screen.c

一个很有名的浏览器

}

/* Time critical section. */
static inline void
add_char16(struct string *screen, struct screen_driver *driver,
	   struct screen_char *ch, struct screen_state *state)
{
	unsigned char border = (ch->attr & SCREEN_ATTR_FRAME);
	unsigned char underline = (ch->attr & SCREEN_ATTR_UNDERLINE);
	unsigned char bold = (ch->attr & SCREEN_ATTR_BOLD);

	if (border != state->border && driver->frame_seqs) {
		state->border = border;
		add_term_string(screen, driver->frame_seqs[!!border]);
	}

	if (underline != state->underline && driver->underline) {
		state->underline = underline;
		add_term_string(screen, driver->underline[!!underline]);
	}

	if (bold != state->bold) {
		state->bold = bold;
		if (bold) {
			add_bytes_to_string(screen, "\033[1m", 4);
		} else {
			/* Force repainting of the other attributes. */
			state->color[0] = ch->color[0] + 1;
		}
	}

	if (!compare_color(ch->color, state->color)) {
		copy_color(state->color, ch->color);

		add_bytes_to_string(screen, "\033[0", 3);

		if (driver->color_mode == COLOR_MODE_16) {
			unsigned char code[6] = ";30;40";
			unsigned char bgcolor = TERM_COLOR_BACKGROUND(ch->color);

			code[2] += TERM_COLOR_FOREGROUND(ch->color);

			if (!driver->transparent || bgcolor != 0) {
				code[5] += bgcolor;
				add_bytes_to_string(screen, code, 6);
			} else {
				add_bytes_to_string(screen, code, 3);
			}

		} else if (ch->attr & SCREEN_ATTR_STANDOUT) {
			/* Flip the fore- and background colors for highlighing
			 * purposes. */
			add_bytes_to_string(screen, ";7", 2);
		}

		if (underline && driver->underline) {
			add_bytes_to_string(screen, ";4", 2);
		}

		/* Check if the char should be rendered bold. */
		if (bold) {
			add_bytes_to_string(screen, ";1", 2);
		}

		add_bytes_to_string(screen, "m", 1);
	}

	add_char_data(screen, driver, ch->data, border);
}

#ifdef CONFIG_256_COLORS
static struct string color256_seqs[] = {
	/* foreground: */	TERM_STRING("\033[0;38;5;%dm"),
	/* background: */	TERM_STRING("\033[48;5;%dm"),
};

static inline void
add_char_color(struct string *screen, struct string *seq, unsigned char color)
{
	unsigned char color_buf[3];
	unsigned char *color_pos = color_buf;
	int seq_pos = 0;
       	int color_len = 1;

	check_string_magic(seq);
	for (; seq->source[seq_pos] != '%'; seq_pos++) ;

	add_bytes_to_string(screen, seq->source, seq_pos);

	if (color < 10) {
		color_pos += 2;
	} else {
		int color2;

		++color_len;
		if (color < 100) {
			++color_pos;
		} else {
			++color_len;

			if (color < 200) {
				color_buf[0] = '1';
				color -= 100;
			} else {
				color_buf[0] = '2';
				color -= 200;
			}
		}

		color2 = (color % 10);
		color /= 10;
		color_buf[1] = '0' + color;
		color = color2;
	}

	color_buf[2] = '0' + color;

	add_bytes_to_string(screen, color_pos, color_len);

	seq_pos += 2; /* Skip "%d" */
	add_bytes_to_string(screen, &seq->source[seq_pos], seq->length - seq_pos);
}

#define add_background_color(str, seq, chr) add_char_color(str, &(seq)[1], (chr)->color[1])
#define add_foreground_color(str, seq, chr) add_char_color(str, &(seq)[0], (chr)->color[0])

/* Time critical section. */
static inline void
add_char256(struct string *screen, struct screen_driver *driver,
	    struct screen_char *ch, struct screen_state *state)
{
	unsigned char attr_delta = (ch->attr ^ state->attr);

	if (attr_delta) {
		if ((attr_delta & SCREEN_ATTR_FRAME) && driver->frame_seqs) {
			state->border = !!(ch->attr & SCREEN_ATTR_FRAME);
			add_term_string(screen, driver->frame_seqs[state->border]);
		}

		if ((attr_delta & SCREEN_ATTR_UNDERLINE) && driver->underline) {
			state->underline = !!(ch->attr & SCREEN_ATTR_UNDERLINE);
			add_term_string(screen, driver->underline[state->underline]);
		}

		if (attr_delta & SCREEN_ATTR_BOLD) {
			if (ch->attr & SCREEN_ATTR_BOLD) {
				add_bytes_to_string(screen, "\033[1m", 4);
			} else {
				/* Force repainting of the other attributes. */
				state->color[0] = ch->color[0] + 1;
			}
		}

		state->attr = ch->attr;
	}

	if (!compare_color(ch->color, state->color)) {
		copy_color(state->color, ch->color);

		add_foreground_color(screen, color256_seqs, ch);
		if (!driver->transparent || ch->color[1] != 0) {
			add_background_color(screen, color256_seqs, ch);
		}

		if (ch->attr & SCREEN_ATTR_BOLD)
			add_bytes_to_string(screen, "\033[1m", 4);

		if (ch->attr & SCREEN_ATTR_UNDERLINE && driver->underline) {
			state->underline = !!(ch->attr & SCREEN_ATTR_UNDERLINE);
			add_term_string(screen, driver->underline[state->underline]);
		}
	}

	add_char_data(screen, driver, ch->data, ch->attr & SCREEN_ATTR_FRAME);
}
#endif

#define add_chars(image_, term_, driver_, state_, ADD_CHAR)			\
{										\
	struct terminal_screen *screen = (term_)->screen;			\
	int y = screen->dirty_from;					\
	int ypos = y * (term_)->width;						\
	int prev_y = -1;							\
	int xmax = (term_)->width - 1;						\
	int ymax = (term_)->height - 1;						\
	struct screen_char *current = &screen->last_image[ypos];	\
	struct screen_char *pos = &screen->image[ypos];		\
	struct screen_char *prev_pos = NULL; /* Warning prevention. */	\
										\
	int_upper_bound(&screen->dirty_to, ymax);				\
										\
	for (; y <= screen->dirty_to; y++) {					\
		int is_last_line = (y == ymax);					\
		int x = 0;						\
										\
		for (; x <= xmax; x++, current++, pos++) {			\
			/*  Workaround for terminals without
			 *  "eat_newline_glitch (xn)", e.g., the cons25 family
			 *  of terminals and cygwin terminal.
			 *  It prevents display distortion, but char at bottom
			 *  right of terminal will not be drawn.
			 *  A better fix would be to correctly detects
			 *  terminal type, and/or add a terminal option for
			 *  this purpose. */					\
										\
			if (is_last_line && x == xmax)				\
				break;						\
										\
			if (compare_bg_color(pos->color, current->color)) {	\
				/* No update for exact match. */		\
				if (compare_fg_color(pos->color, current->color)\
				    && pos->data == current->data		\
				    && pos->attr == current->attr)		\
					continue;				\
										\
				/* Else if the color match and the data is
				 * ``space''. */				\
				if (pos->data <= ' ' && current->data <= ' '	\
				    && pos->attr == current->attr)		\
					continue;				\
			}							\
										\
			/* Move the cursor when @prev_pos is more than 10 chars
			 * away. */						\
			if (prev_y != y || prev_pos + 10 <= pos) {		\
				add_cursor_move_to_string(image_, y + 1, x + 1);\
				prev_pos = pos;					\
				prev_y = y;					\
			}							\
				 						\
			for (; prev_pos <= pos ; prev_pos++)			\
				ADD_CHAR(image_, driver_, prev_pos, state_);	\
		}								\
	}									\
}

/* Updating of the terminal screen is done by checking what needs to be updated
 * using the last screen. */
void
redraw_screen(struct terminal *term)
{
	struct screen_driver *driver;
	struct string image;
	struct screen_state state = { 0xFF, 0xFF, 0xFF, 0, { 0xFF, 0xFF } };
	struct terminal_screen *screen = term->screen;

	if (!screen || screen->dirty_from > screen->dirty_to) return;
	if (term->master && is_blocked()) return;

	driver = get_screen_driver(term);
	if (!driver) return;

	if (!init_string(&image)) return;

	switch (driver->color_mode) {
	case COLOR_MODE_MONO:
	case COLOR_MODE_16:
		add_chars(&image, term, driver, &state, add_char16);
		break;
#ifdef CONFIG_256_COLORS
	case COLOR_MODE_256:
		add_chars(&image, term, driver, &state, add_char256);
		break;
#endif
	case COLOR_MODES:
	case COLOR_MODE_DUMP:
	default:
		INTERNAL("Invalid color mode (%d).", driver->color_mode);
		return;
	}

	if (image.length) {
		if (driver->color_mode)
			add_bytes_to_string(&image, "\033[37;40m", 8);

		add_bytes_to_string(&image, "\033[0m", 4);

		/* If we ended in border state end the frame mode. */
		if (state.border && driver->frame_seqs)
			add_term_string(&image, driver->frame_seqs[0]);

	}

	/* Even if nothing was redrawn, we possibly still need to move
	 * cursor. */
	if (image.length
	    || screen->cx != screen->lcx
	    || screen->cy != screen->lcy) {
		screen->lcx = screen->cx;
		screen->lcy = screen->cy;

		add_cursor_move_to_string(&image, screen->cy + 1,
						  screen->cx + 1);
	}

	if (image.length) {
		if (term->master) want_draw();
		hard_write(term->fdout, image.source, image.length);
		if (term->master) done_draw();
	}

	done_string(&image);

	copy_screen_chars(screen->last_image, screen->image, term->width * term->height);
	screen->dirty_from = term->height;
	screen->dirty_to = 0;
}

void
erase_screen(struct terminal *term)
{
	if (term->master) {
		if (is_blocked()) return;
		want_draw();
	}

	hard_write(term->fdout, "\033[2J\033[1;1H", 10);
	if (term->master) done_draw();
}

void
beep_terminal(struct terminal *term)
{
#ifdef CONFIG_WIN32
	MessageBeep(MB_ICONEXCLAMATION);
#else
	hard_write(term->fdout, "\a", 1);
#endif
}

struct terminal_screen *
init_screen(void)
{
	struct terminal_screen *screen;

	screen = mem_calloc(1, sizeof(*screen));
	if (!screen) return NULL;

	screen->lcx = -1;
	screen->lcy = -1;

	return screen;
}

/* The two images are allocated in one chunk. */
/* TODO: It seems allocation failure here is fatal. We should do something! */
void
resize_screen(struct terminal *term, int width, int height)
{
	struct terminal_screen *screen;
	struct screen_char *image;
	size_t size, bsize;

	assert(term && term->screen);

	screen = term->screen;

	assert(width >= 0);
	assert(height >= 0);

	size = width * height;
	if (size <= 0) return;

	bsize = size * sizeof(*image);

	image = mem_realloc(screen->image, bsize * 2);
	if (!image) return;

	screen->image = image;
	screen->last_image = image + size;

	memset(screen->image, 0, bsize);
	memset(screen->last_image, 0xFF, bsize);

	term->width = width;
	term->height = height;
	set_screen_dirty(screen, 0, height);
}

void
done_screen(struct terminal_screen *screen)
{
	mem_free_if(screen->image);
	mem_free(screen);
}