selection(n) Tk Built-In Commands selection(n)
selection - Manipulate the X selection
selection option ?arg arg ...?
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
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 Com-
munication 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 selection is to be returned (the desired ``target'' for conver-
sion, 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.
selection handle ?-selection selection? ?-type type? ?-format format? window command
Creates a handler for selection requests, such that command will be executed when-
ever 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 selec-
tion 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 num-
bers 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 characters to retrieve. The command should |
return a value consisting of at most maxChars of the selection, starting at posi- |
tion offset. For very large selections (larger than maxChars) the selection will |
be retrieved using several invocations of command with increasing offset values. |
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 com- |
mand'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 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 being used to retrieve the selection then the value is con-
verted 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 appli-
cation 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. Selec-
tion defaults to PRIMARY.
clear, format, handler, ICCCM, own, selection, target, type
Tk 8.1 selection(n)