diff options
Diffstat (limited to 'share/doc/usd/22.trofftut/tt09')
| -rw-r--r-- | share/doc/usd/22.trofftut/tt09 | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/share/doc/usd/22.trofftut/tt09 b/share/doc/usd/22.trofftut/tt09 new file mode 100644 index 000000000000..d6da03b8408a --- /dev/null +++ b/share/doc/usd/22.trofftut/tt09 @@ -0,0 +1,319 @@ +.\" This module is believed to contain source code proprietary to AT&T. +.\" Use and redistribution is subject to the Berkeley Software License +.\" Agreement and your Software Agreement with AT&T (Western Electric). +.\" Copyright (C) Caldera International Inc. 2001-2002. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions are +.\" met: +.\" +.\" Redistributions of source code and documentation must retain the above +.\" copyright notice, this list of conditions and the following +.\" disclaimer. +.\" +.\" Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" +.\" This product includes software developed or owned by Caldera +.\" International, Inc. Neither the name of Caldera International, Inc. +.\" nor the names of other contributors may be used to endorse or promote +.\" products derived from this software without specific prior written +.\" permission. +.\" +.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA +.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +.\" DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE +.\" FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR +.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, +.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE +.\" OR OTHERWISE) RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN +.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" +.NH +Titles, Pages and Numbering +.PP +This is an area where things get tougher, +because nothing is done for you automatically. +Of necessity, some of this section is a cookbook, +to be copied literally until you get some experience. +.PP +Suppose you want a title at the top of each page, +saying just +.sp 3p +.lt 2.8i +.tl 'left top'center top'right top' +.lt +.sp 3p +In +.UL roff , +one can say +.P1 2 +^he 'left top'center top'right top' +^fo 'left bottom'center bottom'right bottom' +.P2 +to get headers and footers automatically on every page. +Alas, this doesn't work so easily in +.UL troff , +a serious hardship for the novice. +Instead you have to do a lot of specification (or use +a macro package, which makes it effortless). +.PP +You have to say what the actual title is (easy); +when to print it (easy enough); +and what to do at and around the title line (harder). +Taking these in reverse order, +first we define a macro +.BD .NP +(for `new page') to process +titles and the like at the end of one page +and the beginning of the next: +.P1 +^de NP +\(fmbp +\(fmsp 0.5i +\&.tl 'left top'center top'right top' +\(fmsp 0.3i +^^ +.P2 +To make sure we're at the top of a page, +we issue a `begin page' command +.BD \(fmbp , +which causes a skip to top-of-page +(we'll explain the +.BD \(fm +shortly). +Then we space down half an inch, +print the title +(the use of +.BD .tl +should be self explanatory; later we will discuss parameterizing the titles), +space another 0.3 inches, +and we're done. +.PP +To ask for +.BD .NP +at the bottom of each page, +we have to say something like +`when the text is within an inch +of the bottom of the page, +start the processing +for a new page.' +This is done with a `when' command +.BD .wh : +.P1 +^wh \-1i NP +.P2 +(No `.' is used before NP; +this is simply the name of a macro, not a macro call.) +The minus sign means +`measure up from the bottom of the page', +so +`\-1i' means `one inch from the bottom'. +.PP +The +.BD .wh +command appears in the input outside the definition of +.BD .NP ; +typically the input would be +.P1 +^de NP +^^^ +^^ +^wh \-1i NP +.P2 +.PP +Now what happens? +As text is actually being output, +.UL troff +keeps track of its vertical position on the page, +and after a line is printed within one inch from the bottom, +the +.BD .NP +macro is activated. +(In the jargon, the +.BD .wh +command sets a +.ul +trap +at the specified place, +which is `sprung' when that point is passed.) +.BD .NP +causes a skip to the top of the next page +(that's what the +.BD \(fmbp +was for), +then prints the title with the appropriate margins. +.PP +Why +.BD \(fmbp +and +.BD \(fmsp +instead of +.BD .bp +and +.BD .sp ? +The answer is that +.BD .sp +and +.BD .bp , +like several other commands, +cause a +.ul +break +to take place. +That is, all the input text collected but not yet printed +is flushed out as soon as possible, +and the next input line is guaranteed to start +a new line of output. +If we had used +.BD .sp +or +.BD .bp +in the +.BD .NP +macro, +this would cause a break in the middle +of the current output line when a new page is started. +The effect would be to print the left-over part of that line +at the top of the page, followed by the next input line on a new output line. +This is +.ul +not +what we want. +Using +.BD \(fm +instead of +.BD . +for a command +tells +.UL troff +that +no break is to take place _ +the output line +currently being filled +should +.ul +not +be forced out before the space or new page. +.PP +The list of commands that cause a break +is short and natural: +.P1 +^bp ^br ^ce ^fi ^nf ^sp ^in ^ti +.P2 +All others cause +.ul +no +break, +regardless of whether you use a +.BD . +or a +.BD \(fm . +If you really need a break, add a +.BD .br +command at the appropriate place. +.PP +One other thing to beware of _ +if you're changing fonts or point sizes a lot, +you may find that +if you cross a page boundary +in an unexpected font or size, +your titles come out in that size and font +instead of what you intended. +Furthermore, the length of a title is independent of the current line length, +so titles will come out at the default length of 6.5 inches +unless you change it, +which is done with the +.BD .lt +command. +.PP +There are several ways to fix the problems of point sizes +and fonts in titles. +For the simplest applications, we can change +.BD .NP +to set the proper size and font for the title, +then restore the previous values, like this: +.P1 2 +.ta .8i +^de NP +\(fmbp +\(fmsp 0.5i +^ft R \e" set title font to roman +^ps 10 \e" and size to 10 point +^lt 6i \e" and length to 6 inches +^tl 'left'center'right' +^ps \e" revert to previous size +^ft P \e" and to previous font +\(fmsp 0.3i +^^ +.P2 +.PP +This version of +.BD .NP +does +.ul +not +work if the fields in the +.BD .tl +command contain size or font changes. +To cope with that +requires +.UL troff 's +`environment' mechanism, +which we will discuss in Section 13. +.PP +To get a footer at the bottom of a page, +you can modify +.BD .NP +so it does +some processing before +the +.BD \(fmbp +command, +or split the job into a footer macro invoked +at the bottom margin and a header macro invoked +at the top of the page. +These variations are left as exercises. +.WS +.PP +Output page numbers are computed automatically +as each page is produced (starting at 1), +but no numbers are printed unless you ask for them explicitly. +To get page numbers printed, +include the character +.BD % +in the +.BD .tl +line at +the position where you want the number to appear. +For example +.P1 +^tl ''- % -'' +.P2 +centers the page number inside hyphens, as on this page. +You can set the page number at any time +with either +.BD .bp\ n , +which immediately starts a new page numbered +.BD n , +or with +.BD .pn\ n , +which sets the page number for the next page +but doesn't cause a skip to the new page. +Again, +.BD .bp\ +n +sets the page number to +.BD n +more than its current value; +.BD .bp +means +.BD .bp\ +1 . |