place(n) Tk Built-In Commands 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.
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 config-ure configure
ure 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 infor-mation information
mation 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 corresponding
ing 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 lowerright
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 mas-ter's master's
ter's border.
If mode is outside then the placer considers the area of the master to include its bor-der; border;
der; 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 speci-fied, specified,
fied, then the height requested internally by the window will be used.
-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 visi-ble. visible.
ble. If this option isn't 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 float-ing-point floating-point
ing-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 mas-ter. master.
ter.
-relwidth size
Size specifies the width for window. In this case the width is specified as a float-ing-point floating-point
ing-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 floatingpoint
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 bot-tom bottom
tom 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 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 use-ful useful
ful in at least two situations. First, for complex window layouts it means you can create a hierar-chy hierarchy
chy 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 geom-etry-management geometry-management
etry-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 that provide configuration options for this purpose.
KEYWORDS
geometry manager, height, location, master, place, rubber sheet, slave, width
Tk place(n)
|