/* $Id$ */
/**************************************************************************
* help.c *
* *
* Copyright (C) 2005 Chris Allegretta *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2, or (at your option) *
* any later version. *
* *
* This program is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the Free Software *
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA *
* 02110-1301, USA. *
* *
**************************************************************************/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "proto.h"
#ifndef DISABLE_HELP
static char *help_text = NULL;
/* The text displayed in the help window. */
/* Our dynamic, shortcut-list-compliant help function. */
void do_help(void)
{
int line = 0;
/* The line number in help_text of the first displayed help
* line. This variable is zero-based. */
bool no_more = FALSE;
/* no_more means the end of the help text is shown, so don't go
* down any more. */
int kbinput = ERR;
bool meta_key, func_key;
bool old_no_help = ISSET(NO_HELP);
#ifndef DISABLE_MOUSE
const shortcut *oldshortcut = currshortcut;
/* We will set currshortcut to allow clicking on the help
* screen's shortcut list. */
#endif
curs_set(0);
blank_edit();
wattroff(bottomwin, A_REVERSE);
blank_statusbar();
/* Set help_text as the string to display. */
help_init();
assert(help_text != NULL);
#ifndef DISABLE_MOUSE
/* Set currshortcut to allow clicking on the help screen's shortcut
* list, after help_init() is called. */
currshortcut = help_list;
#endif
if (ISSET(NO_HELP)) {
/* Make sure that the help screen's shortcut list will actually
* be displayed. */
UNSET(NO_HELP);
window_init();
}
bottombars(help_list);
do {
int i;
int old_line = line;
/* We redisplay the help only if it moved. */
const char *ptr = help_text;
switch (kbinput) {
#ifndef DISABLE_MOUSE
case KEY_MOUSE:
{
int mouse_x, mouse_y;
get_mouseinput(&mouse_x, &mouse_y, TRUE);
}
break;
#endif
case NANO_PREVPAGE_KEY:
case NANO_PREVPAGE_FKEY:
if (line > 0) {
line -= editwinrows - 2;
if (line < 0)
line = 0;
}
break;
case NANO_NEXTPAGE_KEY:
case NANO_NEXTPAGE_FKEY:
if (!no_more)
line += editwinrows - 2;
break;
case NANO_PREVLINE_KEY:
if (line > 0)
line--;
break;
case NANO_NEXTLINE_KEY:
if (!no_more)
line++;
break;
}
if (kbinput == NANO_REFRESH_KEY)
total_redraw();
else {
if (line == old_line && kbinput != ERR)
goto skip_redisplay;
blank_edit();
}
/* Calculate where in the text we should be, based on the
* page. */
for (i = 0; i < line; i++) {
ptr += help_line_len(ptr);
if (*ptr == '\n')
ptr++;
}
for (i = 0; i < editwinrows && *ptr != '\0'; i++) {
size_t j = help_line_len(ptr);
mvwaddnstr(edit, i, 0, ptr, j);
ptr += j;
if (*ptr == '\n')
ptr++;
}
no_more = (*ptr == '\0');
skip_redisplay:
kbinput = get_kbinput(edit, &meta_key, &func_key);
} while (kbinput != NANO_EXIT_KEY && kbinput != NANO_EXIT_FKEY);
#ifndef DISABLE_MOUSE
currshortcut = oldshortcut;
#endif
if (old_no_help) {
blank_bottombars();
wnoutrefresh(bottomwin);
SET(NO_HELP);
window_init();
} else
bottombars(currshortcut);
curs_set(1);
edit_refresh();
/* The help_init() at the beginning allocated help_text. Since
* help_text has now been written to the screen, we don't need it
* anymore. */
free(help_text);
help_text = NULL;
}
/* This function allocates help_text, and stores the help string in it.
* help_text should be NULL initially. */
void help_init(void)
{
size_t allocsize = 0; /* Space needed for help_text. */
const char *htx[3]; /* Untranslated help message. We break
* it up into three chunks in case the
* full string is too long for the
* compiler to handle. */
char *ptr;
const shortcut *s;
#ifndef NANO_SMALL
const toggle *t;
#ifdef ENABLE_NANORC
bool old_whitespace = ISSET(WHITESPACE_DISPLAY);
UNSET(WHITESPACE_DISPLAY);
#endif
#endif
/* First, set up the initial help text for the current function. */
if (currshortcut == whereis_list || currshortcut == replace_list ||
currshortcut == replace_list_2) {
htx[0] = N_("Search Command Help Text\n\n "
"Enter the words or characters you would like to "
"search for, and then press Enter. If there is a "
"match for the text you entered, the screen will be "
"updated to the location of the nearest match for the "
"search string.\n\n The previous search string will be "
"shown in brackets after the search prompt. Hitting "
"Enter without entering any text will perform the "
"previous search. ");
htx[1] = N_("If you have selected text with the mark and then "
"search to replace, only matches in the selected text "
"will be replaced.\n\n The following function keys are "
"available in Search mode:\n\n");
htx[2] = NULL;
} else if (currshortcut == gotoline_list) {
htx[0] = N_("Go To Line Help Text\n\n "
"Enter the line number that you wish to go to and hit "
"Enter. If there are fewer lines of text than the "
"number you entered, you will be brought to the last "
"line of the file.\n\n The following function keys are "
"available in Go To Line mode:\n\n");
htx[1] = NULL;
htx[2] = NULL;
} else if (currshortcut == insertfile_list) {
htx[0] = N_("Insert File Help Text\n\n "
"Type in the name of a file to be inserted into the "
"current file buffer at the current cursor "
"location.\n\n If you have compiled nano with multiple "
"file buffer support, and enable multiple file buffers "
"with the -F or --multibuffer command line flags, the "
"Meta-F toggle, or a nanorc file, inserting a file "
"will cause it to be loaded into a separate buffer "
"(use Meta-< and > to switch between file buffers). ");
htx[1] = N_("If you need another blank buffer, do not enter "
"any filename, or type in a nonexistent filename at "
"the prompt and press Enter.\n\n The following "
"function keys are available in Insert File mode:\n\n");
htx[2] = NULL;
} else if (currshortcut == writefile_list) {
htx[0] = N_("Write File Help Text\n\n "
"Type the name that you wish to save the current file "
"as and press Enter to save the file.\n\n If you have "
"selected text with the mark, you will be prompted to "
"save only the selected portion to a separate file. To "
"reduce the chance of overwriting the current file with "
"just a portion of it, the current filename is not the "
"default in this mode.\n\n The following function keys "
"are available in Write File mode:\n\n");
htx[1] = NULL;
htx[2] = NULL;
}
#ifndef DISABLE_BROWSER
else if (currshortcut == browser_list) {
htx[0] = N_("File Browser Help Text\n\n "
"The file browser is used to visually browse the "
"directory structure to select a file for reading "
"or writing. You may use the arrow keys or Page Up/"
"Down to browse through the files, and S or Enter to "
"choose the selected file or enter the selected "
"directory. To move up one level, select the "
"directory called \"..\" at the top of the file "
"list.\n\n The following function keys are available "
"in the file browser:\n\n");
htx[1] = NULL;
htx[2] = NULL;
} else if (currshortcut == gotodir_list) {
htx[0] = N_("Browser Go To Directory Help Text\n\n "
"Enter the name of the directory you would like to "
"browse to.\n\n If tab completion has not been "
"disabled, you can use the Tab key to (attempt to) "
"automatically complete the directory name.\n\n The "
"following function keys are available in Browser Go "
"To Directory mode:\n\n");
htx[1] = NULL;
htx[2] = NULL;
}
#endif
#ifndef DISABLE_SPELLER
else if (currshortcut == spell_list) {
htx[0] = N_("Spell Check Help Text\n\n "
"The spell checker checks the spelling of all text in "
"the current file. When an unknown word is "
"encountered, it is highlighted and a replacement can "
"be edited. It will then prompt to replace every "
"instance of the given misspelled word in the current "
"file, or, if you have selected text with the mark, in "
"the selected text.\n\n The following other functions "
"are available in Spell Check mode:\n\n");
htx[1] = NULL;
htx[2] = NULL;
}
#endif
#ifndef NANO_SMALL
else if (currshortcut == extcmd_list) {
htx[0] = N_("Execute Command Help Text\n\n "
"This menu allows you to insert the output of a "
"command run by the shell into the current buffer (or "
"a new buffer in multiple file buffer mode). If you "
"need another blank buffer, do not enter any "
"command.\n\n The following keys are available in "
"Execute Command mode:\n\n");
htx[1] = NULL;
htx[2] = NULL;
}
#endif
else {
/* Default to the main help list. */
htx[0] = N_(" nano help text\n\n "
"The nano editor is designed to emulate the "
"functionality and ease-of-use of the UW Pico text "
"editor. There are four main sections of the editor. "
"The top line shows the program version, the current "
"filename being edited, and whether or not the file "
"has been modified. Next is the main editor window "
"showing the file being edited. The status line is "
"the third line from the bottom and shows important "
"messages. The bottom two lines show the most "
"commonly used shortcuts in the editor.\n\n ");
htx[1] = N_("The notation for shortcuts is as follows: "
"Control-key sequences are notated with a caret (^) "
"symbol and can be entered either by using the Control "
"(Ctrl) key or pressing the Escape (Esc) key twice. "
"Escape-key sequences are notated with the Meta (M) "
"symbol and can be entered using either the Esc, Alt, "
"or Meta key depending on your keyboard setup. ");
htx[2] = N_("Also, pressing Esc twice and then typing a "
"three-digit decimal number from 000 to 255 will enter "
"the character with the corresponding value. The "
"following keystrokes are available in the main editor "
"window. Alternative keys are shown in "
"parentheses:\n\n");
}
htx[0] = _(htx[0]);
if (htx[1] != NULL)
htx[1] = _(htx[1]);
if (htx[2] != NULL)
htx[2] = _(htx[2]);
allocsize += strlen(htx[0]);
if (htx[1] != NULL)
allocsize += strlen(htx[1]);
if (htx[2] != NULL)
allocsize += strlen(htx[2]);
/* The space needed for the shortcut lists, at most COLS characters,
* plus '\n'. */
allocsize += (COLS < 24 ? (24 * mb_cur_max()) :
((COLS + 1) * mb_cur_max())) * length_of_list(currshortcut);
#ifndef NANO_SMALL
/* If we're on the main list, we also count the toggle help text.
* Each line has "M-%c\t\t\t", which fills 24 columns, plus a space,
* plus translated text, plus '\n'. */
if (currshortcut == main_list) {
size_t endis_len = strlen(_("enable/disable"));
for (t = toggles; t != NULL; t = t->next)
allocsize += 8 + strlen(t->desc) + endis_len;
}
#endif
/* help_text has been freed and set to NULL unless the user resized
* while in the help screen. */
if (help_text != NULL)
free(help_text);
/* Allocate space for the help text. */
help_text = charalloc(allocsize + 1);
/* Now add the text we want. */
strcpy(help_text, htx[0]);
if (htx[1] != NULL)
strcat(help_text, htx[1]);
if (htx[2] != NULL)
strcat(help_text, htx[2]);
ptr = help_text + strlen(help_text);
/* Now add our shortcut info. Assume that each shortcut has, at the
* very least, an equivalent control key, an equivalent primary meta
* key sequence, or both. Also assume that the meta key values are
* not control characters. We can display a maximum of 3 shortcut
* entries. */
for (s = currshortcut; s != NULL; s = s->next) {
int entries = 0;
/* Control key. */
if (s->ctrlval != NANO_NO_KEY) {
entries++;
/* Yucky sentinel values that we can't handle a better
* way. */
if (s->ctrlval == NANO_CONTROL_SPACE) {
char *space_ptr = display_string(_("Space"), 0, 6,
FALSE);
ptr += sprintf(ptr, "^%s", space_ptr);
free(space_ptr);
} else if (s->ctrlval == NANO_CONTROL_8)
ptr += sprintf(ptr, "^?");
/* Normal values. */
else
ptr += sprintf(ptr, "^%c", s->ctrlval + 64);
*(ptr++) = '\t';
}
/* Function key. */
if (s->funcval != NANO_NO_KEY) {
entries++;
/* If this is the first entry, put it in the middle. */
if (entries == 1) {
entries++;
*(ptr++) = '\t';
}
ptr += sprintf(ptr, "(F%d)", s->funcval - KEY_F0);
*(ptr++) = '\t';
}
/* Primary meta key sequence. If it's the first entry, don't
* put parentheses around it. */
if (s->metaval != NANO_NO_KEY) {
entries++;
/* If this is the last entry, put it at the end. */
if (entries == 2 && s->miscval == NANO_NO_KEY) {
entries++;
*(ptr++) = '\t';
}
/* Yucky sentinel values that we can't handle a better
* way. */
if (s->metaval == NANO_ALT_SPACE && entries == 1) {
char *space_ptr = display_string(_("Space"), 0, 5,
FALSE);
ptr += sprintf(ptr, "M-%s", space_ptr);
free(space_ptr);
} else
/* Normal values. */
ptr += sprintf(ptr, (entries == 1) ? "M-%c" : "(M-%c)",
toupper(s->metaval));
*(ptr++) = '\t';
}
/* Miscellaneous meta key sequence. */
if (entries < 3 && s->miscval != NANO_NO_KEY) {
entries++;
/* If this is the last entry, put it at the end. */
if (entries == 2) {
entries++;
*(ptr++) = '\t';
}
ptr += sprintf(ptr, "(M-%c)", toupper(s->miscval));
*(ptr++) = '\t';
}
/* Make sure all the help text starts at the same place. */
while (entries < 3) {
entries++;
*(ptr++) = '\t';
}
assert(s->help != NULL);
if (COLS > 24) {
char *help_ptr = display_string(s->help, 0, COLS - 24,
FALSE);
ptr += sprintf(ptr, help_ptr);
free(help_ptr);
}
ptr += sprintf(ptr, "\n");
}
#ifndef NANO_SMALL
/* And the toggles... */
if (currshortcut == main_list) {
for (t = toggles; t != NULL; t = t->next) {
assert(t->desc != NULL);
ptr += sprintf(ptr, "M-%c\t\t\t%s %s\n", toupper(t->val),
t->desc, _("enable/disable"));
}
}
#ifdef ENABLE_NANORC
if (old_whitespace)
SET(WHITESPACE_DISPLAY);
#endif
#endif
/* If all went well, we didn't overwrite the allocated space for
* help_text. */
assert(strlen(help_text) <= allocsize + 1);
}
/* Calculate the next line of help_text, starting at ptr. */
size_t help_line_len(const char *ptr)
{
int help_cols = (COLS > 24) ? COLS - 8 : 24;
/* Try to break the line at (COLS - 8) columns if we have more than
* 24 columns, and at 24 columns otherwise. */
size_t retval = break_line(ptr, help_cols, TRUE);
size_t retval_save = retval;
/* Get the length of the entire line up to a null or a newline. */
while (*(ptr + retval) != '\0' && *(ptr + retval) != '\n')
retval += move_mbright(ptr + retval, 0);
/* If the entire line doesn't go more than 8 columns beyond where we
* tried to break it, we should display it as-is. Otherwise, we
* should display it only up to the break. */
if (strnlenpt(ptr, retval) > help_cols + 8)
retval = retval_save;
return retval;
}
#endif /* !DISABLE_HELP */