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'\"

'\" Copyright (c) 1992 The Regents of the University of California.

'\" Copyright (c) 1994-1996 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: place.n,v 1.1.1.1 2002-01-16 10:25:49 markom Exp $

'\"

.so man.macros

.TH place n "" Tk "Tk Built-In Commands"

.BS

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

.SH NAME

place \- Geometry manager for fixed or rubber-sheet placement

.SH SYNOPSIS

\fBplace \fIwindow option value \fR?\fIoption value ...\fR?

.sp

\fBplace configure \fIwindow option value \fR?\fIoption value ...\fR?

.sp

\fBplace forget \fIwindow\fR

.sp

\fBplace info \fIwindow\fR

.sp

\fBplace slaves \fIwindow\fR

.BE

.SH DESCRIPTION

.PP

The placer is a geometry manager for Tk.

It provides simple fixed placement of windows, where you specify

the exact size and location of one window, called the \fIslave\fR,

within another window, called the \fImaster\fR.

The placer also provides rubber-sheet placement, where you specify the

size and location of the slave in terms of the dimensions of

the master, so that the slave changes size and location

in response to changes in the size of the master.

Lastly, the placer allows you to mix these styles of placement so

that, for example, the slave has a fixed width and height but is

centered inside the master.

.PP

If the first argument to the \fBplace\fR command is a window path

name or \fBconfigure\fR then the command arranges for the placer

to manage the geometry of a slave whose path name is \fIwindow\fR.

The remaining arguments consist of one or more \fIoption\-value\fR

pairs that specify the way in which \fIwindow\fR's

geometry is managed.

If the placer is already managing \fIwindow\fR, then the

\fIoption\-value\fR pairs modify the configuration for \fIwindow\fR.

In this form the \fBplace\fR command returns an empty string as result.

The following \fIoption\-value\fR pairs are supported:

.TP

\fB\-in \fImaster\fR

\fIMaster\fR specifes the path name of the window relative

to which \fIwindow\fR is to be placed.

\fIMaster\fR must either be \fIwindow\fR's parent or a descendant

of \fIwindow\fR's parent.

In addition, \fImaster\fR and \fIwindow\fR must both be descendants

of the same top-level window.

These restrictions are necessary to guarantee

that \fIwindow\fR is visible whenever \fImaster\fR is visible.

If this option isn't specified then the master defaults to

\fIwindow\fR's parent.

.TP

\fB\-x \fIlocation\fR

\fILocation\fR specifies the x-coordinate within the master window

of the anchor point for \fIwindow\fR.

The location is specified in screen units (i.e. any of the forms

accepted by \fBTk_GetPixels\fR) and need not lie within the bounds

of the master window.

.TP

\fB\-relx \fIlocation\fR

\fILocation\fR specifies the x-coordinate within the master window

of the anchor point for \fIwindow\fR.

In this case the location is specified in a relative fashion

as a floating-point number:  0.0 corresponds to the left edge

of the master and 1.0 corresponds to the right edge of the master.

\fILocation\fR need not be in the range 0.0\-1.0.

If both \fB\-x\fR and \fB\-relx\fR are specified for a slave

then their values are summed.  For example, \fB\-relx 0.5 \-x \-2\fR

positions the left edge of the slave 2 pixels to the left of the

center of its master.

.TP

\fB\-y \fIlocation\fR

\fILocation\fR specifies the y-coordinate within the master window

of the anchor point for \fIwindow\fR.

The location is specified in screen units (i.e. any of the forms

accepted by \fBTk_GetPixels\fR) and need not lie within the bounds

of the master window.

.TP

\fB\-rely \fIlocation\fR

\fILocation\fR specifies the y-coordinate within the master window

of the anchor point for \fIwindow\fR.

In this case the value is specified in a relative fashion

as a floating-point number:  0.0 corresponds to the top edge

of the master and 1.0 corresponds to the bottom edge of the master.

\fILocation\fR need not be in the range 0.0\-1.0.

If both \fB\-y\fR and \fB\-rely\fR are specified for a slave

then their values are summed.  For example, \fB\-rely 0.5 \-x 3\fR

positions the top edge of the slave 3 pixels below the

center of its master.

.TP

\fB\-anchor \fIwhere\fR

\fIWhere\fR specifies which point of \fIwindow\fR is to be positioned

at the (x,y) location selected by the \fB\-x\fR, \fB\-y\fR,

\fB\-relx\fR, and \fB\-rely\fR options.

The anchor point is in terms of the outer area of \fIwindow\fR

including its border, if any.

Thus if \fIwhere\fR is \fBse\fR then the lower-right corner of

\fIwindow\fR's border will appear at the given (x,y) location

in the master.

The anchor position defaults to \fBnw\fR.

.TP

\fB\-width \fIsize\fR

\fISize\fR specifies the width for \fIwindow\fR in screen units

(i.e. any of the forms accepted by \fBTk_GetPixels\fR).

The width will be the outer width of \fIwindow\fR including its

border, if any.

If \fIsize\fR is an empty string, or if no \fB\-width\fR

or \fB\-relwidth\fR option is specified, then the width requested

internally by the window will be used.

.TP

\fB\-relwidth \fIsize\fR

\fISize\fR specifies the width for \fIwindow\fR.

In this case the width is specified as a floating-point number

relative to the width of the master: 0.5 means \fIwindow\fR will

be half as wide as the master, 1.0 means \fIwindow\fR will have

the same width as the master, and so on.

If both \fB\-width\fR and \fB\-relwidth\fR are specified for a slave,

their values are summed.  For example, \fB\-relwidth 1.0 \-width 5\fR

makes the slave 5 pixels wider than the master.

.TP

\fB\-height \fIsize\fR

\fISize\fR specifies the height for \fIwindow\fR in screen units

(i.e. any of the forms accepted by \fBTk_GetPixels\fR).

The height will be the outer dimension of \fIwindow\fR including its

border, if any.

If \fIsize\fR is an empty string, or if no \fB\-height\fR or

\fB\-relheight\fR option is specified, then the height requested

internally by the window will be used.

.TP

\fB\-relheight \fIsize\fR

\fISize\fR specifies the height for \fIwindow\fR.

In this case the height is specified as a floating-point number

relative to the height of the master: 0.5 means \fIwindow\fR will

be half as high as the master, 1.0 means \fIwindow\fR will have

the same height as the master, and so on.

If both \fB\-height\fR and \fB\-relheight\fR are specified for a slave,

their values are summed.  For example, \fB\-relheight 1.0 \-height \-2\fR

makes the slave 2 pixels shorter than the master.

.TP

\fB\-bordermode \fImode\fR

\fIMode\fR determines the degree to which borders within the

master are used in determining the placement of the slave.

The default and most common value is \fBinside\fR.

In this case the placer considers the area of the master to

be the innermost area of the master, inside any border:

an option of \fB\-x 0\fR corresponds to an x-coordinate just

inside the border and an option of \fB\-relwidth 1.0\fR

means \fIwindow\fR will fill the area inside the master's

border.

If \fImode\fR is \fBoutside\fR then the placer considers

the area of the master to include its border;

this mode is typically used when placing \fIwindow\fR

outside its master, as with the options \fB\-x 0 \-y 0 \-anchor ne\fR.

Lastly, \fImode\fR may be specified as \fBignore\fR, in which

case borders are ignored:  the area of the master is considered

to be its official X area, which includes any internal border but

no external border.  A bordermode of \fBignore\fR is probably

not very useful.

.PP

If the same value is specified separately with

two different options, such as \fB\-x\fR and \fB\-relx\fR, then

the most recent option is used and the older one is ignored.

.PP

The \fBplace slaves\fR command returns a list of all the slave

windows for which \fIwindow\fR is the master.

If there are no slaves for \fIwindow\fR then an empty string is

returned.

.PP

The \fBplace forget\fR command causes the placer to stop managing

the geometry of \fIwindow\fR.  As a side effect of this command

\fIwindow\fR will be unmapped so that it doesn't appear on the

screen.

If \fIwindow\fR isn't currently managed by the placer then the

command has no effect.

\fBPlace forget\fR returns an empty string as result.

.PP

The \fBplace info\fR command returns a list giving the current

configuration of \fIwindow\fR.

The list consists of \fIoption\-value\fR pairs in exactly the

same form as might be specified to the \fBplace configure\fR

command.

If the configuration of a window has been retrieved with

\fBplace info\fR, that configuration can be restored later by

first using \fBplace forget\fR to erase any existing information

for the window and then invoking \fBplace configure\fR with

the saved information.

.SH "FINE POINTS"

.PP

It is not necessary for the master window to be the parent

of the slave window.

This feature is useful in at least two situations.

First, for complex window layouts it means you can create a

hierarchy of subwindows whose only purpose

is to assist in the layout of the parent.

The ``real children'' of the parent (i.e. the windows that

are significant for the application's user interface) can be

children of the parent yet be placed inside the windows

of the geometry-management hierarchy.

This means that the path names of the ``real children''

don't reflect the geometry-management hierarchy and users

can specify options for the real children

without being aware of the structure of the geometry-management

hierarchy.

.PP

A second reason for having a master different than the slave's

parent is to tie two siblings together.

For example, the placer can be used to force a window always to

be positioned centered just below one of its

siblings by specifying the configuration

.CS

\fB\-in \fIsibling\fB \-relx 0.5 \-rely 1.0 \-anchor n \-bordermode outside\fR

.CE

Whenever the sibling is repositioned in the future, the slave

will be repositioned as well.

.PP

Unlike many other geometry managers (such as the packer)

the placer does not make any attempt to manipulate the geometry of

the master windows or the parents of slave windows (i.e. it doesn't

set their requested sizes).

To control the sizes of these windows, make them windows like

frames and canvases that provide configuration options for this purpose.

.SH KEYWORDS

geometry manager, height, location, master, place, rubber sheet, slave, width