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text(n) Tk Built-In Commands text(n)
____________________________________________________________________________________________________________
NAME
text, tk_textCopy, tk_textCut, tk_textPaste - Create and manipulate text widgets
SYNOPSIS
text pathName ?options?
tk_textCopy pathName
tk_textCut pathName
tk_textPaste pathName
STANDARD OPTIONS
-background -highlightthickness -relief
-borderwidth -insertbackground -selectbackground
-cursor -insertborderwidth -selectborderwidth
-exportselection -insertofftime -selectforeground
-font -insertontime -setgrid
-foreground -insertwidth -takefocus
-highlightbackground -padx -xscrollcommand
-highlightcolor -pady -yscrollcommand
See the options manual entry for details on the standard options.
WIDGET-SPECIFIC OPTIONS
Command-Line Name:-autoseparators
Database Name: autoSeparators
Database Class: AutoSeparators
Specifies a boolean that says whether separators are automatically inserted in the undo stack.
Only meaningful when the -undo option is true.
Command-Line Name:-blockcursor
Database Name: blockCursor
Database Class: BlockCursor
Specifies a boolean that says whether the blinking insertion cursor should be drawn as a char- |
acter-sized rectangular block. If false (the default) a thin vertical line is used for the |
insertion cursor.
Command-Line Name:-endline
Database Name: endLine
Database Class: EndLine
Specifies an integer line index representing the last line of the underlying textual data |
store that should be contained in the widget. This allows a text widget to reflect only a |
portion of a larger piece of text. Instead of an integer, the empty string can be provided |
to this configuration option, which will configure the widget to end at the very last line in |
the textual data store.
Command-Line Name:-height
Database Name: height
Database Class: 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.
Command-Line Name:-inactiveselectbackground
Database Name: inactiveSelectBackground
Database Class: Foreground
Specifies the colour to use for the selection (the sel tag) when the window does not have the |
input focus. If empty, {}, then no selection is shown when the window does not have the |
focus.
Command-Line Name:-maxundo
Database Name: maxUndo
Database Class: MaxUndo
Specifies the maximum number of compound undo actions on the undo stack. A zero or a negative
value imply an unlimited undo stack.
Command-Line Name:-spacing1
Database Name: spacing1
Database Class: 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 dis-play. display.
play. This option may be overridden with -spacing1 options in tags.
Command-Line Name:-spacing2
Database Name: spacing2
Database Class: Spacing2
For lines that wrap (so that they cover more than one line on the display) this option speci-fies specifies
fies 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.
Command-Line Name:-spacing3
Database Name: spacing3
Database Class: 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 dis-play. display.
play. This option may be overridden with -spacing3 options in tags.
Command-Line Name:-startline
Database Name: startLine
Database Class: StartLine
Specifies an integer line index representing the first line of the underlying textual data |
store that should be contained in the widget. This allows a text widget to reflect only a |
portion of a larger piece of text. Instead of an integer, the empty string can be provided to |
this configuration option, which will configure the widget to start at the very first line in |
the textual data store.
Command-Line Name:-state
Database Name: state
Database Class: 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.
Command-Line Name:-tabs
Database Name: tabs
Database Class: 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 of which is a distance relative to the
left edge of the widget (excluding borders, padding, etc). Each position may optionally be
followed in the next list element by one of the keywords left, right, center, or numeric,
which specifies how to justify text relative to the tab stop. Left is the default; it causes
the text following the tab character to be positioned with its left edge at the tab position.
Right means that the right edge of the text following the tab character is positioned at the
tab position, and center means that the text is centered at the tab position. Numeric means
that the decimal point in the text is positioned at the tab position; if there is no decimal
point then the least significant digit of the number is positioned just to the left of the tab
position; if there is no number in the text then the text is right-justified at the tab posi-tion. position.
tion. For example, "-tabs {2c left 4c 6c center}" creates three tab stops at two-centimeter
intervals; the first two use left justification and the third uses center justification.
If the list of tab stops does not have enough elements to cover all of the tabs in a text
line, then Tk extrapolates new tab stops using the spacing and alignment from the last tab
stop in the list. Tab distances must be strictly positive, and must always increase from one
tab stop to the next (if not, an error is thrown). The value of the tabs option may be over-ridden overridden
ridden by -tabs options in tags.
If no -tabs option is specified, or if it is specified as an empty list, then Tk uses default
tabs spaced every eight (average size) characters. To achieve a different standard spacing,
for example every 4 characters, simply configure the widget with "-tabs "[expr {4 * [font mea-sure measure
sure $font 0]}] left" -tabstyle wordprocessor".
Command-Line Name:-tabstyle
Database Name: tabStyle
Database Class: TabStyle
Specifies how to interpret the relationship between tab stops on a line and tabs in the text
of that line. The value must be tabular (the default) or wordprocessor. Note that tabs are
interpreted as they are encountered in the text. If the tab style is tabular then the n'th
tab character in the line's text will be associated with the n'th tab stop defined for that
line. If the tab character's x coordinate falls to the right of the n'th tab stop, then a gap
of a single space will be inserted as a fallback. If the tab style is wordprocessor then any
tab character being laid out will use (and be defined by) the first tab stop to the right of
the preceding characters already laid out on that line. The value of the tabstyle option may
be overridden by -tabstyle options in tags.
Command-Line Name:-undo
Database Name: undo
Database Class: Undo
Specifies a boolean that says whether the undo mechanism is active or not.
Command-Line Name:-width
Database Name: width
Database Class: Width
Specifies the desired width for the window in units of characters in the font given by the
-font option. If the font does not have a uniform width then the width of the character "0"
is used in translating from character units to screen units.
Command-Line Name:-wrap
Database Name: wrap
Database Class: 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 do not fit
on the screen are not displayed. In the other modes each line of text will be broken up into
several screen lines if necessary to keep all the characters visible. In char mode a screen
line break may occur after any character; in word mode a line break will only be made at word
boundaries.
____________________________________________________________________________________________________________
DESCRIPTION
The text command creates a new window (given by the pathName argument) and makes it into a text wid-get. widget.
get. Additional options, described above, may be specified on the command line or in the option
database to configure aspects of the text such as its default background color and relief. The text
command returns the path name of the new window.
A text widget displays one or more lines of text and allows that text to be edited. Text widgets
support four different kinds of annotations on the text, called tags, marks, embedded windows or
embedded images. Tags allow different portions of the text to be displayed with different fonts and
colors. In addition, Tcl commands can be associated with tags so that scripts are invoked when par-ticular particular
ticular actions such as keystrokes and mouse button presses occur in particular ranges of the text.
See TAGS below for more details.
The second form of annotation consists of floating markers in the text called "marks". Marks are
used to keep track of various interesting positions in the text as it is edited. See MARKS below for
more details.
The third form of annotation allows arbitrary windows to be embedded in a text widget. See EMBEDDED
WINDOWS below for more details.
The fourth form of annotation allows Tk images to be embedded in a text widget. See EMBEDDED IMAGES
below for more details.
The text widget also has a built-in undo/redo mechanism. See THE UNDO MECHANISM below for more
details.
The text widget allows for the creation of peer widgets. These are other text widgets which share |
the same underlying data (text, marks, tags, images, etc). See PEER WIDGETS below for more details.
INDICES
Many of the widget commands for texts take one or more indices as arguments. An index is a string
used to indicate a particular place within a text, such as a place to insert characters or one end-point endpoint
point of a range of characters to delete. Indices have the syntax
base modifier modifier modifier ...
Where base gives a starting point and the modifiers adjust the index from the starting point (e.g.
move forward or backward one character). Every index must contain a base, but the modifiers are
optional. Most modifiers (as documented below) allow an optional submodifier. Valid submodifiers |
are any and display. If the submodifier is abbreviated, then it must be followed by whitespace, but |
otherwise there need be no space between the submodifier and the following modifier. Typically the |
display submodifier adjusts the meaning of the following modifier to make it refer to visual or non- |
elided units rather than logical units, but this is explained for each relevant case below. Lastly, |
where count is used as part of a modifier, it can be positive or negative, so "base - -3 lines" is |
perfectly valid (and equivalent to "base +3lines").
The base for an index must have one of the following forms:
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 num-bered numbered
bered 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 gen-erates generates
erates 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.
pathName Indicates the position of the embedded window whose name is pathName. This form gener-ates generates
ates an error if there is no embedded window by the given name.
imageName Indicates the position of the embedded image whose name is imageName. This form gener-ates generates
ates 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 ?submodifier? 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 index in the text. Spaces on either side of count are optional. If the |
display submodifier is given, elided characters are skipped over without being counted. If |
any is given, then all characters are counted. For historical reasons, if neither modifier is |
given then the count actually takes place in units of index positions (see indices for |
details). This behaviour may be changed in a future major release, so if you need an index |
count, you are encouraged to use indices instead wherever possible.
- count ?submodifier? chars
Adjust the index backward by count characters, moving to earlier lines in the text if neces-sary. necessary.
sary. If there are fewer than count characters in the text before the current index, then set
the index to the first index in the text (1.0). Spaces on either side of count are optional. |
If the display submodifier is given, elided characters are skipped over without being counted. |
If any is given, then all characters are counted. For historical reasons, if neither modifier |
is given then the count actually takes place in units of index positions (see indices for |
details). This behaviour may be changed in a future major release, so if you need an index |
count, you are encouraged to use indices instead wherever possible.
+ count ?submodifier? indices
Adjust the index forward by count index positions, moving to later lines in the text if neces- |
sary. If there are fewer than count index positions in the text after the current index, then |
set the index to the last index position in the text. Spaces on either side of count are |
optional. Note that an index position is either a single character or a single embedded image |
or embedded window. If the display submodifier is given, elided indices are skipped over |
without being counted. If any is given, then all indices are counted; this is also the |
default behaviour if no modifier is given.
- count ?submodifier? indices
Adjust the index backward by count index positions, moving to earlier lines in the text if |
necessary. If there are fewer than count index positions in the text before the current |
index, then set the index to the first index position (1.0) in the text. Spaces on either |
side of count are optional. If the display submodifier is given, elided indices are skipped |
over without being counted. If any is given, then all indices are counted; this is also the |
default behaviour if no modifier is given.
+ count ?submodifier? 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. If the display submodifier is given, then each visual dis- |
play line is counted separately. Otherwise, if any (or no modifier) is given, then each logi- |
cal line (no matter how many times it is visually wrapped) counts just once. If the relevant |
lines are not wrapped, then these two methods of counting are equivalent.
- count ?submodifier? lines
Adjust the index backward by count logical lines, retaining the same character position within |
the line. If there are fewer than count lines before the line containing the current index, |
then set the index to refer to the same character position on the first line of the text. |
Then, if the line is not long enough to contain a character at the indicated character posi- |
tion, adjust the character position to refer to the last character of the line (the newline). |
Spaces on either side of count are optional. If the display submodifier is given, then each |
visual display line is counted separately. Otherwise, if any (or no modifier) is given, then |
each logical line (no matter how many times it is visually wrapped) counts just once. If the |
relevant lines are not wrapped, then these two methods of counting are equivalent.
?submodifier? linestart
Adjust the index to refer to the first index on the line. If the display submodifier is |
given, this is the first index on the display line, otherwise on the logical line.
?submodifier? lineend
Adjust the index to refer to the last index on the line (the newline). If the display submod- |
ifier is given, this is the last index on the display line, otherwise on the logical line.
?submodifier? 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. If the display submodifier is given, this |
only examines non-elided characters, otherwise all characters (elided or not) are examined.
?submodifier? 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 the display submodifier is given, this only examines non-elided characters, oth- |
erwise all characters (elided or not) are examined. |
If more than one modifier is present then they are applied in left-to-right order. For example, the |
index "end - 1 chars" refers to the next-to-last character in the text and "insert wordstart - 1 c" |
refers to the character just before the first one in the word containing the insertion cursor. Modi- |
fiers are applied one by one in this left to right order, and after each step the resulting index is |
constrained to be a valid index in the text widget. So, for example, the index "1.0 -1c +1c" refers |
to the index "2.0". |
Where modifiers result in index changes by display lines, display chars or display indices, and the |
base refers to an index inside an elided tag, that base index is considered to be equivalent to the |
first following non-elided index.
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 characters " " (space), +, or -: these characters have special meaning in
indices, so tags containing them cannot be used as indices. There may be any number of tags associ-ated associated
ated 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 tagrelated
related functions described below. When a tag is defined (by associating it with characters or set-ting setting
ting its display options or binding commands to it), it is given a priority higher than any existing
tag. The priority order of tags may be redefined using the "pathName tag raise" and "pathName tag
lower" widget commands.
Tags serve three purposes in text widgets. First, they control the way information is displayed on
the screen. By default, characters are displayed as determined by the -background, -font, and -fore-ground -foreground
ground options for the text widget. However, display options may be associated with individual tags
using the "pathName tag configure" widget command. If a character has been tagged, then the display
options associated with the tag override the default display style. The following options are cur-rently currently
rently 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 has not 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 (characters, images, embedded
windows, etc) is not displayed and takes no space on screen, but further on behaves just as
normal data.
-fgstipple bitmap
Bitmap specifies a bitmap that is used as a stipple pattern when drawing text and other fore-ground foreground
ground information such as underlines. It may have any of the forms accepted by Tk_GetBitmap.
If bitmap has not been specified, or if it is specified as an empty string, then a solid fill
will be used.
-font fontName
FontName is the name of a font to use for drawing characters. It may have any of the forms
accepted by Tk_GetFont.
-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 non-elided character of a display line has a tag for which this option has been
specified, then justify determines how to justify the line. It must be one of left, right, or
center. If a line wraps, then the justification for each line on the display is determined by
the first non-elided character of that display line.
-lmargin1 pixels
If the first non-elided character of a text line has a tag for which this option has been
specified, then pixels specifies how much the line should be indented from the left edge of
the window. Pixels may have any of the standard forms for screen distances. If a line of
text wraps, this option only applies to the first line on the display; the -lmargin2 option
controls the indentation for subsequent lines.
-lmargin2 pixels
If the first non-elided character of a display line has a tag for which this option has been
specified, and if the display line is not the first for its text line (i.e., the text line has
wrapped), then pixels specifies how much the line should be indented from the left edge of the
window. Pixels may have any of the standard forms for screen distances. This option is only
used when wrapping is enabled, and it only applies to the second and later display lines for a
text line.
-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 Tcl_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 non-elided character of a display line has a tag for which this option has been
specified, then pixels specifies how wide a margin to leave between the end of the line and
the right edge of the window. Pixels may have any of the standard forms for screen distances.
This option is only used when wrapping is enabled. If a text line wraps, the right margin for
each line on the display is determined by the first non-elided character of that display line.
-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 dis-play display
play lines for a single text line. Pixels may have any of the standard forms for screen dis-tances. distances.
tances.
-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 non-elided
character on that display line. If this option is specified as an empty string, it cancels
the option, leaving it unspecified for the tag (the default). If the option is specified as a
non-empty string that is an empty list, such as -tags { }, then it requests default 8-charac-ter 8-character
ter tabs as described for the -tags widget option.
-tabstyle style
Style specifies either the tabular or wordprocessor style of tabbing to use for the text wid-get. widget.
get. This option only applies to a display line if it applies to the first non-elided charac-ter character
ter 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).
-underline boolean
Boolean specifies whether or not to draw an underline underneath characters. It may have any
of the forms accepted by Tcl_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 has not been specified
for a particular tag, or if it is specified as an empty string, then that option will never be used;
the next-highest-priority tag's option will used instead. If no tag specifies a particular display
option, then the default style for the widget will be used.
The second purpose for tags is event bindings. You can associate bindings with a tag in much the
same way you can associate bindings with a widget class: whenever particular X events occur on char-acters characters
acters with the given tag, a given Tcl command will be executed. Tag bindings can be used to give
behaviors to ranges of characters; among other things, this allows hypertext-like features to be
implemented. For details, see the description of the "pathName tag bind" widget command below. Tag |
bindings are shared between all peer widgets (including any bindings for the special sel tag).
The third use for tags is in managing the selection. See THE SELECTION below. With the exception of |
the special sel tag, all tags are shared between peer text widgets, and may be manipulated on an |
equal basis from any such widget. The sel tag exists separately and independently in each peer text |
widget (but any tag bindings to sel are shared).
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 is not associated with particular characters. Instead, a mark is associated
with the gap between two characters. Only a single position may be associated with a mark at any
given time. If the characters around a mark are deleted the mark will still remain; it will just
have new neighbor characters. In contrast, if the characters containing a tag are deleted then the
tag will no longer have an association with characters in the file. Marks may be manipulated with
the "pathName mark" widget command, and their current locations may be determined by using the mark
name as an index in widget commands.
Each mark also has a "gravity", which is either left or right. The gravity for a mark specifies what
happens to the mark when text is inserted at the point of the mark. If a mark has left gravity, then
the mark is treated as if it were attached to the character on its left, so the mark will remain to
the left of any text inserted at the mark position. If the mark has right gravity, new text inserted
at the mark position will appear to the left of the mark (so that the mark remains rightmost). The
gravity for a mark defaults to right.
The name space for marks is different from that for tags: the same name may be used for both a mark
and a tag, but they will refer to different things.
Two marks have special significance. First, the mark insert is associated with the insertion cursor,
as described under THE INSERTION CURSOR below. Second, the mark current is associated with the char-acter character
acter 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). Nei-ther Neither
ther of these special marks may be deleted. With the exception of these two special marks, all marks |
are shared between peer text widgets, and may be manipulated on an equal basis from any peer.
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 unit's worth of index space |
in the text widget, and it may be referred to either by the name of its embedded window or by its
position in the widget's index space. If the range of text containing the embedded window is deleted
then the window is destroyed. Similarly if the text widget as a whole is deleted, then the window is |
destroyed.
When an embedded window is added to a text widget with the pathName window create widget command,
several configuration options may be associated with it. These options may be modified later with
the pathName window configure widget command. 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 script
Specifies a Tcl script that may be evaluated to create the window for the annotation. If no
-window option has been specified for the annotation this script will be evaluated when the
annotation is about to be displayed on the screen. Script must create a window for the anno-tation annotation
tation and return the name of that window as its result. Two substitutions will be performed |
in script before evaluation. %W will be substituted by the name of the parent text widget, |
and %% will be substituted by a single %. If the annotation's window should ever be deleted,
script will be evaluated again the next time the annotation is displayed.
-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.
-pady pixels
Pixels specifies the amount of extra space to leave on the top and on the bottom of the embed-ded embedded
ded window. It may have any of the usual forms defined for a screen distance.
-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 verti-cally vertically
cally 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 pathName
Specifies the name of a window to display in the annotation. Note that if a pathName has been |
set, then later configuring a window to the empty string will not delete the widget corre- |
sponding to the old pathName. Rather it will remove the association between the old pathName |
and the text widget. If multiple peer widgets are in use, it is usually simpler to use the |
-create option if embedded windows are desired in each peer.
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 modi-fied modified
fied or scrolled. Each embedded image occupies one unit's worth of index space in the text widget, |
and it may be referred to either by its position in the widget's index space, or the name it is
assigned when the image is inserted into the text widget with pathName image create. If the range of
text containing the embedded image is deleted then that copy of the image is removed from the screen.
When an embedded image is added to a text widget with the pathName image create widget command, a
name unique to this instance of the image is returned. This name may then be used to refer to this
image instance. The name is taken to be the value of the -name option (described below). If the
-name option is not provided, the -image name is used instead. If the imageName is already in use in
the text widget, then #nn is added to the end of the imageName, where nn is an arbitrary integer.
This insures the imageName is unique. Once this name is assigned to this instance of the image, it
does not change, even though the -image or -name values can be changed with pathName image configure.
When an embedded image is added to a text widget with the pathName image create widget command, sev-eral several
eral configuration options may be associated with it. These options may be modified later with the
pathName image configure widget command. 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 Ima-geName ImageName
geName 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 embed-ded embedded
ded 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 "pathName tag delete" widget command. Furthermore, the selectBackground, selectBorderWidth, and
selectForeground options for the text widget are tied to the -background, -borderwidth, and -fore-ground -foreground
ground options for the sel tag: changes in either will automatically be reflected in the other. |
Also the -inactiveselectbackground option for the text widget is used instead of -selectbackground |
when the text widget does not have the focus. This allows programmatic control over the visualiza- |
tion of the sel tag for foreground and background windows, or to have sel not shown at all (when |
-inactiveselectbackground is empty) for background windows. Each peer text widget has its own sel |
tag which can be separately configured and set.
THE 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 "pathName mark unset" widget command. The
insert mark represents the position of the insertion cursor, and the insertion cursor will automati-cally automatically
cally 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 programmati-cally programmatically
cally as well. Whenever the flag changes state a <<Modified>> virtual event is generated. See the
pathName edit modified widget command for more details.
THE UNDO MECHANISM
The text widget has an unlimited undo and redo mechanism (when the -undo widget option is true) which
records every insert and delete action on a stack.
Boundaries (called "separators") are inserted between edit actions. The purpose of these separators
is to group inserts, deletes and replaces into one compound edit action. When undoing a change
everything between two separators will be undone. The undone changes are then moved to the redo
stack, so that an undone edit can be redone again. The redo stack is cleared whenever new edit
actions are recorded on the undo stack. The undo and redo stacks can be cleared to keep their depth
under control.
Separators are inserted automatically when the -autoseparators widget option is true. You can insert
separators programmatically as well. If a separator is already present at the top of the undo stack
no other will be inserted. That means that two separators on the undo stack are always separated by
at least one insert or delete action.
The undo mechanism is also linked to the modified flag. This means that undoing or redoing changes
can take a modified text widget back to the unmodified state or vice versa. The modified flag will
be set automatically to the appropriate state. This automatic coupling does not work when the modi-fied modified
fied flag has been set by the user, until the flag has been reset again.
See below for the pathName edit widget command that controls the undo mechanism.
PEER WIDGETS
The text widget has a separate store of all its data concerning each line's textual contents, marks, |
tags, images and windows, and the undo stack. |
While this data store cannot be accessed directly (i.e. without a text widget as an intermediary), |
multiple text widgets can be created, each of which present different views on the same underlying |
data. Such text widgets are known as peer text widgets. |
As text is added, deleted, edited and coloured in any one widget, and as images, marks, tags are |
adjusted, all such changes will be reflected in all peers. |
All data and markup is shared, except for a few small details. First, the sel tag may be set and |
configured (in its display style) differently for each peer. Second, each peer has its own insert |
and current mark positions (but all other marks are shared). Third, embedded windows, which are |
arbitrary other widgets, cannot be shared between peers. This means the -window option of embedded |
windows is independently set for each peer (it is advisable to use the -create script capabilities to |
allow each peer to create its own embedded windows as needed). Fourth, all of the configuration |
options of each peer (e.g. -font, etc) can be set independently, with the exception of -undo, -max- |
Undo, -autoSeparators (i.e. all undo, redo and modified state issues are shared). |
Finally any single peer need not contain all lines from the underlying data store. When creating a |
peer, a contiguous range of lines (e.g. only lines 52 through 125) may be specified. This allows a |
peer to contain just a small portion of the overall text. The range of lines will expand and con- |
tract as text is inserted or deleted. The peer will only ever display complete lines of text (one |
cannot share just part of a line). If the peer's contents contracts to nothing (i.e. all complete |
lines in the peer widget have been deleted from another widget), then it is impossible for new lines |
to be inserted. The peer will simply become an empty shell on which the background can be config- |
ured, but which will never show any content (without manual reconfiguration of the start and end |
lines). Note that a peer which does not contain all of the underlying data store still has indices |
numbered from "1.0" to "end". It is simply that those indices reflect a subset of the total data, |
and data outside the contained range is not accessible to the peer. This means that the command |
peerName index end may return quite different values in different peers. Similarly, commands like |
peerName tag ranges will not return index ranges outside that which is meaningful to the peer. The |
configuration options -startline and -endline may be used to control how much of the underlying data |
is contained in any given text widget. |
Note that peers are really peers. Deleting the "original" text widget will not cause any other peers |
to be deleted, or otherwise affected. |
See below for the pathName peer widget command that controls the creation of peer widgets.
WIDGET COMMAND
The text command creates a new Tcl command whose name is the same as the path name of the text's win-dow. window.
dow. This command may be used to invoke various operations on the widget. It has the following gen-eral general
eral form:
pathName option ?arg arg ...?
PathName is the name of the command, which is the same as the text widget's path name. Option and
the args determine the exact behavior of the command. The following commands are possible for text
widgets:
pathName 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.
pathName cget option
Returns the current value of the configuration option given by option. Option may have any of
the values accepted by the text command.
pathName 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 is not. Op must be one of the
operators <, <=, ==, >=, >, or !=. If op is == then 1 is returned if the two indices refer to
the same character, if op is < then 1 is returned if index1 refers to an earlier character in
the text than index2, and so on.
pathName configure ?option? ?value option value ...?
Query or modify the configuration options of the widget. If no option is specified, returns a
list describing all of the available options for pathName (see Tk_ConfigureInfo for informa-
tion 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 correspond-ing corresponding
ing sublist of the value returned if no option is specified). If one or more option-value
pairs are specified, then the command modifies the given widget option(s) to have the given
value(s); in this case the command returns an empty string. Option may have any of the val-ues values
ues accepted by the text command. |
pathName count ?options? index1 |
index2 | |
Counts the number of relevant things between the two indices. If index1 is after index2, the |
result will be a negative number (and this holds for each of the possible options). The |
actual items which are counted depend on the options given. The result is a list of integers, |
one for the result of each counting option given. Valid counting options are -chars, -dis- |
playchars, -displayindices, -displaylines, -indices, -lines, -xpixels and -ypixels. The |
default value, if no option is specified, is -indices. There is an additional possible option |
-update which is a modifier. If given, then all subsequent options ensure that any possible |
out of date information is recalculated. This currently only has any effect for the -ypixels |
count (which, if -update is not given, will use the text widget's current cached value for |
each line). The count options are interpreted as follows: |
-chars ||
count all characters, whether elided or not. Do not count embedded windows or images. |
-display- |
chars | |
count all non-elided characters. |
-dis- |
playindices | |
count all non-elided characters, windows and images. |
-display- |
lines | |
count all display lines (i.e. counting one for each time a line wraps) from the line of |
the first index up to, but not including the display line of the second index. There- |
fore if they are both on the same display line, zero will be returned. By definition |
displaylines are visible and therefore this only counts portions of actual visible |
lines. |
-indices ||
count all characters and embedded windows or images (i.e. everything which counts in |
text-widget index space), whether they are elided or not. |
-lines ||
count all logical lines (irrespective of wrapping) from the line of the first index up |
to, but not including the line of the second index. Therefore if they are both on the |
same line, zero will be returned. Logical lines are counted whether they are currently |
visible (non-elided) or not. |
-xpix- |
els | |
count the number of horizontal pixels from the first pixel of the first index to (but |
not including) the first pixel of the second index. To count the total desired width |
of the text widget (assuming wrapping is not enabled), first find the longest line and |
then use ".text count -xpixels "${line}.0" "${line}.0 lineend"". |
-ypix- |
els | |
count the number of vertical pixels from the first pixel of the first index to (but not |
including) the first pixel of the second index. If both indices are on the same dis- |
play line, zero will be returned. To count the total number of vertical pixels in the |
text widget, use ".text count -ypixels 1.0 end", and to ensure this is up to date, use |
".text count -update -ypixels 1.0 end". |
The command returns a positive or negative integer corresponding to the number of items |
counted between the two indices. One such integer is returned for each counting option given, |
so a list is returned if more than one option was supplied. For example ".text count -xpixels |
-ypixels 1.3 4.5" is perfectly valid and will return a list of two elements. |
pathName 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 debug-ging debugging
ging 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 debug-ging debugging
ging is turned on. There is a single debugging switch shared by all text widgets: turning
debugging on or off in any widget turns it on or off for all widgets. For widgets with large
amounts of text, the consistency checks may cause a noticeable slow-down.
When debugging is turned on, the drawing routines of the text widget set the global variables
tk_textRedraw and tk_textRelayout to the lists of indices that are redrawn. The values of
these variables are tested by Tk's test suite.
pathName 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 does not specify a position
later in the text than index1 then no characters are deleted. If index2 is not specified then
the single character at index1 is deleted. It is not allowable to delete characters in a way
that would leave the text without a newline as the last character. The command returns an
empty string. If more indices are given, multiple ranges of text will be deleted. All
indices are first checked for validity before any deletions are made. They are sorted and the
text is removed from the last range to the first range so deleted text does not cause an unde-sired undesired
sired 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.
pathName 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 cor-ner corner
ner 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.
pathName 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, image, and window. The corresponding
value is the text, mark name, tag name, image name, or window name. The index information is
the index of the start of the text, mark, tag transition, image or window. One or more of the
following switches (or abbreviations thereof) may be specified to control the dump:
-all Return information about all elements: text, marks, tags, images and windows. This is
the default.
-command command
Instead of returning the information as the result of the dump operation, invoke the
command on each element of the text widget within the range. The command has three
arguments appended to it before it is evaluated: the key, value, and index.
-image Include information about images in the dump results.
-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 segments 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.
pathName 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:
pathName edit modified ?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.
pathName edit redo
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.
pathName edit reset
Clears the undo and redo stacks.
pathName edit separator
Inserts a separator (boundary) on the undo stack. Does nothing when the -undo option is
false.
pathName edit undo
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.
pathName get ?-displaychars? -- 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 pathName get. If the |
-displaychars option is given, then, within each range, only those characters which are not |
elided will be returned. This may have the effect that some of the returned ranges are empty |
strings.
pathName image option ?arg arg ...?
This command is used to manipulate embedded images. The behavior of the command depends on
the option argument that follows the tag argument. The following forms of the command are
currently supported:
pathName image cget 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 the section EMBEDDED IMAGES.
pathName image configure index ?option value ...?
Query or modify the configuration options for an embedded image. If no option is spec-ified, specified,
ified, returns a list describing all of the available options for the embedded image at
index (see Tk_ConfigureInfo for information on the format of this list). If option is
specified with no value, then the command returns a list describing the one named
option (this list will be identical to the corresponding sublist of the value returned
if no option is specified). If one or more option-value pairs are specified, then the
command modifies the given option(s) to have the given value(s); in this case the com-mand command
mand returns an empty string. See EMBEDDED IMAGES for information on the options that
are supported.
pathName image create index ?option value ...?
This command creates a new image annotation, which will appear in the text at the posi-tion position
tion 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.
pathName image names
Returns a list whose elements are the names of all image instances currently embedded
in window.
pathName index index
Returns the position corresponding to index in the form line.char where line is the line num-ber number
ber and char is the character number. Index may have any of the forms described under INDICES
above.
pathName 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 pathName insert widget command had been
issued for each pair, in order. The last tagList argument may be omitted.
pathName 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 cur-rently currently
rently supported:
pathName mark gravity 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.
pathName mark names
Returns a list whose elements are the names of all the marks that are currently set.
pathName mark next index
Returns the name of the next mark at or after index. If index is specified in numeri-cal numerical
cal 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 pathName dump operation. If a mark has been set to the special end index, then it
appears to be after end with respect to the pathName mark next operation. An empty
string is returned if there are no marks after index.
pathName mark previous 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 imme-diately immediately
diately 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 pathName mark pre-vious previous
vious 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 pathName dump operation. An
empty string is returned if there are no marks before index.
pathName mark set 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 does not exist, a new
mark is created. This command returns an empty string.
pathName mark unset 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 "pathName
mark names". This command returns an empty string.
pathName peer option args
This command is used to create and query widget peers. It has two forms, depending on option: |
pathName peer create newPathName |
?options? | |
Creates a peer text widget with the given newPathName, and any optional standard con- |
figuration options (as for the text command). By default the peer will have the same |
start and end line as the parent widget, but these can be overridden with the standard |
configuration options. |
pathName peer |
names | |
Returns a list of peers of this widget (this does not include the widget itself). The |
order within this list is undefined. |
pathName replace index1 index2 chars ?tagList chars tagList |
...? | |
Replaces the range of characters between index1 and index2 with the given characters and tags. |
See the section on pathName insert for an explanation of the handling of the tagList... argu- |
ments, and the section on pathName delete for an explanation of the handling of the indices. |
If index2 corresponds to an index earlier in the text than index1, an error will be generated. |
The deletion and insertion are arranged so that no unnecessary scrolling of the window or |
movement of insertion cursor occurs. In addition the undo/redo stack are correctly modified, |
if undo operations are active in the text widget. The command returns an empty string. |
pathName scan option args
This command is used to implement scanning on texts. It has two forms, depending on option:
pathName scan mark x y
Records x and y and the current view in the text window, for use in conjunction with
later pathName scan dragto commands. Typically this command is associated with a mouse
button press in the widget. It returns an empty string.
pathName scan dragto x y
This command computes the difference between its x and y arguments and the x and y
arguments to the last pathName scan mark command for the widget. It then adjusts the
view by 10 times the difference in coordinates. This command is typically associated
with mouse motion events in the widget, to produce the effect of dragging the text at
high speed through the window. The return value is an empty string.
pathName search ?switches? pattern index ?stopIndex?
Searches the text in pathName starting at index for a range of characters that matches pat-tern. pattern.
tern. 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 (it is not allowed to be at index). |
Note that, for a variety of reasons, backwards searches can be substantially slower |
than forwards searches (particularly when using -regexp), so it is recommended that |
performance-critical code use forward searches.
-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). The default matching auto- |
matically passes both the -lineanchor and -linestop options to the regexp engine |
(unless -nolinestop is used), so that ^$ match beginning and end of line, and ., [^ |
sequences will never match the newline character \n.
-nolinestop
This allows . and [^ sequences to match the newline character \n, which they will oth- |
erwise not do (see the regexp command for details). This option is only meaningful if |
-regexp is also given, and an error will be thrown otherwise. For example, to match |
the entire text, use "pathName search -nolinestop -regexp ".*" 1.0".
-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 index positions between beginning and end of the matching range will be
stored in the variable. If there are no embedded images or windows in the matching
range (and there are no elided characters if -elide is not given), this is equivalent
to the number of characters matched. In either case, the range matchIdx to matchIdx +
$count chars will return the entire matched text.
-all Find all matches in the given range and return a list of the indices of the first char- |
acter of each match. If a -count varName switch is given, then varName is also set to |
a list containing one element for each successful match. Note that, even for exact |
searches, the elements of this list may be different, if there are embedded images, |
windows or hidden text. Searches with -all behave very similarly to the Tcl command |
regexp -all, in that overlapping matches are not normally returned. For example, |
applying an -all search of the pattern "\w+" against "hello there" will just match |
twice, once for each word, and matching "Z[a-z]+Z" against "ZooZooZoo" will just match |
once.
-overlap
When performing -all searches, the normal behaviour is that matches which overlap an |
already-found match will not be returned. This switch changes that behaviour so that |
all matches which are not totally enclosed within another match are returned. For |
example, applying an -overlap search of the pattern "\w+" against "hello there" will |
just match twice (i.e. no different to just -all), but matching "Z[a-z]+Z" against |
"ZooZooZoo" will now match twice. An error will be thrown if this switch is used with- |
out -all.
-strictlimits
When performing any search, the normal behaviour is that the start and stop limits are |
checked with respect to the start of the matching text. With the -strictlimits flag, |
the entire matching range must lie inside the start and stop limits specified for the |
match to be valid.
-elide Find elided (hidden) text as well. By default only displayed text is searched.
-- This switch has no effect except to terminate the list of switches: the next argument
will be treated as pattern even if it starts with -.
The matching range may be within a single line of text, or run across multiple lines (if parts |
of the pattern can match a new-line). For regular expression matching one can use the various |
newline-matching features such as $ to match the end of a line, ^ to match the beginning of a |
line, and to control whether . is allowed to match a new-line. If stopIndex is specified, the
search stops at that index: for forward searches, no match at or after stopIndex will be con-sidered; considered;
sidered; for backward searches, no match earlier in the text than stopIndex will be consid-ered. considered.
ered. If stopIndex is omitted, the entire text will be searched: when the beginning or end of
the text is reached, the search continues at the other end until the starting location is
reached again; if stopIndex is specified, no wrap-around will occur. This means that, for
example, if the search is -forwards but stopIndex is earlier in the text than startIndex,
nothing will ever be found. See KNOWN BUGS below for a number of minor limitations of the
pathName search command.
pathName 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 win-dow. window.
dow. If index is far out of view, then the command centers index in the window.
pathName 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 cur-rently currently
rently supported:
pathName tag add 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 is not tagged). A single command may con-tain contain
tain 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.
pathName tag bind 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 widget command is similar to the bind command except
that it operates on characters in a text rather than entire widgets. See the bind man-ual manual
ual entry for complete details on the syntax of sequence and the substitutions per-formed performed
formed 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 char-acter, character,
acter, and a Leave event triggers for a tag when it ceases to be present on the current
character. Enter and Leave events can happen either because the current mark moved or
because the character at that position changed. Note that these events are different
than Enter and Leave events for windows. Mouse and keyboard events are directed to the
current character. If a virtual event is used in a binding, that binding can trigger
only if the virtual event is defined by an underlying mouse-related or keyboard-related
event.
It is possible for the current character to have multiple tags, and for each of them to
have a binding for a particular event sequence. When this occurs, one binding is
invoked for each tag, in order from lowest-priority to highest priority. If there are
multiple matching bindings for a single tag, then the most specific binding is chosen
(see the manual entry for the bind command for details). continue and break commands
within binding scripts are processed in the same way as for bindings created with the
bind command.
If bindings are created for the widget as a whole using the bind command, then those
bindings will supplement the tag bindings. The tag bindings will be invoked first,
followed by bindings for the window as a whole.
pathName tag cget 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 pathName tag
configure widget command.
pathName tag configure tagName ?option? ?value? ?option value ...?
This command is similar to the pathName configure widget command except that it modi-fies modifies
fies options associated with the tag given by tagName instead of modifying options for
the overall text widget. If no option is specified, the command returns a list
describing all of the available options for tagName (see Tk_ConfigureInfo for informa-tion information
tion on the format of this list). If option is specified with no value, then the com-mand command
mand 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.
pathName tag delete 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.
pathName tag lower 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.
pathName tag names ?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 "pathName tag" widget command but have not been deleted by a "pathName tag
delete" widget command, even if no characters are currently marked with the tag). The
list will be sorted in order from lowest priority to highest priority.
pathName tag nextrange 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 consid-ered). considered).
ered). 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 char-acter character
acter 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.
pathName tag prevrange 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 match-ing matching
ing 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.
pathName tag raise 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.
pathName tag ranges 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.
pathName tag remove 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 is not affected). A single command may contain
any number of index1-index2 pairs. If the last index2 is omitted then the tag is
removed from the single character at index1. If there are no characters in the speci-fied specified
fied 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.
pathName window option ?arg arg ...?
This command is used to manipulate embedded windows. The behavior of the command depends on
the option argument that follows the tag argument. The following forms of the command are
currently supported:
pathName window cget 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 the section EMBEDDED WINDOWS.
pathName window configure 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 win-dow window
dow at index (see Tk_ConfigureInfo for information on the format of this list). If
option is specified with no value, then the command returns a list describing the one
named option (this list will be identical to the corresponding sublist of the value
returned if no option is specified). If one or more option-value pairs are specified,
then the command modifies the given option(s) to have the given value(s); in this case
the command returns an empty string. See EMBEDDED WINDOWS for information on the
options that are supported.
pathName window create 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 config-ure configure
ure the annotation. See EMBEDDED WINDOWS for information on the options that are sup-ported. supported.
ported. Returns an empty string.
pathName window names
Returns a list whose elements are the names of all windows currently embedded in win-dow. window.
dow.
pathName 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:
pathName 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 visi-ble visible
ble 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.
pathName xview moveto 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.
pathName xview scroll number what
This command shifts the view in the window left or right according to number and what.
What must be units, pages or pixels. If what is units or pages then number must be an |
integer, otherwise number may be specified in any of the forms acceptable to Tk_GetPix- |
els, such as "2.0c" or "1i" (the result is rounded to the nearest integer value. If no |
units are given, pixels are assumed). If what is units, the view adjusts left or right |
by number average-width characters on the display; if it is pages then the view adjusts |
by number screenfuls; if it is pixels then the view adjusts by number pixels. If num-ber number
ber is negative then characters farther to the left become visible; if it is positive
then characters farther to the right become visible.
pathName 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:
pathName 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 visible pixel of the first char-acter character
acter (or image, etc) in the top line in the window, relative to the text as a whole
(0.5 means it is halfway through the text, for example). The second element gives the
position of the first pixel just after the last visible one in the bottom line of the
window, relative to the text as a whole. These are the same values passed to scroll-bars scrollbars
bars via the -yscrollcommand option.
pathName yview moveto fraction
Adjusts the view in the window so that the pixel given by fraction appears at the top
of the top line of the window. Fraction is a fraction between 0 and 1; 0 indicates
the first pixel of the first character in the text, 0.33 indicates the pixel that is
one-third the way through the text; and so on. Values close to 1 will indicate values |
close to the last pixel in the text (1 actually refers to one pixel beyond the last |
pixel), but in such cases the widget will never scroll beyond the last pixel, and so a |
value of 1 will effectively be rounded back to whatever fraction ensures the last pixel |
is at the bottom of the window, and some other pixel is at the top.
pathName yview scroll number what
This command adjust the view in the window up or down according to number and what.
What must be units, pages or pixels. If what is units or pages then number must be an |
integer, otherwise number may be specified in any of the forms acceptable to Tk_GetPix- |
els, such as "2.0c" or "1i" (the result is rounded to the nearest integer value. If no |
units are given, pixels are assumed). If what is units, the view adjusts up or down by |
number lines on the display; if it is pages then the view adjusts by number screenfuls; |
if it is pixels then the view adjusts by number pixels. If number is negative then
earlier positions in the text become visible; if it is positive then later positions
in the text become visible.
pathName yview ?-pickplace? index
Changes the view in the widget's window to make index visible. If the -pickplace
option is not specified then index will appear at the top of the window. If -pickplace
is specified then the widget chooses where index appears in the window:
[1] If index is already visible somewhere in the window then the command does noth-ing. nothing.
ing.
[2] If index is only a few lines off-screen above the window then it will be posi-tioned positioned
tioned at the top of the window.
[3] If index is only a few lines off-screen below the window then it will be posi-tioned positioned
tioned at the bottom of the window.
[4] Otherwise, index will be centered in the window.
The -pickplace option has been obsoleted by the pathName see widget command (pathName
see handles both x- and y-motion to make a location visible, whereas the -pickplace
mode only handles motion in y).
pathName yview number
This command makes the first character on the line after the one given by number visi-ble visible
ble 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" is dependent on the value of the tcl_wordchars variable. See
tclvars(n).
[1] Clicking mouse button 1 positions the insertion cursor just before the character underneath
the mouse cursor, sets the input focus to this widget, and clears any selection in the widget.
Dragging with mouse button 1 strokes out a selection between the insertion cursor and the
character under the mouse.
[2] Double-clicking with mouse button 1 selects the word under the mouse and positions the inser-tion insertion
tion cursor at the start of the word. Dragging after a double click will stroke out a selec-tion selection
tion consisting of whole words.
[3] Triple-clicking with mouse button 1 selects the line under the mouse and positions the inser-tion insertion
tion cursor at the start of the line. Dragging after a triple click will stroke out a selec-tion selection
tion 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 automati-cally automatically
cally 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. Con-trol-Left Control-Left
trol-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. Con-trol-b Control-b
trol-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 ControlShift-Up
Shift-Up and Control-Shift-Down move the insertion cursor by paragraphs and also extend the
selection. Control-p and Control-n behave the same as Up and Down, respectively.
[11] The Next and Prior keys move the insertion cursor forward or backwards by one screenful and
clear any selection in the text. If the Shift key is held down while Next or Prior is typed,
then the selection is extended to include the new character.
[12] Control-Next and Control-Prior scroll the view right or left by one page without moving the
insertion cursor or affecting the selection.
[13] Home and Control-a move the insertion cursor to the beginning of its display line and clear
any selection in the widget. Shift-Home moves the insertion cursor to the beginning of the
display line and also extends the selection to that point.
[14] End and Control-e move the insertion cursor to the end of the display line and clear any
selection in the widget. Shift-End moves the cursor to the end of the display line and
extends the selection to that point.
[15] Control-Home and Meta-< move the insertion cursor to the beginning of the text and clear any
selection in the widget. Control-Shift-Home moves the insertion cursor to the beginning of
the text and also extends the selection to that point.
[16] Control-End and Meta-> move the insertion cursor to the end of the text and clear any selec-tion selection
tion in the widget. Control-Shift-End moves the cursor to the end of the text and extends the
selection to that point.
[17] The Select key and Control-Space set the selection anchor to the position of the insertion
cursor. They do not affect the current selection. Shift-Select and Control-Shift-Space
adjust the selection to the current position of the insertion cursor, selecting from the
anchor to the insertion cursor if there was not any selection previously.
[18] Control-/ selects the entire contents of the widget.
[19] Control-\ clears any selection in the widget.
[20] The F16 key (labelled Copy on many Sun workstations) or Meta-w copies the selection in the
widget to the clipboard, if there is a selection. This action is carried out by the command
tk_textCopy.
[21] The F20 key (labelled Cut on many Sun workstations) or Control-w copies the selection in the
widget to the clipboard and deletes the selection. This action is carried out by the command
tk_textCut. If there is no selection in the widget then these keys have no effect.
[22] The F18 key (labelled Paste on many Sun workstations) or Control-y inserts the contents of the
clipboard at the position of the insertion cursor. This action is carried out by the command
tk_textPaste.
[23] The Delete key deletes the selection, if there is one in the widget. If there is no selec-tion, selection,
tion, it deletes the character to the right of the insertion cursor.
[24] Backspace and Control-h delete the selection, if there is one in the widget. If there is no
selection, they delete the character to the left of the insertion cursor.
[25] Control-d deletes the character to the right of the insertion cursor.
[26] Meta-d deletes the word to the right of the insertion cursor.
[27] Control-k deletes from the insertion cursor to the end of its line; if the insertion cursor is
already at the end of a line, then Control-k deletes the newline character.
[28] Control-o opens a new line by inserting a newline character in front of the insertion cursor
without moving the insertion cursor.
[29] Meta-backspace and Meta-Delete delete the word to the left of the insertion cursor.
[30] Control-x deletes whatever is selected in the text widget after copying it to the clipboard.
[31] Control-t reverses the order of the two characters to the right of the insertion cursor.
[32] Control-z (and Control-underscore on UNIX when tk_strictMotif is true) undoes the last edit
action if the -undo option is true. Does nothing otherwise.
[33] Control-Z (or Control-y on Windows) reapplies the last undone edit action if the -undo option
is true. Does nothing otherwise.
If the widget is disabled using the -state option, then its view can still be adjusted and text can
still be selected, but no insertion cursor will be displayed and no text modifications will take
place.
The behavior of texts can be changed by defining new bindings for individual widgets or by redefining
the class bindings.
KNOWN ISSUES
ISSUES CONCERNING CHARS AND INDICES
Before Tk 8.5, the widget used the string "chars" to refer to index positions (which included charac- |
ters, embedded windows and embedded images). As of Tk 8.5 the text widget deals separately and cor- |
rectly with "chars" and "indices". For backwards compatibility, however, the index modifiers "+N |
chars" and "-N chars" continue to refer to indices. One must use any of the full forms "+N any |
chars" or "-N any chars" etc. to refer to actual character indices. This confusion may be fixed in a |
future release by making the widget correctly interpret "+N chars" as a synonym for "+N any chars".
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 practi-cal practical
cal on most workstations. Text is represented internally with a modified B-tree structure that makes
operations relatively efficient even with large texts. Tags are included in the B-tree structure in
a way that allows tags to span large ranges or have many disjoint smaller ranges without loss of
efficiency. Marks are also implemented in a way that allows large numbers of marks. In most cases
it is fine to have large numbers of unique tags, or a tag that has many distinct ranges.
One performance problem can arise if you have hundreds or thousands of different tags that all have
the following characteristics: the first and last ranges of each tag are near the beginning and end
of the text, respectively, or a single tag range covers most of the text widget. The cost of adding
and deleting tags like this is proportional to the number of other tags with the same properties. In
contrast, there is no problem with having thousands of distinct tags if their overall ranges are
localized and spread uniformly throughout the text.
Very long text lines can be expensive, especially if they have many marks and tags within them.
The display line with the insert cursor is redrawn each time the cursor blinks, which causes a steady
stream of graphics traffic. Set the insertOffTime attribute to 0 avoid this.
KNOWN BUGS
The pathName search -regexp sub-command attempts to perform sophisticated regexp matching across mul- |
tiple lines in an efficient fashion (since Tk 8.5), examining each line individually, and then in |
small groups of lines, whether searching forwards or backwards. Under certain conditions the search |
result might differ from that obtained by applying the same regexp to the entire text from the widget |
in one go. For example, when searching with a greedy regexp, the widget will continue to attempt to |
add extra lines to the match as long as one of two conditions are true: either Tcl's regexp library |
returns a code to indicate a longer match is possible (but there are known bugs in Tcl which mean |
this code is not always correctly returned); or if each extra line added results in at least a par- |
tial match with the pattern. This means in the case where the first extra line added results in no |
match and Tcl's regexp system returns the incorrect code and adding a second extra line would actu- |
ally match, the text widget will return the wrong result. In practice this is a rare problem, but it |
can occur, for example: |
pack [text .t] |
will not find a match when one exists of 19 characters starting from the first "b". |
Whenever one possible match is fully enclosed in another, the search command will attempt to ensure |
only the larger match is returned. When performing backwards regexp searches it is possible that Tcl |
will not always achieve this, in the case where a match is preceded by one or more short, non-over- |
lapping matches, all of which are preceded by a large match which actually encompasses all of them. |
The search algorithm used by the widget does not look back arbitrarily far for a possible match which |
might cover large portions of the widget. For example: |
pack [text .t] |
matches at "5.0" when a true greedy match would match at "1.0". Similarly if we add -all to this |
case, it matches at all of "5.0", "4.0", "3.0" and "1.0", when really it should only match at "1.0" |
since that match encloses all the others.
SEE ALSO
entry(n), scrollbar(n)
KEYWORDS
text, widget, tkvars
Tk 8.5 text(n)
|
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