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 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.
- 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
window. 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 corresponding sublist of
the value returned if no option is specified). If one or more
option-value pairs are specified, then the command 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
border will appear at the given (x,y) location in the master. 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 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.
- -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 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
is not specified then the master 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 -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.
- -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.
- -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.
- -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 does not appear on the screen. If window is not
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 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” do not 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 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, master, place, rubber sheet, slave,
width