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Diffstat (limited to 'doc/context/sources/general/manuals/pagecolumns/pagecolumns.tex')
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1 files changed, 395 insertions, 0 deletions
diff --git a/doc/context/sources/general/manuals/pagecolumns/pagecolumns.tex b/doc/context/sources/general/manuals/pagecolumns/pagecolumns.tex new file mode 100644 index 000000000..40a396e1b --- /dev/null +++ b/doc/context/sources/general/manuals/pagecolumns/pagecolumns.tex @@ -0,0 +1,395 @@ +% macros=mkvi language=uk + +\definemeasure[onecolumn] [\columnwidth] +\definemeasure[twocolumns] [\dimexpr\plustwo \columnwidth+ \columndistance\relax] +\definemeasure[threecolumns][\dimexpr\plusthree\columnwidth+\plustwo \columndistance\relax] +\definemeasure[fourcolumns] [\dimexpr\plusfour \columnwidth+\plusthree\columndistance\relax] + +\usemodule[abr-04] + +\setupbodyfont + [dejavu,11pt] + +\definefont[QuiteLarge][SansBold sa 2.50] +\definefont[NotSoLarge][SansBold sa 1.25] + +\setuplayout + [backspace=.1\paperwidth, + topspace=.025\paperheight, + header=0.025\paperheight, + footer=0.025\paperheight, + headerdistance=0.025\paperheight, + footerdistance=0.025\paperheight, + width=middle, + height=middle] + +\setuppagenumbering + [alternative=doublesided, + location=] + +\setupwhitespace + [line] + +\setupblank + [line] + +\setuptyping + [blank=halfline] + +\startsetups [pagenumber] + \hbox to .2\paperwidth { + \hss + Page \pagenumber + \hss + } +\stopsetups + +\setupfooter [before=\vfill,after=\vfill,style=\bf,color=color-4] +\setupheader [before=\vfill,after=\vfill,style=\bf,color=color-4] + +\setupfootertexts [] [\setups{pagenumber}] +\setupheadertexts [] [\setups{chapterhead}] + +\startsetups [chapterhead] + \hbox to .2\paperwidth { + \hss + \getmarking[chapter] + \hss + } +\stopsetups + +\setuphead + [chapter] + [header=empty] + +\definecolor[color-3][.5(red,black)] +\definecolor[color-2][.5(green,black)] +\definecolor[color-1][.5(blue,black)] +\definecolor[color-4][.5(white,black)] +\definecolor[color-5][.5(white,color-4)] +\definecolor[color-6][.2(white,color-4)] + +\definecolor[fakerulecolor][white] + +\usemodule[typesetting] + +\setupcombination + [style=mono] + +\startuseMPgraphic{page} +StartPage ; + path p ; + numeric n; n := PageNumber ; + numeric w; w := bbwidth(Page) ; + numeric h; h := bbheight(Page) ; + def DrawBit (expr bit, dx, dy) = + path p ; p := unitsquare xyscaled(w/5,h/40) shifted (dx*w/10,dy*(h-h/40)) ; + if n div bit > 0 : + n := n - (n div bit)*bit ; + fill p withcolor \MPcolor{color-1} ; + else : + fill p withcolor \MPcolor{color-2} ; + fi ; + enddef ; + DrawBit(32,7,1) ; + DrawBit(16,4,1) ; + DrawBit( 8,1,1) ; + DrawBit( 4,7,0) ; + DrawBit( 2,4,0) ; + DrawBit( 1,1,0) ; +StopPage ; +\stopuseMPgraphic + +\startuniqueMPgraphic{frame} + fill OverlayBox withcolor \MPcolor{color-5} ; +\stopuniqueMPgraphic + +\startuniqueMPgraphic{contrast} + fill OverlayBox withcolor \MPcolor{color-4} ; +\stopuniqueMPgraphic + +\defineoverlay[page] [\useMPgraphic{page}] +\defineoverlay[frame] [\useMPgraphic{frame}] +\defineoverlay[contrast][\useMPgraphic{contrast}] + +\setuphead + [chapter] + [style=\QuiteLarge, + color=color-3, + number=no] + +\setuplist + [chapter] + [command=\MyListCommand, + alternative=command] + +\starttexdefinition unexpanded MyListCommand #1#2#3 + \snaptogrid + [line,-line]\vbox { + \tfb + \setstrut + \strut#2 + \quad#3 + } +\stoptexdefinition + +\setupmargindata + [style=\tttf, + color=color-3] + +\starttexdefinition unexpanded ShowFile #1 + \margintext + {\cldcontext{string.match("#1","\letterpercent d+")}} + \typefile + [range={environment}] + {#1} +\stoptexdefinition + +% \typefile[range=4] {...} +% \typefile[range={=}]{...} % start after comment lines + +\starttexdefinition unexpanded ShowEnvironmentFile #1 + \margintext + {\cldcontext{string.match("#1","\letterpercent d+")}} + \typefile + [range={=startenvironment}] + {#1} +\stoptexdefinition + +\startdocument + +\startMPpage +StartPage ; + path p ; numeric w, h, d ; picture q ; + if true : + q := image(draw textext.urt("\ssbf PAGES") withcolor \MPcolor{color-6}) ; + else : + q := image(draw textext.urt("\ssbf PAGECOLUMNS") withcolor \MPcolor{color-6}) ; + fi ; + w := bbwidth(Page) ; + h := bbheight(Page) ; + d := h/100 ; + fill Page withcolor \MPcolor{color-1} ; + p := Page xysized (w,d) ; + for i := 5d step 2d until h-5d : + fill p shifted (0,i) withcolor \MPcolor{color-2} ; + endfor + p := Page xysized(w/10,h) ; + for i = 0, .3, .6, .9 : + fill p shifted (i*w,0) withcolor \MPcolor{color-1} withtransparency(1,.75) ; + endfor ; + def do_it(expr sz, sh) = + p := Page xysized sz ; + fill p shifted sh withcolor \MPcolor{color-3} withtransparency(1,.5) ; + draw q xysized (bbwidth(p),bbheight(p)) shifted sh ; + enddef ; + do_it ((8w/10,13d),(.1w,81d)) ; + do_it ((5w/10,13d),(.4w,67d)) ; + do_it ((2w/10,17d),(.1w,20d)) ; + do_it ((2w/10,15d),(.1w,56d)) ; + do_it ((1w/10,10d),(.4w,40d)) ; + do_it ((2w/10,13d),(.7w,27d)) ; + draw textext.urt("\ssbf Hans Hagen") + xysized (5w/10,5d) + shifted (.4w,6d) + withcolor \MPcolor{color-5} ; +StopPage ; +\stopMPpage + +\page[empty] \setuppagenumber[number=1] + +\setupbackgrounds + [page] + [background=page] + +\starttitle[title=Contents] + + \placelist[chapter] + +\stoptitle + +\startchapter[title=Introduction] + +{\em This manual as well as the mechanism it describes is under construction. Don't +use page columns in production. Experimenting is of course fine.} + +The \TEX\ engine is a progressive typesetter: it takes input and does something +with it and can do that for quite a while. It can process massive input and +produce massive output. In that process it never looks back. Now, it is of course +possible to collect content and delay some aspects of the rendering but to what +extent that content can be manipulated is limited. In \LUATEX\ one can do a bit +more but even then the basic typesetting process is mostly linear. + +When a text gets typeset there are several properties that play a role: + +\startitemize +\startitem + the width of the lines in a paragraph which is the main unit of processing +\stopitem +\startitem + the target height of what gets output, normally this is the height of the + text area, excluding headers and footers +\stopitem +\startitem + the parameters that determine when the so called output routine gets called, + for instance successive broken lines, widow and club penalties +\stopitem +\startitem + the presence of so called inserts, for instance footnotes or floating bodies +\stopitem +\startitem + the space between lines and paragraphs +\stopitem +\startitem + explicitly entered elements or spacing or injected by macros hooked into for + instance \type {\everypar} +\stopitem +\stopitemize + +It is important to realize that \TEX\ has no concept of what a page is. It takes +input and occasionally hand over the intermediate result to the output routine. +There decisions are made to flush out a page, either of not with ornaments like +headers, footers, content left over from previous encounters, footnotes as well +as maybe specific trickery liked by the backend that targets at some viewer. + +That said, so called multi|-|column layouts are {\em not} part of the concepts +present in \TEX. As far as the engine is concerned there is only one column. +Among the reasons for not having a native mechanism for columns is that it is +very hard to come up with a mechanism for splitting them in ways that suits +everybody. In fact, the amount of control needed would make such a mechanism very +complex and still limited. You can compare this to math typesetting. That +subspace has some fixed characteristics if only because otherwise mathematicians +could not communicate. However, there is some control over spacing and one can to +some extend intervene. In \LUATEX\ some of the hard coded properties are made +configureable but still one gets pretty much what the engine considers right. +Such an approach would not work with columns. In fact, it doesn't even work well +with tables, for which \TEX\ provides the alignment mechanism: different kind of +tables demand different solutions, which is why in \CONTEXT\ we have old +fashioned tables, tabulated tables (that span pages and can contain paragraphs), +natural as well as extreme tables that resemble \HTML\ tables, line tables and +framed tables. + +So, when we want to support columns we need to write something in \TEX\ lingua +and for that the \type {\vsplit} operation can be of help. So far we have in +\CONTEXT\ four mechanisms: + +\startitemize[n] +\startitem + the original \MKII\ mechanism that permits mixed single and multi|-|column + text flows, with limited support for floating bodies +\stopitem +\startitem + a reimplementation of mixed columns in a mix of \TEX\ and \LUA, a bit better + with balancing and penalties for keeping section heads with the text, but + with very limited support for floating bodies; it works ok with grids +\stopitem +\startitem + a reimplementation of \MKII\ columnsets, a mechanism that is meant for + magazine like layouts where floats can span columns and positioned at will: + this one assumes relative simple text flows but as a bonus provides spreads; + this one is strongly grid based +\stopitem +\startitem + page based columns, where we use the normal (single column) page builder to + collect columns that then get combined into a page: this one is quite robust + but one has to keep an eye on floats as we don't span across columns + otherwise than in top or bottom floats but, on the other hand, one can use so + called side floats; this one is still experimental +\stopitem +\stopitemize + +Given specific demands one can come up with alternatives but it's very hard to +combine all demands into one mechanismn simply because anything can be part of +the text flow. Because it is not much fun to write such mechanisms and because +no project ever pays for fundamental development, one just has to accept what +\CONTEXT\ provides, be it with limitations. + +The first mechanism is more or less obsolete and replaced by the second. For +instance, we now use the second one when we have an itemize that demands columns. +I must admit that I don't like columns and never use them. I was involved in +projects where the designer wanted columns but in the end the complexity of the +content didn't work well with that that decision: inconsistent whitespace (due to +many small sections, lots of images, many tables, math formulas, etc) as well as +the result having more pages that the single column variant with side and margin +floats. Occasionally I use columned itemize or columned tables of contents and of +course registers are often in columns. + +One can wonder why columns are supported anyway. It's mostly useful for +newspapers that have wide pages or journals that have small print. For magazines +and special layout it's fine too although it can look bad when columns are narrow +and fancy layout tricks are used. I guess that at some point their use will +disappear. A document on a phone or tablet is one narrow columns. An internet +page is one long column. A printed book, given that there will be such items in +the future is normally typeset in one column. And journals as well as newspapers +more and more get replaced by media that better serve their purpose. So, apart +from an intellectual challenge, implementing extensive multi|-|column support is +a waste of energy. Which is why we can accept limitations. + +\stopchapter + +\startchapter[title=Just text] + +As with the other mechanism you can define a column instance and use that later. +You can also directly pass the settings with the \type {\startpagecolumns} command +but best is to define an instance. + +\FourPages{pagecolumns-001} + +\ShowFile{pagecolumns-001} + +We always start at a new page and end on a new one. Footnotes and such don't span +columns and we don't balance. When the number of columns equals one you get the +normal routine but with the requested settings. + +\stopchapter + +\startchapter[title=Floats] + +You can have floating bodies in columns. When a float doesn't fit it will be +flushed at the top of the next page. + +\FourPages{pagecolumns-002} + +\ShowFile{pagecolumns-002} + +\SixPages{pagecolumns-007} + +\ShowFile{pagecolumns-007} + +Side floats are also supported but we don't treat them special so you get the +same behaviour as with single column layouts. + +\FourPages{pagecolumns-005} + +\ShowFile{pagecolumns-005} + +\FourPages{pagecolumns-003} + +\ShowFile{pagecolumns-003} + + +\stopchapter + +\startchapter[title=Footnotes] + +Footnotes are supported but we assume sane usage. You can always revert to +endnotes if needed. + +\FourPages{pagecolumns-004} + +\ShowFile{pagecolumns-004} + +\stopchapter + +\startchapter[title=Pages] + +Going to a new page happens with \type {\page} and progressing to the next column +with \type {\column}. + +\FourSpread{pagecolumns-006} + +\ShowFile{pagecolumns-006} + +\stopchapter + +\stopdocument |