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diff --git a/doc/context/sources/general/manuals/metafun/metafun-styles.tex b/doc/context/sources/general/manuals/metafun/metafun-styles.tex new file mode 100644 index 000000000..f82359117 --- /dev/null +++ b/doc/context/sources/general/manuals/metafun/metafun-styles.tex @@ -0,0 +1,445 @@ +% language=uk +% +% copyright=pragma-ade readme=readme.pdf licence=cc-by-nc-sa + +\startcomponent metafun-styles + +\environment metafun-environment + +\startchapter[title={Defining styles}] + +\index {layout} +\index {styles} + +\startintro + +Since the integration of \METAPOST\ into \CONTEXT, a complete new range of layout +fetaures became available. In this document we have introduced several ways to +include graphics in your document definition. In this chapter we go one step +further and make dynamic graphics part of a document style. + +\stopintro + +\startsection[title={Adaptive buttons}] + +So far we have seen a lot of graphic ingredients that you can use to make your +documents more attractive. In this chapter we will define a simple document +style. This style was written for the \PDFTEX\ presentations at the TUG 2000 +conference in Oxford (UK). + +This style exploits a few tricks, like graphics calculated using positional +information. It also demonstrates how you can make menu buttons that dynamically +adapt their shapes to the rest of the page layout. + +\startbuffer[screens] +\startlinecorrection[blank] +\setupcombinations[distance=.0125\textwidth] +\startcombination[5*1] + {\typesetfile[mfun-77\ScrNum.tex][page=1,width=.19\textwidth]} {page 1} + {\typesetfile[mfun-77\ScrNum.tex][page=2,width=.19\textwidth]} {page 2} + {\typesetfile[mfun-77\ScrNum.tex][page=3,width=.19\textwidth]} {page 3} + {\typesetfile[mfun-77\ScrNum.tex][page=4,width=.19\textwidth]} {page 4} + {\typesetfile[mfun-77\ScrNum.tex][page=5,width=.19\textwidth]} {page 5} +\stopcombination +\stoplinecorrection +\stopbuffer + +\def\ScrNum{1} \getbuffer[screens] + +Later we will see an instance with some more randomness in the graphics. While +writing this style, the random alternative made me think of those organic +buildings with non equal windows |<|we have a few of those in The Netherlands|>|, +so I decided to label this style as \type {pre-organic}. If you use \CONTEXT, you +can load this style with: + +\starttyping +\usemodule[pre-organic] +\stoptyping + +At the end of this file, there is a small test file, so when you process the file +\type {s-pre-19.tex} \footnote {This style is the 19\high{th} presentation style. +Those numbered styles are internally mapped onto more meaningful names like in +this case \type {pre-organic}.} with the options \type {--mode=demo} and \type +{--pdf}, you will get a demo document. + +We use one of the standard screen \quote {paper} sizes, and map it onto the same +size, so that we get a nicely cropped page. Other screen sizes are \type {S4} and +\type {S5}. + +\starttyping +\setuppapersize[S6][S6] +\stoptyping + +Like in this \METAFUN\ manual, we use the Palatino as main bodyfont. This font is +quite readable on even low resolution screens, although I admit that this style +is developed using an $1400\times1050$ pixel \kap {lcd} screen, so the author may +be a little biased. + +\starttyping +\setupbodyfont[ppl] +\stoptyping + +The layout specification sets up a text area and a right edge area where the +menus will go (see \in {chapter} [sec:page] for a more in depth discussion on the +layout areas). Watch how we use a rather large edge distance. By setting the +header and footer dimensions to zero, we automatically get rid of page body +ornaments, like the page number. + +\starttyping +\setuplayout + [topspace=48pt, + backspace=48pt, + cutspace=12pt, + width=400pt, + margin=0cm, + rightedge=88pt, + rightedgedistance=48pt, + header=0cm, + footer=0cm, + height=middle] +\stoptyping + +We use a moderate, about a line height, inter||paragraph white space. + +\starttyping +\setupwhitespace[big] +\stoptyping + +Of course we use colors, since on computer displays they come for free. + +\starttyping +\setupcolors[state=start] + +\definecolor [red] [r=.75] +\definecolor [yellow] [r=.75,g=.75] +\definecolor [gray] [s=.50] +\definecolor [white] [s=.85] +\stoptyping + +Because it is an interactive document, we have to enable hyperlinks and alike. +However, in this style, we disable the viewer's \quote {highlight a hyperlink +when it's clicked on} feature. We will use a menu, so we enable menus. Later we +will see the contrast color |<|hyperlinks gets that color when we are already on +the location|>| in action. + +\starttyping +\setupinteraction + [state=start, + click=off, + color=red, + contrastcolor=gray, + menu=on] +\stoptyping + +The menu itself is set up as follows. Because we will calculate menu buttons +based on their position on the page, we have to keep track of the positions. +Therefore, we set the \type {position} variable to \type {yes}. + +\starttyping +\setupinteractionmenu + [right] + [frame=off, + position=yes, + align=middle, + topoffset=-.75cm, + bottomoffset=-.75cm, + color=gray, + contrastcolor=gray, + style=bold, + before=, + after=] +\stoptyping + +The menu content is rather sober: just a list of topics and a close button. Later +we will define the command that generates topic entries. The alternative \type +{right} lets the topic list inherit its characteristics from the menu. + +\starttyping +\startinteractionmenu[right] + \placelist[Topic][alternative=right] + \vfill + \but [CloseDocument] close \\ +\stopinteractionmenu +\stoptyping + +We have now arrived at the more interesting part of the style definition: the +graphic that goes in the page background. Because this graphic will change, we +define a useable \METAPOST\ graphic. Page backgrounds are recalculated each page, +opposite to the other backgrounds that are calculated when a new background is +defined, or when repetitive calculation is turned on. + +\starttyping +\setupbackgrounds [page] [background=page] +\defineoverlay [page] [\useMPgraphic{page}] +\setupMPvariables [page] [alternative=3] +\stoptyping + +We will implement three alternative backgrounds. First we demonstrate the +relatively simple super ellipsed one. The main complication is that we want the +button shapes to follow the right edge of the curve that surrounds the text. We +don't know in advance how many lines of text there will be in a button, and we +also don't know at what height it will end up. Therefore, we need to calculate +each button shape independently and for that purpose we need to know its position +(see \in {chapter} [sec:positioning]). In \in {figure} [fig:style] you can see +what lines we need in order to be calculate the button shapes. + +\startpostponing + +\startmode[screen] + \placefigure + [here][fig:style] + {The lines used to calculate the button shapes.} + {\externalfigure[mfun-774.pdf][page=1,height=.85\textheight]} +\stopmode + +\startnotmode[screen] + \placefigure + [here][fig:style] + {The auxiliary lines used to calculate the button shapes.} + {\rotate{\externalfigure[mfun-774.pdf][page=1,height=\textwidth]}} +\stopnotmode + +\page + +\stoppostponing + +We separate the calculation of the button shape from the rest by embedding it in +its own usable graphic container. The \type {StartPage}||\type {StopPage} pair +takes care of proper placement of the whole graphic. + +\starttyping +\startuseMPgraphic{page} + + \includeMPgraphic{rightsuperbutton} + + StartPage ; + + path p, q ; pickup pencircle scaled 3pt ; + + p := Field[Text][Text] enlarged 36pt superellipsed .90 ; + + fill Page withcolor \MPcolor{yellow} ; + fill p withcolor \MPcolor{white} ; + draw p withcolor \MPcolor{red} ; + + p := Field[Text][Text] enlarged 48pt superellipsed .90 ; + + def right_menu_button (expr nn, rr, pp, xx, yy, ww, hh, dd) = + if (pp>0) and (rr>0) : + q := rightsuperbutton(p,xx,yy,RightEdgeWidth,hh) ; + fill q withcolor \MPcolor{white} ; + draw q withcolor if rr=2 : \MPcolor{gray} + else : \MPcolor{red} fi ; + fi ; + enddef ; + + \MPmenubuttons{right} + + StopPage ; +\stopuseMPgraphic +\stoptyping + +The \TEX\ macro \type {\MPmenubuttons} expands into a list of (in this case four) +calls to the \METAPOST\ macro \type {right_menu_button}. This list is generated +by \CONTEXT\ when it generates the menu. Because the page background is applied +last, this list is available at that moment. + +\starttyping +... (expr nn, rr, pp, xx, yy, ww, hh, dd) ... +\stoptyping + +This rather long list of arguments represents the following variables: number, +referred page, current page, x coordinate, y coordinate, width, height and depth. +The last six variables originate from the positioning mechanism. Because the +variables are only available after a second \TEX\ pass, we only draw a button +shape when the test for the page numbers succeeds. + +\starttyping +\startuseMPgraphic{rightsuperbutton} + vardef rightsuperbutton (expr pat, xpos, ypos, wid, hei) = + + save p, ptop, pbot, t, b, edge, shift, width, height ; + path p, ptop, pbot ; pair t, b ; + numeric edge, shift, width, height ; + + edge := xpos + wid ; shift := ypos + hei ; + + p := rightpath pat ; + + ptop := ((-infinity,shift)--(edge,shift)) ; + pbot := ((-infinity,shift-hei)--(edge,shift-hei)) ; + + t := p intersectionpoint ptop ; + b := p intersectionpoint pbot ; + + p := subpath(0,xpart (p intersectiontimes ptop)) of p ; + p := subpath(xpart (p intersectiontimes pbot),length(p)) of p ; + + (p -- t -- point 1 of ptop & + point 1 of ptop -- point 1 of pbot & + point 1 of pbot -- b + -- cycle) + + enddef ; +\stopuseMPgraphic +\stoptyping + +The calculation of the button itself comes down to combining segments of the main +shape and auxiliary lines. The \type {rightpath} macro returns the right half of +the path provided. This half is shown as a non dashed line. + +Topics are identified with \type {\Topic}, which is an instance of chapter +headings. The number is made invisible. Since it still is a numbered section +header, \CONTEXT\ will write the header to the table of contents. + +\starttyping +\definehead [Topic] [chapter] +\setuphead [Topic] [number=no] +\stoptyping + +We will use a bold font in the table of contents. We also force a complete list. + +\starttyping +\setuplist + [Topic] + [criterium=all, + style=bold, + before=, + after=] +\stoptyping + +The \type {\TitlePage} macro looks horrible, because we want to keep the +interface simple: a list of small sentences, separated by \type {\\}. + +\starttyping +\def\TitlePage#1% + {\startstandardmakeup + \switchtobodyfont[big] + \def\\{\vfill\bfb\let\\=\par} + \bfd\setupinterlinespace\gray + \vskip.5cm#1\\\vskip.5cm % \\ is really needed -) + \stopstandardmakeup} +\stoptyping + +A presentation that uses this style, may look like the one below. You can choose +among three alternatives. + +\starttyping +\useenvironment[pre-organic] \setupoutput[pdftex] + +\setupMPvariables[page][alternative=1] + +\starttext + +\TitlePage + {A Few Nice Quotes\\ + A Simple Style Demo\\ + Hans Hagen, August 2000} + +\Topic {Douglas R. Hofstadter} \input douglas \page +\Topic {Donald E. Knuth} \input knuth \page +\Topic {Edward R. Tufte} \input tufte \page +\Topic {Hermann Zapf} \input zapf \page + +\stoptext +\stoptyping + +We will not implement the two other alternative shapes: squeezed and randomized. + +\def\ScrNum{2} \getbuffer[screens] +\def\ScrNum{3} \getbuffer[screens] + +We combine all alternatives into one page graphic. The alternative is chosen by +setting the \type {alternative} variable, as we demonstrated in the example. + +\starttyping +\startuseMPgraphic{page} + + \includeMPgraphic{rightsuperbutton} + + StartPage ; + + numeric alternative, seed, superness, squeezeness, randomness ; + path p, q ; transform t ; +\stoptyping + +This is one of those cases where a transform variable is useful. We need to store +the random seed value because we want the larger path that is used in the +calculations to have the same shape. + +\starttyping + alternative := \MPvar{alternative} ; + seed := uniformdeviate 100 ; + + if alternative > 10 : + superness := .85 + ((\realfolio-1)/max(\lastpage,1)) * .25 ; + squeezeness := 12pt - ((\realfolio-1)/max(\lastpage,1)) * 10pt ; + else : + superness := .90 ; + squeezeness := 12pt ; + fi ; + + randomness := squeezeness ; + + alternative := alternative mod 10 ; +\stoptyping + +If you read closely, you will notice that when we add 10 to the alternative, we +get a page dependant graphic. So, in fact we have five alternatives. We use +\CONTEXT\ macros to fetch the (real) page number and the number of the last page. +In further calculations we use the lower alternative numbers, which is why we +apply a \type {mod}. + +The rest of the code is not so much different from the previous definition. The +hard coded point sizes match the page dimensions (600pt by 450pt) quite well. + +\starttyping + t := identity if alternative=3: shifted (9pt,-9pt) fi ; + + randomseed := seed ; + + p := Field[Text][Text] enlarged if + alternative = 1 : 36pt superellipsed superness elseif + alternative = 2 : 36pt squeezed squeezeness elseif + alternative = 3 : 36pt randomized randomness else + : 36pt fi ; + + pickup pencircle scaled 3pt ; + + fill Page withcolor \MPcolor{yellow} ; + fill p withcolor \MPcolor{white} ; + draw p withcolor \MPcolor{red} ; + + randomseed := seed ; + + p := ( Field[Text][Text] enlarged if + alternative = 1 : 48pt superellipsed superness elseif + alternative = 2 : 48pt squeezed squeezeness elseif + alternative = 3 : 36pt randomized randomness else + : 48pt fi ) transformed t ; + + def right_menu_button (expr nn, rr, pp, xx, yy, ww, hh, dd) = + if (pp>0) and (rr>0) : + q := rightsuperbutton(p,xx,yy,RightEdgeWidth,hh) ; + fill q withcolor \MPcolor{white} ; + draw q withcolor if rr=2 : \MPcolor{gray} + else : \MPcolor{red} fi ; + fi ; + enddef ; + + \MPmenubuttons{right} + + StopPage ; +\stopuseMPgraphic +\stoptyping + +When we choose the alternatives~21 and~22 we get this result: + +\def\ScrNum{5} \getbuffer[screens] +\def\ScrNum{6} \getbuffer[screens] + +\stopsection + +\stopchapter + +\stopcomponent |