text.n

linux系统下的音频通信

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.