mcviewer: add syntax highlighting via external command

configure.ac

@@ -698,6 +698,7 @@ tests/src/Makefile
 tests/src/filemanager/Makefile
 tests/src/editor/Makefile
 tests/src/editor/edit_complete_word_cmd_test_data.txt
+tests/src/viewer/Makefile
 tests/src/vfs/Makefile
 tests/src/vfs/extfs/Makefile
 tests/src/vfs/extfs/helpers-list/Makefile

doc/hints/mc.hint

@@ -62,6 +62,8 @@ Hint: To look at the output of a command in the viewer, use M-!
 
 Hint: F13 (or Shift-F3) invokes the viewer in raw mode.
 
+Hint: Press Shift-F8 in the viewer for syntax highlighting. 's' chooses the backend.
+
 Hint: You may specify the editor for F4 with the shell variable EDITOR.
 
 Hint: You may specify the external viewer with the shell vars VIEWER or PAGER.

doc/man/mc.1.in

@@ -2933,6 +2933,30 @@ Some character sequences, which appear most often in preformatted manual
 pages, are displayed bold and underlined, thus making a pretty display
 of your files.
 .PP
+The viewer supports syntax highlighting via an external highlighter.
+Press
+.B Shift\-F8
+to toggle syntax highlighting.  Press
+.B s
+to choose the highlighting backend.
+Five backends are supported:
+.BR bat ,
+.BR chroma ,
+.BR highlight ,
+.BR pygmentize ,
+and
+.BR source\-highlight .
+A custom command can also be configured via the backend chooser dialog.
+The command template must contain
+.B %s
+as a placeholder for the filename.
+The viewer pipes the file through the chosen highlighter and renders
+the ANSI\-colored output.  The backend and file extension are shown in
+the status bar, e.g.
+.IR [bat:py] .
+The syntax mode and backend choice are persisted in
+.IR ~/.config/mc/ini .
+.PP
 When in hex mode, the search function accepts text in quotes and
 constant numbers.  Text in quotes is matched exactly after removing
 the quotes.  Each number matches one byte.  You can mix quoted text
@@ -3025,6 +3049,14 @@ Jump to the next file.
 .B C\-b
 Jump to the previous file.
 .TP
+.B Shift\-F8
+Toggle syntax highlighting.  Requires an external highlighter
+.RB ( bat ", " chroma ", " highlight ", " pygmentize ", or " source\-highlight ).
+.TP
+.B s
+Open the syntax highlighting backend chooser dialog.  Installed
+backends and a "Custom..." option for arbitrary commands are shown.
+.TP
 .B Alt\-r
 Toggle the ruler.
 .TP

lib/keybind.c

@@ -350,6 +350,8 @@ static name_keymap_t command_names[] = {
     ADD_KEYMAP_NAME (HexMode),
     ADD_KEYMAP_NAME (MagicMode),
     ADD_KEYMAP_NAME (NroffMode),
+    ADD_KEYMAP_NAME (SyntaxMode),
+    ADD_KEYMAP_NAME (SyntaxOptions),
     ADD_KEYMAP_NAME (BookmarkGoto),
     ADD_KEYMAP_NAME (Ruler),
     ADD_KEYMAP_NAME (SearchForward),

lib/keybind.h

@@ -319,6 +319,8 @@ enum
     CK_WrapMode = 600L,
     CK_MagicMode,
     CK_NroffMode,
+    CK_SyntaxMode,
+    CK_SyntaxOptions,
     CK_HexMode,
     CK_HexEditMode,
     CK_BookmarkGoto,

misc/mc.default.keymap

@@ -419,6 +419,8 @@ HalfPageDown = d
 HalfPageUp = u
 Top = home; ctrl-home; ctrl-pgup; a1; alt-lt; g
 Bottom = end; ctrl-end; ctrl-pgdn; c1; alt-gt; shift-g
+SyntaxMode = f18
+SyntaxOptions = s
 BookmarkGoto = m
 Bookmark = r
 FileNext = ctrl-f

misc/mc.emacs.keymap

@@ -421,6 +421,8 @@ HalfPageDown = d
 HalfPageUp = u
 Top = home; ctrl-home; ctrl-pgup; a1; alt-lt; g
 Bottom = end; ctrl-end; ctrl-pgdn; c1; alt-gt; shift-g
+SyntaxMode = f18
+SyntaxOptions = s
 BookmarkGoto = m
 Bookmark = r
 FileNext = ctrl-f

misc/mc.vim.keymap

@@ -288,6 +288,8 @@ HalfPageDown = d
 HalfPageUp = u
 Top = home; ctrl-home; ctrl-pgup; a1; alt-lt; g
 Bottom = end; ctrl-end; ctrl-pgdn; c1; alt-gt; shift-g
+SyntaxMode = f18
+SyntaxOptions = s
 BookmarkGoto = m
 Bookmark = r
 FileNext = ctrl-f

src/keymap.c

@@ -563,6 +563,8 @@ static const global_keymap_ini_t default_viewer_keymap[] = {
     { "SearchBackwardContinue", "ctrl-r" },
     { "SearchOppositeContinue", "shift-n" },
     { "History", "alt-shift-e" },
+    { "SyntaxMode", "s" },
+    { "SyntaxOptions", "shift-s" },
     {
         NULL,
         NULL,

src/setup.c

@@ -68,6 +68,7 @@
 #endif
 
 #include "src/viewer/mcviewer.h"  // For the externs
+#include "src/viewer/syntax.h"    // mcview_syntax_command
 
 #include "setup.h"
 
@@ -310,6 +311,7 @@ static const struct
     { "mouse_close_dialog", &mouse_close_dialog },
     { "drop_menus", &drop_menus },
     { "wrap_mode", &mcview_global_flags.wrap },
+    { "syntax_mode", &mcview_global_flags.syntax },
     { "old_esc_mode", &old_esc_mode },
     { "cd_symlinks", &mc_global.vfs.cd_symlinks },
     { "show_all_if_ambiguous", &mc_global.widget.show_all_if_ambiguous },
@@ -418,6 +420,7 @@ static const struct
     { "editor_stop_format_chars", &edit_options.stop_format_chars, "-+*\\,.;:&>" },
 #endif
     { "mcview_eof", &mcview_show_eof, "" },
+    { "syntax_command", &mcview_syntax_command, MCVIEW_SYNTAX_DEFAULT_CMD },
     { NULL, NULL, NULL },
 };
 

src/viewer/Makefile.am

@@ -3,6 +3,7 @@ noinst_LTLIBRARIES = libmcviewer.la
 
 libmcviewer_la_SOURCES = \
 	actions_cmd.c \
+	ansi.c ansi.h \
 	ascii.c \
 	coord_cache.c \
 	datasource.c \
@@ -16,6 +17,7 @@ libmcviewer_la_SOURCES = \
 	mcviewer.h \
 	move.c \
 	nroff.c \
-	search.c
+	search.c \
+	syntax.c syntax.h
 
 AM_CPPFLAGS = -I$(top_srcdir) $(GLIB_CFLAGS)

src/viewer/actions_cmd.c

@@ -67,6 +67,7 @@
 #include "src/keymap.h"
 
 #include "internal.h"
+#include "syntax.h"
 
 /*** global variables ****************************************************************************/
 
@@ -156,7 +157,14 @@ mcview_hook (void *v)
     if (fe == NULL)
         return;
 
-    mcview_done (view);
+    // save global flags — quick view panel refresh must not clobber
+    // flags set by the standalone viewer (e.g. syntax mode toggled via F3)
+    {
+        mcview_mode_flags_t saved_global = mcview_global_flags;
+
+        mcview_done (view);
+        mcview_global_flags = saved_global;
+    }
     mcview_init (view);
     mcview_load (view, 0, fe->fname->str, 0, 0, 0);
     mcview_display (view);
@@ -466,6 +474,31 @@ mcview_execute_cmd (WView *view, long command)
     case CK_NroffMode:
         mcview_toggle_nroff_mode (view);
         break;
+    case CK_SyntaxMode:
+        // warn if trying to enable syntax but highlighter is missing
+        if (!view->mode_flags.syntax && !mcview_syntax_command_available ())
+        {
+            message (D_ERROR, _ ("Syntax Highlighting"), "%s",
+                     _ ("No syntax highlighting tool found.\n"
+                        "Please install one of:\n"
+                        "  bat, chroma, highlight,\n"
+                        "  pygmentize, source-highlight\n"
+                        "or press Shift-S to set a custom command."));
+            break;
+        }
+        mcview_toggle_syntax_mode (view);
+        break;
+    case CK_SyntaxOptions:
+        if (mcview_syntax_options_dialog ())
+        {
+            // backend changed — re-toggle to reload with new command
+            if (view->mode_flags.syntax)
+            {
+                view->mode_flags.syntax = FALSE;
+                mcview_toggle_syntax_mode (view);
+            }
+        }
+        break;
     case CK_Home:
         mcview_moveto_bol (view);
         break;