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 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 bottom-right corner 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 cellinfo master column row
- Returns a list giving information about the slave currently held in the
grid cell specified by column and row. The first element of
the list is the name of the slave, and the rest have the same option-value
form that might be specified to grid configure (the same form as returned
by grid info).
- grid columnconfigure master index ?-option value...?
- Set the column properties of the index column of the geometry
master, master. The valid options are -minsize, -weight,
-pad and -name. 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 -pad option
specifies a pad distance that will be added either side of the
column; adjacent columns merge their padding, creating a pad sized
to the larger of the pads on either column. The -name option
associates a name with the column, which can then be used as an index to
refer to that column.
- grid 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 index
- Insert the slave so that it occupies the indexth 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 index
- Insert the slave so that it occupies the indexth 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.
It is an error if any slave covers an area already covered
by an existing slave of the grid.
- grid columndelete master index0 ?index1?
- Deletes columns from index0 up to but not including index1,
If index1 is not given, it defaults to index0+1. The deleted
columns may not contain cells spanned by slaves outside the deleted
columns.
- grid columnindex master index
- Returns index as a numerical index into the column.
- grid columninsert master index ?count?
- Inserts count (default 1) new columns just before index. The
inserted rows may not split a spanning cell.
- 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...?
- Set the row properties of the index row of the geometry master,
master. The valid options are -minsize, -weight, -pad and
-name. 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 -pad option specifies a pad distance that will be
added either side of the row; adjacent rows merge their padding,
creating a pad sized to the larger of the pads on either row.
The -name option associates a name with the row, which can then be
used as an index to refer to that row.
- grid rowdelete master index0 ?index1?
- Deletes rows from index0 up to but not including index1, If
index1 is not given, it defaults to index0+1. The deleted
rows may not contain cells spanned by slaves outside the deleted
columns.
- grid rowindex master index
- Returns index as a numerical index into the row.
- grid rowinsert master index ?count?
- Inserts count (default 1) new rows just before index. The
inserted rows may not split a spanning cell.
- grid size master
- Returns the size of the grid (in columns then rows) for master. The
size is determined either by the largest row or column that has been
occupied by a slave, or the largest column or row that has been explicitly
configured.
- 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.
An index is either a non-negative integer value, the string
end, (one beyond the last index in the row or column in question),
or a name identifying a row or column previously named with the
-name option to rowconfigure or columnconfigure.
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 -, ^, 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.
- 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 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 their minimum sizes, the layout is clipped on the
bottom and right.
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.
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.