Provided by: perl-tk_804.033-2build1_amd64 
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 overridden 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 overridden 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 overridden 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.
SEE ALSO
Tk::ROText Tk::TextUndo
KEYWORDS
text, widget