message(n) Tk Built-In Commands message(n)
message - Create and manipulate message widgets
message pathName ?options?
-anchor -highlightbackground -takefocus
-background -highlightcolor -text
-borderwidth -highlightthickness -textvariable
-cursor -padx -width
See the options manual entry for details on the standard options.
Database Name: aspect
Database Class: Aspect
Specifies a non-negative integer value indicating desired aspect
ratio for the text. The aspect ratio is specified as
100*width/height. 100 means the text should be as wide as it is
tall, 200 means the text should be twice as wide as it is tall,
50 means the text should be twice as tall as it is wide, and so
on. Used to choose line length for text if width option isn't
specified. Defaults to 150.
Database Name: justify
Database Class: Justify
Specifies how to justify lines of text. Must be one of left,
center, or right. Defaults to left. This option works together
with the anchor, aspect, padX, padY, and width options to pro-
vide a variety of arrangements of the text within the window.
The aspect and width options determine the amount of screen
space needed to display the text. The anchor, padX, and padY
options determine where this rectangular area is displayed
within the widget's window, and the justify option determines
how each line is displayed within that rectangular region. For
example, suppose anchor is e and justify is left, and that the
message window is much larger than needed for the text. The the
text will displayed so that the left edges of all the lines line
up and the right edge of the longest line is padX from the right
side of the window; the entire text block will be centered in
the vertical span of the window.
Database Name: width
Database Class: Width
Specifies the length of lines in the window. The value may have
any of the forms acceptable to Tk_GetPixels. If this option has
a value greater than zero then the aspect option is ignored and
the width option determines the line length. If this option has
a value less than or equal to zero, then the aspect option
determines the line length.
The message command creates a new window (given by the pathName argu-
ment) and makes it into a message widget. Additional options,
described above, may be specified on the command line or in the option
database to configure aspects of the message such as its colors, font,
text, and initial relief. The message command returns its pathName
argument. At the time this command is invoked, there must not exist a
window named pathName, but pathName's parent must exist.
A message is a widget that displays a textual string. A message widget
has three special features. First, it breaks up its string into lines
in order to produce a given aspect ratio for the window. The line
breaks are chosen at word boundaries wherever possible (if not even a
single word would fit on a line, then the word will be split across
lines). Newline characters in the string will force line breaks; they
can be used, for example, to leave blank lines in the display.
The second feature of a message widget is justification. The text may
be displayed left-justified (each line starts at the left side of the
window), centered on a line-by-line basis, or right-justified (each
line ends at the right side of the window).
The third feature of a message widget is that it handles control char-
acters and non-printing characters specially. Tab characters are
replaced with enough blank space to line up on the next 8-character
boundary. Newlines cause line breaks. Other control characters (ASCII
code less than 0x20) and characters not defined in the font are dis-
played as a four-character sequence \xhh where hh is the two-digit hex-
adecimal number corresponding to the character. In the unusual case
where the font doesn't contain all of the characters in
``0123456789abcdef\x'' then control characters and undefined characters
are not displayed at all.
The message command creates a new Tcl command whose name is pathName.
This command may be used to invoke various operations on the widget.
It has the following general form:
pathName option ?arg arg ...?
Option and the args determine the exact behavior of the command. The
following commands are possible for message widgets:
pathName cget option
Returns the current value of the configuration option given by
option. Option may have any of the values accepted by the mes-
pathName configure ?option? ?value option value ...?
Query or modify the configuration options of the widget. If no
option is specified, returns a list describing all of the avail-
able options for pathName (see Tk_ConfigureInfo for information
on the format of this list). If option is specified with no
value, then the command returns a list describing the one named
option (this list will be identical to the corresponding sublist
of the value returned if no option is specified). If one or
more option-value pairs are specified, then the command modifies
the given widget option(s) to have the given value(s); in this
case the command returns an empty string. Option may have any
of the values accepted by the message command.
When a new message is created, it has no default event bindings: mes-
sages are intended for output purposes only.
Tabs don't work very well with text that is centered or right-justi-
fied. The most common result is that the line is justified wrong.
Tk 4.0 message(n)