omitted, then the return value will
                     describe all of the tags that exist for  the  text  (this
                     includes all tags that have been named in a ``widget-name
                     tag'' widget procedure but  haven't  been  deleted  by  a
                     ``widget-name  tag  delete'' widget procedure, even if no
                     characters are currently marked with the tag).  The  list
                     will  be  sorted in order from lowest priority to highest
                     priority.

              (widget-name 'tag 'nextrange tagName index1 )

              (widget-name 'tag 'nextrange tagName index1  index2)
                     This procedure searches the text for a range  of  charac-
                     ters tagged with tagName where the first character of the
                     range is no earlier than the character at index1  and  no
                     later  than  the  character  just  before index2 (a range
                     starting at index2 will not be considered).   If  several
                     matching ranges exist, the first one is chosen.  The pro-
                     cedure's return value is a list containing two  elements,
                     which  are  the index of the first character of the range
                     and the index of the character just after the last one in
                     the range.  If no matching range is found then the return
                     value is an empty list.  If index2 is not given  then  it



STk                            3.1                             20





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


                     defaults to the end of the text.

              (widget-name 'tag 'prevrange tagName index1 )

              (widget-name 'tag 'prevrange tagName index1  index2)
                     This  command searches the text for a range of characters
                     tagged with tagName where  the  first  character  of  the
                     range  is  before  the character at index1 and no earlier
                     than the character at index2 (a range starting at  index2
                     will  be  considered).  If several matching ranges exist,
                     the one closest  to  index1  is  chosen.   The  command's
                     return value is a list containing two elements, which are
                     the index of the first character of  the  range  and  the
                     index  of  the  character  just after the last one in the
                     range.  If no matching range is  found  then  the  return
                     value is an empty string.  If index2 is not given then it
                     defaults to the beginning of the text.

              (widget-name'tag 'raise tagName )

              (widget-name'tag 'raise tagName  aboveThis)
                     Changes the priority of tag tagName so that  it  is  just
                     higher  in priority than the tag whose name is aboveThis.
                     If aboveThis  is  omitted,  then  tagName's  priority  is
                     changed to make it highest priority of all tags.

              (widget-name 'tag 'ranges tagName)
                     Returns  a list describing all of the ranges of text that
                     have been tagged with tagName.  The first two elements of
                     the list describe the first tagged range in the text, the
                     next two elements describe the second range, and  so  on.
                     The  first element of each pair contains the index of the
                     first character of the range, and the second  element  of
                     the  pair  contains the index of the character just after
                     the last one in the range.  If there  are  no  characters
                     tagged with tag then an empty list is returned.

              (widget-name 'tag 'remove tagName index1 ?index2 index1 index2
              ...?)
                     Remove the tag tagName from all of the characters  start-
                     ing  at index1 and ending just before index2 (the charac-
                     ter at index2 isn't affected).  A  single  procedure  may
                     contain  any  number of index1-index2 pairs.  If the last
                     index2 is omitted then the single character at index1  is
                     tagged.   If  there  are  no  characters in the specified
                     range (e.g. index1 is past the end of the file or  index2
                     is  less  than or equal to index1) then the procedure has
                     no effect.  This procedure returns an empty list.

       (widget-name 'window option ?arg arg ...?)
              This procedure is used  to  manipulate  embedded  windows.   The
              behavior  of  the  procedure depends on the option argument that
              follows the tag argument.  The following forms of the  procedure
              are currently supported:



STk                            3.1                             21





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


              (widget-name 'window 'cget index option)
                     Returns the value of a configuration option for an embed-
                     ded window.  Index identifies the  embedded  window,  and
                     option specifies a particular configuration option, which
                     must be one of the ones listed in  the  section  EMBEDDED
                     WINDOWS.

              (widget-name 'window 'configure index ?option value ...?)
                     Query or modify the configuration options for an embedded
                     window.  If  no  option  is  specified,  returns  a  list
                     describing  all of the available options for the embedded
                     window at index (see Tk_ConfigureInfo for information  on
                     the format of this list).  If option is specified with no
                     value, then the procedure returns a list  describing  the
                     one named option (this list will be identical to the cor-
                     responding sublist of the value returned if no option  is
                     specified).  If one or more option-value pairs are speci-
                     fied, then the procedure modifies the given option(s)  to
                     have  the  given  value(s);   in  this case the procedure
                     returns an empty list.  See EMBEDDED WINDOWS for informa-
                     tion on the options that are supported.

              (widget-name 'window 'create index ?option value ...?)
                     This  procedure  creates  a  new window annotation, which
                     will appear in the text at the position given  by  index.
                     Any number of option-value pairs may be specified to con-
                     figure the annotation.  See EMBEDDED WINDOWS for informa-
                     tion on the options that are supported.  Returns an empty
                     list.

              (widget-name 'window 'names)
                     Returns a list whose elements are the names of  all  win-
                     dows currently embedded in window.

       (widget-name 'xview option args)
              This  procedure is used to query and change the horizontal posi-
              tion of the text in the widget's window.  It can take any of the
              following forms:

              (widget-name 'xview)
                     Returns  a list containing two elements.  Each element is
                     a real fraction between 0 and 1;  together they  describe
                     the  portion  of  the  document's horizontal span that is
                     visible in the window.  For example, if the first element
                     is  .2  and  the second element is .6, 20% of the text is
                     off-screen to the left, the middle 40% is visible in  the
                     window,  and  40% of the text is off-screen to the right.
                     The fractions refer only to the lines that  are  actually
                     visible  in  the  window:  if the lines in the window are
                     all very short, so that they are  entirely  visible,  the
                     returned  fractions  will  be  0 and 1, even if there are
                     other lines in the text that are much wider than the win-
                     dow.   These are the same values passed to scrollbars via
                     the :xscrollprocedure option.



STk                            3.1                             22





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


              (widget-name 'xview 'moveto fraction)
                     Adjusts the view in the window so that  fraction  of  the
                     horizontal  span  of  the text is off-screen to the left.
                     Fraction is a fraction between 0 and 1.

              (widget-name 'xview 'scroll number what)
                     This procedure 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 abbre-
                     viation  of  one  of  these.   If what is units, the view
                     adjusts left or right by number average-width  characters
                     on  the display;  if it is pages then the view adjusts by
                     number screenfuls.  If number is negative then characters
                     farther  to  the  left become visible;  if it is positive
                     then characters farther to the right become visible.

       (widget-name 'yview ?args?)
              This procedure is used to query and change the vertical position
              of the text in the widget's window.  It can take any of the fol-
              lowing forms:

              (widget-name 'yview)
                     Returns a list containing two elements, both of which are
                     real  fractions between 0 and 1.  The first element gives
                     the position of the first character in the  top  line  in
                     the window, relative to the text as a whole (0.5 means it
                     is halfway through the text, for  example).   The  second
                     element  gives  the  position of the character just after
                     the last one in the bottom line of the  window,  relative
                     to the text as a whole.  These are the same values passed
                     to scrollbars via the :yscrollprocedure option.

              (widget-name 'yview 'moveto fraction)
                     Adjusts the view in the  window  so  that  the  character
                     given  by fraction appears on the top line of the window.
                     Fraction is a fraction between 0 and 1;  0 indicates  the
                     first character in the text, 0.33 indicates the character
                     one-third the way through the text, and so on.

              (widget-name 'yview 'scroll number what)
                     This procedure adjust 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 by number lines on the dis-
                     play;  if it is pages then the  view  adjusts  by  number
                     screenfuls.  If number is negative then earlier positions
                     in the text become visible;  if it is positive then later
                     positions in the text become visible.

              (widget-name yview  index)

              (widget-name yview :pickplace index)
                     Changes  the  view  in  the widget's window to make index
                     visible.  If the :pickplace option isn't  specified  then



STk                            3.1                             23





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


                     index  will  appear  at the top of the window.  If :pick-
                     place is specified then the widget  chooses  where  index
                     appears in the window:

                      [1]    If index is already visible somewhere in the win-
                             dow then the procedure does nothing.

                      [2]    If index is only a few lines off-screen above the
                             window  then  it will be positioned at the top of
                             the window.

                      [3]    If index is only a few lines off-screen below the
                             window  then  it will be positioned at the bottom
                             of the window.

                      [4]    Otherwise, index will be centered in the  window.

                     The  :pickplace option has been obsoleted by the see wid-
                     get procedure (see handles both x- and y-motion to make a
                     location  visible, whereas :pickplace only handles motion
                     in y).

              (widget-name 'yview number)
                     This procedure makes the  first  character  on  the  line
                     after  the  one given by number visible at the top of the
                     window.  Number must be an integer.  This procedure  used
                     to be used for scrolling, but now it is obsolete.


BINDINGS
       Tk  automatically  creates  class bindings for texts that give them the
       following default behavior.  In the descriptions below, ``word'' refers
       to  a  contiguous group of letters, digits, or ``_'' characters, or any
       single character other than these.

       [1]    Clicking mouse button 1  positions  the  insertion  cursor  just
              before the character underneath the mouse cursor, sets the input
              focus to this widget, and clears any selection  in  the  widget.
              Dragging with mouse button 1 strokes out a selection between the
              insertion cursor and the character under the mouse.

       [2]    Double-clicking with mouse button 1 selects the word  under  the
              mouse and positions the insertion cursor at the beginning of the
              word.  Dragging after a double click will stroke out a selection
              consisting of whole words.

       [3]    Triple-clicking  with  mouse button 1 selects the line under the
              mouse and positions the insertion cursor at the beginning of the
              line.  Dragging after a triple click will stroke out a selection
              consisting of whole lines.

       [4]    The ends of the selection can be adjusted by dragging with mouse
              button  1 while the Shift key is down;  this will adjust the end
              of the selection that was  nearest  to  the  mouse  cursor  when



STk                            3.1                             24





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


              button  1  was  pressed.  If the button is double-clicked before
              dragging then the selection will be adjusted in units  of  whole
              words;   if  it  is  triple-clicked  then  the selection will be
              adjusted in units of whole lines.

       [5]    Clicking mouse button 1 with the Control key down  will  reposi-
              tion the insertion cursor without affecting the selection.

       [6]    If  any  normal printing characters are typed, they are inserted
              at the point of the insertion cursor.

       [7]    The view in the widget can be adjusted by  dragging  with  mouse
              button  2.   If  mouse  button  2  is clicked without moving the
              mouse, the selection
               is copied into the text at the position of  the  mouse  cursor.
              The  Insert  key also inserts the selection, but at the position
              of the insertion cursor.

       [8]    If the mouse is dragged out of the  widget  while  button  1  is
              pressed,  the  entry will automatically scroll to make more text
              visible (if there is more text off-screen on the side where  the
              mouse left the window).

       [9]    The  Left and Right keys move the insertion cursor one character
              to the left or right;  they also  clear  any  selection  in  the
              text.   If  Left or Right is typed with the Shift key down, then
              the insertion cursor moves and  the  selection  is  extended  to
              include  the new character.  Control-Left and Control-Right move
              the insertion cursor by words, and Control-Shift-Left  and  Con-
              trol-Shift-Right  move  the  insertion  cursor by words and also
              extend the selection.  Control-b and Control-f behave  the  same
              as  Left  and Right, respectively.  Meta-b and Meta-f behave the
              same as Control-Left and Control-Right, respectively.

       [10]   The Next and Prior keys move the  insertion  cursor  forward  or
              backwards  by one screenful and clear any selection in the text.
              If the Shift key is held down while Next or Prior is typed, then
              the  selection  is  extended to include the new character.  Con-
              trol-v moves the view down  one  screenful  without  moving  the
              insertion cursor or adjusting the selection.

       [11]   Control-Next  and Control-Prior scroll the view right or left by
              one page without moving the insertion cursor  or  affecting  the
              selection.

       [12]   Home and Control-a move the insertion cursor to the beginning of
              its line and clear any  selection  in  the  widget.   Shift-Home
              moves the insertion cursor to the beginning of the line and also
              extends the selection to that point.

       [13]   End and Control-e move the insertion cursor to the  end  of  the
              line and clear any selection in the widget.  Shift-End moves the
              cursor to the end of the line and extends the selection to  that
              point.



STk                            3.1                             25





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


       [14]   Control-Home  and Meta-< move the insertion cursor to the begin-
              ning of the text and clear any selection in  the  widget.   Con-
              trol-Shift-Home  moves  the insertion cursor to the beginning of
              the text and also extends the selection to that point.

       [15]   Control-End and Meta-> move the insertion cursor to the  end  of
              the  text and clear any selection in the widget.  Control-Shift-
              End moves the cursor to the end of  the  text  and  extends  the
              selection to that point.

       [16]   The Select key and Control-Space set the selection anchor to the
              position of the insertion cursor.  They don't affect the current
              selection.   Shift-Select  and  Control-Shift-Space  adjust  the
              selection to the  current  position  of  the  insertion  cursor,
              selecting  from  the anchor to the insertion cursor if there was
              not any selection previously.

       [17]   Control-/ selects the entire contents of the widget.

       [18]   Control-\ clears any selection in the widget.

       [19]   The F16 key (labelled Copy on many Sun workstations)  or  Meta-w
              copies the selection in the widget to the clipboard, if there is
              a selection.

       [20]   The F20 key (labelled Cut on many Sun workstations) or Control-w
              copies  the selection in the widget to the clipboard and deletes
              the selection.  If there is no  selection  in  the  widget  then
              these keys have no effect.

       [21]   The  F18  key  (labelled Paste on many Sun workstations) or Con-
              trol-y inserts the contents of the clipboard at the position  of
              the insertion cursor.

       [22]   The  Delete  key  deletes  the selection, if there is one in the
              widget.  If there is no selection, it deletes the  character  to
              the right of the insertion cursor.

       [23]   Backspace and Control-h delete the selection, if there is one in
              the widget.  If there is no selection, they delete the character
              to the left of the insertion cursor.

       [24]   Control-d  deletes  the  character to the right of the insertion
              cursor.

       [25]   Meta-d deletes the word to the right of the insertion cursor.

       [26]   Control-k deletes from the insertion cursor to the  end  of  its
              line;  if  the insertion cursor is already at the end of a line,
              then Control-k deletes the newline character.

       [27]   Control-o opens a new line by inserting a newline  character  in
              front  of the insertion cursor without moving the insertion cur-
              sor.



STk                            3.1                             26





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


       [28]   Meta-backspace and Meta-Delete delete the word to  the  left  of
              the insertion cursor.

       [29]   Control-x deletes whatever is selected in the text widget.

       [30]   Control-t  reverses the order of the two characters to the right
              of the insertion cursor.

       If the widget is disabled using the :state option, then  its  view  can
       still be adjusted and text can still be selected, but no insertion cur-
       sor will be displayed and no text modifications will take place.

       The behavior of texts can be changed by defining new bindings for indi-
       vidual widgets or by redefining the class bindings.


PERFORMANCE ISSUES
       Text widgets should run efficiently under a variety of conditions.  The
       text widget uses about 2-3 bytes of main memory for each byte of  text,
       so  texts  containing  a  megabyte  or more should be practical on most
       workstations.  Text is represented internally with  a  modified  B-tree
       structure  that  makes  operations relatively efficient even with large
       texts.  Tags are included in the B-tree structure in a way that  allows
       tags  to span large ranges or have many disjoint smaller ranges without
       loss of efficiency.  Marks are also implemented in a  way  that  allows
       large numbers of marks.  In most cases it is fine to have large numbers
       of unique tags, or a tag that has many distinct ranges.

       One performance problem can arise if you have hundreds or thousands  of
       different  tags  that all have the following characteristics: the first
       and last ranges of each tag are near the beginning and end of the text,
       respectively,  or  a  single  tag range covers most of the text widget.
       The cost of adding and deleting tags like this is proportional  to  the
       number  of  other tags with the same properties.  In contrast, there is
       no problem with having thousands of  distinct  tags  if  their  overall
       ranges are localized and spread uniformly throughout the text.

       Very  long  text  lines  can be expensive, especially if they have many
       marks and tags within them.

       The display line with the insert cursor is redrawn each time the cursor
       blinks,  which  causes  a  steady  stream of graphics traffic.  Set the
       insertOffTime attribute to 0 avoid this.














STk                            3.1                             27


