place - Geometry manager for fixed or rubber-sheet placement

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
container. 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
response to changes in the size of the container. Lastly, the placer allows you to mix these styles of
placement so that, for example, the content has a fixed width and height but is centered inside the
container.

placewindowoptionvalue ?optionvalue...?
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 placeconfigure
command.

placeconfigurewindow ?option? ?valueoptionvalue...?
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 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:

-anchorwhereWhere 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 container. The anchor
position defaults to nw.

-bordermodemodeMode 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 container to be the innermost area of the container,
inside any border: an option of -x0 corresponds to an x-coordinate just inside the border
and an option of -relwidth1.0 means window will fill the area inside the container's
border.

If mode is outside then the placer considers the area of the container to include its
border; this mode is typically used when placing window outside its container, as with the
options -x0-y0-anchorne. Lastly, mode may be specified as ignore, in which case
borders are ignored: 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.

-heightsizeSize 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.

-incontainerContainer 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 descendants of the same top-level window. These
restrictions are necessary to guarantee that window is visible whenever container is
visible. If this option is not specified then the other window defaults to window's
parent.

-relheightsizeSize 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, -relheight1.0-height-2 makes the content 2 pixels shorter than the container.

-relwidthsizeSize 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, -relwidth1.0-width5 makes the content 5 pixels wider than the container.

-relxlocationLocation 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 floating-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 content then their values are summed. For example, -relx0.5-x-2
positions the left edge of the content 2 pixels to the left of the center of its container.

-relylocationLocation 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, -rely0.5-x3
positions the top edge of the content 3 pixels below the center of its container.

-widthsizeSize 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.

-xlocationLocation 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.

-ylocationLocation 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 options, such as -x and -relx, then
the most recent option is used and the older one is ignored.

placecontentwindow
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.

placeforgetwindow
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.

placeinfowindow
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 placeconfigure command.

placeslaveswindow
Synonym for placecontentwindow.

If the configuration of a window has been retrieved with placeinfo, that configuration can be restored
later by first using placeforget to erase any existing information for the window and then invoking
placeconfigure with the saved information.

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

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 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 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
-insibling-relx0.5-rely1.0-anchorn-bordermodeoutside
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.

Keywords

       geometry manager, height, location, container, place, rubber sheet, content, width

Tk                                                                                                    place(3tk)

Name

       place - Geometry manager for fixed or rubber-sheet placement

Synopsis

placeoptionarg ?arg...?
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