annotate base/TempWriteFile.h @ 1376:d9511f9e04d7 dev/refactor-piper-related

Introduce some POD structs for describing an external server application and the desired libraries to load from it, and disambiguating between empty list request and invalid list request. This allows for overriding PiperVampPluginFactory behaviour for using a PluginScan to populate the list request.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef SV_TEMP_WRITE_FILE_H
#define SV_TEMP_WRITE_FILE_H

#include <QTemporaryFile>

/**
 * A class that manages the creation of a temporary file with a given
 * prefix and the renaming of that file to the prefix after use.  For
 * use when saving a file over an existing one, to avoid clobbering
 * the original before the save is complete.
 */
class TempWriteFile
{
public:
    TempWriteFile(QString targetFileName); // may throw FileOperationFailed

    /**
     * Destroy the temporary file object.  If moveToTarget has not
     * been called, the associated temporary file will be deleted
     * without being copied to the target location.
     */
    ~TempWriteFile();

    /**
     * Return the name of the temporary file.  Unless the constructor
     * threw an exception, this file will have been created already
     * (but it will not be open).
     *
     * (If moveToTarget has already been called, return an empty
     * string.)
     */
    QString getTemporaryFilename();

    /**
     * Rename the temporary file to the target filename.
     */
    void moveToTarget();

protected:
    QString m_target;
    QString m_temp;
};


#endif