view data/fileio/PlaylistFileReader.cpp @ 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 file copyright 2007 QMUL.
    
    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.
*/

#include "PlaylistFileReader.h"

#include <QFile>
#include <QTextStream>
#include <QStringList>
#include <QFileInfo>
#include <QDir>

#include <iostream>

PlaylistFileReader::PlaylistFileReader(QString path) :
    m_source(path),
    m_file(0)
{
    if (!m_source.isAvailable()) {
        m_error = QFile::tr("File or URL \"%1\" could not be retrieved")
            .arg(path);
        return;
    }
    init();
}

PlaylistFileReader::PlaylistFileReader(FileSource source) :
    m_source(source),
    m_file(0)
{
    if (!m_source.isAvailable()) {
        m_error = QFile::tr("File or URL \"%1\" could not be retrieved")
            .arg(source.getLocation());
        return;
    }
    init();
}

PlaylistFileReader::~PlaylistFileReader()
{
    if (m_file) m_file->close();
    delete m_file;
}

void
PlaylistFileReader::init()
{
    if (!m_source.isAvailable()) return;

    m_source.waitForData();

    QString filename = m_source.getLocalFilename();

    m_file = new QFile(filename);
    bool good = false;

    if (!m_file->exists()) {
	m_error = QFile::tr("File \"%1\" does not exist")
            .arg(m_source.getLocation());
    } else if (!m_file->open(QIODevice::ReadOnly | QIODevice::Text)) {
	m_error = QFile::tr("Failed to open file \"%1\"")
            .arg(m_source.getLocation());
    } else {
	good = true;
    }

    if (good) {
        if (!m_source.isRemote()) {
            m_basedir = QFileInfo(filename).dir().canonicalPath();
        }
    }

    if (!good) {
	delete m_file;
	m_file = 0;
    }
}

bool
PlaylistFileReader::isOK() const
{
    return (m_file != 0);
}

QString
PlaylistFileReader::getError() const
{
    return m_error;
}

PlaylistFileReader::Playlist
PlaylistFileReader::load() const
{
    if (!m_file) return Playlist();

    QTextStream in(m_file);
    in.seek(0);

    Playlist playlist;

    while (!in.atEnd()) {

        // cope with old-style Mac line endings (c.f. CSVFileReader)
        // as well as DOS/Unix style

        QString chunk = in.readLine();
        QStringList lines = chunk.split('\r', QString::SkipEmptyParts);
        
        for (int li = 0; li < lines.size(); ++li) {

            QString line = lines[li];

            if (line.startsWith("#")) continue;

            // line is expected to be a URL or a file path.  If it
            // appears to be a local relative file path, then we
            // should check whether it can be resolved relative to the
            // location of the playlist file and, if so, do so.

            if (!FileSource::isRemote(line)) {
                if (QFileInfo(line).isRelative() && m_basedir != "") {
                    QString testpath = QDir(m_basedir).filePath(line);
                    if (QFileInfo(testpath).exists() &&
                        QFileInfo(testpath).isFile()) {
                        cerr << "Path \"" << line
                                  << "\" is relative, resolving to \""
                                  << testpath << "\""
                                  << endl;
                        line = testpath;
                    }
                }
            }

            playlist.push_back(line);
        }
    }

    return playlist;
}

void
PlaylistFileReader::getSupportedExtensions(std::set<QString> &extensions)
{
    extensions.insert("m3u");
}