Provided by: tk8.4-doc_8.4.20-7_all 
NAME
grid - Geometry manager that arranges widgets in a grid
SYNOPSIS
grid option arg ?arg ...?
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DESCRIPTION
The grid command 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 command can
have any of several forms, depending on the option argument:
grid slave ?slave ...? ?options?
If the first argument to grid is suitable as the first slave argument to grid configure, either a
window name (any value starting with .) or one of the characters x or ^ (see the RELATIVE
PLACEMENT section below), then the command is processed in the same way as grid configure.
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 2
options are -minsize, -weight, -uniform and -pad. If one or more options are provided, then index
may be given as a list of column indices 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 -uniform option, when a non-empty value is supplied, 2
places the column in a uniform group with other columns that have the same value for -uniform. 2
The space for columns belonging to a uniform group is allocated so that their sizes are always in 2
strict proportion to their -weight values. See THE GRID ALGORITHM below for further details. 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 a 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 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. Amount may be a list of two values to specify padding for left
and right separately. 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. Amount may be a list of two values to specify padding for
top and bottom separately. 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 command 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 {}, 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 ?boolean?
If boolean has a true boolean value such as 1 or on 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 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.
grid rowconfigure master index ?-option value...?
Query or set the row properties of the index row of the geometry master, master. The valid 2
options are -minsize, -weight, -uniform and -pad. If one or more options are provided, then index
may be given as a list of row indices 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 -uniform option, when a non-empty value is supplied, places the row 2
in a uniform group with other rows that have the same value for -uniform. The space for rows 2
belonging to a uniform group is allocated so that their sizes are always in strict proportion to 2
their -weight values. See THE GRID ALGORITHM below for further details. 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 a 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 ?-option value?
If no options are supplied, a list of all of the slaves in master are returned, most recently
manages 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 command 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 command, and the presence of the
characters -, x, and ^ in grid command 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, nor may it be the
first slave argument to grid configure.
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. After that the rows or columns in each uniform group adapt to each other. 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.
When multiple rows or columns belong to a uniform group, the space allocated to them is always in
proportion to their weights. (A weight of zero is considered to be 1.) In other words, a row or column
configured with -weight 1 -uniform a will have exactly the same size as any other row or column
configured with -weight 1 -uniform a. A row or column configured with -weight 2 -uniform b will be
exactly twice as large as one that is configured with -weight 1 -uniform b.
More technically, each row or column in the group will have a size equal to k*weight for some constant k.
The constant k is chosen so that no row or column becomes smaller than its minimum size. For example, if
all rows or columns in a group have the same weight, then each row or column will have the same size as
the largest row or column in the group.
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 their 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 command 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.
EXAMPLES
A toplevel window containing a text widget and two scrollbars:
# Make the widgets
toplevel .t
text .t.txt -wrap none -xscroll {.t.h set} -yscroll {.t.v set}
scrollbar .t.v -orient vertical -command {.t.txt xview}
scrollbar .t.h -orient horizontal -command {.t.txt xview}
# Lay them out
grid .t.txt .t.v -sticky nsew
grid .t.h -sticky nsew
# Tell the text widget to take all the extra room
grid rowconfigure .t 0 -weight 1
grid columnconfigure .t 0 -weight 1
Three widgets of equal width, despite their different "natural" widths:
button .b -text "Foo"
entry .e -variable foo
label .l -text "This is a fairly long piece of text"
grid .b .e .l -sticky ew
grid columnconfigure . {0 1 2} -uniform allTheSame
SEE ALSO
pack(3tk), place(3tk)
KEYWORDS
geometry manager, location, grid, cell, propagation, size, pack
Tk 8.4 grid(3tk)