scripts/kconfig/lxdialog/textbox.c - linux - Git at Google

 // 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;
 }
	// 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;
	}