// SPDX-License-Identifier: GPL-2.0+/* *  textbox.c -- implements the text box * *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk) *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com) */ #include "dialog.h" static int hscroll;static int begin_reached, end_reached, page_length;static const char *buf, *page;static size_t start, end; /* * Go back 'n' lines in text. Called by dialog_textbox(). * 'page' will be updated to point to the desired line in 'buf'. */static void back_lines(int n){	int i; 	begin_reached = 0;	/* Go back 'n' lines */	for (i = 0; i < n; i++) {		if (*page == '\0') {			if (end_reached) {				end_reached = 0;				continue;			}		}		if (page == buf) {			begin_reached = 1;			return;		}		page--;		do {			if (page == buf) {				begin_reached = 1;				return;			}			page--;		} while (*page != '\n');		page++;	}} /* * Return current line of text. Called by dialog_textbox() and print_line(). * 'page' should point to start of current line before calling, and will be * updated to point to start of next line. */static char *get_line(void){	int i = 0;	static char line[MAX_LEN + 1]; 	end_reached = 0;	while (*page != '\n') {		if (*page == '\0') {			end_reached = 1;			break;		} else if (i < MAX_LEN)			line[i++] = *(page++);		else {			/* Truncate lines longer than MAX_LEN characters */			if (i == MAX_LEN)				line[i++] = '\0';			page++;		}	}	if (i <= MAX_LEN)		line[i] = '\0';	if (!end_reached)		page++;		/* move past '\n' */ 	return line;} /* * Print a new line of text. */static void print_line(WINDOW *win, int row, int width){	char *line; 	line = get_line();	line += MIN(strlen(line), hscroll);	/* Scroll horizontally */	wmove(win, row, 0);	/* move cursor to correct line */	waddch(win, ' ');	waddnstr(win, line, MIN(strlen(line), width - 2)); 	/* Clear 'residue' of previous line */	wclrtoeol(win);} /* * Print a new page of text. */static void print_page(WINDOW *win, int height, int width){	int i, passed_end = 0; 	page_length = 0;	for (i = 0; i < height; i++) {		print_line(win, i, width);		if (!passed_end)			page_length++;		if (end_reached && !passed_end)			passed_end = 1;	}	wnoutrefresh(win);} /* * Print current position */static void print_position(WINDOW *win){	int percent; 	wattrset(win, dlg.position_indicator.atr);	wbkgdset(win, dlg.position_indicator.atr & A_COLOR);	percent = (page - buf) * 100 / strlen(buf);	wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);	wprintw(win, "(%3d%%)", percent);} /* * refresh window content */static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,			     int cur_y, int cur_x){	start = page - buf; 	print_page(box, boxh, boxw);	print_position(dialog);	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */	wrefresh(dialog); 	end = page - buf;} /* * Display text from a file in a dialog box. * * keys is a null-terminated array */int dialog_textbox(const char *title, const char *tbuf, int initial_height,		   int initial_width, int *_vscroll, int *_hscroll,		   int (*extra_key_cb)(int, size_t, size_t, void *), void *data){	int i, x, y, cur_x, cur_y, key = 0;	int height, width, boxh, boxw;	WINDOW *dialog, *box;	bool done = false; 	begin_reached = 1;	end_reached = 0;	page_length = 0;	hscroll = 0;	buf = tbuf;	page = buf;	/* page is pointer to start of page to be displayed */ 	if (_vscroll && *_vscroll) {		begin_reached = 0; 		for (i = 0; i < *_vscroll; i++)			get_line();	}	if (_hscroll)		hscroll = *_hscroll; do_resize:	getmaxyx(stdscr, height, width);	if (height < TEXTBOX_HEIGHT_MIN || width < TEXTBOX_WIDTH_MIN)		return -ERRDISPLAYTOOSMALL;	if (initial_height != 0)		height = initial_height;	else		if (height > 4)			height -= 4;		else			height = 0;	if (initial_width != 0)		width = initial_width;	else		if (width > 5)			width -= 5;		else			width = 0; 	/* center dialog box on screen */	x = (getmaxx(stdscr) - width) / 2;	y = (getmaxy(stdscr) - height) / 2; 	draw_shadow(stdscr, y, x, height, width); 	dialog = newwin(height, width, y, x);	keypad(dialog, TRUE); 	/* Create window for box region, used for scrolling text */	boxh = height - 4;	boxw = width - 2;	box = subwin(dialog, boxh, boxw, y + 1, x + 1);	wattrset(box, dlg.dialog.atr);	wbkgdset(box, dlg.dialog.atr & A_COLOR); 	keypad(box, TRUE); 	/* register the new window, along with its borders */	draw_box(dialog, 0, 0, height, width,		 dlg.dialog.atr, dlg.border.atr); 	wattrset(dialog, dlg.border.atr);	mvwaddch(dialog, height - 3, 0, ACS_LTEE);	for (i = 0; i < width - 2; i++)		waddch(dialog, ACS_HLINE);	wattrset(dialog, dlg.dialog.atr);	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);	waddch(dialog, ACS_RTEE); 	print_title(dialog, title, width); 	print_button(dialog, " Exit ", height - 2, width / 2 - 4, TRUE);	wnoutrefresh(dialog);	getyx(dialog, cur_y, cur_x);	/* Save cursor position */ 	/* Print first page of text */	attr_clear(box, boxh, boxw, dlg.dialog.atr);	refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x); 	while (!done) {		key = wgetch(dialog);		switch (key) {		case 'E':	/* Exit */		case 'e':		case 'X':		case 'x':		case 'q':		case '\n':			done = true;			break;		case 'g':	/* First page */		case KEY_HOME:			if (!begin_reached) {				begin_reached = 1;				page = buf;				refresh_text_box(dialog, box, boxh, boxw,						 cur_y, cur_x);			}			break;		case 'G':	/* Last page */		case KEY_END: 			end_reached = 1;			/* point to last char in buf */			page = buf + strlen(buf);			back_lines(boxh);			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);			break;		case 'K':	/* Previous line */		case 'k':		case KEY_UP:			if (begin_reached)				break; 			back_lines(page_length + 1);			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);			break;		case 'B':	/* Previous page */		case 'b':		case 'u':		case KEY_PPAGE:			if (begin_reached)				break;			back_lines(page_length + boxh);			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);			break;		case 'J':	/* Next line */		case 'j':		case KEY_DOWN:			if (end_reached)				break; 			back_lines(page_length - 1);			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);			break;		case KEY_NPAGE:	/* Next page */		case ' ':		case 'd':			if (end_reached)				break; 			begin_reached = 0;			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);			break;		case '0':	/* Beginning of line */		case 'H':	/* Scroll left */		case 'h':		case KEY_LEFT:			if (hscroll <= 0)				break; 			if (key == '0')				hscroll = 0;			else				hscroll--;			/* Reprint current page to scroll horizontally */			back_lines(page_length);			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);			break;		case 'L':	/* Scroll right */		case 'l':		case KEY_RIGHT:			if (hscroll >= MAX_LEN)				break;			hscroll++;			/* Reprint current page to scroll horizontally */			back_lines(page_length);			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);			break;		case KEY_ESC:			if (on_key_esc(dialog) == KEY_ESC)				done = true;			break;		case KEY_RESIZE:			back_lines(height);			delwin(box);			delwin(dialog);			on_key_resize();			goto do_resize;		default:			if (extra_key_cb && extra_key_cb(key, start, end, data)) {				done = true;				break;			}		}	}	delwin(box);	delwin(dialog);	if (_vscroll) {		const char *s; 		s = buf;		*_vscroll = 0;		back_lines(page_length);		while (s < page && (s = strchr(s, '\n'))) {			(*_vscroll)++;			s++;		}	}	if (_hscroll)		*_hscroll = hscroll;	return key;}