Text(3pm) User Contributed Perl Documentation Text(3pm)NAMETk::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
perl v5.26.0 2017-07-22 Text(3pm)
