Go to main content

man pages section 3: Library Interfaces and Headers

Exit Print View

Updated: Wednesday, July 27, 2022
 
 

Tk::Text (3)

Name

Tk::Text - Create and manipulate Text widgets

Synopsis

$text = $parent->Text(?options?);

-background    -highlightbackground     -insertontime  -selectborderwidth
-borderwidth   -highlightcolor     -insertwidth   -selectforeground
-cursor   -highlightthickness -padx     -setgrid
-exportselection    -insertbackground   -pady     -takefocus
-font     -insertborderwidth  -relief   -xscrollcommand
-foreground    -insertofftime -selectbackground   -yscrollcommand

Description

User Contributed Perl Documentation                                    Text(3)



NAME
       Tk::Text - Create and manipulate Text widgets

SYNOPSIS
       $text = $parent->Text(?options?);

       -background    -highlightbackground     -insertontime  -selectborderwidth
       -borderwidth   -highlightcolor     -insertwidth   -selectforeground
       -cursor   -highlightthickness -padx     -setgrid
       -exportselection    -insertbackground   -pady     -takefocus
       -font     -insertborderwidth  -relief   -xscrollcommand
       -foreground    -insertofftime -selectbackground   -yscrollcommand

WIDGET-SPECIFIC OPTIONS
       Name:     height
       Class:    Height
       Switch:   -height
           Specifies the desired height for the window, in units of characters
           in the font given by the -font option.  Must be at least one.

       Name:     spacing1
       Class:    Spacing1
       Switch:   -spacing1
           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.

       Name:     spacing2
       Class:    Spacing2
       Switch:   -spacing2
           For lines that wrap (so that they cover more than one line on the
           display) this option specifies additional space to provide between
           the display lines that represent a single 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.

       Name:     spacing3
       Class:    Spacing3
       Switch:   -spacing3
           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.

       Name:     state
       Class:    State
       Switch:   -state
           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.

       Name:     tabs
       Class:    Tabs
       Switch:   -tabs
           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 position may optionally be followed in the next
           list element by one of the keywords left, right, center, or
           numeric, which specifies how to justify 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 following 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 position.  For example, -tabs => [qw/2c left 4c 6c center/]
           creates three tab stops at two-centimeter intervals;  the first two
           use left justification 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.

       Name:     width
       Class:    Width
       Switch:   -width
           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 of the character ``0'' is used in
           translating from character units to screen units.

       Name:     wrap
       Class:    Wrap
       Switch:   -wrap
           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
           necessary 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 method creates a new window (given by the $text argument) and
       makes it into a text widget.  Additional options, described above, may
       be specified on the command line or in the option database to configure
       aspects of the text such as its default background color and relief.
       The text command returns the path name of the new window.

       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
       different fonts and colors.  In addition, perl/Tk callbacks 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
       interesting 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.

       The Perl/Tk Text widget does not support undo/redo, use the TextUndo
       widget instead.

INDICES
       Many of the methods 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 modifiers adjust the index
       from the starting point (e.g. move forward or backward one character).
       Every index must contain a base, but the modifiers are optional.

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

       line.char
           Indicates char'th character on line line.  Lines are numbered from
           1 for consistency with other UNIX programs that use this numbering
           scheme.  Within a line, characters are numbered from 0.  If char is
           end then it refers to the newline character that ends the line.

       @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 characters 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
           Indicates the position of the embedded window referenced by
           $widget.  This form generates an error if $widget does not
           reference to an embedded window.

       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
       abbreviation 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
           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
       containing the insertion cursor.

TAGS
       The first form of annotation in text widgets is a tag.  A tag is a
       textual 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 characters, or several ranges of characters.  An individual
       character may 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
       display options or binding callbacks to it), it is given a priority
       higher than any existing tag.  The priority order of tags may be
       redefined using the ``$text->tagRaise'' and ``$text->tagLower''
       methods.

       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 ``$text->tagConfigure'' method.  If a
       character has been tagged, then the display options associated 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
           associated 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_GetPixels.
           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.

       -elide => boolean
           Elide  specifies whether the data should be elided.  Elided data is
           not displayed and takes no space on screen,  but  further  on
           behaves just as normal data.

       -data => value
           Allows an arbitrary perl scalar value to be associated with the
           tag.

       -fgstipple => bitmap
           Bitmap specifies a bitmap that is used as a stipple pattern when
           drawing text and other foreground information such as underlines.
           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.

       -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 display 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.  Pixels 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 standard 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 superscripts and a
           negative offset can be used for subscripts.  Pixels 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 display line.

       -spacing1 => pixels
           Pixels specifies how much additional space should be left above
           each text line, using any of the standard forms for screen
           distances.  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
           distances.  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 display
           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 -tabs = " ">, then it requests default 8-character
           tabs as described for the tabs 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_GetBoolean.

       -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
       display options conflict, then the options of the highest priority tag
       are used.  If a particular display option hasn't been specified for a
       particular 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
       bindings 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 <perl/Tk callback|Tk::callbacks> 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 tagBind widget
       method below.

       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
       single 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 association with characters in the file.  Marks may be
       manipulated with the ``$text->mark'' text widget method, and their
       current locations may be determined by using the mark name as an index
       in methods.

       Each mark also has a gravity, which is either left or right.  The
       gravity 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
       different things.

       Two marks have special significance.  First, the mark insert is
       associated with the insertion cursor, as described under "THE INSERTION
       CURSOR" below.  Second, the mark current is associated with the
       character closest to the mouse and is adjusted automatically to track
       the mouse position 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
       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 widgetCreate
       method, several configuration options may be associated with it.  These
       options may be  modified later with the widgetConfigure method.  The
       following options are currently supported:

       -align => where
           If the window is not as tall as the line in which it is displayed,
           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 window 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 => callback
           Specifies a callback that may be evaluated to create the window for
           the annotation.  If no -window option has been specified for the
           annotation this callback will be evaluated when the annotation is
           about to be displayed on the screen.  Callback must create a window
           for the annotation and return the name of that window as its
           result.  If the annotation's window should ever be deleted,
           callback 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 (see Tk_GetPixels).

       -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 (see Tk_GetPixels).

       -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 vertically
           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
           Specifies the name of a 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
       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 with imageCreate.  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
       method, 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 imageCreate
       method, several configuration options may be associated with it.  These
       options may be modified later with the image configure method.  The
       following options are currently supported:

       -align => where
           If the image is not as tall as the line in which it is displayed,
           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 referenced
           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.

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.

       [4] Whenever the sel tag range changes a virtual event <<Selection>> is
           generated.

           The sel tag is automatically defined when a text widget is created,
           and it may not be deleted with the ``$text->tagDelete'' method.
           Furthermore, the selectBackground, selectBorderWidth, and
           selectForeground options for the text widget are tied to the
           -background, -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 ``$text->markUnset'' widget command.  The insert mark
       represents the position of the insertion cursor, and the insertion
       cursor will automatically be drawn at this point whenever the text
       widget has the input focus.

THE MODIFIED FLAG
       The text widget can keep track of changes to the content of the  widget
       by means of the modified flag. Inserting or deleting text will set this
       flag. The flag can be queried, set and cleared programatically as well.
       Whenever  the flag changes state a <<Modified>> virtual event is gener-
       ated. See the edit modified widget command for more details.

WIDGET METHODS
       The Text method creates a widget object.  This object supports the
       configure and cget methods described in Tk::options which can be used
       to enquire and modify the options described above.  The widget also
       inherits all the methods provided by the generic Tk::Widget class.

       The following additional methods are available for text widgets.  In
       addition, the extended text widget methods as documented in "Mastering
       Perl/Tk" are included in this pod (with permission from the publisher,
       O'Reilly and Associates Inc.).

       $text->adjustSelect
           Moves the end point of the selection and anchor point to the mouse
           pointer location.

       $text->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.

       $text->clipboardColumnCopy
           Performs a rectangular copy of the currently selected text with
           basic compensation for tab characters.

       $text->clipboardColumnCut
           Performs a rectangular cut of the currently selected text with
           basic compensation for tab characters.

       $text->clipboardColumnPaste
           Performs a rectangular paste of the text in the clipboard. The
           upper-left corner is specified by the current position of the
           insert mark with basic compensation for tab characters.

       $text->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 relationship
           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.

       $text->Contents(?args?)
           Query or change the entire contents of the text widget. If no
           arguments are given, the entire contents of the text widget are
           returned. If any arguments are given, the entire contents of the
           text widget are deleted and replaced by the argument list.

       $text->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
           command returns an empty string.  If boolean is not specified then
           the command returns on or off to indicate whether or not debugging
           is turned on.  There is a single debugging switch shared by all
           text widgets:  turning debugging on or off in any widget turns it
           on or off for all widgets.  For widgets with large amounts of text,
           the consistency checks may cause a noticeable slow-down.

       $text->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 single 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 command returns an empty string.  If more indices
           are given, multiple ranges of text will be deleted.  All indices
           are first checked for  validity  before any deletions are made.
           They are sorted and the text is removed from the last range to the
           first range to deleted text does  not cause  a  undesired  index
           shifting  side-effects.  If multiple ranges with the same start
           index are  given,  then  the  longest range  is used.  If
           overlapping ranges are given, then they will be merged into spans
           that do not cause deletion of text  outside the given ranges due to
           text shifted during deletion.

       $text->deleteSelected
           Delete the currently selected text.

       $text->deleteTextTaggedWith(tag)
           Delete the text tagged with the tag parameter.

       $text->deleteToEndofLine
           Delete from the insert mark location to the end of line.

       $text->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.

       $text->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 $text.
           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 => callback
               Instead of returning the information as the result of the dump
               operation, invoke the callback on each element of the text
               widget within the range.  The callback has three arguments
               appended to it before it is evaluated: the 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 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.

       $text->edit(  option, ?arg, arg ...? );
           This  command controls the undo mechanism and the modified flag.
           The exact behavior of the command depends on the option argument
           that follows the edit argument.  The following forms of the command
           are currently supported:

           $text->editModified( ?boolean? );
               If boolean is not specified, returns the modified flag of the
               widget. The insert, delete, edit undo and  edit  redo commands
               or the user can set or clear the modified flag.  If boolean is
               specified, sets the modified  flag  of  the widget to boolean.

           $text->editRedo;
               (Not implemented, use TextUndo.)  When the -undo option is
               true, reapplies the last undone edits provided no other edits
               were done since then. Generates an error when the redo stack is
               empty.  Does nothing when the -undo option is false.

           $text->editReset;
               (Not implemented, use TextUndo.) Clears the undo and redo
               stacks.

           $text->editSeparator;
               (Not implemented, use TextUndo.) Inserts a separator (boundary)
               on the undo stack. Does nothing when the -undo option is false.

           $text->editUndo;
               (Not implemented, use TextUndo.) Undoes the last edit action
               when the -undo option is true.  An edit action is defined as
               all the insert and delete commands that are recorded on the
               undo stack in between two separators. Generates an error when
               the undo stack is empty.  Does nothing when the -undo option is
               false.

       $text->FindAll(mode, case, pattern)
           Removes any current selections and then performs a global text
           search. All matches are tagged with the sel tag.

           mode can be be -exact or -regexp. See the search command for more
           information

           case can be -nocase or -case. See the search command for more
           information

           pattern is an exact string to match if mode is -exact or a regular
           expression if the match mode is -regexp.

       $text->FindAndReplaceAll(mode, case, find, replace)
           Same as the FindAll method, however additionally substitutes the
           matched text with the characters replace.

       $text->FindAndReplacePopUp
           Creates a find-and-replace popup window if one does not already
           exist.  If there is currently selected text, then the 'find' field
           will be 'pre-filled' with the selection.

       $text->FindNext(direction, mode, case, pattern)
           Removes any current selections and then performs a forward or
           reverse text search. All matches are tagged with the sel tag.
           direction can be -forwards or -backwards. mode, case and pattern
           are as for the FindAll method.

       $text->FindPopUp
           Creates a find popup, if one does not yet exist. If there is
           currently selected text, then the 'find' field will be 'pre-filled'
           with the selection.

       $text->FindSelectionNext
           Gets the currently selected text and removes all selections. It
           then finds the next exact, case-sensitive string that matches in a
           forward direction and selects the text and makes the new selection
           visible.

       $text->FindSelectionPrevious
           Gets the currently selected text and removes all selections. It
           then finds the next exact, case-sensitive string that matches in a
           reverse direction and selects the text and makes the new selection
           visible.

       $text->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.  If multiple index pairs are given, multiple ranges of text
           will be returned in a list.  Invalid ranges will not be represented
           with empty strings in the list.  The ranges are returned in the
           order passed to get.

       $text->getSelected
           Return the currently selected text.

       $text->GetTextTaggedWith(tag)
           Return the text tagged with the tag parameter.

       $text->GotoLineNumber(line_number)
           Set the insert mark to line_number and ensures the line is visible.

       $text->GotoLineNumberPopUp(line_number)
           Displays a popup, pre-filling it with selected numeric text (if
           any), or the line number from GotoLineNumber (if any).

       $text->image(option, ?arg, arg, ...?)
       $text->imageOption(?arg, arg, ...?)
           This method is used to manipulate embedded images.  The behavior of
           the method depends on the option argument that follows the image
           prefix.  The following forms of the methods are currently
           supported:

           $text->imageCget(index, option)
                   Returns the value of a configuration option for an embedded
                   image.  Index identifies the embedded image, and option
                   specifies a particular configuration option, which must be
                   one of the ones listed in "EMBEDDED IMAGES".

           $text->imageConfigure(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::options 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 option(s) to
                   have the given value(s);  in this case the command returns
                   an empty string.  See "EMBEDDED IMAGES" for information on
                   the options that are supported.

           $text->imageCreate(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 configure
                   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.

           $text->imageNames
                   Returns a list whose elements are the names of all image
                   instances currently embedded in $text.

       $text->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.

       $text->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 command had been issued for
           each pair, in order.  The last tagList argument may be omitted.

       $text->Insert(string)
           Do NOT confuse this with the lower-case insert method.  Insert
           string at the point of the insertion cursor. If there is a
           selection in the text, and it covers the point of the insertion
           cursor, then it deletes the selection before inserting.

       $text->InsertKeypress(character)
           Inserts character at the insert mark. If in overstrike mode, it
           firsts deletes the character at the insert mark.

       $text->InsertSelection
           Inserts the current selection at the insert mark.

       $text->insertTab
           Inserts a tab (\t) character at the insert mark.

       $text->mark(option, ?arg, arg, ...?)
           This command is used to manipulate marks.  The exact behavior of
           the command depends on the option argument that follows the mark
           argument.  The following forms of the command are currently
           supported:

           $text->markGravity(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.

           $text->markNames
                   Returns a list whose elements are the names of all the
                   marks that are currently set.

           $text->markNext(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
                   immediately 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 widget in the same order as the mark information
                   returned by the dump operation.  If a mark has been set to
                   the special end index, then it appears to be after end with
                   respect to the mark next operation.  An empty string is
                   returned if there are no marks after index.

           $text->markPrevious(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 string is returned if there are no marks before
                   index.

           $text->markSet(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 command returns an empty string.

           $text->markUnset(markName?, markName, markName, ...?)
                   Remove the mark corresponding to each of the markName
                   arguments.  The removed marks will not be usable in indices
                   and will not be returned by future calls to
                   ``$text->markNames''.  This command returns an empty
                   string.

       $text->markExists(markname)
           Returns true if markname exists - false otherwise.

       $text->menu(?menu?)
           If menu reference is given as an argument, then the text widget
           menu is adjusted to use this new menu. If the menu argument is
           undef, then this command disables the current text widget menu.  If
           the menu argument is omitted altogether, then the current text
           widget menu reference is returned.

       $text->openLine
           Inserts a newline (\n) at the insert mark.

       $text->OverstrikeMode(?boolean?)
           Returns the overstrike mode if boolean is omitted or sets the
           overstrike mode to boolean. True means overstrike mode is enabled.

       $text->PostPopupMenu(x,y)
           Creates a popup menu at the specified (x,y) pixel coordinates. The
           default menu has File, Edit, Search and View menu items which
           cascade to sub-menus for further commands. There is an implicit
           <Button-3> binding to this method that posts the menu over the
           cursor.

       $text->ResetAnchor
           Sets the selection anchor to whichever end is farthest from the
           index argument.

       $text->scan(option, args) or
       $text->scanoption(args)
           This method is used to implement scanning on texts.  It has two
           forms, depending on option:

           $text->scanMark(x, y)
                   Records x and y and the current view in the text window,
                   for use in conjunction with later scanDragto method.
                   Typically this method is associated with a mouse button
                   press in the widget.  It returns an empty string.

           $text->scanDragto(x, y)
                   This command computes the difference between its x and y
                   arguments and the x and y arguments to the last scanMark
                   method for the widget.  It then adjusts the view by 10
                   times the difference in coordinates.  This command is
                   typically associated with mouse motion events in the
                   widget, to produce the effect of dragging the text at high
                   speed through the window.  The return value is an empty
                   string.

       $text->search(?switches,? pattern, index, ?stopIndex?)
           Searches the text in $text 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 following 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 position
                   given by index.  This is the default.

           -backwards
                   The search will proceed backward through the text, finding
                   the matching range closest to index whose first character
                   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 command for details).

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

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

           -hidden Find hidden text as well. By default only displayed text is
                   found.

           --      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 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.

       $text->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
           command does nothing.  If index is a short distance out of view,
           the command adjusts the view just enough to make index visible at
           the edge of the window.  If index is far out of view, then the
           command centers index in the window.

       $text->selectAll
           Selects all the text in the widget.

       $text->selectLine
           Selects the line with the insert mark.

       $text->selectWord
           Selects the word with the insert mark.

       $text->SetCursor(position)
           Moves the insert mark to position.

       $text->tag(option, ?arg, arg, ...?)
           This command is used to manipulate tags.  The exact behavior of the
           command depends on the option argument that follows the tag
           argument.  The following forms of the command are currently
           supported:

           $text->tagAdd(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 command 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 command has no effect.

           $text->tagBind(tagName, ?sequence?, ?script?)
                   This command 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 method is similar to the
                   bind command except that it operates on characters in a
                   text rather than entire widgets.  See the Tk::bind
                   documentation 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 the
                   same sequence and tagName (if the first character of script
                   is ``+'' then script augments an existing binding rather
                   than replacing it).  In this case the return value is an
                   empty string.  If script is omitted then the command
                   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 command returns a list of
                   all the sequences for which bindings 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
                   triggers 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
                   current 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
                   particular 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 bindings
                   for a single tag, then the most specific binding is chosen
                   (see the the documentation for the bind command for
                   details).  continue and break commands within binding
                   scripts are processed in the same way as for bindings
                   created with the bind command.

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

           $text->tagCget(tagName, option)
                   This command 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
                   method.

           $text->tagConfigure(tagName, ?option?, ?value?, ?option, value,
           ...?)
                   This command is similar to the configure method 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 command returns a
                   list describing all of the available options for tagName
                   (see Tk::options 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 option(s) to have the given value(s) in
                   tagName; in this case the command returns an empty string.
                   See "TAGS" above for details on the options available for
                   tags.

           $text->tagDelete(tagName, ?tagName, ...?)
                   Deletes all tag information for each of the tagName
                   arguments.  The command removes the tags from all
                   characters in the file and also deletes any other
                   information associated with the tags, such as bindings and
                   display information.  The command returns an empty string.

           $text->tagLower(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.

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

           $text->tagNextrange(tagName, index1, ?index2?)
                   This command searches the text for a range of characters
                   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 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 end
                   of the text.

           $text->tagPrevrange(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.

           $text->tagRaise(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.

           $text->tagRanges(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 string is returned.

           $text->tagRemove(tagName, index1, ?index2, index1, index2, ...?)
                   Remove the tag tagName from all of the characters starting
                   at index1 and ending just before index2 (the character at
                   index2 isn't affected).  A single command 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 command has no effect.  This command
                   returns an empty string.

       $text->ToggleInsertMode
           Toggles the current overstrike mode.

       $text->unselectAll
           Unselects all the text in the widget.

       $text->WhatLineNumberPopup
           Creates a popup that displays the current line number of the insert
           mark.

       $text->widget(option?, arg, arg, ...?)
       $text->widgetOption(?arg, arg, ...?)
           This method is used to manipulate embedded windows.  The behavior
           of the method depends on the option argument that follows the
           window argument.  The following forms of the method are currently
           supported:

           $text->windowCget(index, option)
                   Returns the value of a configuration option for an embedded
                   window.  Index identifies the embedded window, and option
                   specifies a particular configuration option, which must be
                   one of the ones listed in "EMBEDDED WINDOWS" above.

           $text->windowConfigure(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::options 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 option(s) to
                   have the given value(s);  in this case the command returns
                   an empty string.  See "EMBEDDED WINDOWS" above for
                   information on the options that are supported.

           $text->windowCreate(index?, option, value, ...?)
                   This command 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 configure
                   the annotation.  See "EMBEDDED WINDOWS" above for
                   information on the options that are supported.  Returns an
                   empty string.

           $text->windowNames
                   Returns a list whose elements are the names of all windows
                   currently embedded in $text.

       $text->xview(option, args)
           This command is used to query and change the horizontal position of
           the text in the widget's window.  It can take any of the following
           forms:

           $text->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 window.  These are the same values
                   passed to scrollbars via the -xscrollcommand option.

           $text->xviewMoveto(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.

           $text->xviewScroll(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 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.

       $text->yview(?args?)
           This command is used to query and change the vertical position of
           the text in the widget's window.  It can take any of the following
           forms:

           $text->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 -yscrollcommand option.

           $text->yviewMoveto(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.

           $text->yviewScroll(number, what)
                   This command 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 display;  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.

           $text->yview(?-pickplace,? index)
                   Changes the view in the $text's window to make index
                   visible.  If the -pickplace option isn't specified then
                   index will appear at the top of the window.  If -pickplace
                   is specified then the widget chooses where index appears in
                   the window:

                   [1]         If index is already visible somewhere in the
                               window then the command 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 widget command (see
       handles both x- and y-motion to make a location visible, whereas
       -pickplace only handles motion in y).

       $text->yview(number)
           This command 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 command 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 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 reposition
           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 Control-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 Up and Down keys move the insertion cursor one line up or down
           and clear any selection in the text.  If Up 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-Up and
           Control-Down move the insertion cursor by paragraphs (groups of
           lines separated by blank lines), and Control-Shift-Up and Control-
           Shift-Down move the insertion cursor by paragraphs and also extend
           the selection.  Control-p and Control-n behave the same as Up and
           Down, respectively.

       [11]
           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.  Control-v
           moves the view down one screenful without moving the insertion
           cursor or adjusting the selection.

       [12]
           Control-Next and Control-Prior scroll the view right or left by one
           page without moving the insertion cursor or affecting the
           selection.

       [13]
           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.

       [14]
           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.

       [15]
           Control-Home and Meta-< move the insertion cursor to the beginning
           of the text and clear any selection in the widget.  Control-Shift-
           Home moves the insertion cursor to the beginning of the text and
           also extends the selection to that point.

       [16]
           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.

       [17]
           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.

       [18]
           Control-/ selects the entire contents of the widget.

       [19]
           Control-\ clears any selection in the widget.

       [20]
           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.

       [21]
           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.

       [22]
           The F18 key (labelled Paste on many Sun workstations) or Control-y
           inserts the contents of the clipboard at the position of the
           insertion cursor.

       [23]
           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.

       [24]
           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.

       [25]
           Control-d deletes the character to the right of the insertion
           cursor.

       [26]
           Meta-d deletes the word to the right of the insertion cursor.

       [27]
           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.

       [28]
           Control-o opens a new line by inserting a newline character in
           front of the insertion cursor without moving the insertion cursor.

       [29]
           Meta-backspace and Meta-Delete delete the word to the left of the
           insertion cursor.

       [30]
           Control-x deletes whatever is selected in the text widget.

       [31]
           Control-t reverses the order of the two characters to the right of
           the insertion cursor.

       [32]
           Control-z (and Control-underscore on UNIX when tk_strictMotif is
           true)  undoes  the last edit action if the -undo option is true.
           Does nothing otherwise.

       [33]
           Control-Z (or Control-y on Windows) reapplies the last undone edit
           action if the -undo option is true. Does nothing otherwise.

       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
       cursor will be displayed and no text modifications will take place.

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

TIED INTERFACE
       The Perl/Tk Text widget also has built-in TIEHANDLE methods for print
       and printf statements. This means you can print to file handles tied to
       a Text widget, and the tied methods automatically insert the print
       statement's arguments into the Text widget.

       For example:

        #!/usr/local/bin/perl -w
        use POSIX 'acos';
        use Tk;
        use strict;

        my $mw = MainWindow->new;
        my $text = $mw->Text(qw/-width 40 -height 10/)->pack;

        tie *STDOUT, ref $text, $text;

        print "Hello Text World!\n";
        printf "pi ~= %1.5f", acos(-1.0);

        MainLoop;

       To tie a scrolled Text widget, use the Subwidget method to get to the
       "real" widget:

        my $text = $mw->Scrolled('Text')->pack;
        tie *STDOUT, 'Tk::Text', $text->Subwidget('scrolled');

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 option to 0 avoid this.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+----------------------------+
       |ATTRIBUTE TYPE |      ATTRIBUTE VALUE       |
       +---------------+----------------------------+
       |Availability   | library/perl-5/perl-tk-532 |
       +---------------+----------------------------+
       |Stability      | Volatile                   |
       +---------------+----------------------------+

SEE ALSO
       Tk::ROText Tk::TextUndo

KEYWORDS
       text, widget



NOTES
       Source code for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from
       http://search.cpan.org/CPAN/authors/id/S/SR/SREZIC/Tk-804.036.tar.gz.

       Further information about this software can be found on the open source
       community website at http://search.cpan.org/~srezic/Tk.



perl v5.32.0                      2019-10-20                           Text(3)