fish-shell/src/output.cpp
Fabian Homborg 95103893e6 output: Allow "--background foo" and "-b foo" for background colors
This only accepted "--background=". Really what we need to do is do an
actual getopt, but that wants a null-terminated array and is tightly
coupled to set_color.

Fixes #8053.
2021-06-10 10:42:30 +02:00

441 lines
16 KiB
C++

// Generic output functions.
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <cstring>
#if HAVE_CURSES_H
#include <curses.h>
#elif HAVE_NCURSES_H
#include <ncurses.h>
#elif HAVE_NCURSES_CURSES_H
#include <ncurses/curses.h>
#endif
#if HAVE_TERM_H
#include <term.h>
#elif HAVE_NCURSES_TERM_H
#include <ncurses/term.h>
#endif
#include <limits.h>
#include <cwchar>
#include <memory>
#include <string>
#include <vector>
#include "color.h"
#include "common.h"
#include "env.h"
#include "fallback.h" // IWYU pragma: keep
#include "flog.h"
#include "output.h"
#include "wcstringutil.h"
#include "wutil.h" // IWYU pragma: keep
/// Whether term256 and term24bit are supported.
static color_support_t color_support = 0;
/// Returns true if we think tparm can handle outputting a color index
static bool term_supports_color_natively(unsigned int c) {
return static_cast<unsigned>(max_colors) >= c + 1;
}
color_support_t output_get_color_support() { return color_support; }
void output_set_color_support(color_support_t val) { color_support = val; }
unsigned char index_for_color(rgb_color_t c) {
if (c.is_named() || !(output_get_color_support() & color_support_term256)) {
return c.to_name_index();
}
return c.to_term256_index();
}
static bool write_color_escape(outputter_t &outp, const char *todo, unsigned char idx, bool is_fg) {
if (term_supports_color_natively(idx)) {
// Use tparm to emit color escape.
writembs(outp, tparm(const_cast<char *>(todo), idx));
return true;
}
// We are attempting to bypass the term here. Generate the ANSI escape sequence ourself.
char buff[16] = "";
if (idx < 16) {
// this allows the non-bright color to happen instead of no color working at all when a
// bright is attempted when only colors 0-7 are supported.
//
// TODO: enter bold mode in builtin_set_color in the same circumstance- doing that combined
// with what we do here, will make the brights actually work for virtual consoles/ancient
// emulators.
if (max_colors == 8 && idx > 8) idx -= 8;
snprintf(buff, sizeof buff, "\x1B[%dm", ((idx > 7) ? 82 : 30) + idx + !is_fg * 10);
} else {
snprintf(buff, sizeof buff, "\x1B[%d;5;%dm", is_fg ? 38 : 48, idx);
}
outp.writestr(buff);
return true;
}
static bool write_foreground_color(outputter_t &outp, unsigned char idx) {
if (!cur_term) return false;
if (set_a_foreground && set_a_foreground[0]) {
return write_color_escape(outp, set_a_foreground, idx, true);
} else if (set_foreground && set_foreground[0]) {
return write_color_escape(outp, set_foreground, idx, true);
}
return false;
}
static bool write_background_color(outputter_t &outp, unsigned char idx) {
if (!cur_term) return false;
if (set_a_background && set_a_background[0]) {
return write_color_escape(outp, set_a_background, idx, false);
} else if (set_background && set_background[0]) {
return write_color_escape(outp, set_background, idx, false);
}
return false;
}
void outputter_t::flush_to(int fd) {
if (fd >= 0 && !contents_.empty()) {
write_loop(fd, contents_.data(), contents_.size());
contents_.clear();
}
}
// Exported for builtin_set_color's usage only.
bool outputter_t::write_color(rgb_color_t color, bool is_fg) {
if (!cur_term) return false;
bool supports_term24bit =
static_cast<bool>(output_get_color_support() & color_support_term24bit);
if (!supports_term24bit || !color.is_rgb()) {
// Indexed or non-24 bit color.
unsigned char idx = index_for_color(color);
return (is_fg ? write_foreground_color : write_background_color)(*this, idx);
}
// 24 bit! No tparm here, just ANSI escape sequences.
// Foreground: ^[38;2;<r>;<g>;<b>m
// Background: ^[48;2;<r>;<g>;<b>m
color24_t rgb = color.to_color24();
char buff[128];
snprintf(buff, sizeof buff, "\x1B[%d;2;%u;%u;%um", is_fg ? 38 : 48, rgb.rgb[0], rgb.rgb[1],
rgb.rgb[2]);
writestr(buff);
return true;
}
/// Sets the fg and bg color. May be called as often as you like, since if the new color is the same
/// as the previous, nothing will be written. Negative values for set_color will also be ignored.
/// Since the terminfo string this function emits can potentially cause the screen to flicker, the
/// function takes care to write as little as possible.
///
/// Possible values for colors are rgb_color_t colors or special values like rgb_color_t::normal()
///
/// In order to set the color to normal, three terminfo strings may have to be written.
///
/// - First a string to set the color, such as set_a_foreground. This is needed because otherwise
/// the previous strings colors might be removed as well.
///
/// - After that we write the exit_attribute_mode string to reset all color attributes.
///
/// - Lastly we may need to write set_a_background or set_a_foreground to set the other half of the
/// color pair to what it should be.
///
/// \param fg Foreground color.
/// \param bg Background color.
void outputter_t::set_color(rgb_color_t fg, rgb_color_t bg) {
// Test if we have at least basic support for setting fonts, colors and related bits - otherwise
// just give up...
if (!cur_term || !exit_attribute_mode) return;
const rgb_color_t normal = rgb_color_t::normal();
bool bg_set = false, last_bg_set = false;
bool is_bold = fg.is_bold() || bg.is_bold();
bool is_underline = fg.is_underline() || bg.is_underline();
bool is_italics = fg.is_italics() || bg.is_italics();
bool is_dim = fg.is_dim() || bg.is_dim();
bool is_reverse = fg.is_reverse() || bg.is_reverse();
if (fg.is_reset() || bg.is_reset()) {
fg = bg = normal;
reset_modes();
// If we exit attibute mode, we must first set a color, or previously colored text might
// lose it's color. Terminals are weird...
write_foreground_color(*this, 0);
writembs(*this, exit_attribute_mode);
return;
}
if ((was_bold && !is_bold) || (was_dim && !is_dim) || (was_reverse && !is_reverse)) {
// Only way to exit bold/dim/reverse mode is a reset of all attributes.
writembs(*this, exit_attribute_mode);
last_color = normal;
last_color2 = normal;
reset_modes();
}
if (!last_color2.is_special()) {
// Background was set.
// "Special" here refers to the special "normal", "reset" and "none" colors,
// that really jus disable the background.
last_bg_set = true;
}
if (!bg.is_special()) {
// Background is set.
bg_set = true;
if (fg == bg)
fg = (bg == rgb_color_t::white()) ? rgb_color_t::black() : rgb_color_t::white();
}
if (enter_bold_mode && enter_bold_mode[0] != '\0') {
if (bg_set && !last_bg_set) {
// Background color changed and is set, so we enter bold mode to make reading easier.
// This means bold mode is _always_ on when the background color is set.
writembs_nofail(*this, enter_bold_mode);
}
if (!bg_set && last_bg_set) {
// Background color changed and is no longer set, so we exit bold mode.
writembs(*this, exit_attribute_mode);
reset_modes();
// We don't know if exit_attribute_mode resets colors, so we set it to something known.
if (write_foreground_color(*this, 0)) {
last_color = rgb_color_t::black();
}
}
}
if (last_color != fg) {
if (fg.is_normal()) {
write_foreground_color(*this, 0);
writembs(*this, exit_attribute_mode);
last_color2 = rgb_color_t::normal();
reset_modes();
} else if (!fg.is_special()) {
write_color(fg, true /* foreground */);
}
}
last_color = fg;
if (last_color2 != bg) {
if (bg.is_normal()) {
write_background_color(*this, 0);
writembs(*this, exit_attribute_mode);
if (!last_color.is_normal()) {
write_color(last_color, true /* foreground */);
}
reset_modes();
last_color2 = bg;
} else if (!bg.is_special()) {
write_color(bg, false /* not foreground */);
last_color2 = bg;
}
}
// Lastly, we set bold, underline, italics, dim, and reverse modes correctly.
if (is_bold && !was_bold && enter_bold_mode && enter_bold_mode[0] != '\0' && !bg_set) {
// The unconst cast is for NetBSD's benefit. DO NOT REMOVE!
writembs_nofail(*this, tparm(const_cast<char *>(enter_bold_mode)));
was_bold = is_bold;
}
if (was_underline && !is_underline) {
writembs_nofail(*this, exit_underline_mode);
}
if (!was_underline && is_underline) {
writembs_nofail(*this, enter_underline_mode);
}
was_underline = is_underline;
if (was_italics && !is_italics && enter_italics_mode && enter_italics_mode[0] != '\0') {
writembs_nofail(*this, exit_italics_mode);
was_italics = is_italics;
}
if (!was_italics && is_italics && enter_italics_mode && enter_italics_mode[0] != '\0') {
writembs_nofail(*this, enter_italics_mode);
was_italics = is_italics;
}
if (is_dim && !was_dim && enter_dim_mode && enter_dim_mode[0] != '\0') {
writembs_nofail(*this, enter_dim_mode);
was_dim = is_dim;
}
if (is_reverse && !was_reverse) {
// Some terms do not have a reverse mode set, so standout mode is a fallback.
if (enter_reverse_mode && enter_reverse_mode[0] != '\0') {
writembs_nofail(*this, enter_reverse_mode);
was_reverse = is_reverse;
} else if (enter_standout_mode && enter_standout_mode[0] != '\0') {
writembs_nofail(*this, enter_standout_mode);
was_reverse = is_reverse;
}
}
}
// tputs accepts a function pointer that receives an int only.
// Use the following lock to redirect it to the proper outputter.
// Note we can't use owning_lock because the tputs_writer must access it and owning_lock is not
// recursive.
static std::mutex s_tputs_receiver_lock;
static outputter_t *s_tputs_receiver{nullptr};
static int tputs_writer(tputs_arg_t b) {
ASSERT_IS_LOCKED(s_tputs_receiver_lock);
assert(s_tputs_receiver && "null s_tputs_receiver");
char c = static_cast<char>(b);
s_tputs_receiver->writestr(&c, 1);
return 0;
}
int outputter_t::term_puts(const char *str, int affcnt) {
// Acquire the lock, use a scoped_push to substitute in our receiver, then call tputs. The
// scoped_push will restore it.
scoped_lock locker{s_tputs_receiver_lock};
scoped_push<outputter_t *> push(&s_tputs_receiver, this);
s_tputs_receiver->begin_buffering();
// On some systems, tputs takes a char*, on others a const char*.
// Like tparm, we just cast it to unconst, that should work everywhere.
int res = tputs(const_cast<char *>(str), affcnt, tputs_writer);
s_tputs_receiver->end_buffering();
return res;
}
void outputter_t::writestr(const wchar_t *str, size_t len) {
wcs2string_appending(str, len, &contents_);
maybe_flush();
}
outputter_t &outputter_t::stdoutput() {
ASSERT_IS_MAIN_THREAD();
static outputter_t res(STDOUT_FILENO);
return res;
}
/// Given a list of rgb_color_t, pick the "best" one, as determined by the color support. Returns
/// rgb_color_t::none() if empty.
rgb_color_t best_color(const std::vector<rgb_color_t> &candidates, color_support_t support) {
if (candidates.empty()) {
return rgb_color_t::none();
}
rgb_color_t first_rgb = rgb_color_t::none(), first_named = rgb_color_t::none();
for (const auto &color : candidates) {
if (first_rgb.is_none() && color.is_rgb()) {
first_rgb = color;
}
if (first_named.is_none() && color.is_named()) {
first_named = color;
}
}
// If we have both RGB and named colors, then prefer rgb if term256 is supported.
rgb_color_t result = rgb_color_t::none();
bool has_term256 = static_cast<bool>(support & color_support_term256);
if ((!first_rgb.is_none() && has_term256) || first_named.is_none()) {
result = first_rgb;
} else {
result = first_named;
}
if (result.is_none()) {
result = candidates.at(0);
}
return result;
}
/// Return the internal color code representing the specified color.
/// TODO: This code should be refactored to enable sharing with builtin_set_color.
/// In particular, the argument parsing still isn't fully capable.
rgb_color_t parse_color(const env_var_t &var, bool is_background) {
bool is_bold = false;
bool is_underline = false;
bool is_italics = false;
bool is_dim = false;
bool is_reverse = false;
std::vector<rgb_color_t> candidates;
const wchar_t *prefix = L"--background=";
// wcslen is not available as constexpr
size_t prefix_len = wcslen(prefix);
bool next_is_background = false;
wcstring color_name;
for (const wcstring &next : var.as_list()) {
color_name.clear();
if (is_background) {
if (color_name.empty() && next_is_background) {
color_name = next;
next_is_background = false;
} else if (string_prefixes_string(prefix, next)) {
// Look for something like "--background=red".
color_name = wcstring(next, prefix_len);
} else if (next == L"--background" || next == L"-b") {
// Without argument attached the next token is the color
// - if it's another option it's an error.
next_is_background = true;
} else if (next == L"--reverse" || next == L"-r") {
// Reverse should be meaningful in either context
is_reverse = true;
} else if (string_prefixes_string(L"-b", next)) {
// Look for something like "-bred".
// Yes, that length is hardcoded.
color_name = wcstring(next, 2);
}
} else {
if (next == L"--bold" || next == L"-o")
is_bold = true;
else if (next == L"--underline" || next == L"-u")
is_underline = true;
else if (next == L"--italics" || next == L"-i")
is_italics = true;
else if (next == L"--dim" || next == L"-d")
is_dim = true;
else if (next == L"--reverse" || next == L"-r")
is_reverse = true;
else
color_name = next;
}
if (!color_name.empty()) {
rgb_color_t color = rgb_color_t(color_name);
if (!color.is_none()) {
candidates.push_back(color);
}
}
}
rgb_color_t result = best_color(candidates, output_get_color_support());
if (result.is_none()) result = rgb_color_t::normal();
result.set_bold(is_bold);
result.set_underline(is_underline);
result.set_italics(is_italics);
result.set_dim(is_dim);
result.set_reverse(is_reverse);
return result;
}
/// Write specified multibyte string.
void writembs_check(outputter_t &outp, const char *mbs, const char *mbs_name, bool critical,
const char *file, long line) {
if (mbs != nullptr) {
outp.term_puts(mbs, 1);
} else if (critical) {
auto term = env_stack_t::globals().get(L"TERM");
const wchar_t *fmt =
_(L"Tried to use terminfo string %s on line %ld of %s, which is "
L"undefined in terminal of type \"%ls\". Please report this error to %s");
FLOG(error, fmt, mbs_name, line, file, term ? term->as_string().c_str() : L"",
PACKAGE_BUGREPORT);
}
}