hedera/db/db-param.c

/*
 * Copyright (C) 2012 - Juan Ferrer Toribio
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "db-param.h"

/**
 * SECTION: db-param
 * @Short_description: representation of the value of a field 
 * @Title: DbParam
 * 
 * This class represents the value of a field in a #DbIterator.
 **/

G_DEFINE_TYPE (DbParam, db_param, GVN_TYPE_PARAM);

/**
 * db_param_new:
 * @column_name: col name of #DbModel associated to param.
 *
 * Creates a new #DbParam.
 *
 * Return value: the new #DbParam
 **/
GvnParam * db_param_new (const gchar * column_name)
{
	return g_object_new (DB_TYPE_PARAM, "column-name", column_name, NULL);
}

/**
 * db_param_new_with_index:
 * @column_index: col index of #DbModel associated to param.
 *
 * Creates a new #DbParam.
 *
 * Return value: the new #DbParam
 **/
GvnParam * db_param_new_with_index (guint column_index)
{
	return g_object_new (DB_TYPE_PARAM, "column-index", column_index, NULL);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Private

static void db_param_on_value_changed (DbParam * obj, const GValue * value, gpointer data)
{
	db_iterator_set_value (obj->iterator, obj->column_index, value, NULL);
}

static void db_param_on_iterator_status_changed (DbIterator * iterator, gboolean ready, DbParam * obj)
{
	GvnParamClass * klass = GVN_PARAM_GET_CLASS (obj);
	
	if (ready)
	{
		if (obj->column_name)
			obj->column_index = db_iterator_get_column_index (obj->iterator, obj->column_name);
	
		klass->set_spec (GVN_PARAM (obj),
			db_iterator_get_spec (obj->iterator, obj->column_index));
	}
}

static void db_param_on_iterator_iter_changed (DbIterator * iterator, DbParam * obj)
{
	const GValue * value;
	GvnParamClass * klass = GVN_PARAM_GET_CLASS (obj);

	if (db_iterator_get_row (obj->iterator) != -1 && obj->column_index != -1)
	{
		klass->set_status (GVN_PARAM (obj), GVN_PARAM_STATUS_OK);
		value = db_iterator_get_value (obj->iterator, obj->column_index);
	}
	else
	{
		klass->set_status (GVN_PARAM (obj), GVN_PARAM_STATUS_BUSY);
		value = NULL;
	}
	
	g_signal_handlers_block_by_func (obj, db_param_on_value_changed, NULL);

	if (!value)
	{
		GValue tmp_value = G_VALUE_INIT;
		g_value_init (&tmp_value, GVN_TYPE_NULL);
		klass->put_value (GVN_PARAM (obj), &tmp_value);
		g_value_unset (&tmp_value);
	}
	else
		klass->put_value (GVN_PARAM (obj), value);

	g_signal_handlers_unblock_by_func (obj, db_param_on_value_changed, NULL);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Public

/**
 * db_param_get_column_index:
 * @obj: a #DbParam
 *
 * Gets the iterator column referenced by the param.
 *
 * Return value: the column index.
 **/
guint db_param_get_column_index (DbParam * obj)
{
	g_return_val_if_fail (DB_IS_PARAM (obj), 0);

	return obj->column_index;
}

/**
 * db_param_get_column_name:
 * @obj: a #DbParam
 *
 * Gets the iterator column referenced by the param.
 *
 * Return value: the column name.
 **/
const gchar * db_param_get_column_name (DbParam * obj)
{
	g_return_val_if_fail (DB_IS_PARAM (obj), 0);

	return obj->column_name;
}

/**
 * db_param_set_iterator:
 * @obj: a #DbParam
 * @iterator: the #DbIterator
 *
 * Sets the iterator that updates the param value, this property can be set if
 * the parameter does not have a iterator associated yet.
 **/
void db_param_set_iterator (DbParam * obj, DbIterator * iterator)
{
	g_return_if_fail (DB_IS_PARAM (obj));
	g_return_if_fail (DB_IS_ITERATOR (iterator));
	g_return_if_fail (!obj->iterator);

	obj->iterator = g_object_ref (iterator);
	g_object_connect (iterator
		,"signal::iter-changed", db_param_on_iterator_iter_changed, obj
		,"signal::status-changed", db_param_on_iterator_status_changed, obj
		,NULL
	);
	db_param_on_iterator_status_changed (obj->iterator,
		db_iterator_is_ready (iterator), obj);
	db_param_on_iterator_iter_changed (obj->iterator, obj);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Properties

enum
{
	 PROP_ITERATOR = 1
	,PROP_COLUMN_INDEX
	,PROP_COLUMN_NAME
};

static void db_param_set_property (DbParam * obj, guint property_id,
	const GValue * value, GParamSpec * pspec)
{
	switch (property_id)
	{
		case PROP_ITERATOR:
			db_param_set_iterator (obj, g_value_get_object (value));
			break;
		case PROP_COLUMN_INDEX:
			obj->column_index = g_value_get_int (value);
			break;
		case PROP_COLUMN_NAME:
			g_free (obj->column_name);
			obj->column_name = g_value_dup_string (value);
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, property_id, pspec);
	}
}

static void db_param_get_property (DbParam * obj, guint property_id,
	GValue * value, GParamSpec * pspec)
{	
	switch (property_id)
	{
		case PROP_ITERATOR:
			g_value_set_object (value, obj->iterator);
			break;
		case PROP_COLUMN_INDEX:
			g_value_set_int (value, obj->column_index);
			break;
		case PROP_COLUMN_NAME:
			g_value_set_string (value, obj->column_name);
			break;
		default:		
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, property_id, pspec);
	}
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Class

static void db_param_init (DbParam * obj)
{
	obj->column_index = -1;
	obj->column_name = NULL;
	obj->iterator = NULL;
	g_signal_connect (obj, "value-changed",
		G_CALLBACK (db_param_on_value_changed), NULL);
}

static void db_param_finalize (DbParam * obj)
{
	if (obj->iterator)
	{
		g_object_disconnect (obj->iterator
			,"any_signal", db_param_on_iterator_iter_changed, obj
			,"any_signal", db_param_on_iterator_status_changed, obj
			,NULL
		);
		g_clear_object (&obj->iterator);
	}

	g_signal_handlers_disconnect_by_func (obj,
		db_param_on_value_changed, NULL);
	g_free (obj->column_name);
	G_OBJECT_CLASS (db_param_parent_class)->finalize (G_OBJECT (obj));
}

static void db_param_class_init (DbParamClass * k)
{
	GObjectClass * klass = G_OBJECT_CLASS (k);
	klass->finalize = (GObjectFinalizeFunc) db_param_finalize;
	klass->set_property = (GObjectSetPropertyFunc) db_param_set_property;
	klass->get_property = (GObjectGetPropertyFunc) db_param_get_property;

	g_object_class_install_property (klass, PROP_ITERATOR,
		g_param_spec_object ("iterator"
			,_("Iterator")
			,_("The iterator owner of param")
			,DB_TYPE_ITERATOR
			,G_PARAM_READWRITE
	));
	g_object_class_install_property (klass, PROP_COLUMN_INDEX,
		g_param_spec_int ("column-index"
			,_("Column index")
			,_("The referenced column index")
			,-1 ,1024 ,-1
			,G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE
	));
	g_object_class_install_property (klass, PROP_COLUMN_NAME,
		g_param_spec_string ("column-name"
			,_("Column name")
			,_("The referenced column name")
			,NULL
			,G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE
	));
}