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
       manager that arranges widgets in rows and columns inside of another
       window, 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
              starting 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
              bounding box for that cell is returned, where the top left cell
              is numbered from zero.  If both column and row arguments are
              specified, then the bounding box spanning the rows and columns
              indicated 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
              configuration 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
              contained 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.

       (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
                     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
                     contains ^ 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
                     dimensions, this option may be used to position (or
                     stretch) the slave within its cell.  Style  is a string
                     that contains 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
              values 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
              elements 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)

       (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
              PROPAGATION'' below).  If boolean has a false boolean value then
              propagation is disabled for master.  In either of these cases an
              empty list is returned.  If boolean is omitted then the
              procedure returns #f or #t to indicate whether propagation is
              currently 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
              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.

       (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
              master 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
       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
       information.  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
                     number 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
       computed, 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
       additional space is apportioned according to the row and column
       weights.  If all of the weights are zero, the layout is centered within
       its master.  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 minimum sizes, the layout is clipped on the bottom and right.

GEOMETRY PROPAGATION
       The grid geometry manager 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 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 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.  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.
       Otherwise 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
       manager written by Doug. Stein, and the blt_table geometry manager,
       written by George Howlett.


SEE ALSO
       pack, place




STk                                   3.1                              grid(n)
