Tk Built-In Commands grid(1T)
NAME
grid - Geometry manager that arranges widgets in a grid
SYNOPSIS
grid option arg ?arg ...?
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 con-
figure.
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, -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
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Tk Built-In Commands grid(1T)
the layout. The -uniform option, when a non-empty
value is supplied, places the column in a uniform group
with other columns that have the same value for -uni-
form. The space for columns belonging to a uniform
group is allocated so that their sizes are always in
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 RELA-
TIVE 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 immedi-
ately 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 immedi-
ately 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.
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Tk Built-In Commands grid(1T)
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 bot-
tom 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 charac-
ters n, s, e or w. The string can optionally con-
tains 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
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Tk Built-In Commands grid(1T)
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 configura-
tion 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 confi-
guration state of the slave given by slave in the same
option-value form that might be specified to grid con-
figure. 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 options are -min-
size, -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
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Tk Built-In Commands grid(1T)
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 in a uniform group with other rows that have the
same value for -uniform. The space for rows belonging
to a uniform group is allocated so that their sizes are
always in 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 com-
pletely 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 expli-
citly 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 rela-
tive to other slaves in the same grid command, and the
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Tk Built-In Commands grid(1T)
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 com-
pared 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 larg-
est 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 con-
figured with -weight 2 -uniform b will be exactly twice as
large as one that is configured with -weight 1 -uniform b.
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Tk Built-In Commands grid(1T)
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 mas-
ter 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 pro-
pagate 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 addi-
tion, all slaves in one call to grid must have the same mas-
ter.
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.
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Tk Built-In Commands grid(1T)
CREDITS
The grid command is based on ideas taken from the GridBag
geometry manager written by Doug. Stein, and the blttable
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(1T), place(1T)
KEYWORDS
geometry manager, location, grid, cell, propagation, size,
pack
ATRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
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Tk Built-In Commands grid(1T)
ATRIBUTE TYPE ATRIBUTE VALUE
Availability SUNWTk
Interface Stability Uncommitted
NOTES
Source for Tk is available on http:/opensolaris.org.
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