message(n) Tk Built-In Commands message(n)_________________________________________________________________NAMEmessage - Create and manipulate message widgets
SYNOPSISmessage pathName ?options?
STANDARD OPTIONS-anchor-font-highlightthickness-takefocus
-background-foreground-padx-text
-borderwidth-highlightbackground-pady-textvariable
-cursor-highlightcolor-relief-width
See the options manual entry for details on the standard
options.
WIDGET-SPECIFIC OPTIONS
Command-Line Name:-aspect
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.
Command-Line Name:-justify
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 provide 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 dis-
played 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
Tk 4.0 1
message(n) Tk Built-In Commands message(n)
window.
Command-Line Name:-width
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.
_________________________________________________________________DESCRIPTION
The message command creates a new window (given by the
pathName argument) 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 characters 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 hexadecimal number corresponding to the charac-
ter. In the unusual case where the font doesn't contain
all of the characters in ``0123456789abcdef\x'' then con-
trol characters and undefined characters are not displayed
Tk 4.0 2
message(n) Tk Built-In Commands message(n)
at all.
WIDGET COMMAND
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 message command.
pathName configure ?option? ?value option value ...?
Query or modify the configuration options of the
widget. If no option is specified, returns a list
describing all of the available options for path-
Name (see Tk_ConfigureInfo for information on the
format of this list). If option is specified with
no value, then the command returns a list describ-
ing the one named option (this list will be identi-
cal 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.
DEFAULT BINDINGS
When a new message is created, it has no default event
bindings: messages are intended for output purposes only.
BUGS
Tabs don't work very well with text that is centered or
right-justified. The most common result is that the line
is justified wrong.
KEYWORDS
message, widget
Tk 4.0 3
