File: groff.info,  Node: ms keeps and displays,  Next: ms Insertions,  Prev: Indented regions in ms,  Up: ms Body Text

4.6.5.8 Keeps, boxed keeps, and displays
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On occasion, you may want to "keep" several lines of text, or a region
of a document, together on a single page, preventing an automatic page
break within certain boundaries.  This can cause a page break to occur
earlier than it normally would.  For example, you may want to keep two
paragraphs together, or a paragraph that refers to a table, list, or
figure adjacent to the item it discusses.  'ms' provides the 'KS' and
'KE' macros for this purpose.

   You can alternatively specify a "floating keep": if a keep cannot fit
on the current page, 'ms' holds its contents and allows material
following the keep (in the source document) to fill the remainder of the
current page.  When the page breaks, whether by reaching the end or 'bp'
request, 'ms' puts the floating keep at the beginning of the next page.
This is useful for placing large graphics or tables that do not need to
appear exactly where they occur in the source document.

 -- Macro: .KS
 -- Macro: .KF
 -- Macro: .KE
     'KS' begins a keep, 'KF' a floating keep, and 'KE' ends a keep of
     either kind.

   As an alternative to the keep mechanism, the 'ne' request forces a
page break if there is not at least the amount of vertical space
specified in its argument remaining on the page (*note Page Control::).
One application of 'ne' is to reserve space on the page for a figure or
illustration to be included later.

   A "boxed keep" has a frame drawn around it.

 -- Macro: .B1
 -- Macro: .B2
     'B1' begins a keep with a box drawn around it.  'B2' ends a boxed
     keep.

   Boxed keep macros cause breaks; if you need to box a word or phrase
within a line, see the 'BX' macro in *note Typeface and decoration::.
Box lines are drawn as close as possible to the text they enclose so
that they are usable within paragraphs.  If you wish to box one or more
paragraphs, you may improve the appearance by calling 'B1' after the
first paragraphing macro, and by adding a small amount of vertical space
before calling 'B2'.

     .LP
     .B1
     .I Warning:
     Happy Fun Ball may suddenly accelerate to dangerous
     speeds.
     .sp \n[PD]/2 \" space by half the inter-paragraph distance
     .B2

   If you want a boxed keep to float, you will need to enclose the 'B1'
and 'B2' calls within a pair of 'KF' and 'KE' calls.

   "Displays" turn off filling; lines of verse or program code are shown
with their lines broken as in the source document without requiring 'br'
requests between lines.  Displays can be kept on a single page or
allowed to break across pages.  The 'DS' macro begins a kept display of
the layout specified in its first argument; non-kept displays are begun
with dedicated macros corresponding to their layout.

 -- Macro: .DS L
 -- Macro: .LD
     Begin ('DS': kept) left-aligned display.

 -- Macro: .DS [I [indent]]
 -- Macro: .ID [indent]
     Begin ('DS': kept) display indented by INDENT if specified, and by
     the amount of the 'DI' register otherwise.

 -- Macro: .DS B
 -- Macro: .BD
     Begin a ('DS': kept) a block display: the entire display is
     left-aligned, but indented such that the longest line in the
     display is centered on the page.

 -- Macro: .DS C
 -- Macro: .CD
     Begin a ('DS': kept) centered display: each line in the display is
     centered.

 -- Macro: .DS R
 -- Macro: .RD
     Begin a ('DS': kept) right-aligned display.  This is a GNU
     extension.

 -- Macro: .DE
     End any display.

   The distance stored in the 'DD' register is inserted before and after
each pair of display macros; this is a Berkeley extension.  In 'groff'
'ms', this distance replaces any adjacent inter-paragraph distance or
subsequent spacing prior to a section heading.  The 'DI' register is a
GNU extension; its value is an indentation applied to displays created
with '.DS' and '.ID' without arguments, to '.DS I' without an
indentation argument, and to indented equations set with '.EQ'.  Changes
to either register take effect at the next display boundary.