1 files changed, 50 insertions, 6 deletions
diff --git a/tex/context/base/page-bck.mkiv b/tex/context/base/page-bck.mkiv
index 0246e8eb6..01de48e8c 100644
--- a/tex/context/base/page-bck.mkiv
+++ b/tex/context/base/page-bck.mkiv
@@ -55,7 +55,7 @@
 %D This is the only spot where we hav ea low level dependency on the way
 %D parent chains are defined but we want the speed.
 
-\def\page_backgrounds_check_background
+\unexpanded\def\page_backgrounds_check_background
   {\ifcsname\??framed\currentotrbackground:\c!background\endcsname
      \edef\page_background_temp{\csname\??framed\currentotrbackground:\c!background\endcsname}%
      \ifx\page_background_temp\empty
@@ -140,13 +140,15 @@
   {\edef\currentotrbackground{\??layoutbackgrounds#1}%
    \page_backgrounds_check_background}
 
-\def\doifsomebackgroundelse#1%
+\def\doifelsesomebackground#1%
   {\ifcsname\??layoutbackgrounds#1\endcsname
      \expandafter\firstoftwoarguments
    \else
      \expandafter\secondoftwoarguments
    \fi}
 
+\let\doifsomebackgroundelse\doifelsesomebackground
+
 \def\doifsomebackground#1%
   {\ifcsname\??layoutbackgrounds#1\endcsname
      \expandafter\firstofoneargument
@@ -277,7 +279,7 @@
      \page_backgrounds_set_boxes
      \setbox#1\vbox
        {\offinterlineskip
-        \doifmarginswapelse{\copy\leftbackground}{\copy\rightbackground}%
+        \doifelsemarginswap{\copy\leftbackground}{\copy\rightbackground}%
         \box#1}%
    \fi}
 
@@ -343,7 +345,7 @@
      {\dontcomplain
       \swapmargins
       \ifconditional\swapbackgroundmargins
-        \doifmarginswapelse \donothing
+        \doifelsemarginswap \donothing
           {\swapmacros\v!rightmargin\v!leftmargin
            \swapmacros\v!rightedge  \v!leftedge}%
       \fi
@@ -501,7 +503,7 @@
 \unexpanded\def\page_backgrounds_setup_double[#1][#2][#3]% if needed we can speed this up
   {\global\settrue\c_page_backgrounds_some
    \def\page_backgrounds_setup_step##1%
-     {\doifinsetelse{##1}\v_page_backgrounds_double_set
+     {\doifelseinset{##1}\v_page_backgrounds_double_set
         {\page_backgrounds_setup_and_check{##1}{#3}}
         {\def\page_backgrounds_setup_step_nested####1{\page_backgrounds_setup_and_check{##1####1}{#3}}%
          \processcommacommand[#2]\page_backgrounds_setup_step_nested}}%
@@ -510,7 +512,7 @@
 
 \unexpanded\def\page_backgrounds_setup_single[#1][#2][#3]%
   {\global\settrue\c_page_backgrounds_some
-   \doifcommonelse{#1}\v_page_backgrounds_single_set
+   \doifelsecommon{#1}\v_page_backgrounds_single_set
      {\def\page_backgrounds_setup_step##1{\page_backgrounds_setup_and_check{##1}{#2}}%
       \processcommacommand[#1]\page_backgrounds_setup_step
       \the\everybackgroundssetup}%
@@ -607,6 +609,48 @@
 
 \setfalse\c_page_backgrounds_some
 
+%D Sometimes you have a document wide (page) background but need to overload it
+%D locally. In such case (at least in my experience) the only values that get set
+%D are the background and backgroundcolor (if set at all). A full inheritance chain
+%D would complicate things because then we need to use named backgrounds which in
+%D turn will make this mechanism slower. I considered independent local backgrounds
+%D but that also complicates the code (not that much) but isolation means that we
+%D need to set more parameters each time. The following simple approach proabbly
+%D suits most usage.
+%D
+%D \starttyping
+%D \starttext
+%D     \setupbackgrounds[page][background=color,backgroundcolor=red]
+%D     \input tufte \page
+%D     \setupbackgrounds[page][background=,backgroundcolor=]
+%D     \input tufte \page
+%D     \setupbackgrounds[page][background=color,backgroundcolor=red]
+%D     \input tufte \page
+%D     \pushbackground[page]
+%D         \setupbackgrounds[page][background=color,backgroundcolor=green]
+%D         \input tufte \page
+%D     \popbackground
+%D     \input tufte \page
+%D \stoptext
+%D \stoptyping
+
+\unexpanded\def\pushbackground[#1]%
+  {\pushmacro\popbackground
+   \edef\currentotrbackground{\??layoutbackgrounds#1}%
+   \unexpanded\edef\popbackground
+     {\setupframed
+        [\currentotrbackground]
+        [\c!background=\namedframedparameter{\currentotrbackground}\c!background,
+         \c!backgroundcolor=\namedframedparameter{\currentotrbackground}\c!backgroundcolor]%
+      \page_backgrounds_check_background
+      \popmacro\popbackground}%
+   \setupframed
+     [\currentotrbackground]
+     [\c!background=,\c!backgroundcolor=]%
+   \page_backgrounds_check_background}
+
+\let\popbackground\relax
+
 \protect \endinput
 
 % %D The next series is used in local (for instance floating) backgrounds.