selection(n) Tk Built-In Commands 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).
Note that for management of the CLIPBOARD selection (see below), the clipboard command may also be
used.
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 selec-tion selection
tion 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.
selection get ?-displayof window? ?-selection selection? ?-type 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 selec-tion selection
tion 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 Conven-tions Conventions
tions 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 sepa-rated separated
rated by spaces: atoms are converted to their textual names, and anything else is converted to
hexadecimal integers.
selection handle ?-selection selection? ?-type type? ?-format format? window command
Creates a handler for selection requests, such that command will be executed whenever selec-tion selection
tion 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 maxChars: offset specifies a |
starting character position in the selection and maxChars gives the maximum number of charac- |
ters to retrieve. The command should return a value consisting of at most maxChars of the |
selection, starting at position offset. For very large selections (larger than maxChars) the |
selection will be retrieved using several invocations of command with increasing offset val- |
ues. If command returns a string whose length is less than maxChars, the return value is |
assumed to include all of the remainder of the selection; if the length of command's result |
is equal to maxChars then command will be invoked again, until it eventually returns a result |
shorter than maxChars. The value of maxChars will always be relatively large (thousands of |
characters).
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 for-mat format
mat 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 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 dis-play, display,
play, 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.
SEE ALSO
clipboard
KEYWORDS
clear, format, handler, ICCCM, own, selection, target, type
Tk 8.1 selection(n)
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