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Updated: Thursday, June 13, 2019
 
 

pack (1t)

Name

pack - Geometry manager that packs around edges of cavity

Synopsis

pack option arg ?arg ...?

Description

pack(1t)                     Tk Built-In Commands                     pack(1t)



______________________________________________________________________________

NAME
       pack - Geometry manager that packs around edges of cavity

SYNOPSIS
       pack option arg ?arg ...?
______________________________________________________________________________

DESCRIPTION
       The  pack  command  is  used to communicate with the packer, a geometry
       manager that arranges the children of a parent by packing them in order
       around  the edges of the parent.  The pack command can have any of sev-
       eral forms, depending on the option argument:

       pack slave ?slave ...? ?options?
              If the first argument to pack is a window name (any value start-
              ing  with "."), then the command is processed in the same way as
              pack configure.

       pack configure slave ?slave ...? ?options?
              The arguments consist of the names of one or more slave  windows
              followed  by  pairs  of arguments that specify how to manage the
              slaves.  See THE PACKER ALGORITHM below for details on  how  the
              options  are used by the packer.  The following options are sup-
              ported:

              -after other
                     Other must the name of another window.  Use its master as
                     the  master  for  the  slaves, and insert the slaves just
                     after other in the packing order.

              -anchor anchor
                     Anchor must be a valid anchor position such as n  or  sw;
                     it  specifies where to position each slave in its parcel.
                     Defaults to center.

              -before other
                     Other must the name of another window.  Use its master as
                     the  master  for  the  slaves, and insert the slaves just
                     before other in the packing order.

              -expand boolean
                     Specifies whether the slaves should be expanded  to  con-
                     sume  extra  space in their master.  Boolean may have any
                     proper boolean value, such as 1 or no.  Defaults to 0.

              -fill style
                     If a slave's parcel is larger than its  requested  dimen-
                     sions,  this  option  may  be  used to stretch the slave.
                     Style must have one of the following values:

                     none   Give the slave its requested dimensions  plus  any
                            internal  padding requested with -ipadx or -ipady.
                            This is the default.

                     x      Stretch the slave horizontally to fill the  entire
                            width of its parcel (except leave external padding
                            as specified by -padx).

                     y      Stretch the slave vertically to  fill  the  entire
                            height  of  its parcel (except leave external pad-
                            ding as specified by -pady).

                     both   Stretch the slave  both  horizontally  and  verti-
                            cally.

              -in other
                     Insert  the  slave(s) at the end of the packing order for
                     the master window given by other.

              -ipadx amount
                     Amount specifies how much horizontal internal padding  to
                     leave  on  each  side  of the slave(s).  Amount must be a
                     valid screen distance, such as 2 or .5c.  It defaults  to
                     0.

              -ipady amount
                     Amount  specifies  how  much vertical internal padding to
                     leave on each side of the slave(s).  Amount  defaults  to
                     0.

              -padx amount
                     Amount  specifies how much horizontal external padding to
                     leave on each side of the slave(s).  Amount may be a list
                     of two values to specify padding for left and right sepa-
                     rately.  Amount defaults to 0.

              -pady amount
                     Amount specifies how much vertical  external  padding  to
                     leave on each side of the slave(s).  Amount may be a list
                     of two values to specify padding for top and bottom sepa-
                     rately.  Amount defaults to 0.

              -side side
                     Specifies  which  side of the master the slave(s) will be
                     packed against.  Must be left,  right,  top,  or  bottom.
                     Defaults to top.

              If  no  -in,  -after or -before option is specified then each of
              the slaves will be inserted at the end of the packing  list  for
              its  parent unless it is already managed by the packer (in which
              case it will be left where it is).  If one of these  options  is
              specified  then all the slaves will be inserted at the specified
              point.  If any of the slaves are already managed by the geometry
              manager  then any unspecified options for them retain their pre-
              vious values rather than receiving default values.

       pack forget slave ?slave ...?
              Removes each of the slaves from the packing order for its master
              and  unmaps their windows.  The slaves will no longer be managed
              by the packer.

       pack info slave
              Returns a list whose  elements  are  the  current  configuration
              state  of the slave given by slave in the same option-value form
              that might be specified to pack configure.  The first  two  ele-
              ments  of  the list are "-in master" where master is the slave's
              master.

       pack propagate master ?boolean?
              If boolean has a true boolean value such as 1 or on then  propa-
              gation  is  enabled for master, which must be a window name (see
              GEOMETRY PROPAGATION below).  If boolean  has  a  false  boolean
              value  then  propagation  is  disabled for master.  In either of
              these cases an empty string is returned.  If boolean is  omitted
              then  the command returns 0 or 1 to indicate whether propagation
              is currently enabled for  master.   Propagation  is  enabled  by
              default.

       pack slaves master
              Returns  a  list  of  all of the slaves in the packing order for
              master.  The order of the slaves in the  list  is  the  same  as
              their  order in the packing order.  If master has no slaves then
              an empty string is returned.

THE PACKER ALGORITHM
       For each master the packer maintains an ordered list of  slaves  called
       the  packing  list.  The -in, -after, and -before configuration options
       are used to specify the master for each slave and the slave's  position
       in  the  packing  list.   If none of these options is given for a slave
       then the slave is added to the end of the packing list for its parent.

       The packer arranges the slaves for a master  by  scanning  the  packing
       list in order.  At the time it processes each slave, a rectangular area
       within the master is still unallocated.  This area is called  the  cav-
       ity;  for the first slave it is the entire area of the master.

       For each slave the packer carries out the following steps:

       [1]    The  packer  allocates  a rectangular parcel for the slave along
              the side of the cavity given by the slave's  -side  option.   If
              the  side  is  top or bottom then the width of the parcel is the
              width of the cavity and its height is the  requested  height  of
              the  slave  plus  the -ipady and -pady options.  For the left or
              right side the height of the parcel is the height of the  cavity
              and  the  width  is  the  requested  width of the slave plus the
              -ipadx and -padx options.  The parcel may  be  enlarged  further
              because of the -expand option (see EXPANSION below)

       [2]    The  packer chooses the dimensions of the slave.  The width will
              normally be the slave's requested width plus  twice  its  -ipadx
              option  and  the  height  will normally be the slave's requested
              height plus twice its -ipady  option.   However,  if  the  -fill
              option  is  x or both then the width of the slave is expanded to
              fill the width of the parcel, minus twice the -padx option.   If
              the  -fill  option  is y or both then the height of the slave is
              expanded to fill the width of the parcel, minus twice the  -pady
              option.

       [3]    The packer positions the slave over its parcel.  If the slave is
              smaller than the parcel then the -anchor option determines where
              in  the  parcel  the slave will be placed.  If -padx or -pady is
              non-zero, then the given amount of external padding will  always
              be left between the slave and the edges of the parcel.

       Once  a  given  slave  has  been packed, the area of its parcel is sub-
       tracted from the cavity, leaving a smaller rectangular cavity  for  the
       next  slave.   If  a  slave  does not use all of its parcel, the unused
       space in the parcel will not be used by subsequent slaves.  If the cav-
       ity should become too small to meet the needs of a slave then the slave
       will be given whatever space is left in  the  cavity.   If  the  cavity
       shrinks  to  zero  size,  then all remaining slaves on the packing list
       will be unmapped from the screen until the master window becomes  large
       enough to hold them again.

   EXPANSION
       If a master window is so large that there will be extra space left over
       after all of its slaves have been packed, then the extra space is  dis-
       tributed uniformly among all of the slaves for which the -expand option
       is set.  Extra horizontal space is  distributed  among  the  expandable
       slaves  whose  -side is left or right, and extra vertical space is dis-
       tributed among the expandable slaves whose -side is top or bottom.

   GEOMETRY PROPAGATION
       The packer normally computes how large a master must be to just exactly
       meet  the  needs  of  its  slaves,  and it sets the requested width and
       height of the master to these dimensions.  This causes geometry  infor-
       mation to propagate up through a window hierarchy to a top-level window
       so that the entire sub-tree sizes itself to fit the needs of  the  leaf
       windows.   However,  the pack propagate command may be used to turn off
       propagation for one or more masters.  If propagation is  disabled  then
       the  packer  will not set the requested width and height of the packer.
       This may be useful if, for example, you wish for  a  master  window  to
       have a fixed size that you specify.

RESTRICTIONS ON MASTER WINDOWS
       The  master  for  each  slave  must  either  be the slave's parent (the
       default) or a descendant of the slave's parent.   This  restriction  is
       necessary  to  guarantee  that the slave can be placed over any part of
       its master that is visible without danger of the slave being clipped by
       its parent.

PACKING ORDER
       If  the  master  for  a slave is not its parent then you must make sure
       that the slave is higher in the stacking order than the master.  Other-
       wise  the  master  will  obscure the slave and it will appear as if the
       slave has not been packed correctly.  The easiest way to make sure  the
       slave  is  higher than the master is to create the master window first:
       the most recently created window will be highest in the stacking order.
       Or,  you  can  use  the raise and lower commands to change the stacking
       order of either the master or the slave.

EXAMPLE
              # Make the widgets
              label .t -text "This widget is at the top"    -bg red
              label .b -text "This widget is at the bottom" -bg green
              label .l -text "Left\nHand\nSide"
              label .r -text "Right\nHand\nSide"
              text .mid
              .mid insert end "This layout is like Java's BorderLayout"
              # Lay them out
              pack .t   -side top    -fill x
              pack .b   -side bottom -fill x
              pack .l   -side left   -fill y
              pack .r   -side right  -fill y
              pack .mid -expand 1    -fill both


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | runtime/tk-8     |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+
SEE ALSO
       grid(n), place(n)

KEYWORDS
       geometry manager, location, packer, parcel, propagation, size



NOTES
       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source        was        downloaded        from         https://source-
       forge.net/projects/tcl/files/Tcl/8.6.7/tk8.6.7-src.tar.gz/download

       Further information about this software can be found on the open source
       community website at https://www.tcl.tk/.



Tk                                    4.0                             pack(1t)