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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#pragma once
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include "util.h"
typedef struct term_char term_char_t;
typedef struct term_charbuf term_charbuf_t;
typedef struct term_color term_color;
typedef struct term_attr term_attr;
typedef struct term_cell term_cell;
typedef struct term_line term_line;
/*
* Miscellaneous
* Sundry things and external helpers.
*/
int mk_wcwidth(wchar_t ucs4);
int mk_wcwidth_cjk(wchar_t ucs4);
int mk_wcswidth(const wchar_t *str, size_t len);
int mk_wcswidth_cjk(const wchar_t *str, size_t len);
/*
* Ageing
* Redrawing terminals is quite expensive. Therefore, we avoid redrawing on
* each single modification and mark modified cells instead. This way, we know
* which cells to redraw on the next frame. However, a single DIRTY flag is not
* enough for double/triple buffered screens, hence, we use an AGE field for
* each cell. If the cell is modified, we simply increase the age by one. Each
* framebuffer can then remember its last rendered age and request an update of
* all newer cells.
* TERM_AGE_NULL is special. If used as cell age, the cell must always be
* redrawn (forced update). If used as framebuffer age, all cells are drawn.
* This way, we can allow integer wrap-arounds.
*/
typedef uint64_t term_age_t;
#define TERM_AGE_NULL 0
/*
* Characters
* Each cell in a terminal page contains only a single character. This is
* usually a single UCS-4 value. However, Unicode allows combining-characters,
* therefore, the number of UCS-4 characters per cell must be unlimited. The
* term_char_t object wraps the internal combining char API so it can be
* treated as a single object.
*/
struct term_char {
/* never access this value directly */
uint64_t _value;
};
struct term_charbuf {
/* 3 bytes + zero-terminator */
uint32_t buf[4];
};
#define TERM_CHAR_INIT(_val) ((term_char_t){ ._value = (_val) })
#define TERM_CHAR_NULL TERM_CHAR_INIT(0)
term_char_t term_char_set(term_char_t previous, uint32_t append_ucs4);
term_char_t term_char_merge(term_char_t base, uint32_t append_ucs4);
term_char_t term_char_dup(term_char_t ch);
term_char_t term_char_dup_append(term_char_t base, uint32_t append_ucs4);
const uint32_t *term_char_resolve(term_char_t ch, size_t *s, term_charbuf_t *b);
unsigned int term_char_lookup_width(term_char_t ch);
/* true if @ch is TERM_CHAR_NULL, otherwise false */
static inline bool term_char_is_null(term_char_t ch) {
return ch._value == 0;
}
/* true if @ch is dynamically allocated and needs to be freed */
static inline bool term_char_is_allocated(term_char_t ch) {
return !term_char_is_null(ch) && !(ch._value & 0x1);
}
/* true if (a == b), otherwise false; this is (a == b), NOT (*a == *b) */
static inline bool term_char_same(term_char_t a, term_char_t b) {
return a._value == b._value;
}
/* true if (*a == *b), otherwise false; this is implied by (a == b) */
static inline bool term_char_equal(term_char_t a, term_char_t b) {
const uint32_t *sa, *sb;
term_charbuf_t ca, cb;
size_t na, nb;
sa = term_char_resolve(a, &na, &ca);
sb = term_char_resolve(b, &nb, &cb);
return na == nb && !memcmp(sa, sb, sizeof(*sa) * na);
}
/* free @ch in case it is dynamically allocated */
static inline term_char_t term_char_free(term_char_t ch) {
if (term_char_is_allocated(ch))
term_char_set(ch, 0);
return TERM_CHAR_NULL;
}
/* gcc _cleanup_ helpers */
#define _term_char_free_ _cleanup_(term_char_freep)
static inline void term_char_freep(term_char_t *p) {
term_char_free(*p);
}
/*
* Attributes
* Each cell in a terminal page can have its own set of attributes. These alter
* the behavior of the renderer for this single cell. We use term_attr to
* specify attributes.
* The only non-obvious field is "ccode" for foreground and background colors.
* This field contains the terminal color-code in case no full RGB information
* was given by the host. It is also required for dynamic color palettes. If it
* is set to TERM_CCODE_RGB, the "red", "green" and "blue" fields contain the
* full RGB color.
*/
enum {
/* dark color-codes */
TERM_CCODE_BLACK,
TERM_CCODE_RED,
TERM_CCODE_GREEN,
TERM_CCODE_YELLOW,
TERM_CCODE_BLUE,
TERM_CCODE_MAGENTA,
TERM_CCODE_CYAN,
TERM_CCODE_WHITE, /* technically: light grey */
/* light color-codes */
TERM_CCODE_LIGHT_BLACK = TERM_CCODE_BLACK + 8, /* technically: dark grey */
TERM_CCODE_LIGHT_RED = TERM_CCODE_RED + 8,
TERM_CCODE_LIGHT_GREEN = TERM_CCODE_GREEN + 8,
TERM_CCODE_LIGHT_YELLOW = TERM_CCODE_YELLOW + 8,
TERM_CCODE_LIGHT_BLUE = TERM_CCODE_BLUE + 8,
TERM_CCODE_LIGHT_MAGENTA = TERM_CCODE_MAGENTA + 8,
TERM_CCODE_LIGHT_CYAN = TERM_CCODE_CYAN + 8,
TERM_CCODE_LIGHT_WHITE = TERM_CCODE_WHITE + 8,
/* pseudo colors */
TERM_CCODE_FG, /* selected foreground color */
TERM_CCODE_BG, /* selected background color */
TERM_CCODE_RGB, /* color is specified as RGB */
TERM_CCODE_CNT,
};
struct term_color {
uint8_t ccode;
uint8_t red;
uint8_t green;
uint8_t blue;
};
struct term_attr {
term_color fg; /* foreground color */
term_color bg; /* background color */
unsigned int bold : 1; /* bold font */
unsigned int italic : 1; /* italic font */
unsigned int underline : 1; /* underline text */
unsigned int inverse : 1; /* inverse fg/bg */
unsigned int protect : 1; /* protect from erase */
unsigned int blink : 1; /* blink text */
};
/*
* Cells
* The term_cell structure respresents a single cell in a terminal page. It
* contains the stored character, the age of the cell and all its attributes.
*/
struct term_cell {
term_char_t ch; /* stored char or TERM_CHAR_NULL */
term_age_t age; /* cell age or TERM_AGE_NULL */
term_attr attr; /* cell attributes */
unsigned int cwidth; /* cached term_char_lookup_width(cell->ch) */
};
/*
* Lines
* Instead of storing cells in a 2D array, we store them in an array of
* dynamically allocated lines. This way, scrolling can be implemented very
* fast without moving any cells at all. Similarly, the scrollback-buffer is
* much simpler to implement.
* We use term_line to store a single line. It contains an array of cells, a
* fill-state which remembers the amount of blanks on the right side, a
* separate age just for the line which can overwrite the age for all cells,
* and some management data.
*/
struct term_line {
term_line *lines_next; /* linked-list for histories */
term_line *lines_prev; /* linked-list for histories */
unsigned int width; /* visible width of line */
unsigned int n_cells; /* # of allocated cells */
term_cell *cells; /* cell-array */
term_age_t age; /* line age */
unsigned int fill; /* # of valid cells; starting left */
};
int term_line_new(term_line **out);
term_line *term_line_free(term_line *line);
#define _term_line_free_ _cleanup_(term_line_freep)
DEFINE_TRIVIAL_CLEANUP_FUNC(term_line*, term_line_free);
int term_line_reserve(term_line *line, unsigned int width, const term_attr *attr, term_age_t age, unsigned int protect_width);
void term_line_set_width(term_line *line, unsigned int width);
void term_line_write(term_line *line, unsigned int pos_x, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age, bool insert_mode);
void term_line_insert(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age);
void term_line_delete(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age);
void term_line_append_combchar(term_line *line, unsigned int pos_x, uint32_t ucs4, term_age_t age);
void term_line_erase(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age, bool keep_protected);
void term_line_reset(term_line *line, const term_attr *attr, term_age_t age);
void term_line_link(term_line *line, term_line **first, term_line **last);
void term_line_link_tail(term_line *line, term_line **first, term_line **last);
void term_line_unlink(term_line *line, term_line **first, term_line **last);
#define TERM_LINE_LINK(_line, _head) term_line_link((_line), &(_head)->lines_first, &(_head)->lines_last)
#define TERM_LINE_LINK_TAIL(_line, _head) term_line_link_tail((_line), &(_head)->lines_first, &(_head)->lines_last)
#define TERM_LINE_UNLINK(_line, _head) term_line_unlink((_line), &(_head)->lines_first, &(_head)->lines_last)
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