place(n) Tk place(n)
_________________________________________________________________
NAME
place - Geometry manager for fixed or rubber-sheet placement
SYNOPSIS
place window option value ?option value ...?
place configure window option value ?option value ...?
place forget window
place info window
place slaves window
_________________________________________________________________
DESCRIPTION
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 slave, within another
window, called the master. 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.
If the first argument to the place command is a window path
name or configure then the command arranges for the placer
to manage the geometry of a slave whose path name is window.
The remaining arguments consist of one or more option-value
pairs that specify the way in which window's geometry is
managed. If the placer is already managing window, then the
option-value pairs modify the configuration for window. In
this form the place command returns an empty string as
result. The following option-value pairs are supported:
-in master
Master specifes the path name of the window relative to
which window is to be placed. Master must either be
window's parent or a descendant of window's parent. In
addition, master and window must both be descendants of
the same top-level window. These restrictions are
necessary to guarantee that window is visible whenever
master is visible. If this option isn't specified then
the master defaults to window's parent.
-x location
Page 1 (printed 2/26/99)
place(n) Tk place(n)
Location specifies the x-coordinate within the master
window of the anchor point for window. The location is
specified in screen units (i.e. any of the forms
accepted by Tk_GetPixels) and need not lie within the
bounds of the master window.
-relx location
Location specifies the x-coordinate within the master
window of the anchor point for window. 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. Location need not be in the range
0.0-1.0. If both -x and -relx are specified for a
slave then their values are summed. For example, -relx
0.5 -x -2 positions the left edge of the slave 2 pixels
to the left of the center of its master.
-y location
Location specifies the y-coordinate within the master
window of the anchor point for window. The location is
specified in screen units (i.e. any of the forms
accepted by Tk_GetPixels) and need not lie within the
bounds of the master window.
-rely location
Location specifies the y-coordinate within the master
window of the anchor point for window. 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. Location need not be in the range 0.0-1.0.
If both -y and -rely are specified for a slave then
their values are summed. For example, -rely 0.5 -x 3
positions the top edge of the slave 3 pixels below the
center of its master.
-anchor where
Where specifies which point of window is to be
positioned at the (x,y) location selected by the -x,
-y, -relx, and -rely options. The anchor point is in
terms of the outer area of window including its border,
if any. Thus if where is se then the lower-right
corner of window's border will appear at the given
(x,y) location in the master. The anchor position
defaults to nw.
-width size
Size specifies the width for window in screen units
(i.e. any of the forms accepted by Tk_GetPixels). The
width will be the outer width of window including its
border, if any. If size is an empty string, or if no
Page 2 (printed 2/26/99)
place(n) Tk place(n)-width or -relwidth option is specified, then the width
requested internally by the window will be used.
-relwidth size
Size specifies the width for window. In this case the
width is specified as a floating-point number relative
to the width of the master: 0.5 means window will be
half as wide as the master, 1.0 means window will have
the same width as the master, and so on. If both
-width and -relwidth are specified for a slave, their
values are summed. For example, -relwidth 1.0 -width 5
makes the slave 5 pixels wider than the master.
-height size
Size specifies the height for window in screen units
(i.e. any of the forms accepted by Tk_GetPixels). The
height will be the outer dimension of window including
its border, if any. If size is an empty string, or if
no -height or -relheight option is specified, then the
height requested internally by the window will be used.
-relheight size
Size specifies the height for window. In this case the
height is specified as a floating-point number relative
to the height of the master: 0.5 means window will be
half as high as the master, 1.0 means window will have
the same height as the master, and so on. If both
-height and -relheight are specified for a slave, their
values are summed. For example, -relheight 1.0 -height
-2 makes the slave 2 pixels shorter than the master.
-bordermode mode
Mode 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 inside.
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 -x 0 corresponds to an x-
coordinate just inside the border and an option of
-relwidth 1.0 means window will fill the area inside
the master's border. If mode is outside then the
placer considers the area of the master to include its
border; this mode is typically used when placing window
outside its master, as with the options -x 0 -y 0
-anchor ne. Lastly, mode may be specified as ignore,
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 ignore is probably not very useful.
If the same value is specified separately with two different
options, such as -x and -relx, then the most recent option
Page 3 (printed 2/26/99)
place(n) Tk place(n)
is used and the older one is ignored.
The place slaves command returns a list of all the slave
windows for which window is the master. If there are no
slaves for window then an empty string is returned.
The place forget command causes the placer to stop managing
the geometry of window. As a side effect of this command
window will be unmapped so that it doesn't appear on the
screen. If window isn't currently managed by the placer
then the command has no effect. Place forget returns an
empty string as result.
The place info command returns a list giving the current
configuration of window. The list consists of option-value
pairs in exactly the same form as might be specified to the
place configure command. If the configuration of a window
has been retrieved with place info, that configuration can
be restored later by first using place forget to erase any
existing information for the window and then invoking place
configure with the saved information.
FINE POINTS
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.
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
-in sibling -relx 0.5 -rely 1.0 -anchor n -bordermode outside
Whenever the sibling is repositioned in the future, the
slave will be repositioned as well.
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
Page 4 (printed 2/26/99)
place(n) Tk place(n)
that provide configuration options for this purpose.
KEYWORDS
geometry manager, height, location, master, place, rubber
sheet, slave, width
Page 5 (printed 2/26/99)
