Specifies a boolean that says whether the blinking insertion
cursor should be drawn as a character-sized rectangular block. If
false (the default) a thin vertical line is used for the insertion
cursor.
Specifies an integer line index representing the line of the
underlying textual data store that should be just after the last
line contained in the widget. This allows a text widget to reflect
only a portion of a larger piece of text. Instead of an integer,
the empty string can be provided to this configuration option,
which will configure the widget to end at the very last line in the
textual data store.
Specifies the colour to use for the selection (the sel
tag) when the window does not have the input focus. If empty,
{}, then no selection is shown when the window does not have
the focus.
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.
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.
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.
Specifies an integer line index representing the first line of
the underlying textual data store that should be contained in the
widget. This allows a text widget to reflect only a portion of a
larger piece of text. Instead of an integer, the empty string can
be provided to this configuration option, which will configure the
widget to start at the very first line in the textual data
store.
Specifies one of two states for the text: normal or
disabled. If the text is disabled then characters may not be
inserted or deleted and no insertion cursor will be displayed, even
if the input focus is in the widget.
Specifies a set of tab stops for the window. The option's value
consists of a list of screen distances giving the positions of the
tab stops, each of which is a distance relative to the left edge of
the widget (excluding borders, padding, etc). 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 {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.
Tab distances must be strictly positive, and must always increase
from one tab stop to the next (if not, an error is thrown). 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. To achieve a different standard spacing,
for example every 4 characters, simply configure the widget with
“-tabs "[expr {4 * [font measure $font 0]}] left"
-tabstyle wordprocessor”.
Specifies how to interpret the relationship between tab stops
on a line and tabs in the text of that line. The value must be
tabular (the default) or wordprocessor. Note that
tabs are interpreted as they are encountered in the text. If the
tab style is tabular then the n'th tab character in
the line's text will be associated with the n'th tab stop
defined for that line. If the tab character's x coordinate falls to
the right of the n'th tab stop, then a gap of a single space
will be inserted as a fallback. If the tab style is
wordprocessor then any tab character being laid out will use
(and be defined by) the first tab stop to the right of the
preceding characters already laid out on that line. The value of
the tabstyle option may be overridden by -tabstyle
options in tags.
Specifies the desired width for the window in units of
characters in the font given by the -font option. If the
font does not have a uniform width then the width of the
character
“0” is used in translating from character units to
screen units.
Specifies how to handle lines in the text that are too long to
be displayed in a single line of the text's window. The value must
be none or char or word. A wrap mode of
none means that each line of text appears as exactly one
line on the screen; extra characters that do not 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.
The text command creates a new window (given by the
pathName 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, Tcl
commands 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 floating markers in
the text called “marks”. 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 text widget also has a built-in undo/redo mechanism. See
THE UNDO MECHANISM below for more details.
The text widget allows for the creation of peer widgets. These
are other text widgets which share the same underlying data (text,
marks, tags, images, etc). See PEER WIDGETS below for more
details.
Many of the widget commands 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. Most modifiers (as
documented below) allow an optional submodifier. Valid submodifiers
are any and display. If the submodifier is
abbreviated, then it must be followed by whitespace, but otherwise
there need be no space between the submodifier and the following
modifier. Typically the display submodifier adjusts
the meaning of the following modifier to make it refer to
visual or non-elided units rather than logical units, but this is
explained for each relevant case below. Lastly, where count
is used as part of a modifier, it can be positive or negative, so
“base - -3 lines” is perfectly valid (and
equivalent to “base +3lines”).
The base for an index must have one of the following
forms:
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.
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.
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.
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 index in the text. Spaces on either side
of count are optional. If the display submodifier is
given, elided characters are skipped over without being counted. If
any is given, then all characters are counted. For
historical reasons, if neither modifier is given then the count
actually takes place in units of index positions (see
indices for details). This behaviour may be changed in a
future major release, so if you need an index count, you are
encouraged to use indices instead wherever possible.
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 index in the text (1.0). Spaces on
either side of count are optional. If the display
submodifier is given, elided characters are skipped over without
being counted. If any is given, then all characters are
counted. For historical reasons, if neither modifier is given then
the count actually takes place in units of index positions (see
indices for details). This behaviour may be changed in a
future major release, so if you need an index count, you are
encouraged to use indices instead wherever possible.
Adjust the index forward by count index positions,
moving to later lines in the text if necessary. If there are fewer
than count index positions in the text after the current
index, then set the index to the last index position in the text.
Spaces on either side of count are optional. Note that an
index position is either a single character or a single embedded
image or embedded window. If the display submodifier is
given, elided indices are skipped over without being counted. If
any is given, then all indices are counted; this is also the
default behaviour if no modifier is given.
Adjust the index backward by count index positions,
moving to earlier lines in the text if necessary. If there are
fewer than count index positions in the text before the
current index, then set the index to the first index position (1.0)
in the text. Spaces on either side of count are optional. If
the display submodifier is given, elided indices are skipped
over without being counted. If any is given, then all
indices are counted; this is also the default behaviour if no
modifier is given.
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. If
the display submodifier is given, then each visual display
line is counted separately. Otherwise, if any (or no
modifier) is given, then each logical line (no matter how many
times it is visually wrapped) counts just once. If the relevant
lines are not wrapped, then these two methods of counting are
equivalent.
Adjust the index backward by count logical 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. If the display submodifier is
given, then each visual display line is counted separately.
Otherwise, if any (or no modifier) is given, then each
logical line (no matter how many times it is visually wrapped)
counts just once. If the relevant lines are not wrapped, then these
two methods of counting are equivalent.
Adjust the index to refer to the first index on the line. If
the display submodifier is given, this is the first index on
the display line, otherwise on the logical line.
Adjust the index to refer to the last index on the line (the
newline). If the display submodifier is given, this is the
last index on the display line, otherwise on the logical line.
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. If the display
submodifier is given, this only examines non-elided characters,
otherwise all characters (elided or not) are examined.
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 the display submodifier is given, this only examines
non-elided characters, otherwise all characters (elided or not) are
examined.
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. Modifiers are applied one by one in this left to
right order, and after each step the resulting index is constrained
to be a valid index in the text widget. So, for example, the index
“1.0 -1c +1c” refers to the index
“2.0”.
Where modifiers result in index changes by display lines,
display chars or display indices, and the base refers to an
index inside an elided tag, that base index is considered to be
equivalent to the first following non-elided index.
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 characters “ ” (space),
+, or -: these characters have special meaning in
indices, so tags containing them cannot 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 commands to it), it is given a
priority higher than any existing tag. The priority order of tags
may be redefined using the “pathNametag
raise” and “pathNametag lower”
widget commands.
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 “pathNametag configure” widget
command. 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:
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 has not been specified, or if it is specified as an
empty string, then a solid fill will be used for the
background.
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 specifies whether the data should be elided.
Elided data (characters, images, embedded windows, etc) is not
displayed and takes no space on screen, but further on behaves just
as normal data.
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 has
not been specified, or if it is specified as an empty string, then
a solid fill will be used.
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.
If the first non-elided 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 non-elided character of that display line.
If the first non-elided 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.
If the first non-elided 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.
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.
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.
If the first non-elided 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 non-elided
character of that display line.
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.
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.
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.
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 non-elided
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 -tags { }, then it requests
default 8-character tabs as described for the -tags widget
option.
Style specifies either the tabular or
wordprocessor style of tabbing to use for the text widget.
This option only applies to a display line if it applies to the
first non-elided 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).
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 has not 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 Tcl command 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
“pathNametag bind” widget command below.
Tag bindings are shared between all peer widgets (including any
bindings for the special sel tag).
The third use for tags is in managing the selection. See THE
SELECTION below. With the exception of the special sel
tag, all tags are shared between peer text widgets, and may be
manipulated on an equal basis from any such widget. The sel
tag exists separately and independently in each peer text widget
(but any tag bindings to sel are shared).
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 is not 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 “pathNamemark” widget command, and their current locations may
be determined by using the mark name as an index in widget
commands.
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 left of the mark (so that the mark remains rightmost). 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. With the exception of these two special marks, all marks
are shared between peer text widgets, and may be manipulated on an
equal basis from any peer.
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 unit'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. Similarly if the
text widget as a whole is deleted, then the window is destroyed.
When an embedded window is added to a text widget with the
pathNamewindow create widget command, several
configuration options may be associated with it. These options may
be modified later with the pathNamewindow configure
widget command. The following options are currently supported:
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).
Specifies a Tcl script that may be evaluated to create the
window for the annotation. If no -window option has been
specified for the annotation this script will be evaluated when the
annotation is about to be displayed on the screen. Script
must create a window for the annotation and return the name of that
window as its result. Two substitutions will be performed in
script before evaluation. %W will be substituted by
the name of the parent text widget, and %% will be
substituted by a single %. If the annotation's window should
ever be deleted, script will be evaluated again the next
time the annotation is displayed.
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.
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.
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.
Specifies the name of a window to display in the annotation.
Note that if a pathName has been set, then later configuring
a window to the empty string will not delete the widget
corresponding to the old pathName. Rather it will remove the
association between the old pathName and the text widget. If
multiple peer widgets are in use, it is usually simpler to use the
-create option if embedded windows are desired in each
peer.
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 unit'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
pathNameimage
create. If the range of text containing the embedded image
is deleted then that copy of the image is removed from the screen.
When an embedded image is added to a text widget with the
pathNameimage create widget command, a name unique
to this instance of the image is returned. This name may then be
used to refer to this image instance. The name is taken to be the
value of the -name option (described below). If the
-name option is not provided, the -image name is used
instead. If the imageName is already in use in the text
widget, then #nn is added to the end of the
imageName, where nn is an arbitrary integer. This
insures the imageName is unique. Once this name is assigned
to this instance of the image, it does not change, even though the
-image or -name values can be changed with
pathNameimage
configure.
When an embedded image is added to a text widget with the
pathNameimage
create widget command, several configuration options may be
associated with it. These options may be modified later with the
pathNameimage
configure widget command. The following options are
currently supported:
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).
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.
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.
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.
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
“pathNametag delete” widget command.
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. Also the
-inactiveselectbackground option for the text widget is used
instead of -selectbackground when the text widget does not
have the focus. This allows programmatic control over the
visualization of the sel tag for foreground and background
windows, or to have sel not shown at all (when
-inactiveselectbackground is empty) for background windows.
Each peer text widget has its own sel tag which can be
separately configured and set.
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 “pathNamemark
unset” 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 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
programmatically as well. Whenever the flag changes state a
<<Modified>> virtual event is generated. See the
pathNameedit modified widget command for more
details.
The text widget has an unlimited undo and redo mechanism (when the
-undo widget option is true) which records every insert and
delete action on a stack.
Boundaries (called “separators”) are inserted
between edit actions. The purpose of these separators is to group
inserts, deletes and replaces into one compound edit action. When
undoing a change everything between two separators will be undone.
The undone changes are then moved to the redo stack, so that an
undone edit can be redone again. The redo stack is cleared whenever
new edit actions are recorded on the undo stack. The undo and redo
stacks can be cleared to keep their depth under control.
Separators are inserted automatically when the
-autoseparators widget option is true. You can insert
separators programmatically as well. If a separator is already
present at the top of the undo stack no other will be inserted.
That means that two separators on the undo stack are always
separated by at least one insert or delete action.
The undo mechanism is also linked to the modified flag. This
means that undoing or redoing changes can take a modified text
widget back to the unmodified state or vice versa. The modified
flag will be set automatically to the appropriate state. This
automatic coupling does not work when the modified flag has been
set by the user, until the flag has been reset again.
See below for the pathNameedit widget command
that controls the undo mechanism.
The text widget has a separate store of all its data concerning
each line's textual contents, marks, tags, images and windows, and
the undo stack.
While this data store cannot be accessed directly (i.e. without
a text widget as an intermediary), multiple text widgets can be
created, each of which present different views on the same
underlying data. Such text widgets are known as peer text
widgets.
As text is added, deleted, edited and coloured in any one
widget, and as images, marks, tags are adjusted, all such changes
will be reflected in all peers.
All data and markup is shared, except for a few small details.
First, the sel tag may be set and configured (in its display
style) differently for each peer. Second, each peer has its own
insert and current mark positions (but all other
marks are shared). Third, embedded windows, which are arbitrary
other widgets, cannot be shared between peers. This means the
-window option of embedded windows is independently set for
each peer (it is advisable to use the -create script
capabilities to allow each peer to create its own embedded windows
as needed). Fourth, all of the configuration options of each peer
(e.g. -font, etc) can be set independently, with the
exception of -undo, -maxUndo, -autoSeparators
(i.e. all undo, redo and modified state issues are shared).
Finally any single peer need not contain all lines from the
underlying data store. When creating a peer, a contiguous range of
lines (e.g. only lines 52 through 125) may be specified. This
allows a peer to contain just a small portion of the overall text.
The range of lines will expand and contract as text is inserted or
deleted. The peer will only ever display complete lines of text
(one cannot share just part of a line). If the peer's contents
contracts to nothing (i.e. all complete lines in the peer widget
have been deleted from another widget), then it is impossible for
new lines to be inserted. The peer will simply become an empty
shell on which the background can be configured, but which will
never show any content (without manual reconfiguration of the start
and end lines). Note that a peer which does not contain all of the
underlying data store still has indices numbered from
“1.0” to “end”. It is simply that those
indices reflect a subset of the total data, and data outside the
contained range is not accessible to the peer. This means that the
command peerNameindex end may return quite different
values in different peers. Similarly, commands like peerNametag ranges will not return index ranges outside that which
is meaningful to the peer. The configuration options
-startline and -endline may be used to control how
much of the underlying data is contained in any given text
widget.
Note that peers are really peers. Deleting the
“original” text widget will not cause any other peers
to be deleted, or otherwise affected.
See below for the pathNamepeer widget command
that controls the creation of peer widgets.
The text command creates a new Tcl command whose name is the
same as the path name of the text's window. This command may be
used to invoke various operations on the widget. It has the
following general form:
pathName option ?arg arg ...?
PathName is the name of the command, which is the same as
the text widget's path name. Option and the args
determine the exact behavior of the command. The following commands
are possible for text widgets:
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.
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 is not.
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.
Query or modify the configuration options of the widget. If no
option is specified, returns a list describing all of the
available options for pathName (see Tk_ConfigureInfo for information
on the format of this list). If option is specified with no
value, then the command returns a list describing the one
named option (this list will be identical to the corresponding
sublist of the value returned if no option is specified). If
one or more option-value pairs are specified, then the
command modifies the given widget option(s) to have the given
value(s); in this case the command returns an empty string.
Option may have any of the values accepted by the
text command.
Counts the number of relevant things between the two indices.
If index1 is after index2, the result will be a
negative number (and this holds for each of the possible options).
The actual items which are counted depend on the options given. The
result is a list of integers, one for the result of each counting
option given. Valid counting options are -chars,
-displaychars, -displayindices, -displaylines,
-indices, -lines, -xpixels and
-ypixels. The default value, if no option is specified, is
-indices. There is an additional possible option
-update which is a modifier. If given, then all subsequent
options ensure that any possible out of date information is
recalculated. This currently only has any effect for the
-ypixels count (which, if -update is not given, will
use the text widget's current cached value for each line). The
count options are interpreted as follows:
count all display lines (i.e. counting one for each time a line
wraps) from the line of the first index up to, but not including
the display line of the second index. Therefore if they are both on
the same display line, zero will be returned. By definition
displaylines are visible and therefore this only counts portions of
actual visible lines.
count all logical lines (irrespective of wrapping) from the
line of the first index up to, but not including the line of the
second index. Therefore if they are both on the same line, zero
will be returned. Logical lines are counted whether they are
currently visible (non-elided) or not.
count the number of horizontal pixels from the first pixel of
the first index to (but not including) the first pixel of the
second index. To count the total desired width of the text widget
(assuming wrapping is not enabled), first find the longest line and
then use “.text count -xpixels "${line}.0" "${line}.0
lineend"”.
count the number of vertical pixels from the first pixel of the
first index to (but not including) the first pixel of the second
index. If both indices are on the same display line, zero will be
returned. To count the total number of vertical pixels in the text
widget, use “.text count -ypixels 1.0 end”, and to
ensure this is up to date, use “.text count -update -ypixels
1.0 end”.
The command returns a positive or negative integer corresponding
to the number of items counted between the two indices. One such
integer is returned for each counting option given, so a list is
returned if more than one option was supplied. For example
“.text count -xpixels -ypixels 1.3 4.5” is perfectly
valid and will return a list of two elements.
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.
When debugging is turned on, the drawing routines of the text
widget set the global variables tk_textRedraw and
tk_textRelayout to the lists of indices that are redrawn.
The values of these variables are tested by Tk's test suite.
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 does not specify a
position later in the text than index1 then no characters
are deleted. If index2 is not 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 so deleted text does not cause an 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.
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.
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, image, and window. The
corresponding value is the text, mark name, tag name, image
name, or window name. The index information is the index of
the start of the text, mark, tag transition, image or window. One
or more of the following switches (or abbreviations thereof) may be
specified to control the dump:
Instead of returning the information as the result of the dump
operation, invoke the command on each element of the text
widget within the range. The command has three arguments appended
to it before it is evaluated: the key, value, and
index.
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.
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 segments that each end with a newline.
The newline is part of the value.
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.
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:
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.
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.
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.
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 pathNameget. If the
-displaychars option is given, then, within each range, only
those characters which are not elided will be returned. This may
have the effect that some of the returned ranges are empty
strings.
This command is used to manipulate embedded images. The
behavior of the command depends on the option argument that
follows the tag argument. The following forms of the command
are currently supported:
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 the section EMBEDDED
IMAGES.
Query or modify the configuration options for an embedded
image. If no option is specified, returns a list describing
all of the available options for the embedded image at index
(see Tk_ConfigureInfo
for information on the format of this list). If option is
specified with no value, then the command returns a list
describing the one named option (this list will be identical to the
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.
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.
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.
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
pathNameinsert widget command had been issued for
each pair, in order. The last tagList argument may be
omitted.
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:
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.
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 pathNamedump operation.
If a mark has been set to the special end index, then it
appears to be afterend with respect to the
pathNamemark next operation. An empty string is
returned if there are no marks after 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 pathNamemark
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 pathNamedump operation. An empty string is
returned if there are no marks before 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 does not exist, a new mark
is created. This command returns an empty string.
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 “pathNamemark
names”. This command returns an empty string.
Creates a peer text widget with the given newPathName,
and any optional standard configuration options (as for the
text command). By default the peer will have the same start
and end line as the parent widget, but these can be overridden with
the standard configuration options.
Replaces the range of characters between index1 and
index2 with the given characters and tags. See the section
on pathNameinsert for an explanation of the handling
of the tagList... arguments, and the section on
pathNamedelete for an explanation of the handling of
the indices. If index2 corresponds to an index earlier in
the text than index1, an error will be generated.
The deletion and insertion are arranged so that no unnecessary
scrolling of the window or movement of insertion cursor occurs. In
addition the undo/redo stack are correctly modified, if undo
operations are active in the text widget. The command returns an
empty string.
Records x and y and the current view in the text
window, for use in conjunction with later pathNamescan
dragto commands. Typically this command is associated with a
mouse button press in the widget. It returns an empty string.
This command computes the difference between its x and
y arguments and the x and y arguments to the
last pathNamescan mark command 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.
Searches the text in pathName 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:
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.
The search will proceed backward through the text, finding the
matching range closest to index whose first character is
before index (it is not allowed to be at index). Note
that, for a variety of reasons, backwards searches can be
substantially slower than forwards searches (particularly when
using -regexp), so it is recommended that
performance-critical code use forward searches.
Treat pattern as a regular expression and match it
against the text using the rules for regular expressions (see the
regexp command for
details). The default matching automatically passes both the
-lineanchor and -linestop options to the regexp
engine (unless -nolinestop is used), so that ^$ match
beginning and end of line, and ., [^ sequences will
never match the newline character \n.
This allows . and [^ sequences to match the
newline character \n, which they will otherwise not do (see
the regexp command for
details). This option is only meaningful if -regexp is also
given, and an error will be thrown otherwise. For example, to match
the entire text, use “pathNamesearch -nolinestop
-regexp ".*" 1.0”.
The argument following -count gives the name of a
variable; if a match is found, the number of index positions
between beginning and end of the matching range will be stored in
the variable. If there are no embedded images or windows in the
matching range (and there are no elided characters if -elide
is not given), this is equivalent to the number of characters
matched. In either case, the range matchIdx to matchIdx +
$count chars will return the entire matched text.
Find all matches in the given range and return a list of the
indices of the first character of each match. If a -countvarName switch is given, then varName is also set to
a list containing one element for each successful match. Note that,
even for exact searches, the elements of this list may be
different, if there are embedded images, windows or hidden text.
Searches with -all behave very similarly to the Tcl command
regexp -all, in that overlapping matches are not normally
returned. For example, applying an -all search of the
pattern “\w+” against “hello there” will
just match twice, once for each word, and matching
“Z[a-z]+Z” against “ZooZooZoo” will just
match once.
When performing -all searches, the normal behaviour is
that matches which overlap an already-found match will not be
returned. This switch changes that behaviour so that all matches
which are not totally enclosed within another match are returned.
For example, applying an -overlap search of the pattern
“\w+” against “hello there” will just match
twice (i.e. no different to just -all), but matching
“Z[a-z]+Z” against “ZooZooZoo” will now
match twice. An error will be thrown if this switch is used without
-all.
When performing any search, the normal behaviour is that the
start and stop limits are checked with respect to the start of the
matching text. With the -strictlimits flag, the entire
matching range must lie inside the start and stop limits specified
for the match to be valid.
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 may be within a single line of text, or run
across multiple lines (if parts of the pattern can match a
new-line). For regular expression matching one can use the various
newline-matching features such as $ to match the end of a
line, ^ to match the beginning of a line, and to control
whether . is allowed to match a new-line. 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. This means that, for
example, if the search is -forwards but stopIndex is
earlier in the text than startIndex, nothing will ever be
found. See KNOWN BUGS below for a number of minor
limitations of the pathNamesearch command.
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.
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:
Associate the tag tagName with all of the characters
starting with index1 and ending just before index2
(the character at index2 is not 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.
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 widget command is
similar to the bind command
except that it operates on characters in a text rather than entire
widgets. See the bind manual
entry for complete details on the syntax of sequence and the
substitutions performed on script before invoking it. If all
arguments are specified then a new binding is created, replacing
any existing binding for 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 manual entry 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.
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
pathNametag configure widget command.
This command is similar to the pathNameconfigure
widget command 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_ConfigureInfo for information
on the format of this list). If option is specified with no
value, then the command returns a list describing the one
named option (this list will be identical to the corresponding
sublist of the value returned if no option is specified). If
one or more option-value pairs are specified, then the
command modifies the given 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.
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.
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.
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 “pathNametag” widget
command but have not been deleted by a “pathNametag delete” widget command, even if no characters are
currently marked with the tag). The list will be sorted in order
from lowest priority to highest priority.
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.
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.
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.
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.
Remove the tag tagName from all of the characters
starting at index1 and ending just before index2 (the
character at index2 is not affected). A single command may
contain any number of index1-index2 pairs. If the
last index2 is omitted then the tag is removed from the
single character at index1. 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.
This command is used to manipulate embedded windows. The
behavior of the command depends on the option argument that
follows the window argument. The following forms of the
command are currently supported:
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 the section EMBEDDED
WINDOWS.
Query or modify the configuration options for an embedded
window. If no option is specified, returns a list describing
all of the available options for the embedded window at
index (see Tk_ConfigureInfo for information
on the format of this list). If option is specified with no
value, then the 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 for information on the options that are supported.
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 for information on the
options that are supported. Returns an empty string.
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.
This command shifts the view in the window left or right
according to number and what. What must be
units, pages or pixels. If what is
units or pages then number must be an integer,
otherwise number may be specified in any of the forms acceptable to
Tk_GetPixels, such as
“2.0c” or “1i” (the result is rounded to
the nearest integer value. If no units are given, pixels are
assumed). 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 it is pixels then the view adjusts by
number pixels. If number is negative then characters
farther to the left become visible; if it is positive then
characters farther to the right become visible.
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 visible pixel of the first character (or image, etc) 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 first pixel just after the last
visible 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.
Adjusts the view in the window so that the pixel given by
fraction appears at the top of the top line of the window.
Fraction is a fraction between 0 and 1; 0 indicates the
first pixel of the first character in the text, 0.33 indicates the
pixel that is one-third the way through the text; and so on. Values
close to 1 will indicate values close to the last pixel in the text
(1 actually refers to one pixel beyond the last pixel), but in such
cases the widget will never scroll beyond the last pixel, and so a
value of 1 will effectively be rounded back to whatever fraction
ensures the last pixel is at the bottom of the window, and some
other pixel is at the top.
This command adjust the view in the window up or down according
to number and what. What must be units,
pages or pixels. If what is units or
pages then number must be an integer, otherwise
number may be specified in any of the forms acceptable to Tk_GetPixels, such as
“2.0c” or “1i” (the result is rounded to
the nearest integer value. If no units are given, pixels are
assumed). 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 it is
pixels then the view adjusts by number pixels. If
number is negative then earlier positions in the text become
visible; if it is positive then later positions in the text become
visible.
Changes the view in the widget's window to make index
visible. If the -pickplace option is not 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
pathNamesee widget command (pathNamesee handles both x- and y-motion to make a location visible,
whereas the -pickplace mode only handles motion in y).
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.
Tk automatically creates class bindings for texts that give them
the following default behavior. In the descriptions below,
“word” is dependent on the value of the
tcl_wordchars variable. See tclvars(n).
[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 start 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 start 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.
[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 display line and clear any selection in the widget.
Shift-Home moves the insertion cursor to the beginning of the
display line and also extends the selection to that point.
[14]
End and Control-e move the insertion cursor to the end of the
display line and clear any selection in the widget. Shift-End moves
the cursor to the end of the display 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 do not 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. This action is carried out by the command
tk_textCopy.
[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. This action is carried out by the command
tk_textCut. 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. This action is carried out by the command
tk_textPaste.
[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 after
copying it to the clipboard.
[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.
Before Tk 8.5, the widget used the string “chars” to
refer to index positions (which included characters, embedded
windows and embedded images). As of Tk 8.5 the text widget deals
separately and correctly with “chars” and
“indices”. For backwards compatibility, however, the
index modifiers “+N chars” and “-N chars”
continue to refer to indices. One must use any of the full forms
“+N any chars” or “-N any chars” etc. to
refer to actual character indices. This confusion may be fixed in a
future release by making the widget correctly interpret “+N
chars” as a synonym for “+N any chars”.
Text widgets should run efficiently under a variety of conditions.
The text widget uses about 2-3 bytes of main memory for each byte
of text, so texts containing a megabyte or more should be practical
on most workstations. Text is represented internally with a
modified B-tree structure that makes operations relatively
efficient even with large texts. Tags are included in the B-tree
structure in a way that allows tags to span large ranges or have
many disjoint smaller ranges without loss of efficiency. Marks are
also implemented in a way that allows large numbers of marks. In
most cases it is fine to have large numbers of unique tags, or a
tag that has many distinct ranges.
One performance problem can arise if you have hundreds or
thousands of different tags that all have the following
characteristics: the first and last ranges of each tag are near the
beginning and end of the text, respectively, or a single tag range
covers most of the text widget. The cost of adding and deleting
tags like this is proportional to the number of other tags with the
same properties. In contrast, there is no problem with having
thousands of distinct tags if their overall ranges are localized
and spread uniformly throughout the text.
Very long text lines can be expensive, especially if they have
many marks and tags within them.
The display line with the insert cursor is redrawn each time the
cursor blinks, which causes a steady stream of graphics traffic.
Set the insertOffTime attribute to 0 avoid this.
The pathNamesearch -regexp sub-command attempts to
perform sophisticated regexp matching across multiple lines in an
efficient fashion (since Tk 8.5), examining each line individually,
and then in small groups of lines, whether searching forwards or
backwards. Under certain conditions the search result might differ
from that obtained by applying the same regexp to the entire text
from the widget in one go. For example, when searching with a
greedy regexp, the widget will continue to attempt to add extra
lines to the match as long as one of two conditions are true:
either Tcl's regexp library returns a code to indicate a longer
match is possible (but there are known bugs in Tcl which mean this
code is not always correctly returned); or if each extra line added
results in at least a partial match with the pattern. This means in
the case where the first extra line added results in no match and
Tcl's regexp system returns the incorrect code and adding a second
extra line would actually match, the text widget will return the
wrong result. In practice this is a rare problem, but it can occur,
for example:
will not find a match when one exists of 19 characters starting
from the first “b”.
Whenever one possible match is fully enclosed in another, the
search command will attempt to ensure only the larger match is
returned. When performing backwards regexp searches it is possible
that Tcl will not always achieve this, in the case where a match is
preceded by one or more short, non-overlapping matches, all of
which are preceded by a large match which actually encompasses all
of them. The search algorithm used by the widget does not look back
arbitrarily far for a possible match which might cover large
portions of the widget. For example:
matches at “5.0” when a true greedy match would match
at “1.0”. Similarly if we add -all to this case,
it matches at all of “5.0”, “4.0”,
“3.0” and “1.0”, when really it should only
match at “1.0” since that match encloses all the
others.