path: root/lib/ephy-node-filter.c

/* 
 *  Copyright (C) 2002 Olivier Martin <omartin@ifrance.com>
 *            (C) 2002 Jorn Baayen <jorn@nl.linux.org>
 *
 *  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.
 *
 *  $Id$
 */

#include "config.h"

#include <stdlib.h>
#include <string.h>
#include <stdarg.h>

#include "ephy-node-filter.h"

static void ephy_node_filter_class_init (EphyNodeFilterClass *klass);
static void ephy_node_filter_init (EphyNodeFilter *node);
static void ephy_node_filter_finalize (GObject *object);
static gboolean ephy_node_filter_expression_evaluate (EphyNodeFilterExpression *expression,
                              EphyNode *node);

enum
{
    CHANGED,
    LAST_SIGNAL
};

#define EPHY_NODE_FILTER_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE ((object), EPHY_TYPE_NODE_FILTER, EphyNodeFilterPrivate))

struct _EphyNodeFilterPrivate
{
    GPtrArray *levels;
};

struct _EphyNodeFilterExpression
{
    EphyNodeFilterExpressionType type;

    union
    {
        struct
        {
            EphyNode *a;
            EphyNode *b;
        } node_args;

        struct
        {
            int prop_id;

            union
            {
                EphyNode *node;
                char *string;
                int number;
            } second_arg;
        } prop_args;
    } args;
};

static GObjectClass *parent_class = NULL;

static guint ephy_node_filter_signals[LAST_SIGNAL] = { 0 };

GType
ephy_node_filter_get_type (void)
{
    static GType type = 0;

    if (G_UNLIKELY (type == 0))
    {
        static const GTypeInfo our_info =
        {
            sizeof (EphyNodeFilterClass),
            NULL,
            NULL,
            (GClassInitFunc) ephy_node_filter_class_init,
            NULL,
            NULL,
            sizeof (EphyNodeFilter),
            0,
            (GInstanceInitFunc) ephy_node_filter_init
        };

        type = g_type_register_static (G_TYPE_OBJECT,
                           "EphyNodeFilter",
                           &our_info, 0);
    }

    return type;
}

static void
ephy_node_filter_class_init (EphyNodeFilterClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);

    parent_class = g_type_class_peek_parent (klass);

    object_class->finalize = ephy_node_filter_finalize;

    ephy_node_filter_signals[CHANGED] =
        g_signal_new ("changed",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (EphyNodeFilterClass, changed),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__VOID,
                  G_TYPE_NONE,
                  0);

    g_type_class_add_private (object_class, sizeof (EphyNodeFilterPrivate));
}

static void
ephy_node_filter_init (EphyNodeFilter *filter)
{
    filter->priv = EPHY_NODE_FILTER_GET_PRIVATE (filter);

    filter->priv->levels = g_ptr_array_new ();
}

static void
ephy_node_filter_finalize (GObject *object)
{
    EphyNodeFilter *filter = EPHY_NODE_FILTER (object);

    ephy_node_filter_empty (filter);

    g_ptr_array_free (filter->priv->levels, TRUE);

    G_OBJECT_CLASS (parent_class)->finalize (object);
}

EphyNodeFilter *
ephy_node_filter_new (void)
{
    return EPHY_NODE_FILTER (g_object_new (EPHY_TYPE_NODE_FILTER, NULL));
}

void
ephy_node_filter_add_expression (EphyNodeFilter *filter,
                     EphyNodeFilterExpression *exp,
                     int level)
{
    while (level >= filter->priv->levels->len)
        g_ptr_array_add (filter->priv->levels, NULL);

    /* FIXME bogosity! This only works because g_list_append (x, data) == x */
    g_ptr_array_index (filter->priv->levels, level) =
        g_list_append (g_ptr_array_index (filter->priv->levels, level), exp);
}

void
ephy_node_filter_empty (EphyNodeFilter *filter)
{
    int i;
    
    for (i = filter->priv->levels->len - 1; i >= 0; i--)
    {
        GList *list, *l;

        list = g_ptr_array_index (filter->priv->levels, i);

        for (l = list; l != NULL; l = g_list_next (l))
        {
            EphyNodeFilterExpression *exp;

            exp = (EphyNodeFilterExpression *) l->data;

            ephy_node_filter_expression_free (exp);
        }

        g_list_free (list);

        g_ptr_array_remove_index (filter->priv->levels, i);
    }
}

void
ephy_node_filter_done_changing (EphyNodeFilter *filter)
{
    g_signal_emit (G_OBJECT (filter), ephy_node_filter_signals[CHANGED], 0);
}

/*
 * We go through each level evaluating the filter expressions. 
 * Every time we get a match we immediately do a break and jump
 * to the next level. We'll return FALSE if we arrive to a level 
 * without matches, TRUE otherwise.
 */
gboolean
ephy_node_filter_evaluate (EphyNodeFilter *filter,
               EphyNode *node)
{
    int i;

    for (i = 0; i < filter->priv->levels->len; i++) {
        GList *l, *list;
        gboolean handled;

        handled = FALSE;

        list = g_ptr_array_index (filter->priv->levels, i);

        for (l = list; l != NULL; l = g_list_next (l)) {
            if (ephy_node_filter_expression_evaluate (l->data, node) == TRUE) {
                handled = TRUE;
                break;
            }
        }

        if (list != NULL && handled == FALSE)
            return FALSE;
    }
    
    return TRUE;
}

EphyNodeFilterExpression *
ephy_node_filter_expression_new (EphyNodeFilterExpressionType type,
                     ...)
{
    EphyNodeFilterExpression *exp;
    va_list valist;

    va_start (valist, type);

    exp = g_new0 (EphyNodeFilterExpression, 1);

    exp->type = type;

    switch (type)
    {
    case EPHY_NODE_FILTER_EXPRESSION_NODE_EQUALS:
        exp->args.node_args.a = va_arg (valist, EphyNode *);
        exp->args.node_args.b = va_arg (valist, EphyNode *);
        break;
    case EPHY_NODE_FILTER_EXPRESSION_EQUALS:
    case EPHY_NODE_FILTER_EXPRESSION_HAS_PARENT:
    case EPHY_NODE_FILTER_EXPRESSION_HAS_CHILD:
        exp->args.node_args.a = va_arg (valist, EphyNode *);
        break;
    case EPHY_NODE_FILTER_EXPRESSION_NODE_PROP_EQUALS:
    case EPHY_NODE_FILTER_EXPRESSION_CHILD_PROP_EQUALS:
        exp->args.prop_args.prop_id = va_arg (valist, int);
        exp->args.prop_args.second_arg.node = va_arg (valist, EphyNode *);
        break;
    case EPHY_NODE_FILTER_EXPRESSION_STRING_PROP_CONTAINS:
    case EPHY_NODE_FILTER_EXPRESSION_STRING_PROP_EQUALS:
        exp->args.prop_args.prop_id = va_arg (valist, int);
        exp->args.prop_args.second_arg.string = g_utf8_casefold (va_arg (valist, char *), -1);
        break;
    case EPHY_NODE_FILTER_EXPRESSION_KEY_PROP_CONTAINS:
    case EPHY_NODE_FILTER_EXPRESSION_KEY_PROP_EQUALS:
    {
        char *folded;

        exp->args.prop_args.prop_id = va_arg (valist, int);

        folded = g_utf8_casefold (va_arg (valist, char *), -1);
        exp->args.prop_args.second_arg.string = g_utf8_collate_key (folded, -1);
        g_free (folded);
        break;
    }
    case EPHY_NODE_FILTER_EXPRESSION_INT_PROP_EQUALS:
    case EPHY_NODE_FILTER_EXPRESSION_INT_PROP_BIGGER_THAN:
    case EPHY_NODE_FILTER_EXPRESSION_INT_PROP_LESS_THAN:
        exp->args.prop_args.prop_id = va_arg (valist, int);
        exp->args.prop_args.second_arg.number = va_arg (valist, int);
        break;
    default:
        break;
    }

    va_end (valist);

    return exp;
}

void
ephy_node_filter_expression_free (EphyNodeFilterExpression *exp)
{
    switch (exp->type)
    {
    case EPHY_NODE_FILTER_EXPRESSION_STRING_PROP_CONTAINS:
    case EPHY_NODE_FILTER_EXPRESSION_STRING_PROP_EQUALS:
    case EPHY_NODE_FILTER_EXPRESSION_KEY_PROP_CONTAINS:
    case EPHY_NODE_FILTER_EXPRESSION_KEY_PROP_EQUALS:
        g_free (exp->args.prop_args.second_arg.string);
        break;
    default:
        break;
    }
    
    g_free (exp);
}

static gboolean
ephy_node_filter_expression_evaluate (EphyNodeFilterExpression *exp,
                      EphyNode *node)
{
    switch (exp->type)
    {
    case EPHY_NODE_FILTER_EXPRESSION_ALWAYS_TRUE:
        return TRUE;
    case EPHY_NODE_FILTER_EXPRESSION_NODE_EQUALS:
        return (exp->args.node_args.a == exp->args.node_args.b);
    case EPHY_NODE_FILTER_EXPRESSION_EQUALS:
        return (exp->args.node_args.a == node); 
    case EPHY_NODE_FILTER_EXPRESSION_HAS_PARENT:
        return ephy_node_has_child (exp->args.node_args.a, node);
    case EPHY_NODE_FILTER_EXPRESSION_HAS_CHILD:
        return ephy_node_has_child (node, exp->args.node_args.a);
    case EPHY_NODE_FILTER_EXPRESSION_NODE_PROP_EQUALS:
    {
        EphyNode *prop;

        prop = ephy_node_get_property_node (node,
                          exp->args.prop_args.prop_id);
        
        return (prop == exp->args.prop_args.second_arg.node);
    }
    case EPHY_NODE_FILTER_EXPRESSION_CHILD_PROP_EQUALS:
    {
        EphyNode *prop;
        GPtrArray *children;
        int i;
        
        children = ephy_node_get_children (node);
        for (i = 0; i < children->len; i++)
        {
            EphyNode *child;
            
            child = g_ptr_array_index (children, i);
            prop = ephy_node_get_property_node 
                (child, exp->args.prop_args.prop_id);
        
            if (prop == exp->args.prop_args.second_arg.node)
            {
                return TRUE;
            }
        }
        
        return FALSE;
    }
    case EPHY_NODE_FILTER_EXPRESSION_STRING_PROP_CONTAINS:
    {
        const char *prop;
        char *folded_case;
        gboolean ret;

        prop = ephy_node_get_property_string (node,
                            exp->args.prop_args.prop_id);
        if (prop == NULL)
            return FALSE;

        folded_case = g_utf8_casefold (prop, -1);
        ret = (strstr (folded_case, exp->args.prop_args.second_arg.string) != NULL);
        g_free (folded_case);

        return ret;
    }
    case EPHY_NODE_FILTER_EXPRESSION_STRING_PROP_EQUALS:
    {
        const char *prop;
        char *folded_case;
        gboolean ret;

        prop = ephy_node_get_property_string (node,
                            exp->args.prop_args.prop_id);

        if (prop == NULL)
            return FALSE;

        folded_case = g_utf8_casefold (prop, -1);
        ret = (strcmp (folded_case, exp->args.prop_args.second_arg.string) == 0);
        g_free (folded_case);

        return ret;
    }
    case EPHY_NODE_FILTER_EXPRESSION_KEY_PROP_CONTAINS:
    {
        const char *prop;

        prop = ephy_node_get_property_string (node,
                            exp->args.prop_args.prop_id);

        if (prop == NULL)
            return FALSE;

        return (strstr (prop, exp->args.prop_args.second_arg.string) != NULL);
    }
    case EPHY_NODE_FILTER_EXPRESSION_KEY_PROP_EQUALS:
    {
        const char *prop;

        prop = ephy_node_get_property_string (node,
                            exp->args.prop_args.prop_id);

        if (prop == NULL)
            return FALSE;

        return (strcmp (prop, exp->args.prop_args.second_arg.string) == 0);
    }
    case EPHY_NODE_FILTER_EXPRESSION_INT_PROP_EQUALS:
    {
        int prop;

        prop = ephy_node_get_property_int (node,
                         exp->args.prop_args.prop_id);

        return (prop == exp->args.prop_args.second_arg.number);
    }
    case EPHY_NODE_FILTER_EXPRESSION_INT_PROP_BIGGER_THAN:
    {
        int prop;

        prop = ephy_node_get_property_int (node,
                         exp->args.prop_args.prop_id);

        return (prop > exp->args.prop_args.second_arg.number);
    }
    case EPHY_NODE_FILTER_EXPRESSION_INT_PROP_LESS_THAN:
    {
        int prop;

        prop = ephy_node_get_property_int (node,
                         exp->args.prop_args.prop_id);

        return (prop < exp->args.prop_args.second_arg.number);
    }
    default:
        break;
    }

    return FALSE;
}