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place(n) Tk Built-In Commands place(n)
NAME
place - Geometry manager for fixed or rubber-sheet placement
SYNOPSIS
place option arg ?arg ...?
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 mas-
ter, 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.
place window option value ?option value ...?
Arrange for the placer to manage the geometry of a slave whose
pathName is window. The remaining arguments consist of one or
more option-value pairs that specify the way in which window's
geometry is managed. Option may have any of the values accepted
by the place configure command.
place configure window ?option? ?value option value ...?
Query or modify the geometry options of the slave given by win-
dow. If no option is specified, this command returns a list
describing the available options (see Tk_ConfigureInfo for
information on the format of this list). If option is specified
with no value, then the command returns a list describing the
one named option (this list will be identical to the correspond-
ing sublist of the value returned if no option is specified).
If one or more option-value pairs are specified, then the com-
mand modifies the given option(s) to have the given value(s); in
this case the command returns an empty string.
The following option-value pairs are supported:
-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 bor-
der will appear at the given (x,y) location in the mas-
ter. The anchor position defaults to nw.
-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 speci-
fied 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 use-
ful.
-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.
-in master
Master specifies the path name of the window relative to
which window is to be placed. Master must either be win-
dow'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 neces-
sary to guarantee that window is visible whenever master
is visible. If this option isn't specified then the mas-
ter defaults to window's parent.
-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.
-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 -rel-
width 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.
-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 float-
ing-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 posi-
tions the left edge of the slave 2 pixels to the left of
the center of its master.
-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 mas-
ter. 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.
-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 -width or
-relwidth option is specified, then the width requested
internally by the window will be used.
-x location
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.
-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.
If the same value is specified separately with two different
options, such as -x and -relx, then the most recent option is
used and the older one is ignored.
place forget window
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. This command
returns an empty string.
place info window
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.
place slaves window
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.
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 subwin-
dows 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-man-
agement 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 reposi-
tioned 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 win-
dows 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.
EXAMPLE
Make the label occupy the middle bit of the toplevel, no matter how it
is resized: label .l -text "In the\nMiddle!" -bg black -fg white place
.l -relwidth .3 -relx .35 -relheight .3 -rely .35
SEE ALSO
grid(n), pack(n)
KEYWORDS
geometry manager, height, location, master, place, rubber sheet, slave,
width
Tk place(n)
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