NAME¶
message - Create and manipulate message widgets
SYNOPSIS¶
message pathName ?
options?
STANDARD OPTIONS¶
-anchor -background -borderwidth
-cursor -font -foreground
-highlightbackground -highlightcolor -highlightthickness
-padx -pady -relief
-takefocus -text -textvariable
See the
options manual entry for details on the standard 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 is not 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 text will be 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.
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 displayed as a four-character sequence
\xhh where
hh is the two-digit hexadecimal number
corresponding to the character. In the unusual case where the font does not
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
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 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.
DEFAULT BINDINGS¶
When a new message is created, it has no default event bindings: messages are
intended for output purposes only.
BUGS¶
Tabs do not work very well with text that is centered or right-justified. The
most common result is that the line is justified wrong.
SEE ALSO¶
label(3tk)
KEYWORDS¶
message, widget
