


grid(n)                Tk Built-In Commands               grid(n)


NAME
       grid - Geometry manager that arranges widgets in a grid

SYNOPSIS
       (grid option arg ?arg ...?)


DESCRIPTION
       The  grid  procedure is used to communicate with the grid geometry man-
       ager that arranges widgets in rows and columns inside of  another  win-
       dow, called the geometry master (or master window).  The grid procedure
       can have any of several forms, depending on the option argument:

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

       (grid 'bbox master)

       (grid 'bbox master column row)

       (grid 'bbox master column row column2 row2)
              With no arguments, the bounding box (in pixels) of the  grid  is
              returned.   The  return value consists of 4 integers.  The first
              two are the pixel offset from the master window (x  then  y)  of
              the top-left corner of the grid, and the second two integers are
              the width and height of the grid, also in pixels.  If  a  single
              column and row is specified on the command line, then the bound-
              ing box for that cell is returned, where the top  left  cell  is
              numbered from zero.  If both column and row arguments are speci-
              fied, then the bounding box spanning the rows and columns  indi-
              cated is returned.

       (grid 'columnconfigure master index ?:option value...?)
              Query  or  set  the column properties of the index column of the
              geometry  master,  master.   The  valid  options  are  :minsize,
              :weight  and  :pad.   If  one or more options are provided, then
              index may be given as a list of column indexes to which the con-
              figuration  options  will  operate on.  The :minsize option sets
              the minimum size, in screen units, that will  be  permitted  for
              this  column.   The  :weight  option (an integer value) sets the
              relative weight for apportioning any extra spaces among columns.
              A  weight of zero (0) indicates the column will not deviate from
              its requested size.  A column whose weight is two will  grow  at
              twice  the  rate  as  a column of weight one when extra space is
              allocated to the layout.  The :pad option specifies  the  number
              of  screen  units  that will be added to the largest window con-
              tained completely in that column when the grid geometry  manager
              requests  a  size from the containing window.  If only an option
              is specified, with no value, the current value of that option is
              returned.  If only the master window and index is specified, all
              the current settings are returned in an list of ":option  value"
              pairs.



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grid(n)                Tk Built-In Commands               grid(n)


       (grid '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.  The characters :,  x and ^, can be specified instead of
              a window name to alter the  default  location  of  a  slave,  as
              described  in  the  ``RELATIVE  PLACEMENT'' section, below.  The
              following options are supported:

              :column n
                     Insert the slave so that it occupies the  nth  column  in
                     the  grid.   Column numbers start with 0.  If this option
                     is not supplied, then the slave is arranged just  to  the
                     right  of  previous slave specified on this call to grid,
                     or column "0" if it is the first slave.  For each x  that
                     immediately  precedes  the  slave, the column position is
                     incremented by one.  Thus the x represents a blank column
                     for this row in the grid.

              :columnspan n
                     Insert  the  slave  so  that it occupies n columns in the
                     grid.  The default is one column, unless the window  name
                     is  followed  by  a  :,  in  which case the columnspan is
                     incremented once for each immediately following :.

              :in other
                     Insert the slave(s) in the master window given by  other.
                     The default is the first slave's parent window.

              :ipadx amount
                     The amount specifies how much horizontal internal padding
                     to leave on each side of the slave(s).  This is space  is
                     added  inside  the slave(s) border.  The amount must be a
                     valid screen distance, such as 2 or .5c.  It defaults  to
                     0.

              :ipady amount
                     The  amount  specifies how much vertical internal padding
                     to leave on on the top and bottom of the slave(s).   This
                     space  is  added  inside the slave(s) border.  The amount
                     defaults to 0.

              :padx amount
                     The amount specifies how much horizontal external padding
                     to  leave  on each side of the slave(s), in screen units.
                     The amount defaults to 0.  This space  is  added  outside
                     the slave(s) border.

              :pady amount
                     The  amount  specifies how much vertical external padding
                     to leave on the top and bottom of the slave(s), in screen
                     units.   The  amount  defaults to 0.  This space is added
                     outside the slave(s) border.

              :row n Insert the slave so that it occupies the nth row  in  the



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grid(n)                Tk Built-In Commands               grid(n)


                     grid.   Row  numbers start with 0.  If this option is not
                     supplied, then the slave is arranged on the same  row  as
                     the previous slave specified on this call to grid, or the
                     first unoccupied row if this is the first slave.

              :rowspan n
                     Insert the slave so that it occupies n rows in the  grid.
                     The  default is one row.  If the next grid procedure con-
                     tains ^ characters instead of slaves that  line  up  with
                     the columns of this slave, then the rowspan of this slave
                     is extended by one.

              :sticky style
                     If a slave's cell is larger  than  its  requested  dimen-
                     sions,  this  option may be used to position (or stretch)
                     the slave within its cell.  Style  is a string that  con-
                     tains  zero  or more of the characters n, s, e or w.  The
                     string can optionally contains spaces or commas, but they
                     are ignored.  Each letter refers to a side (north, south,
                     east, or west) that the slave will "stick" to.  If both n
                     and  s  (or  e  and  w)  are specified, the slave will be
                     stretched to fill the entire height  (or  width)  of  its
                     cavity.   The  sticky  option subsumes the combination of
                     :anchor and :fill that is used by pack.  The  default  is
                     the  empty  string, which causes the slave to be centered
                     in its cavity, at its requested size.

              If any of the slaves are already managed by the geometry manager
              then any unspecified options for them retain their previous val-
              ues rather than receiving default values.

       (grid 'forget slave ?slave ...?)
              Removes each of the slaves from grid for its master  and  unmaps
              their windows.  The slaves will no longer be managed by the grid
              geometry manager.  The configuration options for that window are
              forgotten, so that if the slave is managed once more by the grid
              geometry manager, the initial default settings are used.

       (grid '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 grid configure.  The first  two  ele-
              ments of the list are ``:in master'' where master is the slave's
              master.

       (grid 'location master x y)
              Given  x and y values in screen units  relative  to  the  master
              window,  the  column  and row number at that x and y location is
              returned.  For locations that are above or to the  left  of  the
              grid, -1 is returned.

       (grid 'propagate master)





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grid(n)                Tk Built-In Commands               grid(n)


       (grid 'propagate master boolean)
              If  boolean has a true boolean value then propagation is enabled
              for master, which must be a window name (see ``GEOMETRY PROPAGA-
              TION'' below).  If boolean has a false boolean value then propa-
              gation is disabled for master.  In  either  of  these  cases  an
              empty  list  is returned.  If boolean is omitted then the proce-
              dure returns #f or #t to indicate whether  propagation  is  cur-
              rently enabled for master.  Propagation is enabled by default.

       (grid 'rowconfigure master index )

       (grid 'rowconfigure master index :option value...)
              Query or set the row properties of the index row of the geometry
              master, master.  The valid options  are  :minsize,  :weight  and
              :pad.   If  one  or more options are provided, then index may be
              given as a list  of  row  indeces  to  which  the  configuration
              options  will  operate on.  The :minsize option sets the minimum
              size, in screen units, that will be permitted for this row.  The
              :weight  option  (an integer value) sets the relative weight for
              apportioning any extra spaces among rows.  A weight of zero  (0)
              indicates  the  row will not deviate from its requested size.  A
              row whose weight is two will grow at twice the rate as a row  of
              weight  one  when  extra  space is allocated to the layout.  The
              :pad option specifies the number of screen units  that  will  be
              added  to  the  largest  window contained completely in that row
              when the grid geometry manager requests a size from the contain-
              ing  window.  If only an option is specified, with no value, the
              current value of that option is returned.  If  only  the  master
              window  and  index  is  specified,  all the current settings are
              returned in an list of ":option value" pairs.

       (grid 'remove slave ?slave ...?)
              Removes each of the slaves from grid for its master  and  unmaps
              their windows.  The slaves will no longer be managed by the grid
              geometry manager.  However, the configuration options  for  that
              window are remembered, so that if the slave is managed once more
              by the grid geometry manager, the previous values are  retained.

       (grid 'size master)
              Returns  the size of the grid (in columns then rows) for master.
              The size is determined either by the slave occupying the largest
              row  or  column,  or  the  largest column or row with a minsize,
              weight, or pad that is non-zero.

       (grid 'slaves master)

       (grid 'slaves master :option value)
              If no options are supplied, a list of all of the slaves in  mas-
              ter  are  returned,  most recently managed first.  Option can be
              either :row or :column which causes only the slaves in  the  row
              (or column) specified by value to be returned.

RELATIVE PLACEMENT
       The  grid  procedure contains a limited set of capabilities that permit



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grid(n)                Tk Built-In Commands               grid(n)


       layouts to be created without specifying the row and column information
       for  each  slave.   This  permits  slaves  to  be rearranged, added, or
       removed without the need to explicitly specify row and column  informa-
       tion.   When  no  column  or  row information is specified for a slave,
       default values are chosen for column, row, columnspan  and  rowspan  at
       the  time  the  slave  is managed. The values are chosen based upon the
       current layout of the grid, the position of the slave relative to other
       slaves  in  the same grid procedure, and the presence of the characters
       :, ^, and ^ in grid procedure where slave names are normally  expected.

              -      This  increases  the columnspan of the slave to the left.
                     Several -'s in  a  row  will  successively  increase  the
                     columnspan. A - may not follow a ^ or a x.

              x      This leaves an empty column between the slave on the left
                     and the slave on the right.

              ^      This extends the rowspan of the slave above  the  ^'s  in
                     the grid.  The number of ^'s in a row must match the num-
                     ber of columns spanned by the slave above it.

THE GRID ALGORITHM
       The grid geometry manager lays out its slaves in three steps.   In  the
       first  step,  the  minimum size needed to fit all of the slaves is com-
       puted, then (if propagation is turned on), a request  is  made  of  the
       master  window  to become that size.  In the second step, the requested
       size is compared against the actual size of the master.  If  the  sizes
       are different, then spaces is added to or taken away from the layout as
       needed.  For the final step, each slave is positioned in its row(s) and
       column(s) based on the setting of its sticky flag.

       To  compute  the  minimum  size  of a layout, the grid geometry manager
       first looks at all slaves whose columnspan and rowspan values are  one,
       and  computes  the  nominal size of each row or column to be either the
       minsize for that row or column, or the sum of the padding plus the size
       of  the  largest  slave,  whichever  is greater.  Then the slaves whose
       rowspans or columnspans are greater than one are examined.  If a  group
       of rows or columns need to be increased in size in order to accommodate
       these slaves, then extra space is added to each row or  column  in  the
       group  according  to  its weight.  For each group whose weights are all
       zero, the additional space is apportioned equally.

       For masters whose size is larger than the requested layout,  the  addi-
       tional  space  is  apportioned according to the row and column weights.
       If all of the weights are zero, the layout is centered within its  mas-
       ter.   For  masters  whose  size  is smaller than the requested layout,
       space is taken away from columns and rows according to  their  weights.
       However,  once  a  column  or row shrinks to its minsize, its weight is
       taken to be zero.  If more space needs to be removed from a layout than
       would  be permitted, as when all the rows or columns are at there mini-
       mum sizes, the layout is clipped on the bottom and right.

GEOMETRY PROPAGATION
       The grid geometry manager normally computes how large a master must  be



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grid(n)                Tk Built-In Commands               grid(n)


       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 geome-
       try  information  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 grid propagate procedure may be used
       to turn off propagation for one or more  masters.   If  propagation  is
       disabled  then  grid will not set the requested width and height of the
       master window.  This may be useful if, for example, you wish for a mas-
       ter 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.  In addition, all slaves in one call to grid must have the
       same master.

STACKING 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  hasn't been managed 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.

CREDITS
       The grid command is based on ideas taken from the GridBag geometry man-
       ager  written by Doug. Stein, and the blt_table geometry manager, writ-
       ten by George Howlett.


SEE ALSO
       pack, place






















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