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gtkspell.c

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/* gtkspell - a spell-checking addon for GtkText
 * Copyright (c) 2000 Evan Martin.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
 */

#include "intl.h"
#include <gtk/gtk.h>

#include <sys/types.h>
#ifndef __MINGW32__
#include <sys/wait.h>

#if HAVE_POLL_H
#include <sys/poll.h>
#endif
#endif
#include <unistd.h>   
#include <stdio.h>    
#include <signal.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

/* TODO:
 * handle dictionary changes
 * asynchronous lookups
 */

/* size of the text buffer used in various word-processing routines. */
#define BUFSIZE 1024
/* number of suggestions to display on each menu. */
#define MENUCOUNT 20
#define BUGEMAIL "gtkspell-devel@lists.sourceforge.net"

/* because we keep only one copy of the spell program running, 
 * all ispell-related variables can be static.  
 */
static pid_t spell_pid = -1;
static int fd_write[2], fd_read[2];
static int signal_set_up = 0;

/* FIXME? */
static GdkColor highlight = { 0, 255*256, 0, 0 };

static void entry_insert_cb(GtkText *gtktext, 
        gchar *newtext, guint len, guint *ppos, gpointer d);
static void set_up_signal();

int gtkspell_running() {
    return (spell_pid > 0);
}

static void error_print(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    fprintf(stderr, "gtkspell: ");
    vfprintf(stderr, fmt, ap);
    va_end(ap);
}

/* functions to interface with pipe */
static void writetext(char *text) {
    write(fd_write[1], text, strlen(text));
}
static int readpipe(char *buf, int bufsize) {
    int len;
    len = read(fd_read[0], buf, bufsize-1);
    if (len < 0) {
        error_print("read: %s\n", strerror(errno));
        return -1;
    } else if (len == 0) {
        error_print("pipe closed.\n");
        return -1;
    } else if (len == bufsize-1) {
        error_print("buffer overflowed?\n");
    }

    buf[len] = 0;
    return len;
}
static int readline(char *buf) {
    return readpipe(buf, BUFSIZE);
}

static int readresponse(char *buf) {
    int len;
    len = readpipe(buf, BUFSIZE);

    /* all ispell responses of any reasonable length should end in \n\n.
     * depending on the speed of the spell checker, this may require more
     * reading. */
    if (len >= 2 && (buf[len-1] != '\n' || buf[len-2] != '\n')) {
        len += readpipe(buf+len, BUFSIZE-len);
    }

    /* now we can remove all of the the trailing newlines. */
    while (len > 0 && buf[len-1] == '\n')
        buf[--len] = 0;

    return len;
}


void gtkspell_stop() {
#ifndef __MINGW32__
    if (gtkspell_running()) {
        kill(spell_pid, SIGQUIT); /* FIXME: is this the correct signal? */
        spell_pid = -1;
    }
#endif
}

int gtkspell_start(char *path, char * args[]) {
#ifndef __MINGW32__
    int fd_error[2];
    char buf[BUFSIZE];

    if (gtkspell_running()) {
        error_print("gtkspell_start called while already running.\n");
        gtkspell_stop();
    }

    if (!signal_set_up) {
        set_up_signal();
        signal_set_up = 1;
    }

    pipe(fd_write);
    pipe(fd_read);
    pipe(fd_error);

    spell_pid = fork();
    if (spell_pid < 0) {
        error_print("fork: %s\n", strerror(errno));
        return -1;
    } else if (spell_pid == 0) {
        dup2(fd_write[0], 0);
        dup2(fd_read[1], 1);
        dup2(fd_error[1], 2);
        close(fd_read[0]);
        close(fd_error[0]);
        close(fd_write[1]);

        if (path == NULL) {
            if (execvp(args[0], args) < 0) 
                error_print("execvp('%s'): %s\n", args[0], strerror(errno));
        } else {
            if (execv(path, args) < 0) 
                error_print("execv('%s'): %s\n", path, strerror(errno));
        }
        /* if we get here, we failed.
         * send some text on the pipe to indicate status.
         */
        write(fd_read[1], "!", 1);

        _exit(0);
    } else {
        /* there are at least two ways to fail:
         * - the exec() can fail
         * - the exec() can succeed, but the program can dump the help screen
         * we must check for both.
         */

        #if HAVE_POLL_H
        struct pollfd fds[2];

        fds[0].fd = fd_error[0];
        fds[0].events = POLLIN | POLLERR;
        fds[1].fd = fd_read[0];
        fds[1].events = POLLIN | POLLERR;
        if (poll(fds, 2, 2000) <= 0) {
            /* FIXME: is this needed? */
            error_print("Timed out waiting for spell command.\n");
            gtkspell_stop();
            return -1;
        }
        

        if (fds[0].revents) { /* stderr readable? */
            error_print("Spell command printed on stderr -- probably failed.\n");
            gtkspell_stop();
            return -1;
        }
        
        #endif
        
        readline(buf);
        /* ispell should print something like this:
         * @(#) International Ispell Version 3.1.20 10/10/95
         * if it doesn't, it's an error. */
        if (buf[0] != '@') {
            gtkspell_stop();
            return -1;
        }
    }

    /* put ispell into terse mode.  
     * this makes it not respond on correctly spelled words. */
    sprintf(buf, "!\n");
    writetext(buf);
#endif
    return 0;
}

static GList* misspelled_suggest(char *word) {
    char buf[BUFSIZE];
    char *newword;
    GList *l = NULL;
    int count;

    sprintf(buf, "^%s\n", word); /* guard against ispell control chars */
    writetext(buf);
    readresponse(buf);

    switch (buf[0]) { /* first char is ispell command. */
        case 0: /* no response: word is ok. */
            return NULL;
        case '&': /* misspelled, with suggestions */
            /* & <orig> <count> <ofs>: <miss>, <miss>, <guess>, ... */
            strtok(buf, " "); /* & */
            newword = strtok(NULL, " "); /* orig */
            l = g_list_append(l, g_strdup(newword));
            newword = strtok(NULL, " "); /* count */
            count = atoi(newword);
            strtok(NULL, " "); /* ofs: */

            while ((newword = strtok(NULL, ",")) != NULL) {
                int len = strlen(newword);
                if (newword[len-1] == ' ' || newword[len-1] == '\n') 
                    newword[len-1] = 0;
                if (count == 0) {
                    g_list_append(l, NULL); /* signal the "suggestions" */
                }
                /* add it to the list, skipping the initial space. */
                l = g_list_append(l, 
                        g_strdup(newword[0] == ' ' ? newword+1 : newword));

                count--;
            }
            return l;

        case '#': /* misspelled, no suggestions */
            /* # <orig> <ofs> */
            strtok(buf, " "); /* & */
            newword = strtok(NULL, " "); /* orig */
            l = g_list_append(l, g_strdup(newword));
            return l;
        default:
            error_print("Unsupported spell command '%c'.\n"
                    "This is a bug; mail " BUGEMAIL " about it.\n", buf[0]);
    }
    return NULL;
}

static int misspelled_test(char *word) {
    char buf[BUFSIZE];
    sprintf(buf, "^%s\n", word); /* guard against ispell control chars */
    writetext(buf);
    readresponse(buf);

    if (buf[0] == 0) {
        return 0;
    } else if (buf[0] == '&' || buf[0] == '#') {
        return 1;
    }
    
    error_print("Unsupported spell command '%c'.\n"
            "This is a bug; mail " BUGEMAIL " about it.\n", buf[0]);
    return -1;
}

static gboolean iswordsep(char c) {
    return !isalpha(c) && c != '\'';
}

static gboolean get_word_from_pos(GtkText* gtktext, int pos, char* buf, 
        int *pstart, int *pend) {
    gint start, end;

    if (iswordsep(GTK_TEXT_INDEX(gtktext, pos))) return FALSE;

    for (start = pos; start >= 0; --start) {
        if (iswordsep(GTK_TEXT_INDEX(gtktext, start))) break;
    }
    start++;

    for (end = pos; end <= gtk_text_get_length(gtktext); end++) {
        if (iswordsep(GTK_TEXT_INDEX(gtktext, end))) break;
    }

    if (buf) {
        for (pos = start; pos < end; pos++) 
            buf[pos-start] = GTK_TEXT_INDEX(gtktext, pos);
        buf[pos-start] = 0;
    }

    if (pstart) *pstart = start;
    if (pend) *pend = end;

    return TRUE;
}

static gboolean get_curword(GtkText* gtktext, char* buf, 
        int *pstart, int *pend) {
    int pos = gtk_editable_get_position(GTK_EDITABLE(gtktext));
    return get_word_from_pos(gtktext, pos, buf, pstart, pend);
}

static void change_color(GtkText *gtktext, 
        int start, int end, GdkColor *color) {
    char *newtext = gtk_editable_get_chars(GTK_EDITABLE(gtktext), start, end);
    gtk_text_freeze(gtktext);
    gtk_signal_handler_block_by_func(GTK_OBJECT(gtktext), 
            GTK_SIGNAL_FUNC(entry_insert_cb), NULL);
    
    gtk_text_set_point(gtktext, start);

    if(newtext && end-start > 0)
    {
        gtk_text_forward_delete(gtktext, end-start);
        gtk_text_insert(gtktext, NULL, color, NULL, newtext, end-start);
    }

    gtk_signal_handler_unblock_by_func(GTK_OBJECT(gtktext), 
            GTK_SIGNAL_FUNC(entry_insert_cb), NULL);
    gtk_text_thaw(gtktext);
    g_free(newtext);
}

static gboolean check_at(GtkText *gtktext, int from_pos) {
    int start, end;
    char buf[BUFSIZE];

    if (!get_word_from_pos(gtktext, from_pos, buf, &start, &end)) {
        return FALSE;
    }

    if (misspelled_test(buf)) {
        if (highlight.pixel == 0) {
            /* add an entry for the highlight in the color map. */
            GdkColormap *gc = gtk_widget_get_colormap(GTK_WIDGET(gtktext));
            gdk_colormap_alloc_color(gc, &highlight, FALSE, TRUE);;
        }
        change_color(gtktext, start, end, &highlight);
        return TRUE;
    } else { 
        change_color(gtktext, start, end, 
                &(GTK_WIDGET(gtktext)->style->fg[0]));
        return FALSE;
    }
}

void gtkspell_check_all(GtkText *gtktext) {
    guint origpos;
    guint pos = 0;
    guint len;
    float adj_value;
    
    if (!gtkspell_running()) return;
    
    len = gtk_text_get_length(gtktext);

    adj_value = gtktext->vadj->value;
    gtk_text_freeze(gtktext);
    origpos = gtk_editable_get_position(GTK_EDITABLE(gtktext));
    while (pos < len) {
        while (pos < len && iswordsep(GTK_TEXT_INDEX(gtktext, pos)))
            pos++;
        while (pos < len && !iswordsep(GTK_TEXT_INDEX(gtktext, pos)))
            pos++;
        if (pos > 0)
            check_at(gtktext, pos-1);
    }
    gtk_text_thaw(gtktext);
    gtk_editable_set_position(GTK_EDITABLE(gtktext), origpos);
}

static void entry_insert_cb(GtkText *gtktext, 
        gchar *newtext, guint len, guint *ppos, gpointer d) {
    int origpos;

    if (!gtkspell_running()) return;

    gtk_signal_handler_block_by_func(GTK_OBJECT(gtktext),
                                     GTK_SIGNAL_FUNC(entry_insert_cb),
                                     NULL);
    gtk_text_insert(GTK_TEXT(gtktext), NULL,
            &(GTK_WIDGET(gtktext)->style->fg[0]), NULL, newtext, len);
    gtk_signal_handler_unblock_by_func(GTK_OBJECT(gtktext),
                                     GTK_SIGNAL_FUNC(entry_insert_cb),
                                     NULL);
    gtk_signal_emit_stop_by_name(GTK_OBJECT(gtktext), "insert-text");
    *ppos += len;

    origpos = gtk_editable_get_position(GTK_EDITABLE(gtktext));

    if (iswordsep(newtext[0])) {
        /* did we just end a word? */
        if (*ppos >= 2) check_at(gtktext, *ppos-2);

        /* did we just split a word? */
        if (*ppos < gtk_text_get_length(gtktext))
            check_at(gtktext, *ppos+1);
    } else {
        /* check as they type, *except* if they're typing at the end (the most
         * common case.
         */
        if (*ppos < gtk_text_get_length(gtktext) && 
                !iswordsep(GTK_TEXT_INDEX(gtktext, *ppos)))
            check_at(gtktext, *ppos-1);
    }

    gtk_editable_set_position(GTK_EDITABLE(gtktext), origpos);
}

static void entry_delete_cb(GtkText *gtktext,
        gint start, gint end, gpointer d) {
    int origpos;

    if (!gtkspell_running()) return;

    origpos = gtk_editable_get_position(GTK_EDITABLE(gtktext));
    check_at(gtktext, start-1);
    gtk_editable_set_position(GTK_EDITABLE(gtktext), origpos);
    gtk_editable_select_region(GTK_EDITABLE(gtktext), origpos, origpos);
    /* this is to *UNDO* the selection, in case they were holding shift
     * while hitting backspace. */
}

static void replace_word(GtkWidget *w, gpointer d) {
    int start, end, newword_len;
    char *newword;
    char buf[BUFSIZE];

    /* we don't save their position, 
     * because the cursor is moved by the click. */

    gtk_text_freeze(GTK_TEXT(d));

    gtk_label_get(GTK_LABEL(GTK_BIN(w)->child), &newword);
    get_curword(GTK_TEXT(d), buf, &start, &end);

    newword_len = strlen(newword);

    gtk_text_set_point(GTK_TEXT(d), end);
    gtk_text_backward_delete(GTK_TEXT(d), end-start);
    gtk_text_insert(GTK_TEXT(d), NULL, NULL, NULL, newword, newword_len);

    gtk_text_thaw(GTK_TEXT(d));

    gtk_editable_set_position(GTK_EDITABLE(d), start+newword_len);
}

static GtkMenu *make_menu(GList *l, GtkText *gtktext) {
    GtkWidget *menu, *item;
    char *caption;
    menu = gtk_menu_new(); {
        caption = g_strdup_printf("Not in dictionary: %s", (char*)l->data);
        item = gtk_menu_item_new_with_label(caption);
        /* I'd like to make it so this item is never selectable, like
         * the menu titles in the GNOME panel... unfortunately, the GNOME
         * panel creates their own custom widget to do this! */
        gtk_widget_show(item);
        gtk_menu_append(GTK_MENU(menu), item);

        item = gtk_menu_item_new();
        gtk_widget_show(item);
        gtk_menu_append(GTK_MENU(menu), item);

        l = l->next;
        if (l == NULL) {
            item = gtk_menu_item_new_with_label("(no suggestions)");
            gtk_widget_show(item);
            gtk_menu_append(GTK_MENU(menu), item);
        } else {
            GtkWidget *curmenu = menu;
            int count = 0;
            do {
                if (l->data == NULL && l->next != NULL) {
                    count = 0;
                    curmenu = gtk_menu_new();
                    item = gtk_menu_item_new_with_label("Other Possibilities...");
                    gtk_widget_show(item);
                    gtk_menu_item_set_submenu(GTK_MENU_ITEM(item), curmenu);
                    gtk_menu_append(GTK_MENU(curmenu), item);
                    l = l->next;
                } else if (count > MENUCOUNT) {
                    count -= MENUCOUNT;
                    item = gtk_menu_item_new_with_label("More...");
                    gtk_widget_show(item);
                    gtk_menu_append(GTK_MENU(curmenu), item);
                    curmenu = gtk_menu_new();
                    gtk_menu_item_set_submenu(GTK_MENU_ITEM(item), curmenu);
                }
                item = gtk_menu_item_new_with_label((char*)l->data);
                gtk_signal_connect(GTK_OBJECT(item), "activate",
                        GTK_SIGNAL_FUNC(replace_word), gtktext);
                gtk_widget_show(item);
                gtk_menu_append(GTK_MENU(curmenu), item);
                count++;
            } while ((l = l->next) != NULL);
        }
    }
    return GTK_MENU(menu);
}

static void popup_menu(GtkText *gtktext, GdkEventButton *eb) {
    char buf[BUFSIZE];
    GList *list, *l;

    get_curword(gtktext, buf, NULL, NULL);

    list = misspelled_suggest(buf);
    if (list != NULL) {
        gtk_menu_popup(make_menu(list, gtktext), NULL, NULL, NULL, NULL,
                eb->button, eb->time);
        for (l = list; l != NULL; l = l->next)
            g_free(l->data);
        g_list_free(list);
    }
}

/* ok, this is pretty wacky:
 * we need to let the right-mouse-click go through, so it moves the cursor, 
 * but we *can't* let it go through, because GtkText interprets rightclicks as
 * weird selection modifiers.
 *
 * so what do we do?  forge rightclicks as leftclicks, then popup the menu. 
 * HACK HACK HACK. 
 */
static gint button_press_intercept_cb(GtkText *gtktext, GdkEvent *e, gpointer d) {
    GdkEventButton *eb;
    gboolean retval;

    if (!gtkspell_running()) return FALSE;

    if (e->type != GDK_BUTTON_PRESS) return FALSE;
    eb = (GdkEventButton*) e;

    if (eb->button != 3) return FALSE;

    /* forge the leftclick */
    eb->button = 1;

    gtk_signal_handler_block_by_func(GTK_OBJECT(gtktext), 
            GTK_SIGNAL_FUNC(button_press_intercept_cb), d);
    gtk_signal_emit_by_name(GTK_OBJECT(gtktext), "button-press-event",
            e, &retval);
    gtk_signal_handler_unblock_by_func(GTK_OBJECT(gtktext), 
            GTK_SIGNAL_FUNC(button_press_intercept_cb), d);
    gtk_signal_emit_stop_by_name(GTK_OBJECT(gtktext), "button-press-event");

    /* now do the menu wackiness */
    popup_menu(gtktext, eb);
    return TRUE;
}

void gtkspell_uncheck_all(GtkText *gtktext) {
    int origpos;
    char *text;
    float adj_value;

    adj_value = gtktext->vadj->value;
    gtk_text_freeze(gtktext);
    origpos = gtk_editable_get_position(GTK_EDITABLE(gtktext));
    text = gtk_editable_get_chars(GTK_EDITABLE(gtktext), 0, -1);
    gtk_text_set_point(gtktext, 0);
    gtk_text_forward_delete(gtktext, gtk_text_get_length(gtktext));
    gtk_text_insert(gtktext, NULL, NULL, NULL, text, strlen(text));
    gtk_text_thaw(gtktext);

    gtk_editable_set_position(GTK_EDITABLE(gtktext), origpos);
    gtk_adjustment_set_value(gtktext->vadj, adj_value);
}

void gtkspell_attach(GtkText *gtktext) {
    gtk_signal_connect(GTK_OBJECT(gtktext), "insert-text",
        GTK_SIGNAL_FUNC(entry_insert_cb), NULL);
    gtk_signal_connect_after(GTK_OBJECT(gtktext), "delete-text",
        GTK_SIGNAL_FUNC(entry_delete_cb), NULL);
    gtk_signal_connect(GTK_OBJECT(gtktext), "button-press-event",
            GTK_SIGNAL_FUNC(button_press_intercept_cb), NULL);
}

void gtkspell_detach(GtkText *gtktext) {
    gtk_signal_disconnect_by_func(GTK_OBJECT(gtktext),
        GTK_SIGNAL_FUNC(entry_insert_cb), NULL);
    gtk_signal_disconnect_by_func(GTK_OBJECT(gtktext),
        GTK_SIGNAL_FUNC(entry_delete_cb), NULL);
    gtk_signal_disconnect_by_func(GTK_OBJECT(gtktext), 
            GTK_SIGNAL_FUNC(button_press_intercept_cb), NULL);

    gtkspell_uncheck_all(gtktext);
}

static void sigchld(int param) {
#ifndef __MINGW32__
    if (gtkspell_running() &&
        (waitpid(spell_pid, NULL, WNOHANG) == spell_pid)) {
        spell_pid = 0;
    } else {
        /* a default SIGCHLD handler.
         * what else to do here? */
        waitpid(-1, NULL, WNOHANG);
    }
#endif
}

static void set_up_signal() {
#ifndef __MINGW32__
    struct sigaction sigact;
    memset(&sigact, 0, sizeof(struct sigaction));

    sigact.sa_handler = sigchld;
    sigaction(SIGCHLD, &sigact, NULL);
#endif
}

---

Contact: Andy Maloney     [Documentation generated by doxygen]