grosciteco: folding in woman pages

* Support fold level configuration using `.SCITECO_FOLDLEVEL`.
  This sets the current output line as the fold header and all subsequent lines
  with the given fold level (until another `.SCITECO_FOLDLEVEL` instruction
  is encountered).
* This is now done automatically for man's SH and SS macros,
  so the man-page based woman pages provide folding.
* The folding margin is therefore now always enabled in fallback.teco_ini.

3 files changed, 64 insertions, 0 deletions

diff --git a/doc/grosciteco.tes b/doc/grosciteco.tes
index 9be0f1a..5548f1c 100755
--- a/doc/grosciteco.tes
+++ b/doc/grosciteco.tes
@@ -169,6 +169,12 @@ EBN[input]
           Q[stylestart]ESSTARTSTYLING Q.s,(-Q[stylestart])ESSETSTYLING
         ]*
         L F<
+      !cmd.xXsciteco_foldlevel!
+        C :M#giU.[foldlevel]
+        [* EB 0:M[move]
+          Q.[foldlevel],(ESLINEFROMPOSITION)ESSETLINESTATE
+        ]*
+        L F<
       !cmd.xXtty!
       !cmd.xXdevtag!
         L F<
@@ -342,6 +348,30 @@ J 0U#cs 0U#cd
 :C;>
 
 !*
+ * The fold level is stored in the line state since it is set
+ * while the document is not fully built yet.
+ *!
+J 0U#li 0U[cur.fl] 0U[last.line]
+ESGETLINECOUNT<
+  Q#liESGETLINESTATEU#fl
+  Q#fl"N
+    Q[cur.fl]"N
+      Q#li-Q[last.line]Ux
+      1024%[cur.fl]
+      @:EU[styles]{\[last.line]U.l \x<\[cur.fl],Q.lESSETFOLDLEVEL %.l>^J}
+    '
+    Q#li+1U[last.line] Q#flU[cur.fl]
+    (1024+Q#fl-1)#(2^*13)U#fl
+    @:EU[styles]{\#fl,\#liESSETFOLDLEVEL^J}
+  '
+%#li>
+Q[cur.fl]"N
+  Q#li-Q[last.line]Ux
+  1024%[cur.fl]
+  @:EU[styles]{\[last.line]U.l \x<\[cur.fl],Q.lESSETFOLDLEVEL %.l>^J}
+'
+
+!*
  * Save the clear-text part of the document into <output-woman>
  *!
 2EL EWQ[output-woman]
diff --git a/doc/sciteco.tmac b/doc/sciteco.tmac
index 026e489..8e53407 100644
--- a/doc/sciteco.tmac
+++ b/doc/sciteco.tmac
@@ -66,6 +66,29 @@
 .  device sciteco_setstyling:\\$1
 ..
 .
+.\" Set the fold level of the current line __and__ all following lines.
+.\" This could be called at the beginning of chapters and sections.
+.de SCITECO_FOLDLEVEL
+.  device sciteco_foldlevel:\\$1
+..
+.
+.\" man-page specific extensions.
+.\" FIXME: Is there a reliable way to detect the man-page macros?
+.if dan \{\
+.  rn SH SH-orig
+.  de SH
+.    SH-orig
+.    SCITECO_FOLDLEVEL 1
+.    nop \\$*
+.  .
+.  rn SS SS-orig
+.  de SS
+.    SS-orig
+.    SCITECO_FOLDLEVEL 2
+.    nop \\$*
+.  .
+.\}
+.
 .\"
 .\" Effectively disable paragraph filling in man pages.
 .\" Word wrapping will be performed by Scintilla.
diff --git a/doc/tutorial.ms.in b/doc/tutorial.ms.in
index acbf9ac..f246044 100644
--- a/doc/tutorial.ms.in
+++ b/doc/tutorial.ms.in
@@ -58,6 +58,7 @@ This tutorial guides you through the bare essentials of the editor.
 Try the examples directly on this document.
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Get me out of here!
 .
 .LP
@@ -73,6 +74,7 @@ In the remainder of this document, command examples are therefore formatted as f
 .DE
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Navigation
 .
 .LP
@@ -94,6 +96,7 @@ Using cursor movement or mouse buttons updates the movement
 commands in the command line (the line at the bottom of the screen after \fB*\fP).
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Insertion
 .
 .LP
@@ -115,6 +118,7 @@ There is no \(lqinsert\(rq mode, you are merely providing a string argument
 to the interactively executed \fBI\fP command.
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Deletion
 .
 .LP
@@ -130,6 +134,7 @@ Use the following command instead to discard all changes:
 .DE
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Saving
 .
 .LP
@@ -155,6 +160,7 @@ Remember, you can type CTRL+W to undo even the file write and restore the
 previous state of the file.
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Loading
 .
 .LP
@@ -184,6 +190,7 @@ in a typical UNIX shell!
 Of course, you can press CTRL+W to revert opening the file.
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Search and replace
 .
 .LP
@@ -210,6 +217,7 @@ so \fBS\fP\*$ repeats the last search and \fBFR\fP\*($$ repeats the last
 search-replace operation.
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Q-Registers
 .
 .LP
@@ -232,6 +240,7 @@ This however might not work out of the box if you are running the ncurses
 version of \*(ST.
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Programming
 .
 .LP
@@ -247,6 +256,7 @@ of performing a search-replace operation on the entire buffer:
 .DE
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Customize
 .
 .LP
@@ -271,6 +281,7 @@ $ @PACKAGE@ --no-profile
 .DE
 .
 .NH 2
+.SCITECO_FOLDLEVEL 1
 Further reading
 .
 .LP