diff options
Diffstat (limited to 'doc/text.n')
| -rw-r--r-- | doc/text.n | 1621 |
1 files changed, 1621 insertions, 0 deletions
diff --git a/doc/text.n b/doc/text.n new file mode 100644 index 0000000..606249d --- /dev/null +++ b/doc/text.n @@ -0,0 +1,1621 @@ +'\" +'\" Copyright (c) 1992 The Regents of the University of California. +'\" Copyright (c) 1994-1996 Sun Microsystems, Inc. +'\" +'\" See the file "license.terms" for information on usage and redistribution +'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. +'\" +'\" SCCS: @(#) text.n 1.68 97/10/31 12:58:41 +'\" +.so man.macros +.TH text n 4.0 Tk "Tk Built-In Commands" +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +text \- Create and manipulate text widgets +.SH SYNOPSIS +\fBtext\fR \fIpathName \fR?\fIoptions\fR? +.SO +\-background \-highlightbackground \-insertontime \-selectborderwidth +\-borderwidth \-highlightcolor \-insertwidth \-selectforeground +\-cursor \-highlightthickness \-padx \-setgrid +\-exportselection \-insertbackground \-pady \-takefocus +\-font \-insertborderwidth \-relief \-xscrollcommand +\-foreground \-insertofftime \-selectbackground \-yscrollcommand +.SE +.SH "WIDGET-SPECIFIC OPTIONS" +.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 \-spacing1 spacing1 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 overriden with \fB\-spacing1\fR options in +tags. +.OP \-spacing2 spacing2 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 overriden with \fB\-spacing2\fR options in +tags. +.OP \-spacing3 spacing3 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 overriden with \fB\-spacing3\fR options in +tags. +.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 +and no insertion cursor will be displayed, even if the input focus is +in the widget. +.OP \-tabs tabs Tabs +Specifies a set of tab stops for the window. The option's value consists +of a list of screen distances giving the positions of the tab stops. Each +position may optionally be followed in the next list element +by one of the keywords \fBleft\fR, \fBright\fR, \fBcenter\fR, +or \fBnumeric\fR, which specifies how to justify +text relative to the tab stop. \fBLeft\fR is the default; it causes +the text following the tab character to be positioned with its left edge +at the tab position. \fBRight\fR means that the right edge of the text +following the tab character is positioned at the tab position, and +\fBcenter\fR means that the text is centered at the tab position. +\fBNumeric\fR 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, \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. +If the list of tab stops does not have enough elements to cover all +of the tabs in a text line, then Tk extrapolates new tab stops using +the spacing and alignment from the last tab stop in the list. +The value of the \fBtabs\fR option may be overridden by \fB\-tabs\fR +options in tags. +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. +.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. +.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 +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 \fBchar\fR mode a screen line break may occur after any character; +in \fBword\fR mode a line break will only be made at word boundaries. +.BE + +.SH DESCRIPTION +.PP +The \fBtext\fR command creates a new window (given by the +\fIpathName\fR 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 \fBtext\fR command returns the +path name of the new window. +.PP +A text widget displays one or more lines of text and allows that +text to be edited. +.VS +Text widgets support four different kinds of annotations on the +text, called tags, marks, embedded windows or embedded images. +.VE +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. +.PP +The second form of annotation consists of marks, which are floating +markers in the text. +Marks are used to keep track of various interesting positions in the +text as it is edited. +See MARKS below for more details. +.PP +The third form of annotation allows arbitrary windows to be +embedded in a text widget. +See EMBEDDED WINDOWS below for more details. +.PP +.VS +The fourth form of annotation allows Tk images to be embedded in a text +widget. +See EMBEDDED IMAGES below for more details. +.VE + +.SH INDICES +.PP +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 +.CS +\fIbase modifier modifier modifier ...\fR +.CE +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. +.PP +The \fIbase\fR for an index must have one of the following forms: +.TP 12 +\fIline\fB.\fIchar\fR +Indicates \fIchar\fR'th character on line \fIline\fR. +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 \fIchar\fR is \fBend\fR then it refers to the newline character +that ends the line. +.TP 12 +\fB@\fIx\fB,\fIy\fR +Indicates the character that covers the pixel whose x and y coordinates +within the text's window are \fIx\fR and \fIy\fR. +.TP 12 +\fBend\fR +Indicates the end of the text (the character just after the last +newline). +.TP 12 +\fImark\fR +Indicates the character just after the mark whose name is \fImark\fR. +.TP 12 +\fItag\fB.first\fR +Indicates the first character in the text that has been tagged with +\fItag\fR. +This form generates an error if no characters are currently tagged +with \fItag\fR. +.TP 12 +\fItag\fB.last\fR +Indicates the character just after the last one in the text that has +been tagged with \fItag\fR. +This form generates an error if no characters are currently tagged +with \fItag\fR. +.TP 12 +\fIpathName\fR +Indicates the position of the embedded window whose name is +\fIpathName\fR. +This form generates an error if there is no embedded window +by the given name. +.TP 12 +.VS +\fIimageName\fR +Indicates the position of the embedded image whose name is +\fIimageName\fR. +This form generates an error if there is no embedded image +by the given name. +.VE +.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 +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 +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 +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 +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 +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 +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. +.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'' +refers to the next-to-last character in the text and +``\fBinsert wordstart \- 1 c\fR'' refers to the character just before +the first one in the word containing the insertion cursor. + +.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 the characters `` '' (space), \fB+\fR, or \fB\-\fR: +these characters have special meaning in indices, so tags containing +them can't be used as indices. +There may be any number of tags associated with characters in a +text. +Each tag may refer to a single character, a range of characters, or +several ranges of characters. +An individual character may have any number of tags associated with it. +.PP +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 +``\fIpathName \fBtag raise\fR'' and ``\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 +text widget. +However, display options may be associated with individual tags +using the ``\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: +.TP +\fB\-background \fIcolor\fR +\fIColor\fR specifies the background color to use for characters +associated with the tag. +It may have any of the forms accepted by \fBTk_GetColor\fR. +.TP +\fB\-bgstipple \fIbitmap\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 +as an empty string, then a solid fill will be used for the +background. +.TP +\fB\-borderwidth \fIpixels\fR +\fIPixels\fR specifies the width of a 3-D border to draw around +the background. +It may have any of the forms accepted by \fBTk_GetPixels\fR. +This option is used in conjunction with the \fB\-relief\fR +option to give a 3-D appearance to the background for characters; +it is ignored unless the \fB\-background\fR option +has been set for the tag. +.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 +as an empty string, then a solid fill will be used. +.TP +\fB\-font \fIfontName\fR +\fIFontName\fR is the name of a font to use for drawing characters. +It may have any of the forms accepted by \fBTk_GetFontStruct\fR. +.TP +\fB\-foreground \fIcolor\fR +\fIColor\fR specifies the color to use when drawing text and other +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 +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. +.TP +\fB\-lmargin1 \fIpixels\fR +If the first 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. +\fIPixels\fR 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 \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 +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 +the left edge of the window. +\fIPixels\fR 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. +.TP +\fB\-offset \fIpixels\fR +\fIPixels\fR 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. +\fIPixels\fR may have any of the standard forms for screen +distances. +.TP +\fB\-overstrike \fIboolean\fR +Specifies whether or not to draw a horizontal rule through +the middle of characters. +\fIBoolean\fR may have any of the forms accepted by \fBTk_GetBoolean\fR. +.TP +\fB\-relief \fIrelief\fR +\fIRelief\fR specifies the 3-D relief to use for drawing backgrounds, +in any of the forms accepted by \fBTk_GetRelief\fR. +This option is used in conjunction with the \fB\-borderwidth\fR +option to give a 3-D appearance to the background for characters; +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 +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. +\fIPixels\fR may have any of the standard forms for screen +distances. +This option is only used when wrapping is enabled. +If a text line wraps, the right margin for each line on the +display is determined by the first character of that display +line. +.TP +\fB\-spacing1 \fIpixels\fR +\fIPixels\fR 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. +.TP +\fB\-spacing2 \fIpixels\fR +For lines that wrap, this option specifies how much additional +space to leave between the display lines for a single text line. +\fIPixels\fR may have any of the standard forms for screen +distances. +.TP +\fB\-spacing3 \fIpixels\fR +\fIPixels\fR 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. +.TP +\fB\-tabs \fItabList\fR +\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. +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 +widget option. +.TP +\fB\-underline \fIboolean\fR +\fIBoolean\fR specifies whether or not to draw an underline underneath +characters. +It may have any of the forms accepted by \fBTk_GetBoolean\fR. +.TP +\fB\-wrap \fImode\fR +\fIMode\fR specifies how to handle lines that are wider than the +text's window. +It has the same legal values as the \fB\-wrap\fR option +for the text widget: \fBnone\fR, \fBchar\fR, or \fBword\fR. +If this tag option is specified, it overrides the \fB\-wrap\fR option +for the text widget. +.PP +If a character has several tags associated with it, and if their +display options conflict, then the options of the highest priority +tag are used. +If a particular display option hasn't been specified for a +particular tag, or if it is specified as an empty string, then +that option will never be used; the next-highest-priority +tag's option will used instead. +If no tag specifies a particular display option, then the default +style for the widget will be used. +.PP +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 \fBtag bind\fR widget +command below. +.PP +The third use for tags is in managing the selection. +See THE SELECTION below. + +.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 +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 ``\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 \fIgravity\fR, 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 +were attached to the character on its left, so the mark will +remain to the left of any text inserted at the mark position. +If the mark has right gravity, new text inserted at the mark +position will appear to the right of the mark. The gravity +for a mark defaults to \fBright\fR. +.PP +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. +.PP +Two marks have special significance. +First, the mark \fBinsert\fR is associated with the insertion cursor, +as described under THE INSERTION CURSOR below. +Second, the mark \fBcurrent\fR 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: \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. + +.SH EMBEDDED WINDOWS +.PP +The third form of annotation in text widgets is an embedded window. +Each embedded window annotation causes a window to be displayed +at a particular point in the text. +There may be any number of embedded windows in a text widget, +and any widget may be used as an embedded window (subject to the +usual rules for geometry management, which require the text window +to be the parent of the embedded window or a descendant of its +parent). +The embedded window's position on the screen will be updated as the +text is modified or scrolled, and it will be mapped and unmapped as +it moves into and out of the visible area of the text widget. +Each embedded window occupies one character's worth of index space +in the text widget, and it may be referred to either by the name +of its embedded window or by its position in the widget's +index space. +If the range of text containing the embedded window is deleted then +the window is destroyed. +.PP +When an embedded window is added to a text widget with the +\fBwindow create\fR widget command, several configuration +options may be associated with it. +These options may be modified later with the \fBwindow configure\fR +widget command. +The following options are currently supported: +.TP +\fB\-align \fIwhere\fR +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. +\fIWhere\fR must have one of the values \fBtop\fR (align the top of the window +with the top of the line), \fBcenter\fR (center the window +within the range of the line), \fBbottom\fR (align the bottom of the +window with the bottom of the line's area), +or \fBbaseline\fR (align the bottom of the window with the baseline +of the line). +.TP +\fB\-create \fIscript\fR +Specifies a Tcl script that may be evaluated to create the window +for the annotation. +If no \fB\-window\fR option has been specified for the annotation +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. +If the annotation's window should ever be deleted, \fIscript\fR +will be evaluated again the next time the annotation is displayed. +.TP +\fB\-padx \fIpixels\fR +\fIPixels\fR 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. +.TP +\fB\-pady \fIpixels\fR +\fIPixels\fR 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. +.TP +\fB\-stretch \fIboolean\fR +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 \fB\-pady\fR option has been specified as well, then the +requested padding will be retained even if the window is +stretched. +.TP +\fB\-window \fIpathName\fR +Specifies the name of a window to display in the annotation. + +.VS +.SH EMBEDDED IMAGES +.PP +The final form of annotation in text widgets is an embedded image. +Each embedded image annotation causes an image to be displayed +at a particular point in the text. +There may be any number of embedded images in a text widget, +and a particular image may be embedded in multiple places in the same +text widget. +The embedded image's position on the screen will be updated as the +text is modified or scrolled. +Each embedded image occupies one character's worth of index space +in the text widget, and it may be referred to either by +its position in the widget's index space, or the name it is assigned +when the image is inserted into the text widget widh \fBimage create\fP. +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 +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 +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. +.PP +When an embedded image is added to a text widget with the +\fBimage create\fR widget command, several configuration +options may be associated with it. +These options may be modified later with the \fBimage configure\fR +widget command. +The following options are currently supported: +.TP +\fB\-align \fIwhere\fR +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. +\fIWhere\fR must have one of the values \fBtop\fR (align the top of the image +with the top of the line), \fBcenter\fR (center the image +within the range of the line), \fBbottom\fR (align the bottom of the +image with the bottom of the line's area), +or \fBbaseline\fR (align the bottom of the image with the baseline +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. +.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 +name of the Tk image is used instead. +If the \fIimageName\fP is already in use, \fI#nn\fP is appended to +the end of the name as described above. +.TP +\fB\-padx \fIpixels\fR +\fIPixels\fR 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. +.TP +\fB\-pady \fIpixels\fR +\fIPixels\fR 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. +.VE + +.SH THE SELECTION +.PP +Selection support is implemented via tags. +If the \fBexportSelection\fR option for the text widget is true +then the \fBsel\fR tag will be associated with the selection: +.IP [1] +Whenever characters are tagged with \fBsel\fR the text widget +will claim ownership of the selection. +.IP [2] +Attempts to retrieve the +selection will be serviced by the text widget, returning all the +characters with the \fBsel\fR tag. +.IP [3] +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. +.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'' +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. + +.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. +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. + +.SH "WIDGET COMMAND" +.PP +The \fBtext\fR 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: +.CS +\fIpathName option \fR?\fIarg arg ...\fR? +.CE +\fIPathName\fR is the name of the command, which is the same as +the text widget's path name. \fIOption\fR and the \fIarg\fRs +determine the exact behavior of the command. The following +commands are possible for text widgets: +.TP +\fIpathName \fBbbox \fIindex\fR +Returns a list of four elements describing the screen area +of the character given by \fIindex\fR. +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. +.TP +\fIpathName \fBcget\fR \fIoption\fR +Returns the current value of the configuration option given +by \fIoption\fR. +\fIOption\fR may have any of the values accepted by the \fBtext\fR +command. +.TP +\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. +\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 +refers to an earlier character in the text than \fIindex2\fR, and +so on. +.TP +\fIpathName \fBconfigure\fR ?\fIoption\fR? \fI?value option value ...\fR? +Query or modify the configuration options of the widget. +If no \fIoption\fR is specified, returns a list describing all of +the available options for \fIpathName\fR (see \fBTk_ConfigureInfo\fR for +information on the format of this list). If \fIoption\fR is specified +with no \fIvalue\fR, 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 \fIoption\fR is specified). If +one or more \fIoption\-value\fR 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. +\fIOption\fR may have any of the values accepted by the \fBtext\fR +command. +.TP +\fIpathName \fBdebug \fR?\fIboolean\fR? +If \fIboolean\fR 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 \fIboolean\fR has a false value then the debugging checks will +be turned off. +In either case the command returns an empty string. +If \fIboolean\fR is not specified then the command returns \fBon\fR +or \fBoff\fR 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. +.TP +\fIpathName \fBdelete \fIindex1 \fR?\fIindex2\fR? +Delete a range of characters from the text. +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 +than \fIindex1\fR then no characters are deleted. +If \fIindex2\fR isn't 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. +.TP +\fIpathName \fBdlineinfo \fIindex\fR +Returns a list with five elements describing the area occupied +by the display line containing \fIindex\fR. +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 \fBnone\fR 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 \fIindex\fR is not visible on +the screen then the return value is an empty list. +.TP +\fIpathName \fBdump \fR?\fIswitches\fR? \fIindex1 \fR?\fIindex2\fR? +Return the contents of the text widget from \fIindex1\fR up to, +but not including \fIindex2\fR, +including the text and +information about marks, tags, and embedded windows. +If \fIindex2\fR is not specified, then it defaults to +one character past \fIindex1\fR. The information is returned +in the following format: +.LP +.RS +\fIkey1 value1 index1 key2 value2 index2\fR ... +.LP +The possible \fIkey\fP values are \fBtext\fP, \fBmark\fP, +\fBtagon\fP, \fBtagoff\fP, and \fBwindow\fP. The corresponding +\fIvalue\fP is the text, mark name, tag name, or window name. +The \fIindex\fP information is the index of the +start of the text, the mark, the tag transition, or the window. +One or more of the following switches (or abbreviations thereof) +may be specified to control the dump: +.TP +\fB\-all\fR +Return information about all elements: text, marks, tags, and windows. +This is the default. +.TP +\fB\-command \fIcommand\fR +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. +.TP +\fB\-mark\fR +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 indicate the +begin and end of each range of each tag, respectively. +.TP +\fB\-text\fR +Include information about text in the dump results. The value is the +text up to the next element or the end of range indicated by \fIindex2\fR. +A text element does not span newlines. A multi-line block of text that +contains no marks or tag transitions will still be dumped as a set +of text seqments that each end with a newline. The newline is part +of the value. +.TP +\fB\-window\fR +Include information about embedded windows in the dump results. +The value of a window is its Tk pathname, unless the window +has not been created yet. (It must have a create script.) +In this case an empty string is returned, and you must query the +window by its index position to get more information. +.RE +.TP +\fIpathName \fBget \fIindex1 \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 +the one whose index is \fIindex2\fR (the character at \fIindex2\fR +will not be returned). +If \fIindex2\fR is omitted then the single character at \fIindex1\fR +is returned. +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 an empty string is returned. +If the specified range contains embedded windows, no information +about them is included in the returned string. +.TP +\fIpathName \fBimage \fIoption \fR?\fIarg arg ...\fR? +This command is used to manipulate embedded images. +The behavior of the command depends on the \fIoption\fR argument +that follows the \fBtag\fR argument. +The following forms of the command are currently supported: +.RS +.TP +\fIpathName \fBimage cget\fR \fIindex option\fR +Returns the value of a configuration option for an embedded image. +\fIIndex\fR identifies the embedded image, and \fIoption\fR +specifies a particular configuration option, which must be one of +the ones listed in the section EMBEDDED IMAGES. +.TP +\fIpathName \fBimage configure \fIindex\fR ?\fIoption value ...\fR? +Query or modify the configuration options for an embedded image. +If no \fIoption\fR is specified, returns a list describing all of +the available options for the embedded image at \fIindex\fR +(see \fBTk_ConfigureInfo\fR for information on the format of this list). +If \fIoption\fR is specified with no \fIvalue\fR, 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 +\fIoption\fR is specified). +If one or more \fIoption\-value\fR pairs are specified, then the command +modifies the given option(s) to have the given value(s); in +this case the command returns an empty string. +See EMBEDDED IMAGES for information on the options that +are supported. +.TP +\fIpathName \fBimage create \fIindex\fR ?\fIoption value ...\fR? +This command creates a new image annotation, which will appear +in the text at the position given by \fIindex\fR. +Any number of \fIoption\-value\fR pairs may be specified to +configure the annotation. +Returns a unique identifier that may be used as an index to refer to +this image. +See EMBEDDED IMAGES for information on the options that +are supported, and a description of the identifier returned. +.TP +\fIpathName \fBimage names\fR +Returns a list whose elements are the names of all image instances currently +embedded in \fIwindow\fR. +.RE +.TP +\fIpathName \fBindex \fIindex\fR +Returns the position corresponding to \fIindex\fR in the form +\fIline.char\fR where \fIline\fR is the line number and \fIchar\fR +is the character number. +\fIIndex\fR may have any of the forms described under INDICES above. +.TP +\fIpathName \fBinsert \fIindex chars \fR?\fItagList chars tagList ...\fR? +Inserts all of the \fIchars\fR arguments just before the character at +\fIindex\fR. +If \fIindex\fR 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 \fIchars\fR argument and no \fItagList\fR, 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 \fItagList\fR 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 \fIchars\fR\-\fItagList\fR argument pairs are present, +they produce the same effect as if a separate \fBinsert\fR widget +command had been issued for each pair, in order. +The last \fItagList\fR argument may be omitted. +.TP +\fIpathName \fBmark \fIoption \fR?\fIarg arg ...\fR? +This command is used to manipulate marks. The exact behavior of +the command depends on the \fIoption\fR argument that follows +the \fBmark\fR argument. The following forms of the command +are currently supported: +.RS +.TP +\fIpathName \fBmark gravity \fImarkName\fR ?\fIdirection\fR? +If \fIdirection\fR is not specified, returns \fBleft\fR or \fBright\fR +to indicate which of its adjacent characters \fImarkName\fR is attached +to. +If \fIdirection\fR is specified, it must be \fBleft\fR or \fBright\fR; +the gravity of \fImarkName\fR is set to the given value. +.TP +\fIpathName \fBmark names\fR +Returns a list whose elements are the names of all the marks that +are currently set. +.TP +\fIpathName \fBmark next \fIindex\fR +Returns the name of the next mark at or after \fIindex\fR. +If \fIindex\fR is specified in numerical form, then the search for +the next mark begins at that index. +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 +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. +An empty string is returned if there are no marks after \fIindex\fR. +.TP +\fIpathName \fBmark previous \fIindex\fR +Returns the name of the mark at or before \fIindex\fR. +If \fIindex\fR is specified in numerical form, then the search for +the previous mark begins with the character just before that index. +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 +step through all the marks in a text widget in the reverse order +as the mark information returned by the \fBdump\fP 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. +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''. +This command returns an empty string. +.RE +.TP +\fIpathName \fBscan\fR \fIoption args\fR +This command is used to implement scanning on texts. It has +two forms, depending on \fIoption\fR: +.RS +.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. +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. +It then adjusts the view by 10 times the difference in coordinates. +This command is typically associated +with mouse motion events in the widget, to produce the effect of +dragging the text at high speed through the window. The return +value is an empty string. +.RE +.TP +\fIpathName \fBsearch \fR?\fIswitches\fR? \fIpattern index \fR?\fIstopIndex\fR? +Searches the text in \fIpathName\fR starting at \fIindex\fR for a range +of characters that matches \fIpattern\fR. +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: +.RS +.TP +\fB\-forwards\fR +The search will proceed forward through the text, finding the first +matching range starting at or after the position given by \fIindex\fR. +This is the default. +.TP +\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. +.TP +\fB\-exact\fR +Use exact matching: the characters in the matching range must be +identical to those in \fIpattern\fR. +This is the default. +.TP +\fB\-regexp\fR +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). +.TP +\fB\-nocase\fR +Ignore case differences between the pattern and the text. +.TP +\fB\-count\fI varName\fR +The argument following \fB\-count\fR gives the name of a variable; +if a match is found, the number of characters in the matching +range will be stored in the variable. +.TP +\fB\-\|\-\fR +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. +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 +text than \fIstopIndex\fR will be considered. +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. +.RE +.TP +\fIpathName \fBsee \fIindex\fR +Adjusts the view in the window so that the character given by \fIindex\fR +is completely visible. +If \fIindex\fR is already visible then the command does nothing. +If \fIindex\fR is a short distance out of view, the command +adjusts the view just enough to make \fIindex\fR visible at the +edge of the window. +If \fIindex\fR is far out of view, then the command centers +\fIindex\fR in the window. +.TP +\fIpathName \fBtag \fIoption \fR?\fIarg arg ...\fR? +This command is used to manipulate tags. The exact behavior of the +command depends on the \fIoption\fR argument that follows the +\fBtag\fR argument. The following forms of the command are currently +supported: +.RS +.TP +\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). +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 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. +.TP +\fIpathName \fBtag bind \fItagName\fR ?\fIsequence\fR? ?\fIscript\fR? +This command associates \fIscript\fR with the tag given by +\fItagName\fR. +Whenever the event sequence given by \fIsequence\fR occurs for a +character that has been tagged with \fItagName\fR, +the script will be invoked. +This widget command is similar to the \fBbind\fR command except that +it operates on characters in a text rather than entire widgets. +See the \fBbind\fR manual entry for complete details +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). +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 +if there is no such binding). +If both \fIscript\fR and \fIsequence\fR are omitted then the command +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, +\fBButtonPress\fR, \fBMotion\fR, and \fBKeyPress\fR) or virtual events. +Event bindings for a text widget use the \fBcurrent\fR mark described +under MARKS above. An \fBEnter\fR event triggers for a tag when the tag +first becomes present on the current character, and a \fBLeave\fR event +triggers for a tag when it ceases to be present on the current character. +\fBEnter\fR and \fBLeave\fR events can happen either because the +\fBcurrent\fR mark moved or because the character at that position +changed. Note that these events are different than \fBEnter\fR and +\fBLeave\fR events for windows. Mouse and keyboard events are directed +to the current character. If a virtual event is used in a binding, that +binding can trigger only if the virtual event is defined by an underlying +mouse-related or keyboard-related event. +.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 +sequence. +When this occurs, one binding is invoked for each tag, in order +from lowest-priority to highest priority. +If there are multiple matching bindings for a single tag, then +the most specific binding is chosen (see the manual entry for +the \fBbind\fR command for details). +\fBcontinue\fR and \fBbreak\fR commands within binding scripts +are processed in the same way as for bindings created with +the \fBbind\fR command. +.PP +If bindings are created for the widget as a whole using the +\fBbind\fR command, then those bindings will supplement the +tag bindings. +The tag bindings will be invoked first, followed by bindings +for the window as a whole. +.RE +.TP +\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. +.TP +\fIpathName \fBtag configure \fItagName\fR ?\fIoption\fR? ?\fIvalue\fR? ?\fIoption value ...\fR? +This command is similar to the \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 +all of the available options for \fItagName\fR (see \fBTk_ConfigureInfo\fR +for information on the format of this list). +If \fIoption\fR is specified with no \fIvalue\fR, 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 \fIoption\fR +is specified). +If one or more \fIoption\-value\fR pairs are specified, then the command +modifies the given option(s) to have the given value(s) in \fItagName\fR; +in this case the command returns an empty string. +See TAGS above for details on the options available for tags. +.TP +\fIpathName \fBtag delete \fItagName \fR?\fItagName ...\fR? +Deletes all tag information for each of the \fItagName\fR +arguments. +The command removes the tags from all characters in the file +and also deletes any other information associated with the tags, +such as bindings and display information. +The command returns an empty string. +.TP +\fIpathName\fB tag lower \fItagName \fR?\fIbelowThis\fR? +Changes the priority of tag \fItagName\fR so that it is just lower +in priority than the tag whose name is \fIbelowThis\fR. +If \fIbelowThis\fR is omitted, then \fItagName\fR's priority +is changed to make it lowest priority of all tags. +.TP +\fIpathName \fBtag names \fR?\fIindex\fR? +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). +The list will be sorted in order from lowest priority to highest +priority. +.TP +\fIpathName \fBtag nextrange \fItagName index1 \fR?\fIindex2\fR? +This command searches the text for a range of characters tagged +with \fItagName\fR where the first character of the range is +no earlier than the character at \fIindex1\fR and no later than +the character just before \fIindex2\fR (a range starting at +\fIindex2\fR will not be considered). +If several matching ranges exist, the first one is chosen. +The command's return value is a list containing +two elements, which are the index of the first character of the +range and the index of the character just after the last one in +the range. +If no matching range is found then the return value is an +empty string. +If \fIindex2\fR is not given then it defaults to the end of the text. +.TP +\fIpathName \fBtag prevrange \fItagName index1 \fR?\fIindex2\fR? +This command searches the text for a range of characters tagged +with \fItagName\fR where the first character of the range is +before the character at \fIindex1\fR and no earlier than +the character at \fIindex2\fR (a range starting at +\fIindex2\fR will be considered). +If several matching ranges exist, the one closest to \fIindex1\fR is chosen. +The command's return value is a list containing +two elements, which are the index of the first character of the +range and the index of the character just after the last one in +the range. +If no matching range is found then the return value is an +empty string. +If \fIindex2\fR is not given then it defaults to the beginning of the text. +.TP +\fIpathName\fB tag raise \fItagName \fR?\fIaboveThis\fR? +Changes the priority of tag \fItagName\fR so that it is just higher +in priority than the tag whose name is \fIaboveThis\fR. +If \fIaboveThis\fR is omitted, then \fItagName\fR's priority +is changed to make it highest priority of all tags. +.TP +\fIpathName \fBtag ranges \fItagName\fR +Returns a list describing all of the ranges of text that have been +tagged with \fItagName\fR. +The first two elements of the list describe the first tagged range +in the text, the next two elements describe the second range, and +so on. +The first element of each pair contains the index of the first +character of the range, and the second element of the pair contains +the index of the character just after the last one in the +range. +If there are no characters tagged with \fItag\fR then an +empty string is returned. +.TP +\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). +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 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. +This command returns an empty string. +.RE +.TP +\fIpathName \fBwindow \fIoption \fR?\fIarg arg ...\fR? +This command is used to manipulate embedded windows. +The behavior of the command depends on the \fIoption\fR argument +that follows the \fBtag\fR argument. +The following forms of the command are currently supported: +.RS +.TP +\fIpathName \fBwindow cget\fR \fIindex option\fR +Returns the value of a configuration option for an embedded window. +\fIIndex\fR identifies the embedded window, and \fIoption\fR +specifies a particular configuration option, which must be one of +the ones listed in the section EMBEDDED WINDOWS. +.TP +\fIpathName \fBwindow configure \fIindex\fR ?\fIoption value ...\fR? +Query or modify the configuration options for an embedded window. +If no \fIoption\fR is specified, returns a list describing all of +the available options for the embedded window at \fIindex\fR +(see \fBTk_ConfigureInfo\fR for information on the format of this list). +If \fIoption\fR is specified with no \fIvalue\fR, 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 +\fIoption\fR is specified). +If one or more \fIoption\-value\fR pairs are specified, then the command +modifies the given option(s) to have the given value(s); in +this case the command returns an empty string. +See EMBEDDED WINDOWS for information on the options that +are supported. +.TP +\fIpathName \fBwindow create \fIindex\fR ?\fIoption value ...\fR? +This command creates a new window annotation, which will appear +in the text at the position given by \fIindex\fR. +Any number of \fIoption\-value\fR pairs may be specified to +configure the annotation. +See EMBEDDED WINDOWS for information on the options that +are supported. +Returns an empty string. +.TP +\fIpathName \fBwindow names\fR +Returns a list whose elements are the names of all windows currently +embedded in \fIwindow\fR. +.RE +.TP +\fIpathName \fBxview \fIoption args\fR +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: +.RS +.TP +\fIpathName \fBxview\fR +Returns a list containing two elements. +Each element is a real fraction between 0 and 1; together they describe +the portion of the document's horizontal span that is visible in +the window. +For example, if the first element is .2 and the second element is .6, +20% of the text is off-screen to the left, the middle 40% is visible +in the window, and 40% of the text is off-screen to the right. +The fractions refer only to the lines that are actually visible in the +window: if the lines in the window are all very short, so that they +are entirely visible, the returned fractions will be 0 and 1, +even if there are other lines in the text that are +much wider than the window. +These are the same values passed to scrollbars via the \fB\-xscrollcommand\fR +option. +.TP +\fIpathName \fBxview moveto\fI fraction\fR +Adjusts the view in the window so that \fIfraction\fR of the horizontal +span of the text is off-screen to the left. +\fIFraction\fR is a fraction between 0 and 1. +.TP +\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. +.RE +.TP +\fIpathName \fByview \fI?args\fR? +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: +.RS +.TP +\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 +top line in the window, relative to the text as a whole (0.5 means +it is halfway through the text, for example). +The second element gives the position of the character just after +the last one in the bottom line of the window, +relative to the text as a whole. +These are the same values passed to scrollbars via the \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. +\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. +.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. +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 +appear at the top of the window. +If \fB\-pickplace\fR is specified then the widget chooses where +\fIindex\fR appears in the window: +.RS +.IP [1] +If \fIindex\fR is already visible somewhere in the window then the +command does nothing. +.IP [2] +If \fIindex\fR is only a few lines off-screen above the window then +it will be positioned at the top of the window. +.IP [3] +If \fIindex\fR is only a few lines off-screen below the window then +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). +.RE +.TP +\fIpathName \fByview \fInumber\fR +This command makes the first character on the line after +the one given by \fInumber\fR visible at the top of the window. +\fINumber\fR must be an integer. +This command used to be used for scrolling, but now it is obsolete. +.RE + +.SH BINDINGS +.PP +Tk automatically creates class bindings for texts that give them +the following default behavior. +In the descriptions below, ``word'' refers to a contiguous group +of letters, digits, or ``_'' characters, or any single character +other than these. +.IP [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. +.IP [2] +Double-clicking with mouse button 1 selects the word under the mouse +and positions the insertion cursor at the beginning of the word. +Dragging after a double click will stroke out a selection consisting +of whole words. +.IP [3] +Triple-clicking with mouse button 1 selects the line under the mouse +and positions the insertion cursor at the beginning of the line. +Dragging after a triple click will stroke out a selection consisting +of whole lines. +.IP [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. +.IP [5] +Clicking mouse button 1 with the Control key down will reposition the +insertion cursor without affecting the selection. +.IP [6] +If any normal printing characters are typed, they are +inserted at the point of the insertion cursor. +.IP [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. +.IP [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). +.IP [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. +.IP [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. +.IP [11] +The Next and Prior keys move the insertion cursor forward or backwards +by one screenful and clear any selection in the text. +If the Shift key is held down while Next or Prior is typed, then +the selection is extended to include the new character. +Control-v moves the view down one screenful without moving the +insertion cursor or adjusting the selection. +.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 +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. +.IP [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. +.IP [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. +.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. +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. +.IP [18] +Control-/ selects the entire contents of the widget. +.IP [19] +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. +.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. +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. +.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 +the insertion cursor. +.IP [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. +.IP [25] +Control-d deletes the character to the right of the insertion cursor. +.IP [26] +Meta-d deletes the word to the right of the insertion cursor. +.IP [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. +.IP [28] +Control-o opens a new line by inserting a newline character in +front of the insertion cursor without moving the insertion cursor. +.IP [29] +Meta-backspace and Meta-Delete delete the word to the left of the +insertion cursor. +.IP [30] +Control-x deletes whatever is selected in the text widget. +.IP [31] +Control-t reverses the order of the two characters to the right of +the insertion cursor. +.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, +but no insertion cursor will be displayed and no text modifications will +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" +.PP +Text widgets should run efficiently under a variety +of conditions. The text widget uses about 2-3 bytes of +main memory for each byte of text, so texts containing a megabyte +or more should be practical on most workstations. +Text is represented internally with a modified B-tree structure +that makes operations relatively efficient even with large texts. +Tags are included in the B-tree structure in a way that allows +tags to span large ranges or have many disjoint smaller ranges +without loss of efficiency. +Marks are also implemented in a way that allows large numbers of +marks. +In most cases it is fine to have large numbers of unique tags, +or a tag that has many distinct ranges. +.PP +One performance problem can arise if you have hundreds or thousands +of different tags that all have the following characteristics: +the first and last ranges of each tag are near the beginning and +end of the text, respectively, +or a single tag range covers most of the text widget. +The cost of adding and deleting tags like this is proportional +to the number of other tags with the same properties. +In contrast, there is no problem with having thousands of distinct +tags if their overall ranges are localized and spread uniformly throughout +the text. +.PP +Very long text lines can be expensive, +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. +.SH KEYWORDS +text, widget |