/*
 * Copyright (C) 2007  Remko Troncon
 *
 * 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 */

#ifndef IODEVICEOPENER_H
#define IODEVICEOPENER_H

#include <QIODevice>
#include <QPointer>

/**
 * An IODeviceOpener is used to ensure that an IODevice is opened.
 * If the QIODevice was not open when the opener was created, it will be closed
 * again when the opener is destroyed.
 *
 * Example:
 *        void foo(QIODevice* device) {
 *            IODeviceOpener opener(device, QIODevice::ReadOnly);
 *            if (!opener.isOpen()) {
 *                qDebug() << "Error opening QIODevice";
 *                return;
 *            }
 *            ...
 *            device->readAll()
 *            ...
 *        }
 */
class IODeviceOpener
{
public:
    /**
     * Opens an QIODevice in a specific mode if the device was not opened
     * yet.
     * If the device was already open but in a different, non-compatible
     * mode than the one requested, isOpen() will return false.
     */
    IODeviceOpener(QIODevice* device, QIODevice::OpenModeFlag mode);

    /**
     * Closes the QIODevice passed to the constructor if the IODevice was not
     * opened at that time.
     */
    ~IODeviceOpener();

    /**
     * Checks whether the io device was opened succesfully in the mode
     * requested.
     */
    bool isOpen() const { return isOpen_; }

private:
    QPointer<QIODevice> device_;
    bool close_;
    bool isOpen_;
};

#endif
