\startcomponent co-en-13 \environment contextref-env \product contextref \chapter[blocks]{Blocks} \section{Introduction} \index{blocks} \index{floats} \index{placing+blocks} A block in \CONTEXT\ is defined as typographical unit that needs specific handling. We distinguish the following block types: \startitemize \head floats Examples of floats are figures, tables, graphics, intermezzos etc. The locations of these blocks are determined by \TEX\ and depends on the available space on a page. \head textblocks Examples of textblocks are questions and answers in a studybook, summaries, definitions or derivatives of formulas. The location of these kind of blocks in the final document cannot be determined beforehand. And the information may be used repeatedly in several settings. \head opposite blocks Opposite (or spread) blocks are typeset on the left||hand page when a single sided output is generated. The layout of the right||hand side page is influenced by the blocks on the left. \head margin blocks Margin blocks are more extensive than single margin words. Text and figures can be placed in the margin with this feature. \stopitemize There are a number of commands that support the use of these block types. These are discussed in this chapter. Furthermore we will discuss other forms of text manipulation. Formulas can also be seen as blocks. Since formulas are covered in a separate chapter we don't go into details here. This chapter is typeset with the option \type {\version [temporary]}. This does not refer to the content but to the typesetting. With this option, design information is placed in the margin. \start % in verband met \versie[voorlopig] \version[temporary] \overfullrule=0pt \section[floats]{Floats} \index{figures+placing} \index{tables+placing} \index{figures+numbering} \index{tables+numbering} \index{figures+listing} \index{tables+listing} \index{placing+figures} \index{placing+tables} \index{numbering+figures} \index{numbering+tables} \index{listing+figures} \index{listing+tables} \macro{\tex{definefloat}} \macro[placefloat]{\tex{place<>}} \macro[placelistoffloats]{\tex{placelistof<>}} \macro[completelistoffloats]{\tex{completelistof<>}} \macro[reservefloat]{\tex{reserve<>}} \macro[setupfloat]{\tex{setup<>}} \macro[startfloattest]{\tex{start<>text}} \macro{\tex{setupfloats}} \macro{\tex{setupcaptions}} Floats are composed of very specific commands. For example a table in \CONTEXT\ is typeset using a shell around \TABLE. Drawings and graphics are made with external packages, as \TEX\ is only capable of reserving space for graphics. Most floats are numbered and may have a caption. A float is defined with the command: \showsetup{definefloat} In \CONTEXT, figures, graphics, tables, and intermezzos are predefined with: \startexample \starttyping \definefloat [figure] [figures] \definefloat [table] [tables] \definefloat [graphic] [graphics] \definefloat [intermezzo] [intermezzos] \stoptyping \stopexample As a result of these definitions you can always use \type {\placefigure}, \type {\placetable}, \type {\placegraphic} and \type {\placeintermezzo}. Of course, you can define your own floats with \type {\definefloat}. You place your newly defined floats with the command: \showsetup{place<>} When a float cannot be placed at a specific location on a page, \CONTEXT\ will search for the most optimal alternative. \CONTEXT\ provides a number of placement options for floats. These are listed in \in {table} [tab:floats]. \placetable [here][tab:floats] {Preferences for float placement.} \starttable[|l|l|] \HL \VL \bf preference \VL \bf result \VL\SR \HL \VL \type{left} \VL left of text \VL\FR \VL \type{right} \VL right of text \VL\MR \VL \type{here} \VL preferably here \VL\MR \VL \type{top} \VL at top of page \VL\MR \VL \type{bottom} \VL at bottom of page \VL\MR \VL \type{inleft} \VL in left margin \VL\MR \VL \type{inright} \VL in right margin \VL\MR \VL \type{inmargin} \VL in the margin (left or right) \VL\MR \VL \type{margin} \VL in the margin (margin float) \VL\MR \VL \type{page} \VL on a new (empty) page \VL\MR \VL \type{opposite} \VL on the left page \VL\MR \VL \type{always} \VL precedence over stored floats \VL\MR \VL \type{force} \VL per se here \VL\LR \HL \stoptable The commands can be used without the left and right brackets. For example: \startexample \starttyping \place...{<>}{<>} \stoptyping \stopexample When the caption is left out, the float number is generated anyway. When the number is not needed you type \type {none}, like in: \starttyping \placefigure{none}{.....} \stoptyping It is mandatory to end this command by an empty line or a \type {\par}. You don't have to embed a table in braces, since the \type {\start} and \type {\stop} commands have them built in: \startbuffer \placetable [here][tab:example] {A very simple example of a table.} \starttable[|c|c|] \HL \VL this \VL is \VL\FR \VL a \VL table \VL\LR \HL \stoptable \stopbuffer \startexample \typebuffer \stopexample \start \setuptables[VL=medium,HL=medium] \getbuffer \stop The vertical whitespace for a float can be reserved with: \showsetup{reserve<>} This command can be used without the left and right bracket. An example of a reservation is: \startbuffer \reservefigure [height=4cm,width=10cm,frame=on][here][fig:reservation] {An example of a reservation.} \stopbuffer \startexample \typebuffer \stopexample Which results in \in{figure}[fig:reservation]. \getbuffer When the content of a float is not yet available, you can type \type {\empty...} instead of \type {\place...}. In this way you can also reserve vertical whitespace. When no option is added, so \argchars\ is typed, the default empty float is used. However, whether the figure or table is available is not that important. You can always type: \startexample \starttyping \placefigure{This is a figure caption.}{} \stoptyping \stopexample As a first argument you can specify a key \type {left} or \type {right} that will cause \CONTEXT\ to let the text flow around the float. The second optional parameter can be a cross reference, to be used later, like \type {\at {page} [fig:schematic process]}. \startexample \starttyping \placefigure[here][fig:demo]{This a figure caption.}{} \stoptyping \stopexample As we will later see, you can also use the next command: \showsetup{start<>text} Preferences are \type {left}, \type {right} or \type {middle}. Furthermore you can specify \type {offset} in case the text should align with the float. Both setups can be combined: \type {[left,offset]}. A list of used floats is generated with the command: \showsetup{placelistof<>} For example, the command \type {\placelistoffigures} would typeset a list of figures. The list follows the numbering convention that is set with the command \type {\setupnumbering}, which was discussed at \at {page} [numbering]. The next command generates a list of floats on a separate page. \showsetup{completelistof<>} Pagebreaks that occur at unwanted locations can be enforced in the same way that is done with a table of contents (see \in{section}[toc]): \startexample \starttyping \completelistof<>[pageboundaries={8.2,20.4}] \stoptyping \stopexample As with tables of content the default local lists are generated. Recalling a list within a chapter produces a list for that specific chapter. So, if you want a list of all figures, you need to specify \type {criterium} as \type {all}. \startbuffer \placelistoffigures[criterium=chapter] \stopbuffer \getbuffer The previous list was produced by saying: \typebuffer The characteristics of a specific class of floats are specified with the command: \showsetup{setupfloat} The (predefined) floats can also be set up with the more meaningful commands \type {\setupfigures}, \type {\setuptables} etc. The height and width relate to the vertical whitespace that should be reserved for an empty float. All settings of \type {\framed} can be used, so when \type {frame} is set to \type {on}, we get a framed float. The next two commands relate to {\em all} floats. The first command is used for setting the layout including the caption: \showsetup{setupfloats} The second command is used for setting the enumerated captions of figures, tables, intermezzos, etc. \showsetup{setupcaptions} You can also set up captions for a specific class of floats, like figures. The first argument of the next command is the name of that class of floats. \showsetup{setupcaption} The commands assigned to \type {before}, \type {after} are are executed before and after placing the float. The parameter \type {inbetween} is executed between the float and the caption. All three normally have a \type {\blank} command assigned. The parameter \type {style} is used for numbering ({\bf Figure~x.y}) and \type {width} for the width of the caption label. The parameter \type {margin} specifies the margin space around a float when it is surrounded by text. The float macros optimize the width of the caption (at \type {top} or \type {bottom}) related to the width of the figure or table. \start \setupcaptions[location=high] \setupfloats[location=left] \placefigure[force]{} \startframedtext \starttyping \setupcaptions[location=high] \setupfloats[location=left] \stoptyping \stopframedtext \stop With the three variables \type{ntop}, \type{nbottom} and \type{nlines} the float storage mechanism can be influenced. The first two variables specify the maximum number of floats that are saved per page at the top or the bottom of a page. By default these variables have the values ~2 and~0. Assume that ten figures, tables and|/|or other floats are stored, then by default two floats will be placed at each new page (if possible). For example, at a forced pagebreak or at the beginning of a new chapter, all stored floats are placed. The parameter \type {nlines} has the default value~4. This means that never less than four lines will be typeset on the page where the floats are placed. We continue with a few examples of floats (figures) placed next to the running text. This looks like: \startexample \starttyping \placefigure[right]{none}{} ... here is where the text starts .... \stoptyping \stopexample For illustrating the mechanism we do need some text. Therefore the examples are used to explain some issues on the float mechanism. Floats are placed automatically. The order of appearance follows the order you have keyed in the source. This means that larger floats are placed somewhere else in your document. When \type{\version[temporary]} is set, you can get information on the float mechanism. By consulting that information you get some insight into the process. \placefigure[right]{none}{\externalfigure[rb00006]} Floats can be surrounded by text. The float at the right was set with \type {\placefigureright[right]{none}{...}}. The float mechanism works automatically. Should it occur that pages are left blank as a result of poor float placement, you will need to make some adaptations manually. You can downsize your figure or table or alter your text. It is also a good practice to define your float some paragraphs up in your source. However, all of this should be done at the final production stage. With the key \type{force} you can force a float to be placed at that exact location. Tables or figures that are preceded by text like: \quote{as we can see in the figure below} may be defined with this option. \placefigure[left]{none}{\externalfigure[rb00008]} In manuals and study books we encounter many illustrations. It is almost unavoidable to manually adapt these for optimal display. However, the float commands in \CONTEXT\ are optimized in such a way that you can produce books with hundreds of floats effortlessly. The worst case is that some floats are stored and placed at the end of the chapter. But this can be influenced with the command \type {\startpostponing}. Postponing is done with the keys \type {always} which can be combined with the location, like \type {[left,always]} or \type {[here,always]}. Because the order of the floats is changed several parses are necessary for the document. These processes can be traced via messages on the terminal. This brings us to a figure that is placed at the left side of a page. The side float mechanism in inspired and based on a mechanism of D.~Comenetz. In the background three mechanisms are active. A mechanism to typeset a figure on top, inbetween, of under existing text. There is a mechanism to place figures on the right or left of a page. And there is a third mechanism to typeset text next to a figure. \startfiguretext[right]{none}{\externalfigure[rb00015]} We see an example of the last mechanism. The text is enclosed by the commands: \starttyping \startfiguretext [right]{none}{\externalfigure[rb00015]} .... \stopfiguretext \stoptyping \stopfiguretext \startfiguretext[left,offset]{none}{\externalfigure[vos1082]} It is obvious that we can also place the figure at the left. With \type {\start...text} we can add the key \type {offset}. Here we used \type {[left,offset]}. When the text is longer than expected, then it will {\em not} flow around the float. By default the floats are handled in the same order they are typed in the source file. This means that the stored figures are placed first. If this is not desired you can type the key \type{always}. The actual float will get priority. \stopfiguretext \startfiguretext[right,middle]{none}{\externalfigure[vos1083]} There are more options. In this case the setup \type {[right,middle]} is given. In the same way we place text \type {high} and \type {low}. When the key \type {long} is used the rest of the text is filled out with empty lines, as here. \stopfiguretext When several figures are set under each other, making them the same width makes for a nice presentation on the page. This looks better. \section{Combining figures} \index{figures+combining} \index{combining} \macro{\tex{startcombination}} \macro{\tex{setupcombinations}} \macro{\tex{placesidebyside}} \macro{\tex{placeontopofeachother}} For reasons of convenience we now discuss a command that enables us to combine floats into one. \showsetup{startcombination} This command is used to place the figures under or next to each other. \startbuffer \placefigure [here] [fig:combinations] {An example of \tex{startcombination...}.} {\startcombination[3*2] {\externalfigure[lb00220]} {a} {\externalfigure[lb00221]} {b} {\externalfigure[lb00222]} {c} {\externalfigure[lb00223]} {d} {\externalfigure[lb00225]} {e} {\externalfigure[lb00226]} {f} \stopcombination} \stopbuffer \getbuffer The example in \in{figure}[fig:combinations] is typeset with the commands: \startexample \typebuffer \stopexample Between \setchars\ we specify how the combination is combined: \type{[3*2]}, \type{[4*2]} etc. When we put two floats next to each other it is sufficient to specify \type{[2]}, \type{[4]} etc. The floats, mostly figures or tables, are specified within two arguments. The first content is placed over the second content: \type{{xxx}{yyy}}. The second argument can be empty: \type{{xxx}{}}. The general construct looks like this: \startexample \starttyping \startcombination[n*m] {text 1} {subcaption 1} {text 2} {subcaption 2} ........ .............. \stopcombination \stoptyping \stopexample The combination can be set up with: \showsetup{setupcombinations} With \type{distance} you specify the horizontal distance between objects. The parameters \type{align} relates to the subcaption. By default the text and objects are centered. The width is the total width of the combination. The three parameters \type{before}, \type{after} and \type{between} are processed in the order of specification in \in{figure}[fig:order of combinations]. There are some examples in \in{figure}[fig:spacing in combinations]. We can see in \in{figure}[fig:no subcaptions] that when the title in the second argument is empty the spacing adapted. \startbuffer \startcombination[4] {\framed{test}} {\framed{a}} {\framed{test}} {\framed{b}} {\framed{test}} {\framed{c}} {\framed{test}} {\framed{d}} \stopcombination \stopbuffer \setbox4=\vbox {\setupcombinations[inbetween={\blank[big]}]\getbuffer} \setbox6=\vbox {\setupcombinations[inbetween={\blank[medium]}]\getbuffer} \setbox8=\vbox {\setupcombinations[inbetween={\blank[small]}]\getbuffer} \placefigure [here][fig:spacing in combinations] {The spacing within combinations (1).} \startcombination[3] {\box4} {\arg{\blank[big]}} {\box6} {\arg{\blank[medium]}} {\box8} {\arg{\blank[small]}} \stopcombination \placefigure [here][fig:order of combinations] {The spacing within combinations (2).} {\forgetall \setupframed[width=4cm] \framed[height=3cm,frame=on]{figure}% \framed[frame=off]{\type{}}% \framed[height=1cm,frame=on]{subtitle}% \framed[frame=off]{\type{}}% \framed[frame=off]{\type{}}} \placefigure [here][fig:no subcaptions] {Combinations without captions.} \startcombination[3] {\externalfigure[vew1095]} {} {\externalfigure[vew1096]} {} {\externalfigure[vew1097]} {} \stopcombination Using combinations require figures that have the correct dimensions or equal proportions. Unequally proportioned figures are hard to combine. The simple version of combining is this: \showsetup{placesidebyside} \showsetup{placeontopofeachother} We use them in this way: \starttyping \placesidebyside {\framed{\Logo[ADE]}} {\framed{\Logo[BUR]}} \placeontopofeachother {\framed{\Logo[ADE]}} {\framed{\Logo[BUR]}} \stoptyping \section[textblocks]{Text blocks} \index{moving text} \index{blocks+moving} \index{blocks+numbering} \index{numbering+blocks} \macro{\tex{defineblocks}} \macro[beginblock]{\tex{begin<>}} \macro{\tex{hideblocks}} \macro{\tex{selectblocks}} \macro{\tex{useblocks}} \macro{\tex{keepblocks}} \macro{\tex{processblocks}} \macro{\tex{setupblock}} \macro{\tex{reset}} For practical reasons we sometimes want to key text somewhere in the source that should be typeset at a completely different location in the typeset document. It is also useful to be able to use text more than once. The commands described below are among the eldest of \CONTEXT. They were one of the reasons to start writing the macropackage. \stop \message{[check i.v.m. versie voorlopig]} You can mark text (a text block) and hide or move that block, but first you have to define it using: \showsetup{defineblock} If necessary you can pass several names in a comma||delimited list. After the definition you can mark text with: \startexample \starttyping \begin<> .................... .................... \end<> \stoptyping \stopexample Between the \type{begin}|| and \type{end} command you can use any command you want. The commands below tell \CONTEXT\ to hide or recall text blocks: \showsetup{hideblocks} \showsetup{useblocks} \showsetup{keepblocks} \showsetup{selectblocks} \showsetup{processblocks} These commands make it necessary to process your text at least twice. You can also recall more than one text block, for example \type {[question,answer]}. In hidden and re||used blocks commands for numbering can be used. Assume that you use questions and answers in your document. By defining the questions as text blocks you can: \startitemize[n,packed,stopper] \item at that location typeset the questions \item[item:reuse] only use the questions and use the answers in a separate chapter \item use questions and answers in a separate chapter \item hide the answers \item etc. \stopitemize When we choose \in{option}[item:reuse] the definitions look like this: \startexample \starttyping \defineenumeration[question][location=top,text=Question] \defineenumeration[answer][location=top,text=Answer] \defineblock[question,answer] \hideblocks[answer] \stoptyping \stopexample A question and answer in the source look like this: \startexample \starttyping \beginquestion \question Why do we use blocks? \par \endquestion \beginanswer \answer I really don't know. \par \endanswer \stoptyping \stopexample The questions are only used in the text. Questions and answers are both numbered. Answers are summoned by: \startexample \starttyping \chapter{Answers} \reset[answer] \useblocks[answer] \stoptyping \stopexample The command \type{\reset...} is necessary for resetting the numbering mechanism. When the answers are used in the same chapter you can use the following commands: \startexample \starttyping \section{Answers} \reset[answer] \selectblocks[answer][criterium=chapter] \stoptyping \stopexample You must be aware of the fact that it may be necessary to (temporarily) disable the reference mechanism also: \startexample \starttyping \setupreferencing[state=stop] \stoptyping \stopexample A more complex situation is this one. Assume that you have several mathematical formulas in your document, and that you want to recapitulate the more complex ones in a separate chapter at the end of the document. You have to specify an \type{[-]} at formulas you do not want repeated. \startexample \starttyping \defineblock[formula] \beginformula \placeformula[newton 1]$$f=ma$$ \endformula This can also be written as: \beginformula[-] \placeformula[newton 2]$$m=f/a$$ \endformula \stoptyping \stopexample When you re||use the formulas only the first one is typeset. The rest of the formulas is processed, so the numbering will not falter. The opposite is also possible. By default all local specifications are undone automatically. This means for example that the enumeration of text elements like questions, answers, definitions, etc. can be temporarily stopped. When numbering should continue you specify: \type {[+]}.\footnote {When you use enumerations within text blocks you can best use the \type {\start...stop} alternative (see~\at {page} [numbering]).} Among the parameters of the number mechanism we (in some cases) use the parameter \type{blockwise}. This parameter relates to numbering within a set of blocks, for example per chapter. You may have a document in which the questions and answers are collected in text blocks. The questions are typeset in the document and the answers in a separate appendix. Answers and question are put at the same location in the source file. When we number the questions and answers per chapter, then question~4.12 is the 12th question in chapter~4. The correct number is used in the appendix. In this example answer~4.12 refers to question~4.12 and not the appendix number. In case we do want the appendix number to be the prefix of the blocknumber we set the parameter \type{blockwise} at \type{no}. This is a rather complex situation and will seldom occur. Earlier we discussed the initializing and resetting of counters. For reasons of uniformity we also have: \showsetup{reset} In future there will be an option to sort blocks. For that purpose a second set of optional \setchars\ in {\useblocks} and \type {\selectblocks} is available. The first argument is used for \quote {tags}. These tags are logical labels that enable us to recall the blocks. \startexample \starttyping \beginremark[important] This is an important message! \endremark \stoptyping \stopexample Now we can recall the \quote {important} messages by: \startexample \starttyping \useblocks[remark][important] \stoptyping \stopexample or: \startexample \starttyping \selectblocks[remark][important][criterium=chapter] \stoptyping \stopexample Here, \type {criterium} has the same function as in lists (like tables of content) and registers: it limits the search. In this case, only the blocks belonging to this chapter will be typeset. More than one \quote {tag} is allowed in a comma delimited list. Text blocks may be nested: \startexample \starttyping \beginpractice \beginquestion \question Is that clear? \par \endquestion \beginanswer \answer Yes it is! \par \endanswer \endpractice \stoptyping \stopexample In this case we use three blocks. Such blocks are stored in a file. This file must be available when the blocks are re||used. This means that the document must be processed at least twice. When blocks are summoned at the end of your source file only one processing step is sufficient but then you have to type the command \type {nomoreblocks} before the blocks are recalled: \showsetup{nomoreblocks} After this command no blocks should be specified. In the future commands will be developed for local adaptations of the layout of text blocks. Until that moment the following command is all there is: \showsetup{setupblock} A block is being processed within a group, in other words: within \argchars. The setup of \type{before} and \type{after} are used outside this group, and the setup of \type{inner} is used within the group. For example if we mark a re||used text block in the margin we can use the following setup: \startbuffer \defineblock[exampletext] \beginexampletext If you wonder why this mechanism was implemented consider an educational document with hundreds of \quote {nice to know} and \quote {need to know} text blocks at several ability levels. \endexampletext \setupblock[exampletext][inner=\margintitle{reused}] \useblocks[exampletext] \stopbuffer \typebuffer The first text is set without an indicator in the margin and the second is. If we would have used \type {before} instead of \type {inner} some grouping problems had occurred. \getbuffer You can import text blocks from other source files. For example if you want to use text blocks from a manual for students in a manual for teachers, you can specify: \startexample \starttyping \setupblock [homework] [file=student, before=\startbackground, after=\stopbackground] \stoptyping \stopexample In that case the blocks are imported from the file \type {student.tex}. In this example these blocks are typeset differently, with a background. When the student material is specified with: \startexample \starttyping \beginhomework[meeting 1] .......... \endhomework \stoptyping \stopexample we can summon the blocks in the teacher's manual with: \startexample \starttyping \useblocks[homework][meeting 1] \stoptyping \stopexample In extensive documents it will take some time to generate these products. But this mechanism garantees we use the same homework descriptions in the students and teachers manual. Furthermore it saves typing and prevents errors. Questions and answers are good examples of text blocks that can be hidden and moved. The example below will illustrate this. Because commands like \type {\question} have a paragraph as an argument the \type {\par}'s and/or empty lines are essential. In the setup we see that questions and answers are coupled. A coupling has a meaning in interactive documents. \startexample \starttyping \defineblock[question] \defineblock[answer] \defineenumeration[question][location=inmargin,coupling=answer] \defineenumeration[answer][location=top,coupling=question] \hideblocks[answer] \starttext \chapter{\CONTEXT} \CONTEXT\ is a macropackage that is based on \TEX. \TEX\ is a typesetting system and a programm. This unique combination is used extensively in \CONTEXT. \beginquestion \startquestion To date, the fact that \TEX\ is a programming language enables \CONTEXT\ to do text manipulations that cannot be done with any other known package. Can you mention one or two features of \CONTEXT\ that are based on the fact that \TEX\ is programming language? \stopquestion \endquestion \beginanswer \answer You can think of features like floating blocks and text block manipulation. \par \endanswer \beginquestion \question Are there any limitations in \TEX ? \par \endquestion \beginanswer \answer Yes and no. The implementation of \TEXEXEC\ is done in \PERL\ rather than in \TEX. \endanswer \TEX\ is a very powerful tool, but much of its power is yet to be unleashed. \CONTEXT\ tries to make a contribution with its user||friendly interface and its support of many features, like interactivety. \chapter{Answers} \useblocks[question,answer] \stoptext \stoptyping \stopexample With \type {\processblocks} blocks are processed but not typeset. Assume that we have two types of questions: \starttyping \defineblock[easyquestion,hardquestion] \stoptyping When both types of questions use the same numbering mechanism, we can recall the hard questions in their original order by hiding the easy questions. \starttyping \processblocks[easyquestion] \useblocks[hardquestion] \stoptyping \section[opposite blocks]{Opposite blocks} \index{mirroring} \index{blocks+moving} \index{moving text} \macro{\tex{startopposite}} In future versions of \CONTEXT\ there will be support of spread based typesetting. For the moment the only command available is: \showsetup{startopposite} Everything between \type{start} and \type{stop} is typeset at the left page in such a way that it is aligned with the last paragraph that is typeset on the right page. \showsetup{setupoppositeplacing} \section[marginblocks]{Margin blocks} \index{margin+blocks} \macro{\tex{startmarginblock}} \macro{\tex{setupmarginblocks}} Within limits you can place text and figures in the margin. In this case the margin is handled as a separate (very narrow) page next to the actual page. \showsetup{startmarginblock} This can be setup with: \showsetup{setupmarginblocks} {\em The mechanism to place blocks is still under construction.} \section[texthiding]{Hiding text} \index{hiding text} \macro{\tex{starthiding}} It is possible to hide text (skip during processing) by: \showsetup{starthiding} \section[postponing]{Postponing text} \index{postponing text} \macro{\tex{startpostponing}} Text elements can be postponed (stored) and placed at the next empty page. This option is needed in case \CONTEXT\ encounters large figures or tables. The postponed textelement is placed at the next page generated by \TEX\ or forced by the user with a manual page break. \showsetup{startpostponing} Several text blocks can be postponed and stored. This proces can be followed on screen during document generation. \startexample \starttyping \startpostponing \placefigure{A rather large figure.}{...} \stoppostponing \stoptyping \stopexample When a lot of text elements are postponed or when a figure uses a complete page we advise you to add \type{\page} after the postponing. Otherwise there is the possibility that a blank page is inserted. This is caused by the fact that the postponing mechanism and the float mechanism are completely independent. \startexample \starttyping \startpostponing \placefigure{A very large figure.}{...} \page \stoppostponing \stoptyping \stopexample \section[buffers]{Buffers} \index{buffers} \index{moving text} \macro{\tex{startbuffer}} \macro{\tex{setupbuffer}} \macro{\tex{getbuffer}} \macro{\tex{typebuffer}} Buffers simplify the moving of text blocks. They are stored in a file with the extension \type {tmp} and are used to bring readability to your source. Furthermore they can be recalled at any location without retyping them. \showsetup{startbuffer} \showsetup{getbuffer} \showsetup{typebuffer} The example below shows the use of these commands. \startbuffer \startbuffer We see that a {\em buffer} works something like a {\em block}.\par \stopbuffer \startlines {\tf \getbuffer} {\bf \getbuffer} {\sl \getbuffer} \stoplines \stopbuffer \startexample \typebuffer \stopexample This results in: \startreality \getbuffer \stopreality The name is optional. A name makes sense only when several buffers are used. Most of the time the default buffer will do. Most examples in this manual are typed in buffers. In \in {chapter} [tables] we can see that the last argument of a \type {\place<>} can be rather extensive. A buffer can be useful when such large tables are defined. \startexample \setuptyping[option=commands] \starttyping \startbuffer ... <> ... \stopbuffer \placetable{A table.}{\getbuffer} \stoptyping \stopexample The buffer is set up with: \showsetup{setupbuffer} The first argument is optional and relates to the buffers you defined yourself. You can define your own buffer with: \showsetup{definebuffer} Be aware of possible conflicting names and use capital letters. After this command \type {/get<>} and \type {/type<>} are available where \type{<>} is the name of the buffer. \stopcomponent