kconfig/menuconfig: lxdialog is now built-in

lxdialog was previously called as an external program causing screen
to flicker when used. With this patch lxdialog is now built-in.
It is loosly based om previous work by:  Petr Baudis <pasky@ucw.cz>

Following is a list of changes:
o Moved build of dialog routings to kconfig Makefile
o menubox + checklist uses a new item list to hold all menu items
o in util.c implmented helper function to deal with item list
o menubox now uses parameters to save scroll state (avoids temp file)
o textbox now get text to be displayed as parameter and not a file
o make sure to properly delete subwin's before main windows
o killed unused files: lxdialog.c msgbox.c
o modified return value for ESC to match direct calling
o in a few places the code has been adjusted to 80 char wide
o in textbox a small refactoring was made to make code remotely readable
o in mconf removed all unused stuff (functions/variables)

Following is a list of know short comings:
a) pressing ESC twice will be interpreted as two ESC presses
b) resize does not work. menuconfig needs to be restarted to be adjusted

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

1 files changed, 64 insertions, 234 deletions

diff --git a/scripts/kconfig/lxdialog/textbox.c b/scripts/kconfig/lxdialog/textbox.c
index 336793b0395..86b0770b038 100644
--- a/scripts/kconfig/lxdialog/textbox.c
+++ b/scripts/kconfig/lxdialog/textbox.c
@@ -27,54 +27,27 @@ static void print_line(WINDOW * win, int row, int width);
 static char *get_line(void);
 static void print_position(WINDOW * win, int height, int width);
 
-static int hscroll, fd, file_size, bytes_read;
-static int begin_reached = 1, end_reached, page_length;
-static char *buf, *page;
+static int hscroll;
+static int begin_reached, end_reached, page_length;
+static const char *buf;
+static const char *page;
 
 /*
  * Display text from a file in a dialog box.
  */
-int dialog_textbox(const char *title, const char *file, int height, int width)
+int dialog_textbox(const char *title, const char *tbuf, int height, int width)
 {
-	int i, x, y, cur_x, cur_y, fpos, key = 0;
+	int i, x, y, cur_x, cur_y, key = 0;
+	int texth, textw;
 	int passed_end;
-	char search_term[MAX_LEN + 1];
 	WINDOW *dialog, *text;
 
-	search_term[0] = '\0';	/* no search term entered yet */
-
-	/* Open input file for reading */
-	if ((fd = open(file, O_RDONLY)) == -1) {
-		endwin();
-		fprintf(stderr, "\nCan't open input file in dialog_textbox().\n");
-		exit(-1);
-	}
-	/* Get file size. Actually, 'file_size' is the real file size - 1,
-	   since it's only the last byte offset from the beginning */
-	if ((file_size = lseek(fd, 0, SEEK_END)) == -1) {
-		endwin();
-		fprintf(stderr, "\nError getting file size in dialog_textbox().\n");
-		exit(-1);
-	}
-	/* Restore file pointer to beginning of file after getting file size */
-	if (lseek(fd, 0, SEEK_SET) == -1) {
-		endwin();
-		fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
-		exit(-1);
-	}
-	/* Allocate space for read buffer */
-	if ((buf = malloc(BUF_SIZE + 1)) == NULL) {
-		endwin();
-		fprintf(stderr, "\nCan't allocate memory in dialog_textbox().\n");
-		exit(-1);
-	}
-	if ((bytes_read = read(fd, buf, BUF_SIZE)) == -1) {
-		endwin();
-		fprintf(stderr, "\nError reading file in dialog_textbox().\n");
-		exit(-1);
-	}
-	buf[bytes_read] = '\0';	/* mark end of valid data */
-	page = buf;		/* page is pointer to start of page to be displayed */
+	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 */
 
 	/* center dialog box on screen */
 	x = (COLS - width) / 2;
@@ -86,7 +59,9 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 	keypad(dialog, TRUE);
 
 	/* Create window for text region, used for scrolling text */
-	text = subwin(dialog, height - 4, width - 2, y + 1, x + 1);
+	texth = height - 4;
+	textw = width - 2;
+	text = subwin(dialog, texth, textw, y + 1, x + 1);
 	wattrset(text, dlg.dialog.atr);
 	wbkgdset(text, dlg.dialog.atr & A_COLOR);
 
@@ -111,8 +86,8 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 	getyx(dialog, cur_y, cur_x);	/* Save cursor position */
 
 	/* Print first page of text */
-	attr_clear(text, height - 4, width - 2, dlg.dialog.atr);
-	print_page(text, height - 4, width - 2);
+	attr_clear(text, texth, textw, dlg.dialog.atr);
+	print_page(text, texth, textw);
 	print_position(dialog, height, width);
 	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
 	wrefresh(dialog);
@@ -124,37 +99,15 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 		case 'e':
 		case 'X':
 		case 'x':
+			delwin(text);
 			delwin(dialog);
-			free(buf);
-			close(fd);
 			return 0;
 		case 'g':	/* First page */
 		case KEY_HOME:
 			if (!begin_reached) {
 				begin_reached = 1;
-				/* First page not in buffer? */
-				if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
-					endwin();
-					fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
-					exit(-1);
-				}
-				if (fpos > bytes_read) {	/* Yes, we have to read it in */
-					if (lseek(fd, 0, SEEK_SET) == -1) {
-						endwin();
-						fprintf(stderr, "\nError moving file pointer in "
-							        "dialog_textbox().\n");
-						exit(-1);
-					}
-					if ((bytes_read =
-					     read(fd, buf, BUF_SIZE)) == -1) {
-						endwin();
-						fprintf(stderr, "\nError reading file in dialog_textbox().\n");
-						exit(-1);
-					}
-					buf[bytes_read] = '\0';
-				}
 				page = buf;
-				print_page(text, height - 4, width - 2);
+				print_page(text, texth, textw);
 				print_position(dialog, height, width);
 				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
 				wrefresh(dialog);
@@ -164,29 +117,10 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 		case KEY_END:
 
 			end_reached = 1;
-			/* Last page not in buffer? */
-			if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
-				endwin();
-				fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
-				exit(-1);
-			}
-			if (fpos < file_size) {	/* Yes, we have to read it in */
-				if (lseek(fd, -BUF_SIZE, SEEK_END) == -1) {
-					endwin();
-					fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
-					exit(-1);
-				}
-				if ((bytes_read =
-				     read(fd, buf, BUF_SIZE)) == -1) {
-					endwin();
-					fprintf(stderr, "\nError reading file in dialog_textbox().\n");
-					exit(-1);
-				}
-				buf[bytes_read] = '\0';
-			}
-			page = buf + bytes_read;
-			back_lines(height - 4);
-			print_page(text, height - 4, width - 2);
+			/* point to last char in buf */
+			page = buf + strlen(buf);
+			back_lines(texth);
+			print_page(text, texth, textw);
 			print_position(dialog, height, width);
 			wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
 			wrefresh(dialog);
@@ -197,20 +131,22 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 			if (!begin_reached) {
 				back_lines(page_length + 1);
 
-				/* We don't call print_page() here but use scrolling to ensure
-				   faster screen update. However, 'end_reached' and
-				   'page_length' should still be updated, and 'page' should
-				   point to start of next page. This is done by calling
-				   get_line() in the following 'for' loop. */
+				/* We don't call print_page() here but use
+				 * scrolling to ensure faster screen update.
+				 * However, 'end_reached' and 'page_length'
+				 * should still be updated, and 'page' should
+				 * point to start of next page. This is done
+				 * by calling get_line() in the following
+				 * 'for' loop. */
 				scrollok(text, TRUE);
 				wscrl(text, -1);	/* Scroll text region down one line */
 				scrollok(text, FALSE);
 				page_length = 0;
 				passed_end = 0;
-				for (i = 0; i < height - 4; i++) {
+				for (i = 0; i < texth; i++) {
 					if (!i) {
 						/* print first line of page */
-						print_line(text, 0, width - 2);
+						print_line(text, 0, textw);
 						wnoutrefresh(text);
 					} else
 						/* Called to update 'end_reached' and 'page' */
@@ -231,8 +167,8 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 		case KEY_PPAGE:
 			if (begin_reached)
 				break;
-			back_lines(page_length + height - 4);
-			print_page(text, height - 4, width - 2);
+			back_lines(page_length + texth);
+			print_page(text, texth, textw);
 			print_position(dialog, height, width);
 			wmove(dialog, cur_y, cur_x);
 			wrefresh(dialog);
@@ -245,7 +181,7 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 				scrollok(text, TRUE);
 				scroll(text);	/* Scroll text region up one line */
 				scrollok(text, FALSE);
-				print_line(text, height - 5, width - 2);
+				print_line(text, texth - 1, textw);
 				wnoutrefresh(text);
 				print_position(dialog, height, width);
 				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
@@ -258,7 +194,7 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 				break;
 
 			begin_reached = 0;
-			print_page(text, height - 4, width - 2);
+			print_page(text, texth, textw);
 			print_position(dialog, height, width);
 			wmove(dialog, cur_y, cur_x);
 			wrefresh(dialog);
@@ -276,7 +212,7 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 				hscroll--;
 			/* Reprint current page to scroll horizontally */
 			back_lines(page_length);
-			print_page(text, height - 4, width - 2);
+			print_page(text, texth, textw);
 			wmove(dialog, cur_y, cur_x);
 			wrefresh(dialog);
 			break;
@@ -288,7 +224,7 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 			hscroll++;
 			/* Reprint current page to scroll horizontally */
 			back_lines(page_length);
-			print_page(text, height - 4, width - 2);
+			print_page(text, texth, textw);
 			wmove(dialog, cur_y, cur_x);
 			wrefresh(dialog);
 			break;
@@ -296,123 +232,42 @@ int dialog_textbox(const char *title, const char *file, int height, int width)
 			break;
 		}
 	}
-
+	delwin(text);
 	delwin(dialog);
-	free(buf);
-	close(fd);
-	return -1;		/* ESC pressed */
+	return 255;		/* ESC pressed */
 }
 
 /*
- * Go back 'n' lines in text file. Called by dialog_textbox().
+ * 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, fpos;
+	int i;
 
 	begin_reached = 0;
-	/* We have to distinguish between end_reached and !end_reached
-	   since at end of file, the line is not ended by a '\n'.
-	   The code inside 'if' basically does a '--page' to move one
-	   character backward so as to skip '\n' of the previous line */
-	if (!end_reached) {
-		/* Either beginning of buffer or beginning of file reached? */
-		if (page == buf) {
-			if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
-				endwin();
-				fprintf(stderr, "\nError moving file pointer in "
-					        "back_lines().\n");
-				exit(-1);
-			}
-			if (fpos > bytes_read) {	/* Not beginning of file yet */
-				/* We've reached beginning of buffer, but not beginning of
-				   file yet, so read previous part of file into buffer.
-				   Note that we only move backward for BUF_SIZE/2 bytes,
-				   but not BUF_SIZE bytes to avoid re-reading again in
-				   print_page() later */
-				/* Really possible to move backward BUF_SIZE/2 bytes? */
-				if (fpos < BUF_SIZE / 2 + bytes_read) {
-					/* No, move less then */
-					if (lseek(fd, 0, SEEK_SET) == -1) {
-						endwin();
-						fprintf(stderr, "\nError moving file pointer in "
-						                "back_lines().\n");
-						exit(-1);
-					}
-					page = buf + fpos - bytes_read;
-				} else {	/* Move backward BUF_SIZE/2 bytes */
-					if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR) == -1) {
-						endwin();
-						fprintf(stderr, "\nError moving file pointer "
-						                "in back_lines().\n");
-						exit(-1);
-					}
-					page = buf + BUF_SIZE / 2;
-				}
-				if ((bytes_read =
-				     read(fd, buf, BUF_SIZE)) == -1) {
-					endwin();
-					fprintf(stderr, "\nError reading file in back_lines().\n");
-					exit(-1);
-				}
-				buf[bytes_read] = '\0';
-			} else {	/* Beginning of file reached */
-				begin_reached = 1;
-				return;
+	/* Go back 'n' lines */
+	for (i = 0; i < n; i++) {
+		if (*page == '\0') {
+			if (end_reached) {
+				end_reached = 0;
+				continue;
 			}
 		}
-		if (*(--page) != '\n') {	/* '--page' here */
-			/* Something's wrong... */
-			endwin();
-			fprintf(stderr, "\nInternal error in back_lines().\n");
-			exit(-1);
+		if (page == buf) {
+			begin_reached = 1;
+			return;
 		}
-	}
-	/* Go back 'n' lines */
-	for (i = 0; i < n; i++)
+		page--;
 		do {
 			if (page == buf) {
-				if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
-					endwin();
-					fprintf(stderr, "\nError moving file pointer in back_lines().\n");
-					exit(-1);
-				}
-				if (fpos > bytes_read) {
-					/* Really possible to move backward BUF_SIZE/2 bytes? */
-					if (fpos < BUF_SIZE / 2 + bytes_read) {
-						/* No, move less then */
-						if (lseek(fd, 0, SEEK_SET) == -1) {
-							endwin();
-							fprintf(stderr, "\nError moving file pointer "
-							                "in back_lines().\n");
-							exit(-1);
-						}
-						page = buf + fpos - bytes_read;
-					} else {	/* Move backward BUF_SIZE/2 bytes */
-						if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR) == -1) {
-							endwin();
-							fprintf(stderr, "\nError moving file pointer"
-							                " in back_lines().\n");
-							exit(-1);
-						}
-						page = buf + BUF_SIZE / 2;
-					}
-					if ((bytes_read =
-					     read(fd, buf, BUF_SIZE)) == -1) {
-						endwin();
-						fprintf(stderr, "\nError reading file in "
-						                "back_lines().\n");
-						exit(-1);
-					}
-					buf[bytes_read] = '\0';
-				} else {	/* Beginning of file reached */
-					begin_reached = 1;
-					return;
-				}
+				begin_reached = 1;
+				return;
 			}
-		} while (*(--page) != '\n');
-	page++;
+			page--;
+		} while (*page != '\n');
+		page++;
+	}
 }
 
 /*
@@ -467,33 +322,14 @@ static void print_line(WINDOW * win, int row, int width)
  */
 static char *get_line(void)
 {
-	int i = 0, fpos;
+	int i = 0;
 	static char line[MAX_LEN + 1];
 
 	end_reached = 0;
 	while (*page != '\n') {
 		if (*page == '\0') {
-			/* Either end of file or end of buffer reached */
-			if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
-				endwin();
-				fprintf(stderr, "\nError moving file pointer in "
-				                "get_line().\n");
-				exit(-1);
-			}
-			if (fpos < file_size) {	/* Not end of file yet */
-				/* We've reached end of buffer, but not end of file yet,
-				   so read next part of file into buffer */
-				if ((bytes_read =
-				     read(fd, buf, BUF_SIZE)) == -1) {
-					endwin();
-					fprintf(stderr, "\nError reading file in get_line().\n");
-					exit(-1);
-				}
-				buf[bytes_read] = '\0';
-				page = buf;
-			} else {
-				if (!end_reached)
-					end_reached = 1;
+			if (!end_reached) {
+				end_reached = 1;
 				break;
 			}
 		} else if (i < MAX_LEN)
@@ -518,17 +354,11 @@ static char *get_line(void)
  */
 static void print_position(WINDOW * win, int height, int width)
 {
-	int fpos, percent;
+	int percent;
 
-	if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
-		endwin();
-		fprintf(stderr, "\nError moving file pointer in print_position().\n");
-		exit(-1);
-	}
 	wattrset(win, dlg.position_indicator.atr);
 	wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
-	percent = !file_size ?
-	    100 : ((fpos - bytes_read + page - buf) * 100) / file_size;
+	percent = (page - buf) * 100 / strlen(buf);
 	wmove(win, height - 3, width - 9);
 	wprintw(win, "(%3d%%)", percent);
 }