place - Geometry manager for fixed or rubber-sheet placement
place option arg ?arg ...?
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.
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.
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
geometry manager, height, location, master, place, rubber sheet,
slave, width