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-rw-r--r--doc/text.n1013
1 files changed, 786 insertions, 227 deletions
diff --git a/doc/text.n b/doc/text.n
index ac61d41..cd595c8 100644
--- a/doc/text.n
+++ b/doc/text.n
@@ -6,7 +6,7 @@
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.so man.macros
-.TH text n 8.4 Tk "Tk Built-In Commands"
+.TH text n 8.5 Tk "Tk Built-In Commands"
.BS
'\" Note: do not modify the .SH NAME line immediately below!
.SH NAME
@@ -14,11 +14,9 @@ text, tk_textCopy, tk_textCut, tk_textPaste \- Create and manipulate text widget
.SH SYNOPSIS
.nf
\fBtext\fR \fIpathName \fR?\fIoptions\fR?
-.VS 8.4
\fBtk_textCopy\fR \fIpathName\fR
\fBtk_textCut\fR \fIpathName\fR
\fBtk_textPaste\fR \fIpathName\fR
-.VE 8.4
.SO
\-background \-highlightthickness \-relief
\-borderwidth \-insertbackground \-selectbackground
@@ -31,20 +29,38 @@ text, tk_textCopy, tk_textCut, tk_textPaste \- Create and manipulate text widget
.SE
.SH "WIDGET-SPECIFIC OPTIONS"
.OP \-autoseparators autoSeparators AutoSeparators
-.VS 8.4
Specifies a boolean that says whether separators are automatically
inserted in the undo stack. Only meaningful when the \fB\-undo\fR
option is true.
-.VE 8.4
+.OP \-blockcursor blockCursor BlockCursor
+.VS 8.5
+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.
+.VE 8.5
+.OP \-endline endLine EndLine
+.VS 8.5
+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.
+.VE 8.5
.OP \-height height Height
Specifies the desired height for the window, in units of characters
in the font given by the \fB\-font\fR option.
Must be at least one.
+.OP \-inactiveselectbackground inactiveSelectBackground Foreground
+.VS 8.5
+Specifies the colour to use for the selection (the \fBsel\fR tag) when
+the window does not have the input focus. If empty, \fB{}\fR, then no
+selection is shown when the window does not have the focus.
+.VE 8.5
.OP \-maxundo maxUndo MaxUndo
-.VS 8.4
Specifies the maximum number of compound undo actions on the undo
stack. A zero or a negative value imply an unlimited undo stack.
-.VE 8.4
.OP \-spacing1 spacing1 Spacing1
Requests additional space above each text line in the widget,
using any of the standard forms for screen distances.
@@ -66,6 +82,15 @@ If a line wraps, this option only applies to the last line
on the display.
This option may be overridden with \fB\-spacing3\fR options in
tags.
+.OP \-startline startLine StartLine
+.VS 8.5
+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.
+.VE 8.5
.OP \-state state State
Specifies one of two states for the text: \fBnormal\fR or \fBdisabled\fR.
If the text is disabled then characters may not be inserted or deleted
@@ -89,36 +114,55 @@ 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, \fB\-tabs {2c left 4c 6c center}\fR creates three
-tab stops at two-centimeter intervals; the first two use left
+For example,
+.QW "\fB\-tabs {2c left 4c 6c center}\fR"
+creates three tab stops at two-centimeter intervals; the first two use left
justification and the third uses center justification.
+.RS
+.PP
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
+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 \fBtabs\fR option may be overridden by \fB\-tabs\fR
options in tags.
+.PP
If no \fB\-tabs\fR option is specified, or if it is specified as
an empty list, then Tk uses default tabs spaced every eight
-(average size) characters.
+(average size) characters. To achieve a different standard spacing,
+for example every 4 characters, simply configure the widget with
+.QW "\fB\-tabs \N'34'[expr {4 * [font measure $font 0]}] left\N'34' \-tabstyle wordprocessor\fR" .
+.RE
+.OP \-tabstyle tabStyle 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 \fBtabular\fR (the
+default) or \fBwordprocessor\fR. Note that tabs are interpreted as they
+are encountered in the text. If the tab style is \fBtabular\fR then the
+\fIn\fR'th tab character in the line's text will be associated with
+the \fIn\fR'th
+tab stop defined for that line. If the tab character's x coordinate
+falls to the right of the \fIn\fR'th tab stop, then a gap of a single space
+will be inserted as a fallback. If the tab style is \fBwordprocessor\fR
+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 \fBtabstyle\fR option may be overridden
+by \fB\-tabstyle\fR options in tags.
.OP \-undo undo Undo
-.VS 8.4
Specifies a boolean that says whether the undo mechanism is active or
not.
-.VE 8.4
.OP \-width width Width
Specifies the desired width for the window in units of characters
in the font given by the \fB\-font\fR option.
-If the font doesn't have a uniform width then the width of the
-character ``0'' is used in translating from character units to
-screen units.
+If the font does not have a uniform width then the width of the character
+.QW 0
+is used in translating from character units to screen units.
.OP \-wrap wrap 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 \fBnone\fR or \fBchar\fR or \fBword\fR.
A wrap mode of \fBnone\fR means that each line of text appears as
-exactly one line on the screen; extra characters that don't fit
+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.
@@ -149,7 +193,8 @@ and mouse button presses occur in particular ranges of the text.
See \fBTAGS\fR below for more details.
.PP
The second form of annotation consists of floating markers in the text
-called "marks".
+called
+.QW marks .
Marks are used to keep track of various interesting positions in the
text as it is edited.
See \fBMARKS\fR below for more details.
@@ -162,10 +207,14 @@ The fourth form of annotation allows Tk images to be embedded in a text
widget.
See \fBEMBEDDED IMAGES\fR below for more details.
.PP
-.VS 8.4
The text widget also has a built-in undo/redo mechanism.
See \fBTHE UNDO MECHANISM\fR below for more details.
-.VE 8.4
+.PP
+.VS 8.5
+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 \fBPEER WIDGETS\fR below for more details.
+.VE 8.5
.SH INDICES
.PP
Many of the widget commands for texts take one or more indices
@@ -181,6 +230,20 @@ Where \fIbase\fR gives a starting point and the \fImodifier\fRs
adjust the index from the starting point (e.g. move forward or
backward one character). Every index must contain a \fIbase\fR,
but the \fImodifier\fRs are optional.
+.VS 8.5
+Most modifiers (as documented below) allow
+an optional submodifier. Valid submodifiers are \fBany\fR
+and \fBdisplay\fR. 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 \fImodifier\fR. Typically the \fBdisplay\fR
+submodifier adjusts the meaning of the following \fImodifier\fR 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 \fIcount\fR
+is used as part of a modifier, it can be positive or negative, so
+.QW "\fIbase\fR \- \-3 lines"
+is perfectly valid (and equivalent to
+.QW "\fIbase\fR +3lines" ).
+.VE 8.5
.PP
The \fIbase\fR for an index must have one of the following forms:
.TP 12
@@ -227,82 +290,163 @@ Indicates the position of the embedded image whose name is
This form generates an error if there is no embedded image
by the given name.
.PP
-If the \fIbase\fP could match more than one of the above forms, such
-as a \fImark\fP and \fIimageName\fP both having the same value, then
+If the \fIbase\fR could match more than one of the above forms, such
+as a \fImark\fR and \fIimageName\fR 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 \fBchars\fR and \fBwordend\fR
may be abbreviated as long as the abbreviation is unambiguous.
.TP
-\fB+ \fIcount\fB chars\fR
-Adjust the index forward by \fIcount\fR characters, moving to later
-lines in the text if necessary. If there are fewer than \fIcount\fR
-characters in the text after the current index, then set the index
-to the last character in the text.
-Spaces on either side of \fIcount\fR are optional.
-.TP
-\fB\- \fIcount\fB chars\fR
+\fB+ \fIcount\fR ?\fIsubmodifier\fR? \fBchars\fR
+.VS 8.5
+Adjust the index forward by \fIcount\fR characters, moving to later lines
+in the text if necessary. If there are fewer than \fIcount\fR characters
+in the text after the current index, then set the index to the last index
+in the text. Spaces on either side of \fIcount\fR are optional. If the
+\fBdisplay\fR submodifier is given, elided characters are skipped over
+without being counted. If \fBany\fR 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 \fBindices\fR
+for details). This behaviour may be changed in a future major release,
+so if you need an index count, you are encouraged to use \fBindices\fR
+instead wherever possible.
+.VE 8.5
+.TP
+\fB\- \fIcount\fR ?\fIsubmodifier\fR? \fBchars\fR
Adjust the index backward by \fIcount\fR characters, moving to earlier
lines in the text if necessary. If there are fewer than \fIcount\fR
-characters in the text before the current index, then set the index
-to the first character in the text.
-Spaces on either side of \fIcount\fR are optional.
-.TP
-\fB+ \fIcount\fB lines\fR
+characters in the text before the current index, then set the index to
+.VS 8.5
+the first index in the text (1.0). Spaces on either side of \fIcount\fR
+are optional. If the \fBdisplay\fR submodifier is given, elided
+characters are skipped over without being counted. If \fBany\fR 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 \fBindices\fR for details). This behaviour may be
+changed in a future major release, so if you need an index count, you are
+encouraged to use \fBindices\fR instead wherever possible.
+.VE 8.5
+.TP
+\fB+ \fIcount\fR ?\fIsubmodifier\fR? \fBindices\fR
+.VS 8.5
+Adjust the index forward by \fIcount\fR index positions, moving to later
+lines in the text if necessary. If there are fewer than \fIcount\fR
+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
+\fIcount\fR are optional. Note that an index position is either a single
+character or a single embedded image or embedded window. If the
+\fBdisplay\fR submodifier is given, elided indices are skipped over
+without being counted. If \fBany\fR is given, then all indices are
+counted; this is also the default behaviour if no modifier is given.
+.VE 8.5
+.TP
+\fB\- \fIcount\fR ?\fIsubmodifier\fR? \fBindices\fR
+.VS 8.5
+Adjust the index backward by \fIcount\fR index positions, moving to
+earlier lines in the text if necessary. If there are fewer than
+\fIcount\fR 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 \fIcount\fR are optional. If the \fBdisplay\fR
+submodifier is given, elided indices are skipped over without being
+counted. If \fBany\fR is given, then all indices are counted; this is
+also the default behaviour if no modifier is given.
+.VE 8.5
+.TP
+\fB+ \fIcount\fR ?\fIsubmodifier\fR? \fBlines\fR
+.VS 8.5
Adjust the index forward by \fIcount\fR lines, retaining the same
character position within the line. If there are fewer than \fIcount\fR
-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
+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 \fIcount\fR are optional.
-.TP
-\fB\- \fIcount\fB lines\fR
-Adjust the index backward by \fIcount\fR lines, retaining the same
-character position within the line. If there are fewer than \fIcount\fR
-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 \fIcount\fR are optional.
-.TP
-\fBlinestart\fR
-Adjust the index to refer to the first character on the line.
-.TP
-\fBlineend\fR
-Adjust the index to refer to the last character on the line (the newline).
-.TP
-\fBwordstart\fR
+character of the line (the newline). Spaces on either side of
+\fIcount\fR are optional. If the \fBdisplay\fR submodifier is given,
+then each visual display line is counted separately. Otherwise, if
+\fBany\fR (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.
+.VE 8.5
+.TP
+\fB\- \fIcount\fR ?\fIsubmodifier\fR? \fBlines\fR
+.VS 8.5
+Adjust the index backward by \fIcount\fR logical lines, retaining the
+same character position within the line. If there are fewer than
+\fIcount\fR 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 \fIcount\fR are optional. If the \fBdisplay\fR submodifier is given,
+then each visual display line is counted separately. Otherwise, if
+\fBany\fR (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.
+.VE 8.5
+.TP
+?\fIsubmodifier\fR? \fBlinestart\fR
+.VS 8.5
+Adjust the index to refer to the first index on the line. If the
+\fBdisplay\fR submodifier is given, this is the first index on the
+display line, otherwise on the logical line.
+.VE 8.5
+.TP
+?\fIsubmodifier\fR? \fBlineend\fR
+.VS 8.5
+Adjust the index to refer to the last index on the line (the
+newline). If the \fBdisplay\fR submodifier is given, this is the last
+index on the display line, otherwise on the logical line.
+.VE 8.5
+.TP
+?\fIsubmodifier\fR? \fBwordstart\fR
+.VS 8.5
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.
-.TP
-\fBwordend\fR
+that are letters, digits, or underscores, or a single character that is
+not one of these. If the \fBdisplay\fR submodifier is given, this only
+examines non-elided characters, otherwise all characters (elided or not)
+are examined.
+.VE 8.5
+.TP
+?\fIsubmodifier\fR? \fBwordend\fR
+.VS 8.5
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.
+word containing the current index. If the current index refers to the
+last character of the text then it is not modified. If the \fBdisplay\fR
+submodifier is given, this only examines non-elided characters, otherwise
+all characters (elided or not) are examined.
.PP
If more than one modifier is present then they are applied in
-left-to-right order. For example, the index ``\fBend \- 1 chars\fR''
+left-to-right order. For example, the index
+.QW "\fBend \- 1 chars\fR"
refers to the next-to-last character in the text and
-``\fBinsert wordstart \- 1 c\fR'' refers to the character just before
+.QW "\fBinsert wordstart \- 1 c\fR"
+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 ``\fB1.0 -1c +1c\fR'' refers to the
-index ``\fB2.0\fR''.
+the resulting index is constrained to be a valid index in the text
+widget. So, for example, the index
+.QW "\fB1.0 \-1c +1c\fR"
+refers to the index
+.QW \fB2.0\fR .
+.PP
+Where modifiers result in index changes by display lines, display chars
+or display indices, and the \fIbase\fR refers to an index inside an
+elided tag,
+that base index is considered to be equivalent to the first following
+non-elided index.
+.VE 8.5
.SH TAGS
.PP
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), \fB+\fR, or \fB\-\fR:
+avoid using the characters
+.QW " "
+(space), \fB+\fR, or \fB\-\fR:
these characters have special meaning in indices, so tags containing
-them can't be used as indices.
+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
@@ -315,16 +459,20 @@ 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
-``\fIpathName \fBtag raise\fR'' and ``\fIpathName \fBtag lower\fR''
+.QW "\fIpathName \fBtag raise\fR"
+and
+.QW "\fIpathName \fBtag lower\fR"
widget commands.
.PP
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
-\fBbackground\fR, \fBfont\fR, and \fBforeground\fR options for the
+\fB\-background\fR, \fB\-font\fR, and \fB\-foreground\fR options for the
text widget.
However, display options may be associated with individual tags
-using the ``\fIpathName \fBtag configure\fR'' widget command.
+using the
+.QW "\fIpathName \fBtag configure\fR"
+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:
@@ -338,7 +486,7 @@ It may have any of the forms accepted by \fBTk_GetColor\fR.
\fIBitmap\fR specifies a bitmap that is used as a stipple pattern
for the background.
It may have any of the forms accepted by \fBTk_GetBitmap\fR.
-If \fIbitmap\fR hasn't been specified, or if it is specified
+If \fIbitmap\fR has not been specified, or if it is specified
as an empty string, then a solid fill will be used for the
background.
.TP
@@ -352,16 +500,17 @@ it is ignored unless the \fB\-background\fR option
has been set for the tag.
.TP
\fB\-elide \fIboolean\fR
-\fIElide\fR specifies whether the data should be elided.
-Elided data is not displayed and takes no space on screen, but further
-on behaves just as normal data.
+\fIElide\fR 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.
.TP
\fB\-fgstipple \fIbitmap\fR
\fIBitmap\fR 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 \fBTk_GetBitmap\fR.
-If \fIbitmap\fR hasn't been specified, or if it is specified
+If \fIbitmap\fR has not been specified, or if it is specified
as an empty string, then a solid fill will be used.
.TP
\fB\-font \fIfontName\fR
@@ -374,15 +523,15 @@ foreground information such as underlines.
It may have any of the forms accepted by \fBTk_GetColor\fR.
.TP
\fB\-justify \fIjustify\fR
-If the first character of a display line has a tag for which this
+If the first non-elided character of a display line has a tag for which this
option has been specified, then \fIjustify\fR determines how to
justify the line.
It must be one of \fBleft\fR, \fBright\fR, or \fBcenter\fR.
If a line wraps, then the justification for each line on the
-display is determined by the first character of that display line.
+display is determined by the first non-elided character of that display line.
.TP
\fB\-lmargin1 \fIpixels\fR
-If the first character of a text line has a tag for which this
+If the first non-elided character of a text line has a tag for which this
option has been specified, then \fIpixels\fR specifies how
much the line should be indented from the left edge of the
window.
@@ -393,7 +542,7 @@ first line on the display; the \fB\-lmargin2\fR option controls
the indentation for subsequent lines.
.TP
\fB\-lmargin2 \fIpixels\fR
-If the first character of a display line has a tag for which this
+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
\fIpixels\fR specifies how much the line should be indented from
@@ -426,7 +575,7 @@ it is ignored unless the \fB\-background\fR option
has been set for the tag.
.TP
\fB\-rmargin \fIpixels\fR
-If the first character of a display line has a tag for which this
+If the first non-elided character of a display line has a tag for which this
option has been specified, then \fIpixels\fR specifies how wide
a margin to leave between the end of the line and the right
edge of the window.
@@ -434,7 +583,7 @@ edge of the window.
distances.
This option is only used when wrapping is enabled.
If a text line wraps, the right margin for each line on the
-display is determined by the first character of that display
+display is determined by the first non-elided character of that display
line.
.TP
\fB\-spacing1 \fIpixels\fR
@@ -461,14 +610,22 @@ line on the display.
\fITabList\fR specifies a set of tab stops in the same form
as for the \fB\-tabs\fR option for the text widget. This
option only applies to a display line if it applies to the
-first character on that display line.
+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 \fB\-tags\0{\0}\fR, then it requests
-default 8-character tabs as described for the \fBtags\fR
+default 8-character tabs as described for the \fB\-tags\fR
widget option.
.TP
+\fB\-tabstyle \fIstyle\fR
+\fIStyle\fR specifies either the \fItabular\fR or
+\fIwordprocessor\fR 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).
+.TP
\fB\-underline \fIboolean\fR
\fIBoolean\fR specifies whether or not to draw an underline underneath
characters.
@@ -485,7 +642,7 @@ for the text widget.
If a character has several tags associated with it, and if their
display options conflict, then the options of the highest priority
tag are used.
-If a particular display option hasn't been specified for a
+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.
@@ -500,17 +657,29 @@ 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 \fBtag bind\fR widget
-command below.
+For details, see the description of the
+.QW "\fIpathName \fBtag bind\fR"
+widget command below.
+.VS 8.5
+Tag bindings are shared between all peer widgets
+(including any bindings for the special \fBsel\fR tag).
+.VE 8.5
.PP
The third use for tags is in managing the selection.
See \fBTHE SELECTION\fR below.
+.VS 8.5
+With the exception of the special \fBsel\fR
+tag, all tags are shared between peer text widgets, and may be
+manipulated on an equal basis from any such widget. The \fBsel\fR
+tag exists separately and independently in each peer text widget (but
+any tag bindings to \fBsel\fR are shared).
+.VE 8.5
.SH MARKS
.PP
The second form of annotation in text widgets is a mark.
Marks are used for remembering particular places in a text.
They are something like tags, in that they have names and
-they refer to places in the file, but a mark isn't associated
+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
@@ -520,12 +689,15 @@ 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 ``\fIpathName \fBmark\fR'' widget
+Marks may be manipulated with the
+.QW "\fIpathName \fBmark\fR"
+widget
command, and their current locations may be determined by using the
mark name as an index in widget commands.
.PP
-Each mark also has a "gravity", which is either \fBleft\fR or
-\fBright\fR.
+Each mark also has a
+.QW gravity ,
+which is either \fBleft\fR or \fBright\fR.
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
@@ -549,6 +721,11 @@ exception: \fBcurrent\fR 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.
+.VS 8.5
+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.
+.VE 8.5
.SH "EMBEDDED WINDOWS"
.PP
The third form of annotation in text widgets is an embedded window.
@@ -562,17 +739,25 @@ parent).
The embedded window's position on the screen will be updated as the
text is modified or scrolled, and it will be mapped and unmapped as
it moves into and out of the visible area of the text widget.
-Each embedded window occupies one character's worth of index space
+Each embedded window occupies one
+.VS 8.5
+unit's
+.VE 8.5
+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.
+.VS 8.5
+Similarly if the text widget as a whole is deleted, then the window is
+destroyed.
+.VE 8.5
.PP
When an embedded window is added to a text widget with the
-\fBwindow create\fR widget command, several configuration
+\fIpathName \fBwindow create\fR widget command, several configuration
options may be associated with it.
-These options may be modified later with the \fBwindow configure\fR
+These options may be modified later with the \fIpathName \fBwindow configure\fR
widget command.
The following options are currently supported:
.TP
@@ -594,6 +779,11 @@ this script will be evaluated when the annotation is about to
be displayed on the screen.
\fIScript\fR must create a window for the annotation and return
the name of that window as its result.
+.VS 8.5
+Two substitutions will be performed in \fIscript\fR before evaluation.
+\fI%W\fR will be substituted by the name of the parent text widget,
+and \fI%%\fR will be substituted by a single \fI%\fR.
+.VE 8.5
If the annotation's window should ever be deleted, \fIscript\fR
will be evaluated again the next time the annotation is displayed.
.TP
@@ -618,6 +808,14 @@ stretched.
.TP
\fB\-window \fIpathName\fR
Specifies the name of a window to display in the annotation.
+.VS 8.5
+Note that if a \fIpathName\fR has been set, then later configuring a
+window to the empty string will not delete the widget corresponding to
+the old \fIpathName\fR. Rather it will remove the association between
+the old \fIpathName\fR and the text widget. If multiple peer widgets
+are in use, it is usually simpler to use the \fB\-create\fR option if
+embedded windows are desired in each peer.
+.VE 8.5
.SH "EMBEDDED IMAGES"
.PP
The final form of annotation in text widgets is an embedded image.
@@ -628,30 +826,34 @@ and a particular image may be embedded in multiple places in the same
text widget.
The embedded image's position on the screen will be updated as the
text is modified or scrolled.
-Each embedded image occupies one character's worth of index space
+Each embedded image occupies one
+.VS 8.5
+unit's
+.VE 8.5
+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 \fBimage create\fP.
+when the image is inserted into the text widget with \fIpathName \fBimage create\fR.
If the range of text containing the embedded image is deleted then
that copy of the image is removed from the screen.
.PP
-When an embedded image is added to a text widget with the \fBimage
+When an embedded image is added to a text widget with the \fIpathName \fBimage
create\fR 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 \fB\-name\fP option
-(described below). If the \fB\-name\fP option is not provided, the
-\fB\-image\fP name is used instead. If the \fIimageName\fP is already
+instance. The name is taken to be the value of the \fB\-name\fR option
+(described below). If the \fB\-name\fR option is not provided, the
+\fB\-image\fR name is used instead. If the \fIimageName\fR is already
in use in the text widget, then \fB#\fInn\fR is added to the end of the
-\fIimageName\fP, where \fInn\fP is an arbitrary integer. This insures
-the \fIimageName\fP is unique.
-Once this name is assigned to this instance of the image, it does not
-change, even though the \fB\-image\fP or \fB\-name\fP values can be changed
-with \fBimage configure\fP.
+\fIimageName\fR, where \fInn\fR is an arbitrary integer. This insures
+the \fIimageName\fR is unique.
+Once this name is assigned to this instance of the image, it does not
+change, even though the \fB\-image\fR or \fB\-name\fR values can be changed
+with \fIpathName \fBimage configure\fR.
.PP
When an embedded image is added to a text widget with the
-\fBimage create\fR widget command, several configuration
+\fIpathName \fBimage create\fR widget command, several configuration
options may be associated with it.
-These options may be modified later with the \fBimage configure\fR
+These options may be modified later with the \fIpathName \fBimage configure\fR
widget command.
The following options are currently supported:
.TP
@@ -667,13 +869,13 @@ of the line).
.TP
\fB\-image \fIimage\fR
Specifies the name of the Tk image to display in the annotation.
-If \fIimage\fP is not a valid Tk image, then an error is returned.
+If \fIimage\fR is not a valid Tk image, then an error is returned.
.TP
\fB\-name \fIImageName\fR
Specifies the name by which this image instance may be referenced in
-the text widget. If \fIImageName\fP is not supplied, then the
+the text widget. If \fIImageName\fR is not supplied, then the
name of the Tk image is used instead.
-If the \fIimageName\fP is already in use, \fI#nn\fP is appended to
+If the \fIimageName\fR is already in use, \fI#nn\fR is appended to
the end of the name as described above.
.TP
\fB\-padx \fIpixels\fR
@@ -702,23 +904,35 @@ If the selection is claimed away by another application or by another
window within this application, then the \fBsel\fR tag will be removed
from all characters in the text.
.IP [4]
-Whenever the \fBsel\fR tag range changes a virtual event
+Whenever the \fBsel\fR tag range changes a virtual event
\fB<<Selection>>\fR is generated.
.PP
The \fBsel\fR tag is automatically defined when a text widget is
-created, and it may not be deleted with the ``\fIpathName \fBtag delete\fR''
+created, and it may not be deleted with the
+.QW "\fIpathName \fBtag delete\fR"
widget command. Furthermore, the \fBselectBackground\fR,
\fBselectBorderWidth\fR, and \fBselectForeground\fR options for
the text widget are tied to the \fB\-background\fR,
\fB\-borderwidth\fR, and \fB\-foreground\fR options for the \fBsel\fR
tag: changes in either will automatically be reflected in the
other.
+.VS 8.5
+Also the
+\fB\-inactiveselectbackground\fR option for the text widget is used
+instead of \fB\-selectbackground\fR when the text widget does not have
+the focus. This allows programmatic control over the visualization of
+the \fBsel\fR tag for foreground and background windows, or to have
+\fBsel\fR not shown at all (when \fB\-inactiveselectbackground\fR is
+empty) for background windows. Each peer text widget has its own
+\fBsel\fR tag which can be separately configured and set.
+.VE 8.5
.SH "THE INSERTION CURSOR"
.PP
The mark named \fBinsert\fR has special significance in text widgets.
It is defined automatically when a text widget is created and it
-may not be unset with the ``\fIpathName \fBmark unset\fR'' widget
-command.
+may not be unset with the
+.QW "\fIpathName \fBmark unset\fR"
+widget command.
The \fBinsert\fR 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.
@@ -726,17 +940,18 @@ this point whenever the text widget has the input focus.
The text widget can keep track of changes to the content of the widget
by means of the modified flag. Inserting or deleting text will set
this flag. The flag can be queried, set and cleared programmatically
-as well. Whenever the flag changes state a \fB<<Modified>>\fR virtual
-event is generated. See the \fBedit modified\fR widget command for
+as well. Whenever the flag changes state a \fB<<Modified>>\fR virtual
+event is generated. See the \fIpathName \fBedit modified\fR widget command for
more details.
.SH "THE UNDO MECHANISM"
.PP
-.VS 8.4
The text widget has an unlimited undo and redo mechanism (when the
\fB\-undo\fR widget option is true) which records every insert and
delete action on a stack.
.PP
-Boundaries (called "separators") are inserted between edit actions. The
+Boundaries (called
+.QW 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
@@ -757,9 +972,70 @@ 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.
.PP
-See below for the \fBedit\fR widget command that controls the undo
+See below for the \fIpathName \fBedit\fR widget command that controls the undo
mechanism.
-.VE 8.4
+.SH "PEER WIDGETS"
+.PP
+.VS 8.5
+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.
+.PP
+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.
+.PP
+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.
+.PP
+All data and markup is shared, except for a few small details. First,
+the \fBsel\fR tag may be set and configured (in its display style)
+differently for each peer. Second, each peer has its own \fBinsert\fR
+and \fBcurrent\fR mark positions (but all other marks are shared).
+Third, embedded windows, which are arbitrary other widgets, cannot be
+shared between peers. This means the \fB\-window\fR option of embedded
+windows is independently set for each peer (it is advisable to use
+the \fB\-create\fR 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. \fB\-font\fR, etc) can be set independently,
+with the exception of \fB\-undo\fR, \fB\-maxUndo\fR, \fB\-autoSeparators\fR
+(i.e. all undo, redo and modified state issues are shared).
+.PP
+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
+.QW 1.0
+to
+.QW 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 \fIpeerName \fBindex end\fR may return quite different
+values in different peers. Similarly, commands like \fIpeerName \fBtag
+ranges\fR will not return index ranges outside that which is meaningful
+to the peer. The configuration options \fB\-startline\fR and
+\fB\-endline\fR may be used to control how much of the underlying data is
+contained in any given text widget.
+.PP
+Note that peers are really peers. Deleting the
+.QW original
+text widget will not cause any other peers to be deleted, or otherwise
+affected.
+.PP
+See below for the \fIpathName \fBpeer\fR widget command that controls the
+creation of peer widgets.
+.VE 8.5
.SH "WIDGET COMMAND"
.PP
The \fBtext\fR command creates a new Tcl command whose
@@ -795,7 +1071,7 @@ command.
\fIpathName \fBcompare\fR \fIindex1 op index2\fR
Compares the indices given by \fIindex1\fR and \fIindex2\fR according
to the relational operator given by \fIop\fR, and returns 1 if
-the relationship is satisfied and 0 if it isn't.
+the relationship is satisfied and 0 if it is not.
\fIOp\fR must be one of the operators <, <=, ==, >=, >, or !=.
If \fIop\fR is == then 1 is returned if the two indices refer to
the same character, if \fIop\fR is < then 1 is returned if \fIindex1\fR
@@ -815,6 +1091,74 @@ modifies the given widget option(s) to have the given value(s); in
this case the command returns an empty string.
\fIOption\fR may have any of the values accepted by the \fBtext\fR
command.
+.VS 8.5
+.TP
+\fIpathName \fBcount\fR \fI?options\fR? \fIindex1 index2\fR
+Counts the number of relevant things between the two indices.
+If \fIindex1\fR is after \fIindex2\fR, 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 \fB\-chars\fR,
+\fB\-displaychars\fR, \fB\-displayindices\fR, \fB\-displaylines\fR,
+\fB\-indices\fR, \fB\-lines\fR, \fB\-xpixels\fR and \fB\-ypixels\fR. The
+default value, if no option is specified, is \fB\-indices\fR. There is an
+additional possible option \fB\-update\fR 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
+\fI\-ypixels\fR count (which, if \fB\-update\fR is not given, will use the text
+widget's current cached value for each line). The count options are
+interpreted as follows:
+.RS
+.IP \fB\-chars\fR
+count all characters, whether elided or not. Do not count
+embedded windows or images.
+.IP \fB\-displaychars\fR
+count all non-elided characters.
+.IP \fB\-displayindices\fR
+count all non-elided characters, windows and images.
+.IP \fB\-displaylines\fR
+count all display lines (i.e. counting one for each
+time a line wraps) from the line of the first index up to, but not
+including the display line of the second index. Therefore if they are
+both on the same display line, zero will be returned. By definition
+displaylines are visible and therefore this only counts portions of
+actual visible lines.
+.IP \fB\-indices\fR
+count all characters and embedded windows or images (i.e.
+everything which counts in text-widget index space), whether they are
+elided or not.
+.IP \fB\-lines\fR
+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.
+.IP \fB\-xpixels\fR
+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
+.QW ".text count \-xpixels \N'34'${line}.0\N'34' \N'34'${line}.0 lineend\N'34'" .
+.IP \fB\-ypixels\fR
+count the number of vertical pixels from the first pixel
+of the first index to (but not including) the first pixel of the second
+index. If both indices are on the same display line, zero will be
+returned. To count the total number of vertical pixels in the text
+widget, use
+.QW ".text count \-ypixels 1.0 end" ,
+and to ensure this is up to date, use
+.QW ".text count \-update \-ypixels 1.0 end" .
+.PP
+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
+.QW ".text count \-xpixels \-ypixels 1.3 4.5"
+is perfectly valid and will return a list of two elements.
+.RE
+.VE 8.5
.TP
\fIpathName \fBdebug \fR?\fIboolean\fR?
If \fIboolean\fR is specified, then it must have one of the true or
@@ -830,13 +1174,13 @@ 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.
+.RS
.PP
-.VS 8.4
When debugging is turned on, the drawing routines of the text widget
set the global variables \fBtk_textRedraw\fR and \fBtk_textRelayout\fR
to the lists of indices that are redrawn. The values of these variables
are tested by Tk's test suite.
-.VE 8.4
+.RE
.TP
\fIpathName \fBdelete \fIindex1 \fR?\fIindex2 ...\fR?
Delete a range of characters from the text.
@@ -844,23 +1188,21 @@ If both \fIindex1\fR and \fIindex2\fR are specified, then delete
all the characters starting with the one given by \fIindex1\fR
and stopping just before \fIindex2\fR (i.e. the character at
\fIindex2\fR is not deleted).
-If \fIindex2\fR doesn't specify a position later in the text
+If \fIindex2\fR does not specify a position later in the text
than \fIindex1\fR then no characters are deleted.
-If \fIindex2\fR isn't specified then the single character at
+If \fIindex2\fR is not specified then the single character at
\fIindex1\fR 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.
-.VS 8.4
If more indices are given, multiple ranges of text will be deleted.
All indices are first checked for validity before any deletions are made.
They are sorted and the text is removed from the last range to the
-first range to deleted text does not cause an undesired index shifting
+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.
-.VE 8.4
.TP
\fIpathName \fBdlineinfo \fIindex\fR
Returns a list with five elements describing the area occupied
@@ -893,10 +1235,10 @@ in the following format:
.RS
\fIkey1 value1 index1 key2 value2 index2\fR ...
.LP
-The possible \fIkey\fP values are \fBtext\fP, \fBmark\fP,
-\fBtagon\fP, \fBtagoff\fP, \fBimage\fP, and \fBwindow\fP. The corresponding
-\fIvalue\fP is the text, mark name, tag name, image name, or window name.
-The \fIindex\fP information is the index of the
+The possible \fIkey\fR values are \fBtext\fR, \fBmark\fR,
+\fBtagon\fR, \fBtagoff\fR, \fBimage\fR, and \fBwindow\fR. The corresponding
+\fIvalue\fR is the text, mark name, tag name, image name, or window name.
+The \fIindex\fR 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:
@@ -909,7 +1251,7 @@ This is the default.
Instead of returning the information as the result of the dump operation,
invoke the \fIcommand\fR on each element of the text widget within the range.
The command has three arguments appended to it before it is evaluated:
-the \fIkey\fP, \fIvalue\fP, and \fIindex\fP.
+the \fIkey\fR, \fIvalue\fR, and \fIindex\fR.
.TP
\fB\-image\fR
Include information about images in the dump results.
@@ -919,7 +1261,7 @@ Include information about marks in the dump results.
.TP
\fB\-tag\fR
Include information about tag transitions in the dump results. Tag
-information is returned as \fBtagon\fP and \fBtagoff\fP elements that
+information is returned as \fBtagon\fR and \fBtagoff\fR elements that
indicate the begin and end of each range of each tag, respectively.
.TP
\fB\-text\fR
@@ -939,7 +1281,6 @@ window by its index position to get more information.
.RE
.TP
\fIpathName \fBedit \fIoption \fR?\fIarg arg ...\fR?
-.VS 8.4
This command controls the undo mechanism and the modified flag. The
exact behavior of the command depends on the \fIoption\fR argument
that follows the \fBedit\fR argument. The following forms of the
@@ -972,9 +1313,8 @@ recorded on the undo stack in between two separators. Generates an
error when the undo stack is empty. Does nothing when the \fB\-undo\fR
option is false.
.RE
-.VE 8.4
.TP
-\fIpathName \fBget \fIindex1 \fR?\fIindex2 ...\fR?
+\fIpathName \fBget\fR \fI?\-displaychars?\fR \fI\-\- index1\fR ?\fIindex2 ...\fR?
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 \fIindex1\fR and ending just before
@@ -987,11 +1327,14 @@ is past the end of the file or \fIindex2\fR is less than or equal
to \fIindex1\fR) then an empty string is returned.
If the specified range contains embedded windows, no information
about them is included in the returned string.
-.VS 8.4
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 \fBget\fR.
-.VE 8.4
+the list. The ranges are returned in the order passed to \fIpathName \fBget\fR.
+.VS 8.5
+If the \fB\-displaychars\fR 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.
+.VE 8.5
.TP
\fIpathName \fBimage \fIoption \fR?\fIarg arg ...\fR?
This command is used to manipulate embedded images.
@@ -1058,7 +1401,7 @@ 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 \fIchars\fR\-\fItagList\fR argument pairs are present,
-they produce the same effect as if a separate \fBinsert\fR widget
+they produce the same effect as if a separate \fIpathName \fBinsert\fR widget
command had been issued for each pair, in order.
The last \fItagList\fR argument may be omitted.
.TP
@@ -1088,11 +1431,11 @@ If \fIindex\fR 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 \fBmark next\fP operation can be used to
+These semantics mean that the \fBmark next\fR 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 \fBdump\fP operation.
-If a mark has been set to the special \fBend\fP index,
-then it appears to be \fIafter\fP \fBend\fP with respect to the \fBmark next\fP operation.
+as the mark information returned by the \fIpathName \fBdump\fR operation.
+If a mark has been set to the special \fBend\fR index,
+then it appears to be \fIafter\fR \fBend\fR with respect to the \fIpathName \fBmark next\fR operation.
An empty string is returned if there are no marks after \fIindex\fR.
.TP
\fIpathName \fBmark previous \fIindex\fR
@@ -1103,25 +1446,61 @@ If \fIindex\fR is the name of a mark, then the search for
the next mark begins immediately before that mark.
This can still return a mark at the same position if
there are multiple marks at the same index.
-These semantics mean that the \fBmark previous\fP operation can be used to
+These semantics mean that the \fIpathName \fBmark previous\fR 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 \fBdump\fP operation.
+as the mark information returned by the \fIpathName \fBdump\fR operation.
An empty string is returned if there are no marks before \fIindex\fR.
.TP
\fIpathName \fBmark set \fImarkName index\fR
Sets the mark named \fImarkName\fR to a position just before the
character at \fIindex\fR.
If \fImarkName\fR already exists, it is moved from its old position;
-if it doesn't exist, a new mark is created.
+if it does not exist, a new mark is created.
This command returns an empty string.
.TP
\fIpathName \fBmark unset \fImarkName \fR?\fImarkName markName ...\fR?
Remove the mark corresponding to each of the \fImarkName\fR arguments.
The removed marks will not be usable in indices and will not be
-returned by future calls to ``\fIpathName \fBmark names\fR''.
+returned by future calls to
+.QW "\fIpathName \fBmark names\fR" .
This command returns an empty string.
.RE
.TP
+\fIpathName \fBpeer\fR \fIoption args\fR
+.VS 8.5
+This command is used to create and query widget peers. It has
+two forms, depending on \fIoption\fR:
+.RS
+.TP
+\fIpathName \fBpeer create \fInewPathName\fR ?\fIoptions\fR?
+Creates a peer text widget with the given \fInewPathName\fR, and any
+optional standard configuration options (as for the \fItext\fR 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.
+.TP
+\fIpathName \fBpeer names\fR
+Returns a list of peers of this widget (this does not include the widget
+itself). The order within this list is undefined.
+.RE
+.TP
+\fIpathName \fBreplace\fR \fIindex1 index2 chars\fR ?\fItagList chars tagList ...\fR?
+Replaces the range of characters between \fIindex1\fR and \fIindex2\fR
+with the given characters and tags. See the section on \fIpathName
+\fBinsert\fR for an explanation of the handling of the \fItagList...\fR
+arguments, and the section on \fIpathName
+\fBdelete\fR for an explanation of the handling of the indices. If
+\fIindex2\fR corresponds to an index earlier in the text than
+\fIindex1\fR, an error will be generated.
+.RS
+.PP
+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.
+.RE
+.VE 8.5
+.TP
\fIpathName \fBscan\fR \fIoption args\fR
This command is used to implement scanning on texts. It has
two forms, depending on \fIoption\fR:
@@ -1129,14 +1508,14 @@ two forms, depending on \fIoption\fR:
.TP
\fIpathName \fBscan mark \fIx y\fR
Records \fIx\fR and \fIy\fR and the current view in the text window,
-for use in conjunction with later \fBscan dragto\fR commands.
+for use in conjunction with later \fIpathName \fBscan dragto\fR commands.
Typically this command is associated with a mouse button press in
the widget. It returns an empty string.
.TP
\fIpathName \fBscan dragto \fIx y\fR
This command computes the difference between its \fIx\fR and \fIy\fR
arguments and the \fIx\fR and \fIy\fR arguments to the last
-\fBscan mark\fR command for the widget.
+\fIpathName \fBscan mark\fR 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
@@ -1161,7 +1540,13 @@ This is the default.
\fB\-backwards\fR
The search will proceed backward through the text, finding the
matching range closest to \fIindex\fR whose first character
-is before \fIindex\fR.
+is before \fIindex\fR
+.VS 8.5
+(it is not allowed to be at \fIindex\fR). Note that, for a variety of
+reasons, backwards searches can be substantially slower than forwards
+searches (particularly when using \fB\-regexp\fR), so it is recommended
+that performance-critical code use forward searches.
+.VE 8.5
.TP
\fB\-exact\fR
Use exact matching: the characters in the matching range must be
@@ -1172,6 +1557,23 @@ This is the default.
Treat \fIpattern\fR as a regular expression and match it against
the text using the rules for regular expressions (see the \fBregexp\fR
command for details).
+.VS 8.5
+The default matching automatically passes
+both the \fB\-lineanchor\fR and \fB\-linestop\fR options
+to the regexp engine (unless \fB\-nolinestop\fR is used), so that
+\fI^$\fR match beginning and end of line, and \fI.\fR, \fI[^\fR
+sequences will never match the newline character \fI\en\fR.
+.VE 8.5
+.TP
+\fB\-nolinestop\fR
+.VS 8.5
+This allows \fI.\fR and \fI[^\fR sequences to match the newline
+character \fI\en\fR, which they will otherwise not do (see the \fBregexp\fR
+command for details). This option is only meaningful if \fB\-regexp\fR
+is also given, and an error will be thrown otherwise. For example,
+to match the entire text, use
+.QW "\fIpathName \fBsearch \-nolinestop \-regexp\fR \N'34'.*\N'34' 1.0" .
+.VE 8.5
.TP
\fB\-nocase\fR
Ignore case differences between the pattern and the text.
@@ -1185,6 +1587,55 @@ elided characters if \fB\-elide\fR is not given), this is equivalent to the
number of characters matched. In either case, the range \fImatchIdx\fR to
\fImatchIdx + $count chars\fR will return the entire matched text.
.TP
+\fB\-all\fR
+.VS 8.5
+Find all matches in the given range and return a list of the indices of
+the first character of each match. If a \fB\-count\fI varName\fR switch is
+given, then \fIvarName\fR 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 \fB\-all\fR behave very
+similarly to the Tcl command \fBregexp \-all\fR, in that overlapping
+matches are not normally returned. For example, applying an
+\fB\-all\fR search of the pattern
+.QW \ew+
+against
+.QW "hello there"
+will just match twice, once for each word, and matching
+.QW "Z[a\-z]+Z"
+against
+.QW ZooZooZoo
+will just match once.
+.VE 8.5
+.TP
+\fB\-overlap\fR
+.VS 8.5
+When performing \fB\-all\fR 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
+\fB\-overlap\fR search of the pattern
+.QW \ew+
+against
+.QW "hello there"
+will just match twice (i.e. no different to just \fB\-all\fR),
+but matching
+.QW Z[a\-z]+Z
+against
+.QW ZooZooZoo
+will now match twice.
+An error will be thrown if this switch is used without \fB\-all\fR.
+.VE 8.5
+.TP
+\fB\-strictlimits\fR
+.VS 8.5
+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 \fB\-strictlimits\fR flag,
+the entire matching range must lie inside the start and stop
+limits specified for the match to be valid.
+.VE 8.5
+.TP
\fB\-elide\fR
Find elided (hidden) text as well. By default only displayed text is
searched.
@@ -1193,12 +1644,15 @@ searched.
This switch has no effect except to terminate the list of switches:
the next argument will be treated as \fIpattern\fR even if it starts
with \fB\-\fR.
-.LP
-The matching range must be entirely within a single line of text.
-For regular expression matching the newlines are removed from the ends
-of the lines before matching: use the \fB$\fR feature in regular
-expressions to match the end of a line.
-For exact matching the newlines are retained.
+.PP
+.VS 8.5
+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 \fB$\fR to match the end of a line, \fB^\fR to match
+the beginning of a line, and to control
+whether \fB.\fR is allowed to match a new-line.
+.VE 8.5
If \fIstopIndex\fR is specified, the search stops at that index:
for forward searches, no match at or after \fIstopIndex\fR will
be considered; for backward searches, no match earlier in the
@@ -1207,6 +1661,10 @@ If \fIstopIndex\fR 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 \fIstopIndex\fR is specified, no wrap-around will occur.
+This means that, for example, if the search is \fB\-forwards\fR
+but \fIstopIndex\fR is earlier in the text than \fIstartIndex\fR,
+nothing will ever be found. See \fBKNOWN BUGS\fR below for a number of
+minor limitations of the \fIpathName \fBsearch\fR command.
.RE
.TP
\fIpathName \fBsee \fIindex\fR
@@ -1229,7 +1687,7 @@ supported:
\fIpathName \fBtag add \fItagName index1 \fR?\fIindex2 index1 index2 ...\fR?
Associate the tag \fItagName\fR with all of the characters starting
with \fIindex1\fR and ending just before
-\fIindex2\fR (the character at \fIindex2\fR isn't tagged).
+\fIindex2\fR (the character at \fIindex2\fR is not tagged).
A single command may contain any number of \fIindex1\fR\-\fIindex2\fR
pairs.
If the last \fIindex2\fR is omitted then the single character at
@@ -1251,8 +1709,9 @@ on the syntax of \fIsequence\fR and the substitutions performed
on \fIscript\fR before invoking it.
If all arguments are specified then a new binding is created, replacing
any existing binding for the same \fIsequence\fR and \fItagName\fR
-(if the first character of \fIscript\fR is ``+'' then \fIscript\fR
-augments an existing binding rather than replacing it).
+(if the first character of \fIscript\fR is
+.QW +
+then \fIscript\fR augments an existing binding rather than replacing it).
In this case the return value is an empty string.
If \fIscript\fR is omitted then the command returns the \fIscript\fR
associated with \fItagName\fR and \fIsequence\fR (an error occurs
@@ -1262,9 +1721,8 @@ returns a list of all the sequences for which bindings have been
defined for \fItagName\fR.
.RS
.PP
-.VS
The only events for which bindings may be specified are those related
-to the mouse and keyboard (such as \fBEnter\fR, \fBLeave\fR,
+to the mouse and keyboard (such as \fBEnter\fR, \fBLeave\fR,
\fBButtonPress\fR, \fBMotion\fR, and \fBKeyPress\fR) or virtual events.
Event bindings for a text widget use the \fBcurrent\fR mark described
under \fBMARKS\fR above. An \fBEnter\fR event triggers for a tag when the tag
@@ -1277,7 +1735,6 @@ changed. Note that these events are different than \fBEnter\fR and
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.
-.VE
.PP
It is possible for the current character to have multiple tags,
and for each of them to have a binding for a particular event
@@ -1301,11 +1758,11 @@ for the window as a whole.
\fIpathName \fBtag cget\fR \fItagName option\fR
This command returns the current value of the option named \fIoption\fR
associated with the tag given by \fItagName\fR.
-\fIOption\fR may have any of the values accepted by the \fBtag configure\fR
-widget command.
+\fIOption\fR may have any of the values accepted by the \fIpathName \fBtag
+configure\fR widget command.
.TP
\fIpathName \fBtag configure \fItagName\fR ?\fIoption\fR? ?\fIvalue\fR? ?\fIoption value ...\fR?
-This command is similar to the \fBconfigure\fR widget command except
+This command is similar to the \fIpathName \fBconfigure\fR widget command except
that it modifies options associated with the tag given by \fItagName\fR
instead of modifying options for the overall text widget.
If no \fIoption\fR is specified, the command returns a list describing
@@ -1339,10 +1796,11 @@ Returns a list whose elements are the names of all the tags that
are active at the character position given by \fIindex\fR.
If \fIindex\fR 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 ``\fIpathName \fBtag\fR'' widget
-command but haven't been deleted by a ``\fIpathName \fBtag delete\fR''
-widget command, even if no characters are currently marked with
-the tag).
+that have been named in a
+.QW "\fIpathName \fBtag\fR"
+widget command but have not been deleted by a
+.QW "\fIpathName \fBtag delete\fR"
+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.
.TP
@@ -1398,11 +1856,11 @@ empty string is returned.
\fIpathName \fBtag remove \fItagName index1 \fR?\fIindex2 index1 index2 ...\fR?
Remove the tag \fItagName\fR from all of the characters starting
at \fIindex1\fR and ending just before
-\fIindex2\fR (the character at \fIindex2\fR isn't affected).
+\fIindex2\fR (the character at \fIindex2\fR is not affected).
A single command may contain any number of \fIindex1\fR\-\fIindex2\fR
pairs.
-If the last \fIindex2\fR is omitted then the single character at
-\fIindex1\fR is tagged.
+If the last \fIindex2\fR is omitted then the tag is removed from the
+single character at \fIindex1\fR.
If there are no characters in the specified range (e.g. \fIindex1\fR
is past the end of the file or \fIindex2\fR is less than or equal
to \fIindex1\fR) then the command has no effect.
@@ -1481,15 +1939,24 @@ span of the text is off-screen to the left.
\fIpathName \fBxview scroll \fInumber what\fR
This command shifts the view in the window left or right according to
\fInumber\fR and \fIwhat\fR.
-\fINumber\fR must be an integer.
-\fIWhat\fR must be either \fBunits\fR or \fBpages\fR or an abbreviation
-of one of these.
-If \fIwhat\fR is \fBunits\fR, the view adjusts left or right by
-\fInumber\fR average-width characters on the display; if it is
-\fBpages\fR then the view adjusts by \fInumber\fR screenfuls.
-If \fInumber\fR is negative then characters farther to the left
-become visible; if it is positive then characters farther to the right
-become visible.
+\fIWhat\fR must be \fBunits\fR, \fBpages\fR or \fBpixels\fR.
+.VS 8.5
+If \fIwhat\fR is \fBunits\fR or \fBpages\fR then \fInumber\fR must be an
+integer, otherwise number may be specified in any of the forms acceptable
+to \fBTk_GetPixels\fR, such as
+.QW 2.0c
+or
+.QW 1i
+(the result is rounded
+to the nearest integer value. If no units are given, pixels are
+assumed). If \fIwhat\fR is \fBunits\fR, the view adjusts left or right by
+\fInumber\fR average-width characters on the display; if it is
+\fBpages\fR then the view adjusts by \fInumber\fR screenfuls; if it is
+\fBpixels\fR then the view adjusts by \fInumber\fR pixels. If
+.VE 8.5
+\fInumber\fR is negative then characters farther to the left become
+visible; if it is positive then characters farther to the right become
+visible.
.RE
.TP
\fIpathName \fByview \fI?args\fR?
@@ -1501,37 +1968,56 @@ It can take any of the following forms:
\fIpathName \fByview\fR
Returns a list containing two elements, both of which are real fractions
between 0 and 1.
-The first element gives the position of the first character in the
+The first element gives the position of the first visible pixel of the
+first character (or image, etc) in the
top line in the window, relative to the text as a whole (0.5 means
it is halfway through the text, for example).
-The second element gives the position of the character just after
-the last one in the bottom line of the window,
+The second element gives the position of the first pixel just after the
+last visible one in the bottom line of the window,
relative to the text as a whole.
These are the same values passed to scrollbars via the \fB\-yscrollcommand\fR
option.
.TP
\fIpathName \fByview moveto\fI fraction\fR
-Adjusts the view in the window so that the character given by \fIfraction\fR
-appears on the top line of the window.
+Adjusts the view in the window so that the pixel given by \fIfraction\fR
+appears at the top of the top line of the window.
\fIFraction\fR is a fraction between 0 and 1; 0 indicates the first
-character in the text, 0.33 indicates the character one-third the
-way through the text, and so on.
+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.
+.VS 8.5
+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.
+.VE 8.5
.TP
\fIpathName \fByview scroll \fInumber what\fR
This command adjust the view in the window up or down according to
\fInumber\fR and \fIwhat\fR.
-\fINumber\fR must be an integer.
-\fIWhat\fR must be either \fBunits\fR or \fBpages\fR.
-If \fIwhat\fR is \fBunits\fR, the view adjusts up or down by
-\fInumber\fR lines on the display; if it is \fBpages\fR then
-the view adjusts by \fInumber\fR screenfuls.
+\fIWhat\fR must be \fBunits\fR, \fBpages\fR or \fBpixels\fR.
+.VS 8.5
+If \fIwhat\fR is \fBunits\fR or \fBpages\fR then \fInumber\fR must be an
+integer, otherwise number may be specified in any of the forms acceptable
+to \fBTk_GetPixels\fR, such as
+.QW 2.0c
+or
+.QW 1i
+(the result is rounded
+to the nearest integer value. If no units are given, pixels are
+assumed). If \fIwhat\fR is \fBunits\fR, the view adjusts up or down by
+\fInumber\fR lines on the display; if it is \fBpages\fR then the view
+adjusts by \fInumber\fR screenfuls; if it is \fBpixels\fR then the view
+adjusts by \fInumber\fR pixels.
+.VE 8.5
If \fInumber\fR is negative then earlier positions in the text
become visible; if it is positive then later positions in the text
become visible.
.TP
\fIpathName \fByview \fR?\fB\-pickplace\fR? \fIindex\fR
Changes the view in the widget's window to make \fIindex\fR visible.
-If the \fB\-pickplace\fR option isn't specified then \fIindex\fR will
+If the \fB\-pickplace\fR option is not specified then \fIindex\fR will
appear at the top of the window.
If \fB\-pickplace\fR is specified then the widget chooses where
\fIindex\fR appears in the window:
@@ -1548,9 +2034,9 @@ it will be positioned at the bottom of the window.
.IP [4]
Otherwise, \fIindex\fR will be centered in the window.
.LP
-The \fB\-pickplace\fR option has been obsoleted by the \fBsee\fR widget
-command (\fBsee\fR handles both x- and y-motion to make a location
-visible, whereas \fB\-pickplace\fR only handles motion in y).
+The \fB\-pickplace\fR option has been obsoleted by the \fIpathName \fBsee\fR widget
+command (\fIpathName \fBsee\fR handles both x- and y-motion to make a location
+visible, whereas the \fB\-pickplace\fR mode only handles motion in y).
.RE
.TP
\fIpathName \fByview \fInumber\fR
@@ -1563,8 +2049,10 @@ This command used to be used for scrolling, but now it is obsolete.
.PP
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 \fBtcl_wordchars\fR variable. See tclvars(n).
+In the descriptions below,
+.QW word
+is dependent on the value of
+the \fBtcl_wordchars\fR variable. See \fBtclvars\fR(n).
.IP [1]
Clicking mouse button 1 positions the insertion cursor
just before the character underneath the mouse cursor, sets the
@@ -1573,12 +2061,12 @@ Dragging with mouse button 1 strokes out a selection between
the insertion cursor and the character under the mouse.
.IP [2]
Double-clicking with mouse button 1 selects the word under the mouse
-and positions the insertion cursor at the end of the word.
+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.
.IP [3]
Triple-clicking with mouse button 1 selects the line under the mouse
-and positions the insertion cursor at the end of the line.
+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.
.IP [4]
@@ -1632,21 +2120,19 @@ The Next and Prior keys move the insertion cursor forward or backwards
by one screenful and clear any selection in the text.
If the Shift key is held down while Next or Prior is typed, then
the selection is extended to include the new character.
-Control-v moves the view down one screenful without moving the
-insertion cursor or adjusting the selection.
.IP [12]
Control-Next and Control-Prior scroll the view right or left by one page
without moving the insertion cursor or affecting the selection.
.IP [13]
Home and Control-a move the insertion cursor to the
-beginning of its line and clear any selection in the widget.
-Shift-Home moves the insertion cursor to the beginning of the line
+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.
.IP [14]
End and Control-e move the insertion cursor to the
-end of the line and clear any selection in the widget.
-Shift-End moves the cursor to the end of the line and extends the selection
-to that point.
+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.
.IP [15]
Control-Home and Meta-< move the insertion cursor to the beginning of
the text and clear any selection in the widget.
@@ -1659,7 +2145,7 @@ Control-Shift-End moves the cursor to the end of the text and extends
the selection to that point.
.IP [17]
The Select key and Control-Space set the selection anchor to the position
-of the insertion cursor. They don't affect the current selection.
+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.
@@ -1670,24 +2156,18 @@ Control-\e clears any selection in the widget.
.IP [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.
-.VS 8.4
This action is carried out by the command \fBtk_textCopy\fR.
-.VE 8.4
.IP [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.
-.VS 8.4
This action is carried out by the command \fBtk_textCut\fR.
-.VE 8.4
If there is no selection in the widget then these keys have no effect.
.IP [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.
-.VS 8.4
This action is carried out by the command \fBtk_textPaste\fR.
-.VE 8.4
.IP [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
@@ -1716,16 +2196,14 @@ Control-x deletes whatever is selected in the text widget
after copying it to the clipboard.
.IP [31]
Control-t reverses the order of the two characters to the right of
-the insertion cursor.
+the insertion cursor.
.IP [32]
-.VS 8.4
Control-z (and Control-underscore on UNIX when \fBtk_strictMotif\fR is
true) undoes the last edit action if the \fB\-undo\fR option is true.
Does nothing otherwise.
.IP [33]
Control-Z (or Control-y on Windows) reapplies the last undone edit
action if the \fB\-undo\fR option is true. Does nothing otherwise.
-.VE 8.4
.PP
If the widget is disabled using the \fB\-state\fR option, then its
view can still be adjusted and text can still be selected,
@@ -1734,7 +2212,34 @@ take place.
.PP
The behavior of texts can be changed by defining new bindings for
individual widgets or by redefining the class bindings.
-.SH "PERFORMANCE ISSUES"
+.SH "KNOWN ISSUES"
+.SS "ISSUES CONCERNING CHARS AND INDICES"
+.VS 8.5
+.PP
+Before Tk 8.5, the widget used the string
+.QW chars
+to refer to index positions (which included characters, embedded
+windows and embedded images). As of Tk 8.5 the text widget deals
+separately and correctly with
+.QW chars
+and
+.QW indices .
+For backwards compatibility, however, the index modifiers
+.QW "+N chars"
+and
+.QW "\-N chars"
+continue to refer to indices.
+One must use any of the full forms
+.QW "+N any chars"
+or
+.QW "\-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
+.QW "+N chars"
+as a synonym for
+.QW "+N any chars" .
+.VE 8.5
+.SS "PERFORMANCE ISSUES"
.PP
Text widgets should run efficiently under a variety
of conditions. The text widget uses about 2-3 bytes of
@@ -1766,10 +2271,64 @@ especially if they have many marks and tags within them.
.PP
The display line with the insert cursor is redrawn each time the
cursor blinks, which causes a steady stream of graphics traffic.
-Set the \fBinsertOffTime\fP attribute to 0 avoid this.
-
+Set the \fBinsertOffTime\fR attribute to 0 avoid this.
+.SS "KNOWN BUGS"
+.VS 8.5
+.PP
+The \fIpathName \fBsearch \-regexp\fR sub-command attempts to perform sophisticated
+regexp matching across multiple lines in an efficient fashion (since Tk
+8.5), examining each line individually, and then in small groups of lines,
+whether searching forwards or backwards. Under certain conditions the
+search result might differ from that obtained by applying the same regexp
+to the entire text from the widget in one go. For example, when
+searching with a greedy regexp, the widget will continue to attempt to
+add extra lines to the match as long as one of two conditions are true:
+either Tcl's regexp library returns a code to indicate a longer match is
+possible (but there are known bugs in Tcl which mean this code is not
+always correctly returned); or if each extra line added results in at
+least a partial match with the pattern. This means in the case where the
+first extra line added results in no match and Tcl's regexp system
+returns the incorrect code and adding a second extra line would actually
+match, the text widget will return the wrong result. In practice this is
+a rare problem, but it can occur, for example:
+.CS
+pack [text .t]
+\&.t insert 1.0 "aaaa\enbbbb\encccc\enbbbb\enaaaa\en"
+\&.t search \-regexp \-\- {(a+|b+\enc+\enb+)+\ena+} 1.0
+.CE
+will not find a match when one exists of 19
+characters starting from the first
+.QW b .
+.PP
+Whenever one possible match is fully enclosed in another, the search
+command will attempt to ensure only the larger match is returned.
+When performing backwards regexp searches it is possible that Tcl
+will not always achieve this, in the case where a match is preceded by
+one or more short, non-overlapping matches, all of which are preceded
+by a large match which actually encompasses all of them. The search
+algorithm used by the widget does not look back arbitrarily far for a
+possible match which might cover large portions of the widget.
+For example:
+.CS
+pack [text .t]
+\&.t insert 1.0 "aaaa\enbbbb\enbbbb\enbbbb\enbbbb\\n"
+\&.t search \-regexp \-backward \-\- {b+\en|a+\en(b+\en)+} end
+.CE
+matches at
+.QW 5.0
+when a true greedy match would match at
+.QW 1.0 .
+Similarly if we add \fB\-all\fR to this case, it matches at all of
+.QW 5.0 ,
+.QW 4.0 ,
+.QW 3.0
+and
+.QW 1.0 ,
+when really it should only match at
+.QW 1.0
+since that match encloses all the others.
+.VE 8.5
.SH "SEE ALSO"
entry(n), scrollbar(n)
-
.SH KEYWORDS
text, widget, tkvars