message(3)
NAME
Tk::Message - Create and manipulate Message widgets
SYNOPSIS
$message = $parent->Message(?options?);
STANDARD OPTIONS
-anchor -font -highlightthickness -takefocus -back ground -foreground -padx -text -border width -highlightbackground -pady -textvariable -cursor -highlightcolor -relief -width
See Tk::options for details of the standard options.
WIDGET-SPECIFIC OPTIONS
- Name: aspect
Class: Aspect
Switch: -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. - Name: justify
Class: Justify
Switch: -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 rectangu lar area is displayed within the widget's window, and
the justify option determines how each line is dis
played 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. - Name: width
Class: Width
Switch: -width - Specifies the length of lines in the window. The
value may have any of the forms acceptable to Tk_Get
Pixels. 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 method creates a new window (given by the
$widget 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 $widget
argument. At the time this command is invoked, there must
not exist a window named $widget, but $widget'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-byline 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 sequencehh 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 then con
trol characters and undefined characters are not displayed
at all.
WIDGET METHODS
The Message method creates a widget object. This object
supports the configure and cget methods described in
Tk::options which can be used to enquire and modify the
options described above. The widget also inherits all the
methods provided by the generic Tk::Widget class.
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