Subversion Repositories or1k_old

'\"

'\" Copyright (c) 1990 The Regents of the University of California.

'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.

'\"

'\" See the file "license.terms" for information on usage and redistribution

'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.

'\"

'\" RCS: @(#) $Id: listbox.n,v 1.1.1.1 2002-01-16 10:25:49 markom Exp $

'\"

.so man.macros

.TH listbox n 8.0 Tk "Tk Built-In Commands"

.BS

'\" Note:  do not modify the .SH NAME line immediately below!

.SH NAME

listbox \- Create and manipulate listbox widgets

.SH SYNOPSIS

\fBlistbox\fR \fIpathName \fR?\fIoptions\fR?

.SO

\-background    \-foreground    \-relief        \-takefocus

\-borderwidth   \-height        \-selectbackground      \-width

\-cursor        \-highlightbackground   \-selectborderwidth     \-xscrollcommand

\-exportselection       \-highlightcolor        \-selectforeground      \-yscrollcommand

\-font  \-highlightthickness    \-setgrid

.SE

.SH "WIDGET-SPECIFIC OPTIONS"

.OP \-height height Height

Specifies the desired height for the window, in lines.

If zero or less, then the desired height for the window is made just

large enough to hold all the elements in the listbox.

.OP \-selectmode selectMode SelectMode

Specifies one of several styles for manipulating the selection.

The value of the option may be arbitrary, but the default bindings

expect it to be either \fBsingle\fR, \fBbrowse\fR, \fBmultiple\fR,

or \fBextended\fR;  the default value is \fBbrowse\fR.

.OP \-width width Width

Specifies the desired width for the window in characters.

If the font doesn't have a uniform width then the width of the

character ``0'' is used in translating from character units to

screen units.

If zero or less, then the desired width for the window is made just

large enough to hold all the elements in the listbox.

.BE

.SH DESCRIPTION

.PP

The \fBlistbox\fR command creates a new window (given by the

\fIpathName\fR argument) and makes it into a listbox widget.

Additional

options, described above, may be specified on the command line

or in the option database

to configure aspects of the listbox such as its colors, font,

text, and relief.  The \fBlistbox\fR command returns its

\fIpathName\fR argument.  At the time this command is invoked,

there must not exist a window named \fIpathName\fR, but

\fIpathName\fR's parent must exist.

.PP

A listbox is a widget that displays a list of strings, one per line.

When first created, a new listbox has no elements.

Elements may be added or deleted using widget commands described

below.  In addition, one or more elements may be selected as described

below.

If a listbox is exporting its selection (see \fBexportSelection\fR

option), then it will observe the standard X11 protocols

for handling the selection.

Listbox selections are available as type \fBSTRING\fR;

the value of the selection will be the text of the selected elements, with

newlines separating the elements.

.PP

It is not necessary for all the elements to be

displayed in the listbox window at once;  commands described below

may be used to change the view in the window.  Listboxes allow

scrolling in both directions using the standard \fBxScrollCommand\fR

and \fByScrollCommand\fR options.

They also support scanning, as described below.

.SH "INDICES"

.PP

Many of the widget commands for listboxes take one or more indices

as arguments.

An index specifies a particular element of the listbox, in any of

the following ways:

.TP 12

\fInumber\fR

Specifies the element as a numerical index, where 0 corresponds

to the first element in the listbox.

.TP 12

\fBactive\fR

Indicates the element that has the location cursor.  This element

will be displayed with an underline when the listbox has the

keyboard focus, and it is specified with the \fBactivate\fR

widget command.

.TP 12

\fBanchor\fR

Indicates the anchor point for the selection, which is set with the

\fBselection anchor\fR widget command.

.TP 12

\fBend\fR

Indicates the end of the listbox.

.VS 8.0

For most commands this refers to the last element in the listbox,

but for a few commands such as \fBindex\fR and \fBinsert\fR

it refers to the element just after the last one.

.VE

.TP 12

\fB@\fIx\fB,\fIy\fR

Indicates the element that covers the point in the listbox window

specified by \fIx\fR and \fIy\fR (in pixel coordinates).  If no

element covers that point, then the closest element to that

point is used.

.LP

In the widget command descriptions below, arguments named \fIindex\fR,

\fIfirst\fR, and \fIlast\fR always contain text indices in one of

the above forms.

.SH "WIDGET COMMAND"

.PP

The \fBlistbox\fR command creates a new Tcl command whose

name is \fIpathName\fR.  This

command may be used to invoke various

operations on the widget.  It has the following general form:

.CS

\fIpathName option \fR?\fIarg arg ...\fR?

.CE

\fIOption\fR and the \fIarg\fRs

determine the exact behavior of the command.  The following

commands are possible for listbox widgets:

.TP

\fIpathName \fBactivate\fR \fIindex\fR

Sets the active element to the one indicated by \fIindex\fR.

.VS 8.0

If \fIindex\fR is outside the range of elements in the listbox

then the closest element is activated.

.VE

The active element is drawn with an underline when the widget

has the input focus, and its index may be retrieved with the

index \fBactive\fR.

.TP

\fIpathName \fBbbox\fR \fIindex\fR

Returns a list of four numbers describing the bounding box of

the text in the element given by \fIindex\fR.

The first two elements of the list give the x and y coordinates

of the upper-left corner of the screen area covered by the text

(specified in pixels relative to the widget) and the last two

elements give the width and height of the area, in pixels.

If no part of the element given by \fIindex\fR is visible on the

screen,

.VS 8.0

or if \fIindex\fR refers to a non-existent element,

.VE

then the result is an empty string;  if the element is

partially visible, the result gives the full area of the element,

including any parts that are not visible.

.TP

\fIpathName \fBcget\fR \fIoption\fR

Returns the current value of the configuration option given

by \fIoption\fR.

\fIOption\fR may have any of the values accepted by the \fBlistbox\fR

command.

.TP

\fIpathName \fBconfigure\fR ?\fIoption\fR? ?\fIvalue option value ...\fR?

Query or modify the configuration options of the widget.

If no \fIoption\fR is specified, returns a list describing all of

the available options for \fIpathName\fR (see \fBTk_ConfigureInfo\fR for

information on the format of this list).  If \fIoption\fR is specified

with no \fIvalue\fR, 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 \fIoption\fR is specified).  If

one or more \fIoption\-value\fR 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.

\fIOption\fR may have any of the values accepted by the \fBlistbox\fR

command.

.TP

\fIpathName \fBcurselection\fR

Returns a list containing the numerical indices of

all of the elements in the listbox that are currently selected.

If there are no elements selected in the listbox then an empty

string is returned.

.TP

\fIpathName \fBdelete \fIfirst \fR?\fIlast\fR?

Deletes one or more elements of the listbox.  \fIFirst\fR and \fIlast\fR

are indices specifying the first and last elements in the range

to delete.  If \fIlast\fR isn't specified it defaults to

\fIfirst\fR, i.e. a single element is deleted.

.TP

\fIpathName \fBget \fIfirst\fR ?\fIlast\fR?

If \fIlast\fR is omitted, returns the contents of the listbox

element indicated by \fIfirst\fR,

.VS 8.0

or an empty string if \fIfirst\fR refers to a non-existent element.

.VE

If \fIlast\fR is specified, the command returns a list whose elements

are all of the listbox elements between \fIfirst\fR and \fIlast\fR,

inclusive.

Both \fIfirst\fR and \fIlast\fR may have any of the standard

forms for indices.

.TP

\fIpathName \fBindex \fIindex\fR

Returns the integer index value that corresponds to \fIindex\fR.

.VS 8.0

If \fIindex\fR is \fBend\fR the return value is a count of the number

of elements in the listbox (not the index of the last element).

.VE

.TP

\fIpathName \fBinsert \fIindex \fR?\fIelement element ...\fR?

Inserts zero or more new elements in the list just before the

element given by \fIindex\fR.  If \fIindex\fR is specified as

\fBend\fR then the new elements are added to the end of the

list.  Returns an empty string.

.TP

\fIpathName \fBnearest \fIy\fR

Given a y-coordinate within the listbox window, this command returns

the index of the (visible) listbox element nearest to that y-coordinate.

.TP

\fIpathName \fBscan\fR \fIoption args\fR

This command is used to implement scanning on listboxes.  It has

two forms, depending on \fIoption\fR:

.RS

.TP

\fIpathName \fBscan mark \fIx y\fR

Records \fIx\fR and \fIy\fR and the current view in the listbox

window;  used in conjunction with later \fBscan dragto\fR commands.

Typically this command is associated with a mouse button press in

the widget.  It returns an empty string.

.TP

\fIpathName \fBscan dragto \fIx y\fR.

This command computes the difference between its \fIx\fR and \fIy\fR

arguments and the \fIx\fR and \fIy\fR arguments to the last

\fBscan mark\fR command for the widget.

It then adjusts the view by 10 times the

difference in coordinates.  This command is typically associated

with mouse motion events in the widget, to produce the effect of

dragging the list at high speed through the window.  The return

value is an empty string.

.RE

.TP

\fIpathName \fBsee \fIindex\fR

Adjust the view in the listbox so that the element given by \fIindex\fR

is visible.

If the element is already visible then the command has no effect;

if the element is near one edge of the window then the listbox

scrolls to bring the element into view at the edge;  otherwise

the listbox scrolls to center the element.

.TP

\fIpathName \fBselection \fIoption arg\fR

This command is used to adjust the selection within a listbox.  It

has several forms, depending on \fIoption\fR:

.RS

.TP

\fIpathName \fBselection anchor \fIindex\fR

Sets the selection anchor to the element given by \fIindex\fR.

.VS 8.0

If \fIindex\fR refers to a non-existent element, then the closest

element is used.

.VE

The selection anchor is the end of the selection that is fixed

while dragging out a selection with the mouse.

The index \fBanchor\fR may be used to refer to the anchor

element.

.TP

\fIpathName \fBselection clear \fIfirst \fR?\fIlast\fR?

If any of the elements between \fIfirst\fR and \fIlast\fR

(inclusive) are selected, they are deselected.

The selection state is not changed for elements outside

this range.

.TP

\fIpathName \fBselection includes \fIindex\fR

Returns 1 if the element indicated by \fIindex\fR is currently

selected, 0 if it isn't.

.TP

\fIpathName \fBselection set \fIfirst \fR?\fIlast\fR?

Selects all of the elements in the range between

\fIfirst\fR and \fIlast\fR, inclusive, without affecting

the selection state of elements outside that range.

.RE

.TP

\fIpathName \fBsize\fR

Returns a decimal string indicating the total number of elements

in the listbox.

.TP

\fIpathName \fBxview \fIargs\fR

This command is used to query and change the horizontal position of the

information in the widget's window.  It can take any of the following

forms:

.RS

.TP

\fIpathName \fBxview\fR

Returns a list containing two elements.

Each element is a real fraction between 0 and 1;  together they describe

the horizontal span that is visible in the window.

For example, if the first element is .2 and the second element is .6,

20% of the listbox's text is off-screen to the left, the middle 40% is visible

in the window, and 40% of the text is off-screen to the right.

These are the same values passed to scrollbars via the \fB\-xscrollcommand\fR

option.

.TP

\fIpathName \fBxview\fR \fIindex\fR

Adjusts the view in the window so that the character position given by

\fIindex\fR is displayed at the left edge of the window.

Character positions are defined by the width of the character \fB0\fR.

.TP

\fIpathName \fBxview moveto\fI fraction\fR

Adjusts the view in the window so that \fIfraction\fR of the

total width of the listbox text is off-screen to the left.

\fIfraction\fR must be a fraction between 0 and 1.

.TP

\fIpathName \fBxview scroll \fInumber what\fR

This command shifts the view in the window left or right according to

\fInumber\fR and \fIwhat\fR.

\fINumber\fR must be an integer.

\fIWhat\fR must be either \fBunits\fR or \fBpages\fR or an abbreviation

of one of these.

If \fIwhat\fR is \fBunits\fR, the view adjusts left or right by

\fInumber\fR character units (the width of the \fB0\fR character)

on the display;  if it is \fBpages\fR then the view adjusts by

\fInumber\fR screenfuls.

If \fInumber\fR is negative then characters farther to the left

become visible;  if it is positive then characters farther to the right

become visible.

.RE

.TP

\fIpathName \fByview \fI?args\fR?

This command is used to query and change the vertical position of the

text in the widget's window.

It can take any of the following forms:

.RS

.TP

\fIpathName \fByview\fR

Returns a list containing two elements, both of which are real fractions

between 0 and 1.

The first element gives the position of the listbox element at the

top of the window, relative to the listbox as a whole (0.5 means

it is halfway through the listbox, for example).

The second element gives the position of the listbox element just after

the last one in the window, relative to the listbox as a whole.

These are the same values passed to scrollbars via the \fB\-yscrollcommand\fR

option.

.TP

\fIpathName \fByview\fR \fIindex\fR

Adjusts the view in the window so that the element given by

\fIindex\fR is displayed at the top of the window.

.TP

\fIpathName \fByview moveto\fI fraction\fR

Adjusts the view in the window so that the element given by \fIfraction\fR

appears at the top of the window.

\fIFraction\fR is a fraction between 0 and 1;  0 indicates the first

element in the listbox, 0.33 indicates the element one-third the

way through the listbox, and so on.

.TP

\fIpathName \fByview scroll \fInumber what\fR

This command adjusts the view in the window up or down according to

\fInumber\fR and \fIwhat\fR.

\fINumber\fR must be an integer.

\fIWhat\fR must be either \fBunits\fR or \fBpages\fR.

If \fIwhat\fR is \fBunits\fR, the view adjusts up or down by

\fInumber\fR lines;  if it is \fBpages\fR then

the view adjusts by \fInumber\fR screenfuls.

If \fInumber\fR is negative then earlier elements

become visible;  if it is positive then later elements

become visible.

.RE

.SH "DEFAULT BINDINGS"

.PP

Tk automatically creates class bindings for listboxes that give them

Motif-like behavior.  Much of the behavior of a listbox is determined

by its \fBselectMode\fR option, which selects one of four ways

of dealing with the selection.

.PP

If the selection mode is \fBsingle\fR or \fBbrowse\fR, at most one

element can be selected in the listbox at once.

In both modes, clicking button 1 on an element selects

it and deselects any other selected item.

In \fBbrowse\fR mode it is also possible to drag the selection

with button 1.

.PP

If the selection mode is \fBmultiple\fR or \fBextended\fR,

any number of elements may be selected at once, including discontiguous

ranges.  In \fBmultiple\fR mode, clicking button 1 on an element

toggles its selection state without affecting any other elements.

In \fBextended\fR mode, pressing button 1 on an element selects

it, deselects everything else, and sets the anchor to the element

under the mouse;  dragging the mouse with button 1

down extends the selection to include all the elements between

the anchor and the element under the mouse, inclusive.

.PP

Most people will probably want to use \fBbrowse\fR mode for

single selections and \fBextended\fR mode for multiple selections;

the other modes appear to be useful only in special situations.

.PP

In addition to the above behavior, the following additional behavior

is defined by the default bindings:

.IP [1]

In \fBextended\fR mode, the selected range can be adjusted by pressing

button 1 with the Shift key down:  this modifies the selection to

consist of the elements between the anchor and the element under

the mouse, inclusive.

The un-anchored end of this new selection can also be dragged with

the button down.

.IP [2]

In \fBextended\fR mode, pressing button 1 with the Control key down

starts a toggle operation: the anchor is set to the element under

the mouse, and its selection state is reversed.  The selection state

of other elements isn't changed.

If the mouse is dragged with button 1 down, then the selection state

of all elements between the anchor and the element under the mouse

is set to match that of the anchor element;  the selection state of

all other elements remains what it was before the toggle operation

began.

.IP [3]

If the mouse leaves the listbox window with button 1 down, the window

scrolls away from the mouse, making information visible that used

to be off-screen on the side of the mouse.

The scrolling continues until the mouse re-enters the window, the

button is released, or the end of the listbox is reached.

.IP [4]

Mouse button 2 may be used for scanning.

If it is pressed and dragged over the listbox, the contents of

the listbox drag at high speed in the direction the mouse moves.

.IP [5]

If the Up or Down key is pressed, the location cursor (active

element) moves up or down one element.

If the selection mode is \fBbrowse\fR or \fBextended\fR then the

new active element is also selected and all other elements are

deselected.

In \fBextended\fR mode the new active element becomes the

selection anchor.

.IP [6]

In \fBextended\fR mode, Shift-Up and Shift-Down move the location

cursor (active element) up or down one element and also extend

the selection to that element in a fashion similar to dragging

with mouse button 1.

.IP [7]

The Left and Right keys scroll the listbox view left and right

by the width of the character \fB0\fR.

Control-Left and Control-Right scroll the listbox view left and

right by the width of the window.

Control-Prior and Control-Next also scroll left and right by

the width of the window.

.IP [8]

The Prior and Next keys scroll the listbox view up and down

by one page (the height of the window).

.IP [9]

The Home and End keys scroll the listbox horizontally to

the left and right edges, respectively.

.IP [10]

Control-Home sets the location cursor to the the first element in

the listbox, selects that element, and deselects everything else

in the listbox.

.IP [11]

Control-End sets the location cursor to the the last element in

the listbox, selects that element, and deselects everything else

in the listbox.

.IP [12]

In \fBextended\fR mode, Control-Shift-Home extends the selection

to the first element in the listbox and Control-Shift-End extends

the selection to the last element.

.IP [13]

In \fBmultiple\fR mode, Control-Shift-Home moves the location cursor

to the first element in the listbox and Control-Shift-End moves

the location cursor to the last element.

.IP [14]

The space and Select keys make a selection at the location cursor

(active element) just as if mouse button 1 had been pressed over

this element.

.IP [15]

In \fBextended\fR mode, Control-Shift-space and Shift-Select

extend the selection to the active element just as if button 1

had been pressed with the Shift key down.

.IP [16]

In \fBextended\fR mode, the Escape key cancels the most recent

selection and restores all the elements in the selected range

to their previous selection state.

.IP [17]

Control-slash selects everything in the widget, except in

\fBsingle\fR and \fBbrowse\fR modes, in which case it selects

the active element and deselects everything else.

.IP [18]

Control-backslash deselects everything in the widget, except in

\fBbrowse\fR mode where it has no effect.

.IP [19]

The F16 key (labelled Copy on many Sun workstations) or Meta-w

copies the selection in the widget to the clipboard, if there is

a selection.

.PP

The behavior of listboxes can be changed by defining new bindings for

individual widgets or by redefining the class bindings.

.SH KEYWORDS

listbox, widget