Tk::Text - Create and manipulate Text widgets
$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
- 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.
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.
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.
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.
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.
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.
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.
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 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 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.
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.
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.
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');
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.