NAME¶
pack-old - Obsolete syntax for packer geometry manager
SYNOPSIS¶
pack after sibling window options ?
window options
...?
pack append parent window options ?
window options
...?
pack before sibling window options ?
window options
...?
pack unpack window
DESCRIPTION¶
Note: this manual entry describes the syntax for the pack
command as it existed before Tk version 3.3. Although this syntax
continues to be supported for backward compatibility, it is obsolete
and should not be used anymore. At some point in the future it may
cease to be supported.
The packer is a geometry manager that arranges the children of a parent by
packing them in order around the edges of the parent. The first child is
placed against one side of the window, occupying the entire span of the window
along that side. This reduces the space remaining for other children as if the
side had been moved in by the size of the first child. Then the next child is
placed against one side of the remaining cavity, and so on until all children
have been placed or there is no space left in the cavity.
The
before,
after, and
append forms of the
pack
command are used to insert one or more children into the packing order for
their parent. The
before form inserts the children before window
sibling in the order; all of the other windows must be siblings of
sibling. The
after form inserts the windows after
sibling, and the
append form appends one or more windows to the
end of the packing order for
parent. If a
window named in any of
these commands is already packed in its parent, it is removed from its current
position in the packing order and repositioned as indicated by the command.
All of these commands return an empty string as result.
The
unpack form of the
pack command removes
window from the
packing order of its parent and unmaps it. After the execution of this command
the packer will no longer manage
window's geometry.
The placement of each child is actually a four-step process; the
options
argument following each
window consists of a list of one or more fields
that govern the placement of that window. In the discussion below, the term
cavity refers to the space left in a parent when a particular child is
placed (i.e. all the space that was not claimed by earlier children in the
packing order). The term
parcel refers to the space allocated to a
particular child; this is not necessarily the same as the child window's final
geometry.
The first step in placing a child is to determine which side of the cavity it
will lie against. Any one of the following options may be used to specify a
side:
- top
- Position the child's parcel against the top of the cavity,
occupying the full width of the cavity.
- bottom
- Position the child's parcel against the bottom of the
cavity, occupying the full width of the cavity.
- left
- Position the child's parcel against the left side of the
cavity, occupying the full height of the cavity.
- right
- Position the child's parcel against the right side of the
cavity, occupying the full height of the cavity.
At most one of these options should be specified for any given window. If no
side is specified, then the default is
top.
The second step is to decide on a parcel for the child. For
top and
bottom windows, the desired parcel width is normally the cavity width
and the desired parcel height is the window's requested height, as passed to
Tk_GeometryRequest. For
left and
right windows, the
desired parcel height is normally the cavity height and the desired width is
the window's requested width. However, extra space may be requested for the
window using any of the following options:
- padx num
- Add num pixels to the window's requested width
before computing the parcel size as described above.
- pady num
- Add num pixels to the window's requested height
before computing the parcel size as described above.
- expand
- This option requests that the window's parcel absorb any
extra space left over in the parent's cavity after packing all the
children. The amount of space left over depends on the sizes requested by
the other children, and may be zero. If several windows have all specified
expand then the extra width will be divided equally among all the
left and right windows that specified expand and the
extra height will be divided equally among all the top and
bottom windows that specified expand.
If the desired width or height for a parcel is larger than the corresponding
dimension of the cavity, then the cavity's dimension is used instead.
The third step in placing the window is to decide on the window's width and
height. The default is for the window to receive either its requested width
and height or the those of the parcel, whichever is smaller. If the parcel is
larger than the window's requested size, then the following options may be
used to expand the window to partially or completely fill the parcel:
- fill
- Set the window's size to equal the parcel size.
- fillx
- Increase the window's width to equal the parcel's width,
but retain the window's requested height.
- filly
- Increase the window's height to equal the parcel's height,
but retain the window's requested width.
The last step is to decide the window's location within its parcel. If the
window's size equals the parcel's size, then the window simply fills the
entire parcel. If the parcel is larger than the window, then one of the
following options may be used to specify where the window should be positioned
within its parcel:
- frame center
- Center the window in its parcel. This is the default if no
framing option is specified.
- frame n
- Position the window with its top edge centered on the top
edge of the parcel.
- frame ne
- Position the window with its upper-right corner at the
upper-right corner of the parcel.
- frame e
- Position the window with its right edge centered on the
right edge of the parcel.
- frame se
- Position the window with its lower-right corner at the
lower-right corner of the parcel.
- frame s
- Position the window with its bottom edge centered on the
bottom edge of the parcel.
- frame sw
- Position the window with its lower-left corner at the
lower-left corner of the parcel.
- frame w
- Position the window with its left edge centered on the left
edge of the parcel.
- frame nw
- Position the window with its upper-left corner at the
upper-left corner of the parcel.
The packer manages the mapped/unmapped state of all the packed children windows.
It automatically maps the windows when it packs them, and it unmaps any
windows for which there was no space left in the cavity.
The packer makes geometry requests on behalf of the parent windows it manages.
For each parent window it requests a size large enough to accommodate all the
options specified by all the packed children, such that zero space would be
leftover for
expand options.
KEYWORDS¶
geometry manager, location, packer, parcel, size