place(3tk) Tk Built-In Commands place(3tk)
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NAME
place - Geometry manager for fixed or rubber-sheet placement
SYNOPSIS
place option arg ?arg ...?
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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 content, within another window, called the con-
tainer. The placer also provides rubber-sheet placement, where you
specify the size and location of the content in terms of the dimensions
of the container, so that the content changes size and location in re-
sponse to changes in the size of the container. Lastly, the placer al-
lows you to mix these styles of placement so that, for example, the
content has a fixed width and height but is centered inside the con-
tainer.
place window option value ?option value ...?
Arrange for the placer to manage the geometry of a content 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 content given by
window. If no option is specified, this command returns a list
describing the available options (see Tk_ConfigureInfo for in-
formation 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 con-
tainer. The anchor position defaults to nw.
-bordermode mode
Mode determines the degree to which borders within the
container are used in determining the placement of the
content. The default and most common value is inside.
In this case the placer considers the area of the con-
tainer to be the innermost area of the container, inside
any border: an option of -x 0 corresponds to an x-coordi-
nate just inside the border and an option of -relwidth
1.0 means window will fill the area inside the con-
tainer's border.
If mode is outside then the placer considers the area of
the container to include its border; this mode is typi-
cally used when placing window outside its container, as
with the options -x 0 -y 0 -anchor ne. Lastly, mode may
be specified as ignore, in which case borders are ig-
nored: the area of the container 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.
-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 container
Container specifies the path name of the window relative
to which window is to be placed. Container must either
be window's parent or a descendant of window's parent.
In addition, container and window must both be descen-
dants of the same top-level window. These restrictions
are necessary to guarantee that window is visible when-
ever container is visible. If this option is not speci-
fied then the other window 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 container: 0.5 means window will be
half as high as the container, 1.0 means window will have
the same height as the container, and so on. If both
-height and -relheight are specified for a content, their
values are summed. For example, -relheight 1.0 -height
-2 makes the content 2 pixels shorter than the container.
-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 container: 0.5 means window will be half
as wide as the container, 1.0 means window will have the
same width as the container, and so on. If both -width
and -relwidth are specified for a content, their values
are summed. For example, -relwidth 1.0 -width 5 makes
the content 5 pixels wider than the container.
-relx location
Location specifies the x-coordinate within the container
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 container and 1.0 corresponds to the right edge of
the container. Location need not be in the range
0.0-1.0. If both -x and -relx are specified for a con-
tent then their values are summed. For example, -relx
0.5 -x -2 positions the left edge of the content 2 pixels
to the left of the center of its container.
-rely location
Location specifies the y-coordinate within the container
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
container and 1.0 corresponds to the bottom edge of the
container. Location need not be in the range 0.0-1.0.
If both -y and -rely are specified for a content then
their values are summed. For example, -rely 0.5 -x 3 po-
sitions the top edge of the content 3 pixels below the
center of its container.
-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 container
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 container window.
-y location
Location specifies the y-coordinate within the container
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 container window.
If the same value is specified separately with two different op-
tions, 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
does not appear on the screen. If window is not currently man-
aged 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 content windows for which window is
the container. If there is no content for window then an empty
string is returned. │
place content window │
Synonym for place slaves window.
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 container window to be the parent of the
content 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 par-
ent. The “real children” of the parent (i.e. the windows that are sig-
nificant for the application's user interface) can be children of the
parent yet be placed inside the windows of the geometry-management hi-
erarchy. This means that the path names of the “real children” do not
reflect the geometry-management hierarchy and users can specify options
for the real children without being aware of the structure of the geom-
etry-management hierarchy.
A second reason for having a container different than the content'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 content 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 container
windows or the parents of content windows (i.e. it does not 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(3tk), pack(3tk)
KEYWORDS
geometry manager, height, location, container, place, rubber sheet,
content, width
Tk place(3tk)
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