grid - Geometry manager that arranges widgets in a grid
grid option arg ?arg ...?
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 a window name (any value starting with ``.''), 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 options are -minsize, -weight and -pad. 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 larg- est window contained completely in that column when the grid geometry manager requests a size from the contain- ing window. If only the option is specified, with no value, the current value of that option is returned.
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:
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 remembered, so that if the slave is managed once more by the grid geometry manager, the previous values are retained.
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 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 and -pad. 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 con- tained completely in that row when the grid geometry manager requests a size from the containing window. If only the option is specified, with no value, the current value of that option is returned.
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.
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.
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.
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 addi- tion, all slaves in one call to grid must have the same mas- ter.
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.
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.
geometry manager, location, grid, cell, propagation, size, pack
Table of Contents