Title: viewer: add ANSI SGR color rendering#47
Merged
Conversation
Add a state machine parser for ANSI SGR (Select Graphic Rendition) escape sequences. Supports standard colors (0-7), bright (8-15), 256-color (38;5;N / 48;5;N), and truecolor (38;2;R;G;B / 48;2;R;G;B) which is approximated to the nearest xterm 256-color palette index. Bold, underline, italic, and individual/global resets are handled. Includes 23 unit tests covering color parsing, attribute tracking, truecolor approximation, escape sequence edge cases, and combined sequences. Signed-off-by: noctuum <25441068+noctuum@users.noreply.github.com>
Integrate the ANSI SGR parser into mcview's text display pipeline. When syntax mode is active, bytes are fed through the parser and ANSI escape sequences are consumed while displayable characters are rendered with the appropriate colors. Key additions: - mcview_ansi_get_color(): maps ANSI parser state to MC color pairs, inheriting the viewer skin's fg/bg when ANSI values are default (fixes background mismatch with source-highlight) - mcview_get_next_maybe_ansi_char(): new rendering layer between raw byte reading and nroff processing - mcview_fill_line_remaining(): fills remaining columns on each line with spaces using the last drawn color, giving full-width background - syntax_fill_color tracking across lines for consistent empty-line coloring Signed-off-by: noctuum <25441068+noctuum@users.noreply.github.com>
Address reviewer feedback on the ANSI SGR parser: Parser improvements: - Add italic (3), blink (5), reverse (7) attribute support - Add individual off codes: 23, 25, 27 - Map SGR 21 (double underline) to regular underline - Fix empty parameter bug: \e[1;;3m now correctly treats empty param as 0 (reset) - Add colon ':' sub-separator with proper nested semantics: \e[38:5:4:7m does NOT set reverse (all sub-params belong to the color group), while \e[38;5;4;7m correctly does - Support de jure truecolor: \e[38:2:CS:R:G:Bm Large file protection: - Skip syntax highlighting for files > 2 MB to avoid long processing times from external highlighters 12 new tests (35 total for ANSI parser). Signed-off-by: noctuum <25441068+noctuum@users.noreply.github.com>
Signed-off-by: Ilia Maslakov <il.smind@gmail.com>
…ering Add mcview_toggle_ansi_mode() and CK_AnsiMode key command (bound to Shift+F9) to allow the user to enable or disable ANSI SGR color rendering in the viewer. The ANSI SGR parser and rendering pipeline were written by noctuum as part of MidnightCommander/mc PR #5065. This commit wires the toggle mechanism so the feature is accessible at runtime. Adapted-by: Ilia Maslakov <il.smind@gmail.com> Signed-off-by: Ilia Maslakov <il.smind@gmail.com>
procyon detects whether stdout is a TTY and emits ANSI color codes only in that case. When mc pipes the output through the viewer, stdout is not a TTY, so colors are stripped. Use script(1) to run procyon inside a pseudo-TTY, preserving its ANSI output so the viewer can render it with AnsiMode enabled. Signed-off-by: Ilia Maslakov <il.smind@gmail.com>
ANSI SGR attributes (color, bold, etc.) legally span newlines: a sequence like ESC[31m applied before '\n' must remain active on the next line until an explicit reset. The previous code called mcview_state_machine_init() on every newline, which wiped the ANSI parser state. Fix: save state->ansi before mcview_state_machine_init() and restore it after, so positional/nroff state is reset per line while ANSI attributes persist. Add test_ansi_state_persists_across_newline to ansi_parser.c to cover this invariant at the parser level. Signed-off-by: Ilia Maslakov <il.smind@gmail.com>
ilia-maslakov
force-pushed
the
DEV_ascii_highlight
branch
from
6e065ed to
0b552f7
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Auto summary
Commits: 7
Files changed: 18
Commit messages
4c45cd9)67dc010)07111db)cadc734)670887d)eae61d3)0b552f7)Changed files
added (3)
src/viewer/ansi.csrc/viewer/ansi.htests/src/viewer/ansi_parser.cmodified (15)
lib/keybind.clib/keybind.hmisc/ext.d/misc.sh.inmisc/mc.default.keymapmisc/mc.emacs.keymapmisc/mc.vim.keymapsrc/viewer/Makefile.amsrc/viewer/actions_cmd.csrc/viewer/ascii.csrc/viewer/display.csrc/viewer/internal.hsrc/viewer/lib.csrc/viewer/mcviewer.csrc/viewer/mcviewer.htests/src/viewer/Makefile.amThis block is auto-generated. Edit outside this section.
Summary
Overview
This branch ports the ANSI color rendering work from MidnightCommander/mc#5065 (author: noctuum) into the local tree, adapting it for integration and adding the missing interactive toggle.
The original PR implements an ANSI SGR escape sequence parser and wires it into mc's internal viewer so that files containing ANSI color codes (log output, decompiled sources, colorized command output)
are displayed with proper foreground/background colors, bold, underline, italic, blink, and reverse attributes.
What is included
src/viewer/ansi.c / ansi.h -- stateful SGR parser supporting
standard 8/16 colors, 256-color (38;5;n / 48;5;n), truecolor
(38;2;r;g;b), and colon sub-separator notation (ITU T.416).
Written by noctuum; adapted by Ilia Maslakov.
src/viewer/ascii.c -- ANSI rendering wired into the text display
pipeline via mcview_get_next_maybe_nroff_char. ANSI state is
now preserved across newlines (SGR attributes legally span lines).
CK_AnsiMode toggle bound to Shift+F9 -- enables/disables ANSI
color rendering at runtime, consistent with the existing F8/F9
MagicMode/NroffMode toggles.
misc/ext.d/misc.sh.in -- .class viewer now runs procyon inside
a pseudo-TTY via script(1) so its native ANSI colors reach the
viewer unchanged.
tests/src/viewer/ansi_parser.c -- 35 unit tests for the SGR
parser covering standard colors, 256-color, truecolor, colon
notation, attribute on/off codes, incomplete escapes, and newline
state persistence.
What is NOT included
The external syntax-highlight command backend from the original PR
was intentionally left out; this branch focuses solely on ANSI
escape sequence rendering.
How to test