selection(n) Tk (4.0) selection(n)
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NAME
selection - Manipulate the X selection
SYNOPSIS
selection option ?arg arg ...?
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DESCRIPTION
This command provides a Tcl interface to the X selection
mechanism and implements the full selection functionality
described in the X Inter-Client Communication Conventions
Manual (ICCCM).
The first argument to selection determines the format of the
rest of the arguments and the behavior of the command. The
following forms are currently supported:
selection clear ?-displayof window? ?-selection selection?
If selection exists anywhere on window'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 and window defaults to ``.''.
Returns an empty string.
type?
selection get ?-displayof window? ?-selection selection? ?-type
Retrieves the value of selection from window's display
and returns it as a result. Selection defaults to
PRIMARY and window defaults to ``.''. 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 the
selection is returned in a non-string format, such as
INTEGER or ATOM, the selection command converts it to
string format as a collection of fields separated by
spaces: atoms are converted to their textual names, and
anything else is converted to hexadecimal integers.
format? window command
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selection(n) Tk (4.0) selection(n)selection handle ?-selection selection? ?-type type? ?-format
Creates a handler for selection requests, such that
command will be executed whenever selection is owned by
window 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
command is an empty string then any existing handler
for window, type, and selection is removed.
When selection is requested, window is the selection
owner, and type is the requested type, command will be
executed as a Tcl command with two additional numbers
appended to it (with space separators). The two
additional numbers 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 command with increasing
offset values. If command 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 command's result is equal
to maxBytes then command 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 command returns an error 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 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 selection requesters that don't use Tk. If Tk is
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selection(n) Tk (4.0) selection(n)
being used to retrieve the selection then the value is
converted back to a string at the requesting end, so
format is irrelevant.
selection own ?-displayof window? ?-selection selection?
selection own ?-command command? ?-selection selection? window
The first form of selection own returns the path name
of the window in this application that owns selection
on the display containing window, or an empty string if
no window in this application owns the selection.
Selection defaults to PRIMARY and window defaults to
``.''.
The second form of selection own causes window to become the
new owner of selection on window's display, returning an
empty string as result. The existing owner, if any, is
notified that it has lost the selection. If command is
specified, it is a Tcl script to execute when some other
window claims ownership of the selection away from window.
Selection defaults to PRIMARY.
KEYWORDS
clear, format, handler, ICCCM, own, selection, target, type
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