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< [[Main Page]] {{todo| [[Visuals]] >Add more examples of usage of textbackgrounds.}}

== Basics == Pages, paragraphs, words can have a background color or [[Overlays|overlay]]. ConTeXt creates these using [[MetaPost]]. But a usual frame is only one object, its contents can’t flow over to the next page. You can use {{todocmd|Add more examples of usage of textbackgroundsdefinetextbackground}} to define a named text background.The environment is based on {{cmd|framed}}and understands its parameters, but can contain several paragraphs and page breaks. After `\definetextbackground[Name]` you can use `\startName ... \stopName` (if there’s no name conflict) or `\starttextbackground[Name] ... \stoptextbackground`. Usually you won’t need {{cmd|setuptextbackground}}.

Pages, The `location` parameter changes the behaviour between `text` (highlighting running text) and `paragraph` (boxed paragraphs, words can have a background: color or screen).

(See, eventually, the [[manual:details.pdf| details]] manual or the {{src|anch-bck.mkvi|source}} for further explanations.)

'''Beware''': The textbackground commands require [[write18]] to examples using {{cmd|startnarrower}} may be enabledmisleading – of course you can use {{cmd|startbackground}} without the `narrower` environment; see that page for more informationit behaves differently without `\starttext ... \stoptext`.

location=paragraph, background=color, backgroundcolor=middlegraylightgray, leftoffset=.5\bodyfontsize, rightoffset=.5\bodyfontsize, topoffset=.5\bodyfontsize, bottomoffset=.5\bodyfontsize, before={\startnarrower\switchtobodyfont[small]}, after={\stopnarrower}, frame=off,]

 \input samplefile{knuth}

\input samplefile{knuth}

\input samplefile{knuth}

{{todo|The background does not show here using the live, online conTeXt processor. Why?}} == backgroundoffset Background Offset ==

location=paragraph, background=color, backgroundcolor=middlegraylightgray, backgroundoffset=.5\bodyfontsize, before={\startnarrower\switchtobodyfont[small]}, after={\stopnarrower}, frame=off,]

 \input samplefile{knuth}

\input samplefile{knuth}

\input samplefile{knuth}\stoptext</context> == Underlining with Text Backgrounds == Underlining is generally frowned upon by experienced TeXnicians. Occasionally,however, it is necessary and {{cmd|ul}} or {{cmd|underbar}} doesn’t do what you want. In thosecases using {{cmd|definetextbackground}} for the underlining may also be tried. <context source="yes">\definetextbackground[underline] [location=text,alternative=1,background=,frame=off] \definestartstop[underline] [before={\starttextbackground[underline]}, after=\stoptextbackground]

\stoptextstartTEXpageAn example with \startunderline underlined\stopunderline\ text.\stopTEXpage</context> If desired, the location of the line can also be adjusted. <context source="yes">\startuseMPgraphic{mpos:par:columnset} % Shift underlining down a touch \iftracepositions show_multi_pars \else draw_multi_pars \fi ; path p ; p := boundingbox currentpicture ; currentpicture := currentpicture shifted (0,-StrutDepth/3) ; setbounds currentpicture to p ;\stopuseMPgraphic \definetextbackground[underline] [location=text,alternative=1,background=,frame=off] \definestartstop[underline] [before={\starttextbackground[underline]}, after=\stoptextbackground] \startTEXpageAn example with \startunderline underlined\stopunderline\ text.\stopTEXpage</context>  === Example: dashed underbar ===(by WS, 4/2011) <context source="yes">\definetextbackground [dashed] [location=text, framecolor=black, alternative=1, voffset=-\strutdp, background=, frame=off, dash=1] \startdashed\samplefile{ward}\stopdashed