screen.c

一个很有名的浏览器

/* Terminal screen drawing routines. */
/* $Id: screen.c,v 1.152.6.5 2005/04/05 21:08:43 jonas Exp $ */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <string.h>

#include "elinks.h"

#include "config/options.h"
#include "intl/charsets.h"
#include "osdep/ascii.h"
#include "osdep/osdep.h"
#include "terminal/color.h"
#include "terminal/draw.h"
#include "terminal/hardio.h"
#include "terminal/kbd.h"
#include "terminal/screen.h"
#include "terminal/terminal.h"
#include "util/conv.h"
#include "util/error.h"
#include "util/memory.h"
#include "util/string.h"


/* TODO: We must use termcap/terminfo if available! --pasky */

unsigned char frame_dumb[48] =	"   ||||++||++++++--|-+||++--|-+----++++++++     ";
static unsigned char frame_vt100[48] =	"aaaxuuukkuxkjjjkmvwtqnttmlvwtqnvvwwmmllnnjla    ";

/* For UTF8 I/O */
static unsigned char frame_vt100_u[48] = {
	177, 177, 177, 179, 180, 180, 180, 191,
	191, 180, 179, 191, 217, 217, 217, 191,
	192, 193, 194, 195, 196, 197, 195, 195,
	192, 218, 193, 194, 195, 196, 197, 193,
	193, 194, 194, 192, 192, 218, 218, 197,
	197, 217, 218, 177,  32, 32,  32,  32
};

static unsigned char frame_freebsd[48] = {
	130, 138, 128, 153, 150, 150, 150, 140,
	140, 150, 153, 140, 139, 139, 139, 140,
	142, 151, 152, 149, 146, 143, 149, 149,
	142, 141, 151, 152, 149, 146, 143, 151,
	151, 152, 152, 142, 142, 141, 141, 143,
	143, 139, 141, 128, 128, 128, 128, 128,
};

static unsigned char frame_koi[48] = {
	144, 145, 146, 129, 135, 178, 180, 167,
	166, 181, 161, 168, 174, 173, 172, 131,
	132, 137, 136, 134, 128, 138, 175, 176,
	171, 165, 187, 184, 177, 160, 190, 185,
	186, 182, 183, 170, 169, 162, 164, 189,
	188, 133, 130, 141, 140, 142, 143, 139,
};

/* Most of this table is just 176 + <index in table>. */
static unsigned char frame_restrict[48] = {
	176, 177, 178, 179, 180, 179, 186, 186,
	205, 185, 186, 187, 188, 186, 205, 191,
	192, 193, 194, 195, 196, 197, 179, 186,
	200, 201, 202, 203, 204, 205, 206, 205,
	196, 205, 196, 186, 205, 205, 186, 186,
	179, 217, 218, 219, 220, 221, 222, 223,
};

#define TERM_STRING(str) INIT_STRING(str, sizeof(str) - 1)

#define add_term_string(str, tstr) \
	add_bytes_to_string(str, (tstr).source, (tstr).length)

static struct string m11_hack_frame_seqs[] = {
	/* end border: */	TERM_STRING("\033[10m"),
	/* begin border: */	TERM_STRING("\033[11m"),
};

static struct string vt100_frame_seqs[] = {
	/* end border: */	TERM_STRING("\x0f"),
	/* begin border: */	TERM_STRING("\x0e"),
};

static struct string underline_seqs[] = {
	/* begin underline: */	TERM_STRING("\033[24m"),
	/* end underline: */	TERM_STRING("\033[4m"),
};

/* Used in {add_char*()} and {redraw_screen()} to reduce the logic. It is
 * updated from terminal._template_.* using option change_hooks. */
/* TODO: termcap/terminfo can maybe gradually be introduced via this
 *	 structure. We'll see. --jonas */
struct screen_driver {
	LIST_HEAD(struct screen_driver);

	/* The terminal._template_.type. Together with the @name member the
	 * uniquely identify the screen_driver. */
	enum term_mode_type type;

	/* Charsets when doing UTF8 I/O. */
	/* [0] is the common charset and [1] is the frame charset.
	 * Test wether to use UTF8 I/O using the use_utf8_io() macro. */
	int charsets[2];

	/* The frame translation table. May be NULL. */
	unsigned char *frame;

	/* The frame mode setup and teardown sequences. May be NULL. */
	struct string *frame_seqs;

	/* The underline mode setup and teardown sequences. May be NULL. */
	struct string *underline;

	/* The color mode */
	enum color_mode color_mode;

	/* These are directly derived from the terminal options. */
	unsigned int transparent:1;

	/* The terminal._template_ name. */
	unsigned char name[1]; /* XXX: Keep last! */
};

static struct screen_driver dumb_screen_driver = {
				NULL_LIST_HEAD,
	/* type: */		TERM_DUMB,
	/* charsets: */		{ -1, -1 },	/* No UTF8 I/O */
	/* frame: */		frame_dumb,
	/* frame_seqs: */	NULL,
	/* underline: */	underline_seqs,
	/* color_mode: */	COLOR_MODE_16,
	/* transparent: */	1,
};

static struct screen_driver vt100_screen_driver = {
				NULL_LIST_HEAD,
	/* type: */		TERM_VT100,
	/* charsets: */		{ -1, -1 },	/* No UTF8 I/O */
	/* frame: */		frame_vt100,
	/* frame_seqs: */	vt100_frame_seqs,
	/* underline: */	underline_seqs,
	/* color_mode: */	COLOR_MODE_16,
	/* transparent: */	1,
};

static struct screen_driver linux_screen_driver = {
				NULL_LIST_HEAD,
	/* type: */		TERM_LINUX,
	/* charsets: */		{ -1, -1 },	/* No UTF8 I/O */
	/* frame: */		NULL,		/* No restrict_852 */
	/* frame_seqs: */	NULL,		/* No m11_hack */
	/* underline: */	underline_seqs,
	/* color_mode: */	COLOR_MODE_16,
	/* transparent: */	1,
};

static struct screen_driver koi8_screen_driver = {
				NULL_LIST_HEAD,
	/* type: */		TERM_KOI8,
	/* charsets: */		{ -1, -1 },	/* No UTF8 I/O */
	/* frame: */		frame_koi,
	/* frame_seqs: */	NULL,
	/* underline: */	underline_seqs,
	/* color_mode: */	COLOR_MODE_16,
	/* transparent: */	1,
};

static struct screen_driver freebsd_screen_driver = {
				NULL_LIST_HEAD,
	/* type: */		TERM_FREEBSD,
	/* charsets: */		{ -1, -1 },	/* No UTF8 I/O */
	/* frame: */		frame_freebsd,
	/* frame_seqs: */	NULL,		/* No m11_hack */
	/* underline: */	underline_seqs,
	/* color_mode: */	COLOR_MODE_16,
	/* transparent: */	1,
};

/* XXX: Keep in sync with enum term_mode_type. */
static struct screen_driver *screen_drivers[] = {
	/* TERM_DUMB: */	&dumb_screen_driver,
	/* TERM_VT100: */	&vt100_screen_driver,
	/* TERM_LINUX: */	&linux_screen_driver,
	/* TERM_KOI8: */	&koi8_screen_driver,
	/* TERM_FREEBSD: */	&freebsd_screen_driver,
};


static INIT_LIST_HEAD(active_screen_drivers);

static void
update_screen_driver(struct screen_driver *driver, struct option *term_spec)
{
	int utf8_io = get_opt_bool_tree(term_spec, "utf_8_io");

	driver->color_mode = get_opt_int_tree(term_spec, "colors");
	driver->transparent = get_opt_bool_tree(term_spec, "transparency");

	if (get_opt_bool_tree(term_spec, "underline")) {
		driver->underline = underline_seqs;
	} else {
		driver->underline = NULL;
	}

	if (utf8_io) {
		driver->charsets[0] = get_opt_int_tree(term_spec, "charset");
		if (driver->type == TERM_LINUX) {
			if (get_opt_bool_tree(term_spec, "restrict_852"))
				driver->frame = frame_restrict;

			driver->charsets[1] = get_cp_index("cp437");

		} else if (driver->type == TERM_FREEBSD) {
			driver->charsets[1] = get_cp_index("cp437");

		} else if (driver->type == TERM_VT100) {
			driver->frame = frame_vt100_u;
			driver->charsets[1] = get_cp_index("cp437");

		} else if (driver->type == TERM_KOI8) {
			driver->charsets[1] = get_cp_index("koi8-r");

		} else {
			driver->charsets[1] = driver->charsets[0];
		}

	} else {
		driver->charsets[0] = -1;
		if (driver->type == TERM_LINUX) {
			if (get_opt_bool_tree(term_spec, "restrict_852"))
				driver->frame = frame_restrict;

			if (get_opt_bool_tree(term_spec, "m11_hack"))
				driver->frame_seqs = m11_hack_frame_seqs;

		} else if (driver->type == TERM_FREEBSD) {
			if (get_opt_bool_tree(term_spec, "m11_hack"))
				driver->frame_seqs = m11_hack_frame_seqs;

		} else if (driver->type == TERM_VT100) {
			driver->frame = frame_vt100;
		}
	}
}

static int
screen_driver_change_hook(struct session *ses, struct option *term_spec,
			  struct option *changed)
{
	enum term_mode_type type = get_opt_int_tree(term_spec, "type");
	struct screen_driver *driver;
	unsigned char *name = term_spec->name;
	int len = strlen(name);

	foreach (driver, active_screen_drivers)
		if (driver->type == type && !memcmp(driver->name, name, len)) {
			update_screen_driver(driver, term_spec);
			break;
		}

	return 0;
}

static inline struct screen_driver *
add_screen_driver(enum term_mode_type type, struct terminal *term, int env_len)
{
	struct screen_driver *driver;

	/* One byte is reserved for name in struct screen_driver. */
	driver = mem_alloc(sizeof(*driver) + env_len);
	if (!driver) return NULL;

	memcpy(driver, screen_drivers[type], sizeof(*driver) - 1);
	memcpy(driver->name, term->spec->name, env_len + 1);

	add_to_list(active_screen_drivers, driver);

	update_screen_driver(driver, term->spec);

	term->spec->change_hook = screen_driver_change_hook;

	return driver;
}

static inline struct screen_driver *
get_screen_driver(struct terminal *term)
{
	enum term_mode_type type = get_opt_int_tree(term->spec, "type");
	unsigned char *name = term->spec->name;
	int len = strlen(name);
	struct screen_driver *driver;

	foreach (driver, active_screen_drivers) {
		if (driver->type != type) continue;
		if (memcmp(driver->name, name, len + 1)) continue;

		/* Some simple probably useless MRU ;) */
		if (driver != active_screen_drivers.next) {
			del_from_list(driver);
			add_to_list(active_screen_drivers, driver);
		}

		return driver;
	}

	return add_screen_driver(type, term, len);
}

void
done_screen_drivers(void)
{
	free_list(active_screen_drivers);
}


/* Adds the term code for positioning the cursor at @x and @y to @string.
 * The template term code is: "\033[<@y>;<@x>H" */
static inline struct string *
add_cursor_move_to_string(struct string *screen, int y, int x)
{
	/* 28 chars for both of the @y and @x numbers should be enough. */
	unsigned char code[32];
	int length = 2;
	int ret;

	code[0] = '\033';
	code[1] = '[';

	ret = longcat(code, &length, y, 30, 0);
	/* Make sure theres atleast room for ';' and `some' number ;) */
	if (ret < 0 || length > 30) return NULL;

	code[length++] = ';';

	ret = longcat(code, &length, x, sizeof(code) - length, 0);
	if (ret < 0 || length > 31) return NULL;

	code[length++] = 'H';

	return add_bytes_to_string(screen, code, length);
}

struct screen_state {
	unsigned char border;
	unsigned char underline;
	unsigned char bold;
	unsigned char attr;
	unsigned char color[2];
};

#ifdef CONFIG_256_COLORS
#define compare_color(a, b)	(!memcmp((a), (b), 2))
#define copy_color(a, b)	memcpy((a), (b), 2)
#else
#define compare_color(a, b)	((a)[0] == (b)[0])
#define copy_color(a, b)	((a)[0] = (b)[0])
#endif

#define compare_bg_color(a, b)	(TERM_COLOR_BACKGROUND(a) == TERM_COLOR_BACKGROUND(b))
#define compare_fg_color(a, b)	(TERM_COLOR_FOREGROUND(a) == TERM_COLOR_FOREGROUND(b))

#define use_utf8_io(driver)	((driver)->charsets[0] != -1)

static inline void
add_char_data(struct string *screen, struct screen_driver *driver,
	      unsigned char data, unsigned char border)
{
	if (!isscreensafe(data)) {
		add_char_to_string(screen, ' ');
		return;
	}

	if (border && driver->frame && data >= 176 && data < 224)
		data = driver->frame[data - 176];

	if (use_utf8_io(driver)) {
		int charset = driver->charsets[!!border];

		add_to_string(screen, cp2utf_8(charset, data));
		return;
	}

	add_char_to_string(screen, data);