NAME

text, tk_textCopy, tk_textCut, tk_textPaste - Create and manipulate 'text' hypertext editing 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 character-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 line of the underlying textual data store that should be just after the last line contained in the widget. This allows a text widget to reflect only a portion of a larger piece of text. Instead of an integer, the empty string can be provided to this configuration option, which will configure the widget to end at the very last line in the textual data store.

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:	-insertunfocussed
Database Name:	insertUnfocussed
Database Class:	InsertUnfocussed

Specifies how to display the insertion cursor when the widget does not have the focus. Must be none (the default) which means to not display the cursor, hollow which means to display a hollow box, or solid which means to display a solid box. Note that hollow and solid will appear very similar when the -blockcursor option is false.

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 display. 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 specifies additional space to provide between the display lines that represent a single line of text. The value may have any of the standard forms for screen distances. This option may be overridden with -spacing2 options in tags.

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 display. 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 position. For example, “-tabs {2c left 4c 6c center}” creates three tab stops at two-centimeter intervals; the first two use left justification and the third uses center justification.

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 widget. Additional options, described above, may be specified on the command line or in the option database to configure aspects of the text such as its default background color and relief. The text command returns the path name of the new window.

A text widget displays one or more lines of text and allows that text to be edited. Text widgets support four different kinds of annotations on the text, called tags, marks, embedded windows or embedded images. Tags allow different portions of the text to be displayed with different fonts and colors. In addition, Tcl commands can be associated with tags so that scripts are invoked when particular actions such as keystrokes and mouse button presses occur in particular ranges of the text. See TAGS below for more details.

The second form of annotation consists of floating markers in the text called “marks”. Marks are used to keep track of various interesting positions in the text as it is edited. See MARKS below for more details.

The third form of annotation allows arbitrary windows to be embedded in a text widget. See EMBEDDED WINDOWS below for more details.

The fourth form of annotation allows Tk images to be embedded in a text widget. See EMBEDDED IMAGES below for more details.

The text widget also has a built-in undo/redo mechanism. See THE UNDO MECHANISM below for more details.

The text widget allows for the creation of peer widgets. These are other text widgets which share the same underlying data (text, marks, tags, images, etc). See PEER WIDGETS below for more details.

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 endpoint of a range of characters to delete. Indices have the syntax

base modifier modifier modifier ...

The base for an index must have one of the following forms:

line.char

Indicates char'th character on line line. Lines are numbered from 1 for consistency with other UNIX programs that use this numbering scheme. Within a line, characters are numbered from 0. If char is end then it refers to the newline character that ends the line.

@x,y

Indicates the character that covers the pixel whose x and y coordinates within the text's window are x and y.

end

Indicates the end of the text (the character just after the last newline).

mark

Indicates the character just after the mark whose name is mark.

tag.first

Indicates the first character in the text that has been tagged with tag. This form generates an error if no characters are currently tagged with tag.

tag.last

Indicates the character just after the last one in the text that has been tagged with tag. This form generates an error if no characters are currently tagged with tag.

pathName

Indicates the position of the embedded window whose name is pathName. This form generates 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 generates an error if there is no embedded image by the given name.

If the base could match more than one of the above forms, such as a mark and imageName both having the same value, then the form earlier in the above list takes precedence. If modifiers follow the base index, each one of them must have one of the forms listed below. Keywords such as chars and wordend may be abbreviated as long as the abbreviation is unambiguous.

+ count ?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 necessary. If there are fewer than count characters in the text before the current index, then set the index to the first index in the text (1.0). Spaces on either side of count are optional. If the display submodifier is given, elided characters are skipped over without being counted. If any is given, then all characters are counted. For historical reasons, if neither modifier is given then the count actually takes place in units of index positions (see INDICES for details). This behavior 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 necessary. If there are fewer than count index positions in the text after the current index, then set the index to the last index position in the text. Spaces on either side of count are optional. Note that an index position is either a single character or a single embedded image or embedded window. If the display submodifier is given, elided indices are skipped over without being counted. If any is given, then all indices are counted; this is also the default behaviour if no modifier is given.

- 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 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.

- 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 position, adjust the character position to refer to the last character of the line (the newline). Spaces on either side of count are optional. If the display submodifier is given, then each visual display line is counted separately. Otherwise, if any (or no modifier) is given, then each logical line (no matter how many times it is visually wrapped) counts just once. If the relevant lines are not wrapped, then these two methods of counting are equivalent.

?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 submodifier 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, otherwise all characters (elided or not) are examined.

If more than one modifier is present then they are applied in left-to-right order. For example, the index “end - 1 chars” refers to the next-to-last character in the text and “insert wordstart - 1 c” refers to the character just before the first one in the word containing the insertion cursor. Modifiers are applied one by one in this left to right order, and after each step the resulting index is constrained to be a valid index in the text widget. So, for example, the index “1.0 -1c +1c” refers to the index “2.0”.

Where modifiers result in index changes by display lines, display chars or display indices, and the base refers to an index inside an elided tag, that base index is considered to be equivalent to the first following non-elided index.

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 associated with characters in a text. Each tag may refer to a single character, a range of characters, or several ranges of characters. An individual character may have any number of tags associated with it.

A priority order is defined among tags, and this order is used in implementing some of the tag-related functions described below. When a tag is defined (by associating it with characters or setting its display options or binding commands to it), it is given a priority higher than any existing tag. The priority order of tags may be redefined using the “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 -foreground 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 currently supported for tags:

-background color

Color specifies the background color to use for characters associated with the tag. It may have any of the forms accepted by Tk_GetColor.

-bgstipple bitmap

Bitmap specifies a bitmap that is used as a stipple pattern for the background. It may have any of the forms accepted by Tk_GetBitmap. If bitmap 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 border to draw around the tag using any of the forms accepted by Tk_GetPixels. This option should be used in conjunction with the -relief option to provide the desired border.

-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 foreground information such as underlines. It may have any of the forms accepted by Tk_GetBitmap. If bitmap has not been specified, or if it is specified as an empty string, then a solid fill will be used.

-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.

-lmargincolor color

Color specifies the background color to use in regions that do not contain characters because they are indented by -lmargin1 or -lmargin2. It may have any of the forms accepted by Tk_GetColor. If color has not been specified, or if it is specified as an empty string, then the color used is specified by the -background tag option (or, if this is also unspecified, by the -background widget option).

-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.

-overstrikefg color

Color specifies the color to use when displaying the overstrike. It may have any of the forms accepted by Tk_GetColor. If color has not been specified, or if it is specified as an empty string, then the color specified by the -foreground tag option is used.

-relief relief

Relief specifies the relief style to use for drawing the border, in any of the forms accepted by Tk_GetRelief. This option is used in conjunction with the -borderwidth option to enable to the desired border appearance.

-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.

-rmargincolor color

Color specifies the background color to use in regions that do not contain characters because they are indented by -rmargin. It may have any of the forms accepted by Tk_GetColor. If color has not been specified, or if it is specified as an empty string, then the color used is specified by the -background tag option (or, if this is also unspecified, by the -background widget option).

-selectbackground color

Color specifies the background color to use when displaying selected items. It may have any of the forms accepted by Tk_GetColor. If color has not been specified, or if it is specified as an empty string, then the color specified by the -background tag option is used.

-selectforeground color

Color specifies the foreground color to use when displaying selected items. It may have any of the forms accepted by Tk_GetColor. If color has not been specified, or if it is specified as an empty string, then the color specified by the -foreground tag option is used.

-spacing1 pixels

Pixels specifies how much additional space should be left above each text line, using any of the standard forms for screen distances. If a line wraps, this option only applies to the first line on the display.

-spacing2 pixels

For lines that wrap, this option specifies how much additional space to leave between the display lines for a single text line. Pixels may have any of the standard forms for screen distances.

-spacing3 pixels

Pixels specifies how much additional space should be left below each text line, using any of the standard forms for screen distances. If a line wraps, this option only applies to the last line on the display.

-tabs tabList

TabList specifies a set of tab stops in the same form as for the -tabs option for the text widget. This option only applies to a display line if it applies to the first non-elided character on that display line. If this option is specified as an empty string, it cancels the option, leaving it unspecified for the tag (the default). If the option is specified as a non-empty string that is an empty list, such as -tags { }, then it requests default 8-character tabs as described for the -tags widget option.

-tabstyle style

Style specifies either the tabular or wordprocessor style of tabbing to use for the text widget. This option only applies to a display line if it applies to the first non-elided character on that display line. If this option is specified as an empty string, it cancels the option, leaving it unspecified for the tag (the default).

-underline boolean

Boolean specifies whether or not to draw an underline underneath characters. It may have any of the forms accepted by Tcl_GetBoolean.

-underlinefg color

Color specifies the color to use when displaying the underline. It may have any of the forms accepted by Tk_GetColor. If color has not been specified, or if it is specified as an empty string, then the color specified by the -foreground tag option is used.

-wrap mode

Mode specifies how to handle lines that are wider than the text's window. This option only applies to a display line if it applies to the first non-elided character on that display line. It has the same legal values as the -wrap option for the text widget: none, char, or word. If this tag option is specified, it overrides the -wrap option for the text widget.

If a character has several tags associated with it, and if their display options conflict, then the options of the highest priority tag are used. If a particular display option has not been specified for a particular tag, or if it is specified as an empty string, then that option will never be used; the next-highest-priority tag's option will used instead. If no tag specifies a particular display option, then the default style for the widget will be used.

The second purpose for tags is event bindings. You can associate bindings with a tag in much the same way you can associate bindings with a widget class: whenever particular X events occur on characters with the given tag, a given Tcl command will be executed. Tag bindings can be used to give behaviors to ranges of characters; among other things, this allows hypertext-like features to be implemented. For details, see the description of the “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 character closest to the mouse and is adjusted automatically to track the mouse position and any changes to the text in the widget (one exception: current is not updated in response to mouse motions if a mouse button is down; the update will be deferred until all mouse buttons have been released). Neither of these special marks may be deleted. With the exception of these two special marks, all marks are shared between peer text widgets, and may be manipulated on an equal basis from any peer.

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.

Eliding an embedded window immediately after scheduling it for creation via pathName window create index -create will prevent it from being effectively created. Uneliding an elided embedded window scheduled for creation via pathName window create index -create will automatically trigger the associated creation script. After destroying an elided embedded window, the latter won't get automatically recreated.

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 annotation and return the name of that window as its result. Two substitutions will be performed in script before evaluation. %W will be substituted by the name of the parent text widget, and %% will be substituted by a single %. If the annotation's window should ever be deleted, script will be evaluated again the next time the annotation is displayed.

-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 embedded 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 vertically to fill its line. If the -pady option has been specified as well, then the requested padding will be retained even if the window is stretched.

-window 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 corresponding to the old pathName. Rather it will remove the association between the old pathName and the text widget. If multiple peer widgets are in use, it is usually simpler to use the -create option if embedded windows are desired in each peer.

EMBEDDED IMAGES

The final form of annotation in text widgets is an embedded image. Each embedded image annotation causes an image to be displayed at a particular point in the text. There may be any number of embedded images in a text widget, and a particular image may be embedded in multiple places in the same text widget.

The embedded image's position on the screen will be updated as the text is modified or scrolled. Each embedded image occupies one 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.

Eliding an embedded image immediately after scheduling it for creation via pathName image create index -create will prevent it from being effectively created. Uneliding an elided embedded image scheduled for creation via pathName image create index -create will automatically trigger the associated creation script. After destroying an elided embedded image, the latter won't get automatically recreated.

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, several 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 ImageName is not supplied, then the name of the Tk image is used instead. If the imageName is already in use, #nn is appended to the end of the name as described above.

-padx pixels

Pixels specifies the amount of extra space to leave on each side of the embedded image. It may have any of the usual forms defined for a screen distance.

-pady pixels

Pixels specifies the amount of extra space to leave on the top and on the bottom of the embedded image. It may have any of the usual forms defined for a screen distance.

THE SELECTION

Selection support is implemented via tags. If the -exportselection option for the text widget is true then the sel tag will be associated with the selection:

[1]

Whenever characters are tagged with sel the text widget will claim ownership of the selection.

[2]

Attempts to retrieve the selection will be serviced by the text widget, returning all the characters with the sel tag.

[3]

If the selection is claimed away by another application or by another window within this application, then the sel tag will be removed from all characters in the text.

[4]

Whenever the sel tag range changes a virtual event <<Selection>> is generated.

The sel tag is automatically defined when a text widget is created, and it may not be deleted with the “pathName tag delete” widget command. Furthermore, the -selectbackground, -selectborderwidth, and -selectforeground options for the text widget are tied to the -background, -borderwidth, and -foreground options for the sel tag: changes in either will automatically be reflected in the other. Also the -inactiveselectbackground option for the text widget is used instead of -selectbackground when the text widget does not have the focus. This allows programmatic control over the visualization of the sel tag for foreground and background windows, or to have sel not shown at all (when -inactiveselectbackground is empty) for background windows. Each peer text widget has its own sel tag which can be separately configured and set.

THE 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 automatically be drawn at this point whenever the text widget has the input focus.

THE MODIFIED FLAG

The text widget can keep track of changes to the content of the widget by means of the modified flag. Inserting or deleting text will set this flag. The flag can be queried, set and cleared programmatically 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 <<UndoStack>> virtual event is generated every time the undo stack or the redo stack becomes empty or unempty.

The undo mechanism is also linked to the modified flag. This means that undoing or redoing changes can take a modified text widget back to the unmodified state or vice versa. The modified flag will be set automatically to the appropriate state. This automatic coupling does not work when the modified flag has been set by the user, until the flag has been reset again.

See below for the 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, -maxundo, -autoseparators (i.e. all undo, redo and modified state issues are shared).

Finally any single peer need not contain all lines from the underlying data store. When creating a peer, a contiguous range of lines (e.g. only lines 52 through 125) may be specified. This allows a peer to contain just a small portion of the overall text. The range of lines will expand and contract as text is inserted or deleted. The peer will only ever display complete lines of text (one cannot share just part of a line). If the peer's contents contracts to nothing (i.e. all complete lines in the peer widget have been deleted from another widget), then it is impossible for new lines to be inserted. The peer will simply become an empty shell on which the background can be configured, but which will never show any content (without manual reconfiguration of the start and end lines). Note that a peer which does not contain all of the underlying data store still has indices numbered from “1.0” to “end”. It is simply that those indices reflect a subset of the total data, and data outside the contained range is not accessible to the peer. This means that the command 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.

ASYNCHRONOUS UPDATE OF LINE HEIGHTS

In order to maintain a responsive user-experience, the text widget calculates lines metrics (line heights in pixels) asynchronously. Because of this, some commands of the text widget may return wrong results if the asynchronous calculations are not finished at the time of calling. This applies to pathName count -ypixels and pathName yview.

Again for performance reasons, it would not be appropriate to let these commands always wait for the end of the update calculation each time they are called. In most use cases of these commands a more or less inaccurate result does not really matter compared to execution speed.

In case accurate result is needed (and if the text widget is managed by a geometry manager), one can resort to pathName sync and pathName pendingsync to control the synchronization of the view of text widgets.

The <<WidgetViewSync>> virtual event fires when the line heights of the text widget become obsolete (due to some editing command or configuration change), and again when the internal data of the text widget are back in sync with the widget view. The detail field (%d substitution) is either true (when the widget is in sync) or false (when it is not).

pathName sync, pathName pendingsync and <<WidgetViewSync>> apply to each text widget independently of its peers.

Examples of use:

## Example 1:
# immediately complete line metrics at any cost (GUI unresponsive)
$w sync
$w yview moveto $fraction
## Example 2:
# synchronously wait for up-to-date line metrics (GUI responsive)
# before executing the scheduled command, but don't block execution flow
$w sync -command [list $w yview moveto $fraction]
## Example 3:
# init
set yud($w) 0
proc updateaction w {
set ::yud($w) 1
# any other update action here...
}
# runtime, synchronously wait for up-to-date line metrics (GUI responsive)
$w sync -command [list updateaction $w]
vwait yud($w)
$w yview moveto $fraction
## Example 4:
# init
set todo($w) {}
proc updateaction w {
foreach cmd $::todo($w) {uplevel #0 $cmd}
set todo($w) {}
}
# runtime
lappend todo($w) [list $w yview moveto $fraction]
$w sync -command [list updateaction $w]
## Example 5:
# init
set todo($w) {}
bind $w <<WidgetViewSync>> {
if {%d} {
foreach cmd $todo(%W) {eval $cmd}
set todo(%W) {}
}
}
# runtime
if {![$w pendingsync]} {
$w yview moveto $fraction
} else {
lappend todo($w) [list $w yview moveto $fraction]
}

WIDGET COMMAND

The text command creates a new Tcl command whose name is the same as the path name of the text's window. This command may be used to invoke various operations on the widget. It has the following general form:

pathName option ?arg arg ...?

pathName 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 information on the format of this list). If option is specified with no value, then the command returns a list describing the one named option (this list will be identical to the corresponding sublist of the value returned if no option is specified). If one or more option-value pairs are specified, then the command modifies the given widget option(s) to have the given value(s); in this case the command returns an empty string. Option may have any of the values accepted by the text command.

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, -displaychars, -displayindices, -displaylines, -indices, -lines, -xpixels and -ypixels. The default value, if no option is specified, is -indices. There is an additional possible option -update which is a modifier. If given (and if the text widget is managed by a geometry manager), 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). This -update option is obsoleted by pathName sync, pathName pendingsync and <<WidgetViewSync>>. The count options are interpreted as follows:

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 debugging checks will be turned off. In either case the command returns an empty string. If boolean is not specified then the command returns on or off to indicate whether or not debugging is turned on. There is a single debugging switch shared by all text widgets: turning debugging on or off in any widget turns it on or off for all widgets. For widgets with large amounts of text, the consistency checks may cause a noticeable slow-down.

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. Attempts to delete characters in a way that would leave the text without a newline as the last character will be tweaked by the text widget to avoid this. In particular, deletion of complete lines of text up to the end of the text will also delete the newline character just before the deleted block so that it is replaced by the new final newline of the text widget. The command returns an empty string. If more indices are given, multiple ranges of text will be deleted. All indices are first checked for validity before any deletions are made. They are sorted and the text is removed from the last range to the first range so deleted text does not cause an undesired index shifting side-effects. If multiple ranges with the same start index are given, then the longest range is used. If overlapping ranges are given, then they will be merged into spans that do not cause deletion of text outside the given ranges due to text shifted during deletion.

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 corner of the area occupied by the line, the third and fourth elements give the width and height of the area, and the fifth element gives the position of the baseline for the line, measured down from the top of the area. All of this information is measured in pixels. If the current wrap mode is none and the line extends beyond the boundaries of the window, the area returned reflects the entire area of the line, including the portions that are out of the window. If the line is shorter than the full width of the window then the area returned reflects just the portion of the line that is occupied by characters and embedded windows. If the display line containing index is not visible on the screen then the return value is an empty list.

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:

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 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 index index

Returns the position corresponding to index in the form line.char where line is the line number and char is the character number. Index may have any of the forms described under INDICES above.

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 currently supported:

pathName peer option args

This command is used to create and query widget peers. It has two forms, depending on option:

pathName pendingsync

Returns 1 if the line heights calculations are not up-to-date, 0 otherwise.

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... arguments, 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.

pathName scan option args

This command is used to implement scanning on texts. It has two forms, depending on option:

pathName search ?switches? pattern index ?stopIndex?

Searches the text in pathName starting at index for a range of characters that matches pattern. If a match is found, the index of the first character in the match is returned as result; otherwise an empty string is returned. One or more of the following switches (or abbreviations thereof) may be specified to control the search:

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 window. If index is far out of view, then the command centers index in the window.

pathName sync ?-command command?

Controls the synchronization of the view of the text widget.

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 currently supported:

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 window argument. The following forms of the command are currently supported:

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 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:

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(3tcl).

[1]

Clicking mouse button 1 positions the insertion cursor just before the character underneath the mouse cursor, sets the input focus to this widget, and clears any selection in the widget. Dragging with mouse button 1 strokes out a selection between the insertion cursor and the character under the mouse.

[2]

Double-clicking with mouse button 1 selects the word under the mouse and positions the insertion cursor at the start of the word. Dragging after a double click will stroke out a selection consisting of whole words.

[3]

Triple-clicking with mouse button 1 selects the line under the mouse and positions the insertion cursor at the start of the line. Dragging after a triple click will stroke out a selection consisting of whole lines.

[4]

The ends of the selection can be adjusted by dragging with mouse button 1 while the Shift key is down; this will adjust the end of the selection that was nearest to the mouse cursor when button 1 was pressed. If the button is double-clicked before dragging then the selection will be adjusted in units of whole words; if it is triple-clicked then the selection will be adjusted in units of whole lines.

[5]

Clicking mouse button 1 with the Control key down will reposition the insertion cursor without affecting the selection.

[6]

If any normal printing characters are typed, they are inserted at the point of the insertion cursor.

[7]

The view in the widget can be adjusted by dragging with mouse button 2. If mouse button 2 is clicked without moving the mouse, the selection is copied into the text at the position of the mouse cursor. The Insert key also inserts the selection, but at the position of the insertion cursor.

[8]

If the mouse is dragged out of the widget while button 1 is pressed, the entry will automatically scroll to make more text visible (if there is more text off-screen on the side where the mouse left the window).

[9]

The Left and Right keys move the insertion cursor one character to the left or right; they also clear any selection in the text. If Left or Right is typed with the Shift key down, then the insertion cursor moves and the selection is extended to include the new character. Control-Left and Control-Right move the insertion cursor by words, and Control-Shift-Left and Control-Shift-Right move the insertion cursor by words and also extend the selection. Control-b and Control-f behave the same as Left and Right, respectively. Meta-b and Meta-f behave the same as Control-Left and Control-Right, respectively.

[10]

The Up and Down keys move the insertion cursor one line up or down and clear any selection in the text. If Up or Right is typed with the Shift key down, then the insertion cursor moves and the selection is extended to include the new character. Control-Up and Control-Down move the insertion cursor by paragraphs (groups of lines separated by blank lines), and Control-Shift-Up and Control-Shift-Down move the insertion cursor by paragraphs and also extend the selection. Control-p and Control-n behave the same as Up and Down, respectively.

[11]

The Next and Prior keys move the insertion cursor forward or backwards by one screenful and clear any selection in the text. If the Shift key is held down while Next or Prior is typed, then the selection is extended to include the new character.

[12]

Control-Next and Control-Prior scroll the view right or left by one page without moving the insertion cursor or affecting the selection.

[13]

Home and Control-a move the insertion cursor to the beginning of its display line and clear any selection in the widget. Shift-Home moves the insertion cursor to the beginning of the display line and also extends the selection to that point.

[14]

End and Control-e move the insertion cursor to the end of the display line and clear any selection in the widget. Shift-End moves the cursor to the end of the display line and extends the selection to that point.

[15]

Control-Home and Meta-< move the insertion cursor to the beginning of the text and clear any selection in the widget. Control-Shift-Home moves the insertion cursor to the beginning of the text and also extends the selection to that point.

[16]

Control-End and Meta-> move the insertion cursor to the end of the text and clear any selection in the widget. Control-Shift-End moves the cursor to the end of the text and extends the selection to that point.

[17]

The Select key and Control-Space set the selection anchor to the position of the insertion cursor. They do not affect the current selection. Shift-Select and Control-Shift-Space adjust the selection to the current position of the insertion cursor, selecting from the anchor to the insertion cursor if there was not any selection previously.

[18]

Control-/ selects the entire contents of the widget.

[19]

Control-\ clears any selection in the widget.

[20]

The F16 key (labelled Copy on many Sun workstations) or Meta-w copies the selection in the widget to the clipboard, if there is a selection. This action is carried out by the command tk_textCopy.

[21]

The F20 key (labelled Cut on many Sun workstations) or Control-w copies the selection in the widget to the clipboard and deletes the selection. This action is carried out by the command tk_textCut. If there is no selection in the widget then these keys have no effect.

[22]

The F18 key (labelled Paste on many Sun workstations) or Control-y inserts the contents of the clipboard at the position of the insertion cursor. This action is carried out by the command tk_textPaste.

[23]

The Delete key deletes the selection, if there is one in the widget. If there is no selection, it deletes the character to the right of the insertion cursor.

[24]

Backspace and Control-h delete the selection, if there is one in the widget. If there is no selection, they delete the character to the left of the insertion cursor.

[25]

Control-d deletes the character to the right of the insertion cursor.

[26]

Meta-d deletes the word to the right of the insertion cursor.

[27]

Control-k deletes from the insertion cursor to the end of its line; if the insertion cursor is already at the end of a line, then Control-k deletes the newline character.

[28]

Control-o opens a new line by inserting a newline character in front of the insertion cursor without moving the insertion cursor.

[29]

Meta-backspace and Meta-Delete delete the word to the left of the insertion cursor.

[30]

Control-x deletes whatever is selected in the text widget after copying it to the clipboard.

[31]

Control-t reverses the order of the two characters to the right of the insertion cursor.

[32]

Control-z 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

pack [text .t]
.t insert 1.0 "aaaa\nbbbb\ncccc\nbbbb\naaaa\n"
.t search -regexp -- {(a+|b+\nc+\nb+)+\na+} 1.0

pack [text .t]
.t insert 1.0 "aaaa\nbbbb\nbbbb\nbbbb\nbbbb\n"
.t search -regexp -backward -- {b+\n|a+\n(b+\n)+} end

SEE ALSO

entry(3tk), scrollbar(3tk)

KEYWORDS

text, widget, tkvars