Tk::selection - Manipulate the X selection
$widget->SelectionOption?(args)?
User Contributed Perl Documentation selection(3)
NAME
Tk::Selection - Manipulate the X selection
SYNOPSIS
$widget->SelectionOption?(args)?
DESCRIPTION
This command provides an interface to the X selection mechanism and
implements the full selection functionality described in the X Inter-
Client Communication Conventions Manual (ICCCM).
The widget object used to invoke the methods below determines which
display is used to access the selection. In order to avoid conflicts
with selection methods of widget classes (e.g. Text) this set of
methods uses the prefix Selection. The following methods are currently
supported:
$widget->SelectionClear?(-selection=>selection)?
If selection exists anywhere on $widget's display, clear it so that
no window owns the selection anymore. Selection specifies the X
selection that should be cleared, and should be an atom name such
as PRIMARY or CLIPBOARD; see the Inter-Client Communication
Conventions Manual for complete details. Selection defaults to
PRIMARY. Returns an empty string.
$widget->SelectionGet?(?-selection=>selection?,?-type=>type?)?
Retrieves the value of selection from $widget's display and returns
it as a result. Selection defaults to PRIMARY.
Type specifies the form in which the selection is to be returned
(the desired ``target'' for conversion, in ICCCM terminology), and
should be an atom name such as STRING or FILE_NAME; see the Inter-
Client Communication Conventions Manual for complete details. Type
defaults to STRING. The selection owner may choose to return the
selection in any of several different representation formats, such
as STRING, ATOM, INTEGER, etc. (this format is different than the
selection type; see the ICCCM for all the confusing details).
If format is not STRING then things get messy, the following
description is from the Tcl/Tk man page as yet incompetely
translated for the perl version - it is misleading at best.
If the selection is returned in a non-string format, such as
INTEGER or ATOM, the SelectionGet converts it to a list of perl
values: atoms are converted to their textual names, and anything
else is converted integers.
A goal of the perl port is to provide better handling of different
formats than Tcl/Tk does, which should be possible given perl's
wider range of ``types''. Although some thought went into this in
very early days of perl/Tk what exactly happens is still "not quite
right" and subject to change.
$widget->SelectionHandle(?-selection=>selection?,?-type=>type?,?-format=>format?
callback)
Creates a handler for selection requests, such that callback will
be executed whenever selection is owned by $widget and someone
attempts to retrieve it in the form given by type (e.g. type is
specified in the selection get command). Selection defaults to
PRIMARY, type defaults to STRING, and format defaults to STRING.
If callback is an empty string then any existing handler for
$widget, type, and selection is removed.
When selection is requested, $widget is the selection owner, and
type is the requested type, callback will be executed with two
additional arguments. The two additional arguments are offset and
maxBytes: offset specifies a starting character position in the
selection and maxBytes gives the maximum number of bytes to
retrieve. The command should return a value consisting of at most
maxBytes of the selection, starting at position offset. For very
large selections (larger than maxBytes) the selection will be
retrieved using several invocations of callback with increasing
offset values. If callback returns a string whose length is less
than maxBytes, the return value is assumed to include all of the
remainder of the selection; if the length of callback's result is
equal to maxBytes then callback will be invoked again, until it
eventually returns a result shorter than maxBytes. The value of
maxBytes will always be relatively large (thousands of bytes).
If callback returns an error (e.g. via die) then the selection
retrieval is rejected just as if the selection didn't exist at all.
The format argument specifies the representation that should be
used to transmit the selection to the requester (the second column
of Table 2 of the ICCCM), and defaults to STRING. If format is
STRING, the selection is transmitted as 8-bit ASCII characters
(i.e. just in the form returned by command).
If format is not STRING then things get messy, the following
description is from the Tcl/Tk man page as yet untranslated for the
perl version - it is misleading at best.
If format is ATOM, then the return value from command is divided
into fields separated by white space; each field is converted to
its atom value, and the 32-bit atom value is transmitted instead of
the atom name. For any other format, the return value from command
is divided into fields separated by white space and each field is
converted to a 32-bit integer; an array of integers is transmitted
to the selection requester.
The format argument is needed only for compatibility with many
selection requesters, except Tcl/Tk. If Tcl/Tk is being used to
retrieve the selection then the value is converted back to a string
at the requesting end, so format is irrelevant.
A goal of the perl port is to provide better handling of different
formats than Tcl/Tk does, which should be possible given perl's
wider range of ``types''. Although some thought went into this in
very early days of perl/Tk what exactly happens is still "not quite
right" and subject to change.
$widget->SelectionOwner?(-selection=>selection)?
SelectionOwner returns the window in this application that owns
selection on the display containing $widget, or an empty string if
no window in this application owns the selection. Selection
defaults to PRIMARY.
$widget->SelectionOwn?(?-command=>callback?,?-selection=>selection?)?
SelectionOwn causes $widget to become the new owner of selection on
$widget's display, returning an empty string as result. The
existing owner, if any, is notified that it has lost the selection.
If callback is specified, it will be executed when some other
window claims ownership of the selection away from $widget.
Selection defaults to PRIMARY.
KEYWORDS
clear, format, handler, ICCCM, own, selection, target, type
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+----------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+----------------------------+
|Availability | library/perl-5/perl-tk-532 |
+---------------+----------------------------+
|Stability | Volatile |
+---------------+----------------------------+
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
http://search.cpan.org/CPAN/authors/id/S/SR/SREZIC/Tk-804.036.tar.gz.
Further information about this software can be found on the open source
community website at http://search.cpan.org/~srezic/Tk.
perl v5.32.0 2013-11-15 selection(3)