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grid(3tk) Tk Built-In Commands grid(3tk) 





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 container (or container window). The grid
    command can have any of several forms, depending on the option
    argument:



  

  
If the first argument to grid is suitable as the first window
      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.

  

  
The anchor value controls how to place the grid within the container
      window when no row/column has any weight. See THE GRID ALGORITHM
      below for further details. The default anchor is nw.

  

  
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 container 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.

  

  
Query or set the column properties of the index column of the
      geometry container, window. 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. Indices may be
      integers, window names or the keyword all. For all the
      options apply to all columns currently occupied be content windows. For a
      window name, that window must be a content of this container and the
      options apply to all columns currently occupied be the content. 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, places the
      column in a uniform group with other columns that have the same
      value for -uniform. 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 container window and
      index is specified, all the current settings are returned in a list of
      “-option value” pairs.

  

  
The arguments consist of the names of one or more content windows followed
      by pairs of arguments that specify how to manage the content. The
      characters -, x and ^, can be specified instead of a
      window name to alter the default location of a window, as described
      in the RELATIVE PLACEMENT section, below. The following options are
      supported:







  

  
Insert the window so that it occupies the nth column in the grid.
      Column numbers start with 0. If this option is not supplied, then the
      window is arranged just to the right of previous window specified on this
      call to grid, or column “0” if it is the first
      window. For each x that immediately precedes the window, the
      column position is incremented by one. Thus the x represents a
      blank column for this row in the grid.

  

  
Insert the window 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 -.

  

  
Insert the window(s) in the container window given by container.
      The default is the first window's parent window.

  

  
The amount specifies how much horizontal internal padding to leave
      on each side of the content. This is space is added inside the content
      border. The amount must be a valid screen distance, such as
      2 or .5c. It defaults to 0.

  

  
The amount specifies how much vertical internal padding to leave on
      the top and bottom of the content. This space is added inside the content
      border. The amount defaults to 0.

  

  
The amount specifies how much horizontal external padding to leave
      on each side of the content, 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 content
      border.

  

  
The amount specifies how much vertical external padding to leave on
      the top and bottom of the content, 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 content
      border.

  

  
Insert the content so that it occupies the nth row in the grid. Row
      numbers start with 0. If this option is not supplied, then the content is
      arranged on the same row as the previous content specified on this call to
      grid, or the next row after the highest occupied row if this is the
      first content.

  

  
Insert the content so that it occupies n rows in the grid. The
      default is one row. If the next grid command contains ^
      characters instead of content that line up with the columns of this
      content, then the rowspan of this content is extended
      by one.

  

  
If a content's cell is larger than its requested dimensions, this option
      may be used to position (or stretch) the content within its cell.
      Style is a string that contains zero or more of the characters
      n, s, e or w. The string can optionally
      contain spaces or commas, but they are ignored. Each letter refers to a
      side (north, south, east, or west) that the content will
      “stick” to. If both n and s (or e and
      w) are specified, the content 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 content to
      be centered in its cavity, at its requested size.




If any of the content is already managed by the geometry manager
    then any unspecified options for them retain their previous values rather
    than receiving default values.





  

  
If no options are supplied, a list of all of the content in window
      is returned, most recently managed first. Option can be either
      -row or -column which causes only the content in the row (or
      column) specified by value to be returned.

  

  
Removes each of the windows from grid for its container and unmaps
      their windows. The content will no longer be managed by the grid geometry
      manager. The configuration options for that window are forgotten, so that
      if the window is managed once more by the grid geometry manager, the
      initial default settings are used.






If the last content window of the container becomes unmanaged,
    this will also send the virtual event <<NoManagedChild>>
    to the container; the container may choose to resize itself (or otherwise
    respond) to such a change.





  

  
Returns a list whose elements are the current configuration state of the
      content given by window in the same option-value form that might be
      specified to grid configure. The first two elements of the list are
      “-in container” where container is the
      windows's container window.

  

  
Given x and y values in screen units relative to the
      container 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.

  

  
If boolean has a true boolean value such as 1 or on
      then propagation is enabled for window, which must be a window name
      (see GEOMETRY PROPAGATION below). If boolean has a false
      boolean value then propagation is disabled for window. 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 window.






Propagation is enabled by default.





  

  
Query or set the row properties of the index row of the geometry
      container, window. 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 row indices to
      which the configuration options will operate on. Indices may be integers,
      window names or the keyword all. For all the options apply
      to all rows currently occupied by content windows. For a window name, that
      window must be a content window of this container and the options apply to
      all rows currently occupied by the container window. 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 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 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 container window and index is specified, all the current settings
      are returned in a list of “-option value” pairs.

  

  
Removes each of the windows from grid for its container and unmaps
      their windows. The content will no longer be managed by the grid geometry
      manager. However, the configuration options for that window are
      remembered, so that if the content window is managed once more by the grid
      geometry manager, the previous values are retained.






If the last content window of the container becomes unmanaged,
    this will also send the virtual event <<NoManagedChild>>
    to the container; the container may choose to resize itself (or otherwise
    respond) to such a change.





  

  
Returns the size of the grid (in columns then rows) for container.
      The size is determined either by the content occupying the largest
      row or column, or the largest column or row with a -minsize,
      -weight, or -pad that is non-zero.

  

  
Synonym for grid content window ?-option value?.








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 content. This permits content 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
    content, default values are chosen for -column, -row,
    -columnspan and -rowspan at the time the content is
    managed. The values are chosen based upon the current layout of the grid,
    the position of the content relative to other contents in the
    same grid command, and the presence of the characters -, x,
    and ^ in grid command where content names are normally
    expected.





  
-

  
This increases the -columnspan of the content to the left.
      Several -'s in a row will successively increase the number of
      columns spanned. A - may not follow a ^ or a x, nor
      may it be the first content argument to grid configure.

  

  
This leaves an empty column between the content on the left and the
      content on the right.

  
^

  
This extends the -rowspan of the content above the
      ^'s in the grid. The number of ^'s in a row must match the
      number of columns spanned by the content above it.










THE GRID ALGORITHM


The grid geometry manager lays out its content in three steps. In
    the first step, the minimum size needed to fit all of the content is
    computed, then (if propagation is turned on), a request is made of the
    container window to become that size. In the second step, the requested size
    is compared against the actual size of the container. If the sizes are
    different, then spaces is added to or taken away from the layout as needed.
    For the final step, each content 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 content 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 content, whichever is greater.
    After that the rows or columns in each uniform group adapt to each other.
    Then the content whose row-spans or column-spans are greater than one are
    examined. If a group of rows or columns need to be increased in size in
    order to accommodate these content, 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 containers 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 placed within its container
    according to the anchor value. For containers 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 placed and clipped according to the
    anchor value.






GEOMETRY PROPAGATION


The grid geometry manager normally computes how large a container
    must be to just exactly meet the needs of its content, and it sets the
    requested width and height of the container 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 containers. If propagation is
    disabled then grid will not set the requested width and height of the
    container window. This may be useful if, for example, you wish for a
    container window to have a fixed size that you specify.






RESTRICTIONS ON CONTAINER WINDOWS


The container for each content must either be the content's parent
    (the default) or a descendant of the content's parent. This restriction is
    necessary to guarantee that the content can be placed over any part of its
    container that is visible without danger of the content being clipped by its
    parent. In addition, all content in one call to grid must have the
    same container.






STACKING ORDER


If the container for a content is not its parent then you must
    make sure that the content is higher in the stacking order than the
    container. Otherwise the container will obscure the content and it will
    appear as if the content has not been managed correctly. The easiest way to
    make sure the content is higher than the container is to create the
    container 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 yview}
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 .t.txt -weight 1
grid columnconfigure .t .t.txt -weight 1




Three widgets of equal width, despite their different
    “natural” widths:






button .b -text "Foo"
entry .e -textvariable foo ; set foo "Hello World!"
label .l -text "This is a fairly long piece of text"
grid .b .e .l -sticky ew
grid columnconfigure . "all" -uniform allTheSame








SEE ALSO


pack(3tk), place(3tk)






KEYWORDS


geometry manager, location, grid, cell, propagation, size,
  pack







  

    8.5
    Tk