path: root/widgets/text/e-completion.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/* ECompletion - A base class for text completion.
 * Copyright (C) 2000, 2001 Ximian, Inc.
 *
 * Author: Miguel de Icaza <miguel@ximian.com>
 * Adapted by Jon Trowbridge <trow@ximian.com>
 *
 */

/*
 * 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 of the
 * License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */


#include <config.h>
#include <string.h> /* strcmp() */
#include <gtk/gtk.h>
#include "e-completion.h"

enum {
    E_COMPLETION_BEGIN_COMPLETION,
    E_COMPLETION_COMPLETION,
    E_COMPLETION_RESTART_COMPLETION,
    E_COMPLETION_CANCEL_COMPLETION,
    E_COMPLETION_END_COMPLETION,
    E_COMPLETION_LAST_SIGNAL
};

static guint e_completion_signals[E_COMPLETION_LAST_SIGNAL] = { 0 };

typedef struct _Match Match;
struct _Match {
    gchar *text;
    double score;
    gpointer extra_data;
    GtkDestroyNotify extra_destroy;
};

struct _ECompletionPrivate {
    gboolean searching;
    gchar *search_text;
    gint pos;
    gint limit;
    gint match_count;
    GList *matches;
    double min_score, max_score;
};

static void e_completion_class_init (ECompletionClass *klass);
static void e_completion_init       (ECompletion *complete);
static void e_completion_destroy    (GtkObject *object);

static Match *match_new       (const gchar *txt, double score, gpointer extra_data, GtkDestroyNotify extra_destroy);
static void   match_free      (Match *);
static void   match_list_free (GList *);

static void     e_completion_add_match     (ECompletion *complete, const gchar *txt, double score, gpointer extra_data, GtkDestroyNotify);
static void     e_completion_clear_matches (ECompletion *complete);
static gboolean e_completion_sort_by_score (ECompletion *complete);
static void     e_completion_restart       (ECompletion *complete);

static GtkObjectClass *parent_class;



GtkType
e_completion_get_type (void)
{
    static GtkType complete_type = 0;
  
    if (!complete_type) {
        GtkTypeInfo complete_info = {
            "ECompletion",
            sizeof (ECompletion),
            sizeof (ECompletionClass),
            (GtkClassInitFunc) e_completion_class_init,
            (GtkObjectInitFunc) e_completion_init,
            NULL, NULL, /* reserved */
            (GtkClassInitFunc) NULL
        };

        complete_type = gtk_type_unique (gtk_object_get_type (), &complete_info);
    }

    return complete_type;
}

static void
e_completion_class_init (ECompletionClass *klass)
{
    GtkObjectClass *object_class = (GtkObjectClass *) klass;

    parent_class = GTK_OBJECT_CLASS (gtk_type_class (gtk_object_get_type ()));

    e_completion_signals[E_COMPLETION_BEGIN_COMPLETION] =
        gtk_signal_new ("begin_completion",
                GTK_RUN_LAST,
                object_class->type,
                GTK_SIGNAL_OFFSET (ECompletionClass, begin_completion),
                gtk_marshal_NONE__POINTER_INT_INT,
                GTK_TYPE_NONE, 3,
                GTK_TYPE_POINTER, GTK_TYPE_INT, GTK_TYPE_INT);

    e_completion_signals[E_COMPLETION_COMPLETION] =
        gtk_signal_new ("completion",
                GTK_RUN_LAST,
                object_class->type,
                GTK_SIGNAL_OFFSET (ECompletionClass, completion),
                gtk_marshal_NONE__POINTER_POINTER,
                GTK_TYPE_NONE, 2,
                GTK_TYPE_POINTER, GTK_TYPE_POINTER);

    e_completion_signals[E_COMPLETION_RESTART_COMPLETION] =
        gtk_signal_new ("restart_completion",
                GTK_RUN_LAST,
                object_class->type,
                GTK_SIGNAL_OFFSET (ECompletionClass, restart_completion),
                gtk_marshal_NONE__NONE,
                GTK_TYPE_NONE, 0);

    e_completion_signals[E_COMPLETION_CANCEL_COMPLETION] =
        gtk_signal_new ("cancel_completion",
                GTK_RUN_LAST,
                object_class->type,
                GTK_SIGNAL_OFFSET (ECompletionClass, cancel_completion),
                gtk_marshal_NONE__NONE,
                GTK_TYPE_NONE, 0);

    e_completion_signals[E_COMPLETION_END_COMPLETION] =
        gtk_signal_new ("end_completion",
                GTK_RUN_LAST,
                object_class->type,
                GTK_SIGNAL_OFFSET (ECompletionClass, end_completion),
                gtk_marshal_NONE__NONE,
                GTK_TYPE_NONE, 0);

    gtk_object_class_add_signals (object_class, e_completion_signals, E_COMPLETION_LAST_SIGNAL);

    object_class->destroy = e_completion_destroy;
}

static void
e_completion_init (ECompletion *complete)
{
    complete->priv = g_new0 (struct _ECompletionPrivate, 1);
}

static void
e_completion_destroy (GtkObject *object)
{
    ECompletion *complete = E_COMPLETION (object);

    g_free (complete->priv->search_text);
    complete->priv->search_text = NULL;

    e_completion_clear_matches (complete);

    g_free (complete->priv);
    complete->priv = NULL;

    if (parent_class->destroy)
        (parent_class->destroy) (object);
}

static Match *
match_new (const gchar *text, double score, gpointer extra_data, GtkDestroyNotify extra_destroy)
{
    Match *m;

    if (text == NULL)
        return NULL;

    m = g_new (Match, 1);
    m->text = g_strdup (text);
    m->score = score;
    m->extra_data = extra_data;
    m->extra_destroy = extra_destroy;
    
    return m;
}

static void
match_free (Match *m)
{
    if (m) {
        g_free (m->text);
        if (m->extra_destroy)
            m->extra_destroy (m->extra_data);
        g_free (m);
    }
}

static void
match_list_free (GList *i)
{
    while (i) {
        match_free ( (Match *) i->data );
        i = g_list_next (i);
    }
}

static void
e_completion_add_match (ECompletion *complete, const gchar *txt, double score, gpointer extra_data, GtkDestroyNotify extra_destroy)
{
    complete->priv->matches = g_list_append (complete->priv->matches, match_new (txt, score, extra_data, extra_destroy));

    if (complete->priv->match_count == 0) {

        complete->priv->min_score = complete->priv->max_score = score;
        
    } else {

        complete->priv->min_score = MIN (complete->priv->min_score, score);
        complete->priv->max_score = MAX (complete->priv->max_score, score);

    }

    ++complete->priv->match_count;
}

static void
e_completion_clear_matches (ECompletion *complete)
{
    match_list_free (complete->priv->matches);
    g_list_free (complete->priv->matches);
    complete->priv->matches = NULL;

    complete->priv->match_count = 0;

    complete->priv->min_score = 0;
    complete->priv->max_score = 0;
}

void
e_completion_begin_search (ECompletion *complete, const gchar *text, gint pos, gint limit)
{
    g_return_if_fail (complete != NULL);
    g_return_if_fail (E_IS_COMPLETION (complete));
    g_return_if_fail (text != NULL);

    /* Stop any prior search. */
    if (complete->priv->searching)
        e_completion_cancel_search (complete);

    g_free (complete->priv->search_text);
    complete->priv->search_text = g_strdup (text);

    complete->priv->pos = pos;
    complete->priv->searching = TRUE;

    e_completion_clear_matches (complete);

    complete->priv->limit = limit > 0 ? limit : G_MAXINT;

    gtk_signal_emit (GTK_OBJECT (complete), e_completion_signals[E_COMPLETION_BEGIN_COMPLETION], text, pos, limit);
}

void
e_completion_cancel_search (ECompletion *complete)
{
    g_return_if_fail (complete != NULL);
    g_return_if_fail (E_IS_COMPLETION (complete));

    /* If there is no search to cancel, just silently return. */
    if (!complete->priv->searching)
        return;

    gtk_signal_emit (GTK_OBJECT (complete), e_completion_signals[E_COMPLETION_CANCEL_COMPLETION]);

    complete->priv->searching = FALSE;
}

gboolean
e_completion_searching (ECompletion *complete)
{
    g_return_val_if_fail (complete != NULL, FALSE);
    g_return_val_if_fail (E_IS_COMPLETION (complete), FALSE);

    return complete->priv->searching;
}

const gchar *
e_completion_search_text (ECompletion *complete)
{
    g_return_val_if_fail (complete != NULL, NULL);
    g_return_val_if_fail (E_IS_COMPLETION (complete), NULL);

    return complete->priv->search_text;
}

gint
e_completion_search_text_pos (ECompletion *complete)
{
    g_return_val_if_fail (complete != NULL, -1);
    g_return_val_if_fail (E_IS_COMPLETION (complete), -1);

    return complete->priv->pos;
}

gint
e_completion_match_count (ECompletion *complete)
{
    g_return_val_if_fail (complete != NULL, 0);
    g_return_val_if_fail (E_IS_COMPLETION (complete), 0);

    return complete->priv->match_count;
}

void
e_completion_foreach_match (ECompletion *complete, ECompletionMatchFn fn, gpointer user_data)
{
    GList *i;

    g_return_if_fail (complete != NULL);
    g_return_if_fail (E_IS_COMPLETION (complete));

    if (fn == NULL)
        return;

    for (i = complete->priv->matches; i != NULL; i = g_list_next (i)) {
        Match *m = (Match *) i->data;
        fn (m->text, m->score, m->extra_data, user_data);
    }
}

gpointer
e_completion_find_extra_data (ECompletion *complete, const gchar *text)
{
    GList *i;

    g_return_val_if_fail (complete != NULL, NULL);
    g_return_val_if_fail (E_IS_COMPLETION (complete), NULL);

    for (i = complete->priv->matches; i != NULL; i = g_list_next (i)) {
        Match *m = (Match *) i->data;
        if (strcmp (m->text, text) == 0)
            return m->extra_data;
    }
    
    return NULL;
}

ECompletion *
e_completion_new (void)
{
    return E_COMPLETION (gtk_type_new (e_completion_get_type ()));
}

static gint
score_cmp_fn (gconstpointer a, gconstpointer b)
{
    double sa = ((const Match *) a)->score;
    double sb = ((const Match *) b)->score;
    gint cmp =  (sa < sb) - (sb < sa);
    if (cmp == 0)
        cmp = g_strcasecmp (((const Match *) a)->text, ((const Match *) b)->text);
    return cmp;
}

static gboolean
e_completion_sort_by_score (ECompletion *complete)
{
    GList *sort_list = NULL, *i, *j;
    gboolean diff;
    gint count;

    /* If all scores are equal, there is nothing to do. */
    if (complete->priv->min_score == complete->priv->max_score)
        return FALSE;

    for (i = complete->priv->matches; i != NULL; i = g_list_next (i)) {
        sort_list = g_list_append (sort_list, i->data);
    }

    sort_list = g_list_sort (sort_list, score_cmp_fn);


    diff = FALSE;
    count = 0;
    i = complete->priv->matches;
    j = sort_list;
    while (i && j && !diff && count < complete->priv->limit) {
        
        if (i->data != j->data)
            diff = TRUE;

        i = g_list_next (i);
        j = g_list_next (j);
        ++count;
    }

    g_list_free (complete->priv->matches);
    complete->priv->matches = sort_list;

    return diff;
}

/* Emit a restart signal and re-declare our matches, up to the limit. */
static void
e_completion_restart (ECompletion *complete)
{
    GList *i;
    gint count = 0;

    gtk_signal_emit (GTK_OBJECT (complete), e_completion_signals[E_COMPLETION_RESTART_COMPLETION]);
    
    i = complete->priv->matches;
    while (i != NULL && count < complete->priv->limit) {
        Match *m = (Match *) i->data;
        gtk_signal_emit (GTK_OBJECT (complete), e_completion_signals[E_COMPLETION_COMPLETION], m->text, m->extra_data);

        i = g_list_next (i);
        ++count;
    }
}

void
e_completion_found_match (ECompletion *complete, const gchar *text)
{
    g_return_if_fail (complete);
    g_return_if_fail (E_IS_COMPLETION (complete));
    g_return_if_fail (text != NULL);

    e_completion_found_match_full (complete, text, 0, NULL, NULL);
}

void
e_completion_found_match_full (ECompletion *complete, const gchar *text, double score, gpointer extra_data, GtkDestroyNotify extra_destroy)
{
    g_return_if_fail (complete);
    g_return_if_fail (E_IS_COMPLETION (complete));
    g_return_if_fail (text != NULL);

    if (! complete->priv->searching) {
        g_warning ("e_completion_found_match(...,\"%s\",...) called outside of a search", text);
        return;
    }

    e_completion_add_match (complete, text, score, extra_data, extra_destroy);

    /* For now, do nothing when we hit the limit --- just don't announce the incoming matches. */
    if (complete->priv->match_count >= complete->priv->limit) {
        return;
    }

    gtk_signal_emit (GTK_OBJECT (complete), e_completion_signals[E_COMPLETION_COMPLETION], text, extra_data);
}

void
e_completion_end_search (ECompletion *complete)
{
    g_return_if_fail (complete != NULL);
    g_return_if_fail (E_IS_COMPLETION (complete));
    g_return_if_fail (complete->priv->searching);

    /* If sorting by score accomplishes anything, issue a restart right before we end. */
    if (e_completion_sort_by_score (complete))
        e_completion_restart (complete);

    gtk_signal_emit (GTK_OBJECT (complete), e_completion_signals[E_COMPLETION_END_COMPLETION]);

    complete->priv->searching = FALSE;
}