# HG changeset patch
# User Chris Cannam
# Date 1238171152 0
# Node ID 3228b7913aa44eb82ab55571f7f2875540b00572
# Parent  44f391ec2172f9a3410d1cd47ffaa075f99d7e9f
* Pull out the widgetry part of FileFinder into widgets/InteractiveFileFinder
  (essentially this is just to avoid a dependency from data/fileio to widgets/
  which is problematic for non-gui programs)

diff -r 44f391ec2172 -r 3228b7913aa4 widgets/FileFinder.cpp
--- a/widgets/FileFinder.cpp	Fri Mar 27 13:10:01 2009 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,521 +0,0 @@
-/* -*- 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 "FileFinder.h"
-#include "data/fileio/FileSource.h"
-#include "data/fileio/AudioFileReaderFactory.h"
-#include "data/fileio/DataFileReaderFactory.h"
-#include "rdf/RDFImporter.h"
-#include "rdf/RDFExporter.h"
-
-#include <QFileInfo>
-#include <QMessageBox>
-#include <QFileDialog>
-#include <QInputDialog>
-#include <QImageReader>
-#include <QSettings>
-
-#include <iostream>
-
-FileFinder *
-FileFinder::m_instance = 0;
-
-FileFinder::FileFinder() :
-    m_lastLocatedLocation("")
-{
-}
-
-FileFinder::~FileFinder()
-{
-}
-
-FileFinder *
-FileFinder::getInstance()
-{
-    if (m_instance == 0) {
-        m_instance = new FileFinder();
-    }
-    return m_instance;
-}
-
-QString
-FileFinder::getOpenFileName(FileType type, QString fallbackLocation)
-{
-    QString settingsKey;
-    QString lastPath = fallbackLocation;
-    
-    QString title = tr("Select file");
-    QString filter = tr("All files (*.*)");
-
-    switch (type) {
-
-    case SessionFile:
-        settingsKey = "sessionpath";
-        title = tr("Select a session file");
-        filter = tr("Sonic Visualiser session files (*.sv)\nRDF files (%1)\nAll files (*.*)").arg(RDFImporter::getKnownExtensions());
-        break;
-
-    case AudioFile:
-        settingsKey = "audiopath";
-        title = "Select an audio file";
-        filter = tr("Audio files (%1)\nAll files (*.*)")
-            .arg(AudioFileReaderFactory::getKnownExtensions());
-        break;
-
-    case LayerFile:
-        settingsKey = "layerpath";
-        filter = tr("All supported files (%1 %2)\nSonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nSpace-separated .lab files (*.lab)\nRDF files (%2)\nMIDI files (*.mid)\nText files (*.txt)\nAll files (*.*)")
-            .arg(DataFileReaderFactory::getKnownExtensions())
-            .arg(RDFImporter::getKnownExtensions());
-        break;
-
-    case LayerFileNoMidi:
-        settingsKey = "layerpath";
-        filter = tr("All supported files (%1 %2)\nSonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nSpace-separated .lab files (*.lab)\nRDF files (%2)\nText files (*.txt)\nAll files (*.*)")
-            .arg(DataFileReaderFactory::getKnownExtensions())
-            .arg(RDFImporter::getKnownExtensions());
-        break;
-
-    case SessionOrAudioFile:
-        settingsKey = "lastpath";
-        filter = tr("All supported files (*.sv %1 %2)\nSonic Visualiser session files (*.sv)\nAudio files (%2)\nRDF files (%1)\nAll files (*.*)")
-            .arg(RDFImporter::getKnownExtensions())
-            .arg(AudioFileReaderFactory::getKnownExtensions());
-        break;
-
-    case ImageFile:
-        settingsKey = "imagepath";
-        {
-            QStringList fmts;
-            QList<QByteArray> formats = QImageReader::supportedImageFormats();
-            for (QList<QByteArray>::iterator i = formats.begin();
-                 i != formats.end(); ++i) {
-                fmts.push_back(QString("*.%1")
-                               .arg(QString::fromLocal8Bit(*i).toLower()));
-            }
-            filter = tr("Image files (%1)\nAll files (*.*)").arg(fmts.join(" "));
-        }
-        break;
-
-    case AnyFile:
-        settingsKey = "lastpath";
-        filter = tr("All supported files (*.sv %1 %2 %3)\nSonic Visualiser session files (*.sv)\nAudio files (%1)\nLayer files (%2)\nRDF files (%3)\nAll files (*.*)")
-            .arg(AudioFileReaderFactory::getKnownExtensions())
-            .arg(DataFileReaderFactory::getKnownExtensions())
-            .arg(RDFImporter::getKnownExtensions());
-        break;
-    };
-
-    if (lastPath == "") {
-        char *home = getenv("HOME");
-        if (home) lastPath = home;
-        else lastPath = ".";
-    } else if (QFileInfo(lastPath).isDir()) {
-        lastPath = QFileInfo(lastPath).canonicalPath();
-    } else {
-        lastPath = QFileInfo(lastPath).absoluteDir().canonicalPath();
-    }
-
-    QSettings settings;
-    settings.beginGroup("FileFinder");
-    lastPath = settings.value(settingsKey, lastPath).toString();
-
-    QString path = "";
-
-    // Use our own QFileDialog just for symmetry with getSaveFileName below
-
-    QFileDialog dialog;
-    dialog.setFilters(filter.split('\n'));
-    dialog.setWindowTitle(title);
-    dialog.setDirectory(lastPath);
-
-    dialog.setAcceptMode(QFileDialog::AcceptOpen);
-    dialog.setFileMode(QFileDialog::ExistingFile);
-    
-    if (dialog.exec()) {
-        QStringList files = dialog.selectedFiles();
-        if (!files.empty()) path = *files.begin();
-        
-        QFileInfo fi(path);
-        
-        if (!fi.exists()) {
-            
-            QMessageBox::critical(0, tr("File does not exist"),
-                                  tr("<b>File not found</b><p>File \"%1\" does not exist").arg(path));
-            path = "";
-            
-        } else if (!fi.isReadable()) {
-            
-            QMessageBox::critical(0, tr("File is not readable"),
-                                  tr("<b>File is not readable</b><p>File \"%1\" can not be read").arg(path));
-            path = "";
-            
-        } else if (fi.isDir()) {
-            
-            QMessageBox::critical(0, tr("Directory selected"),
-                                  tr("<b>Directory selected</b><p>File \"%1\" is a directory").arg(path));
-            path = "";
-
-        } else if (!fi.isFile()) {
-            
-            QMessageBox::critical(0, tr("Non-file selected"),
-                                  tr("<b>Not a file</b><p>Path \"%1\" is not a file").arg(path));
-            path = "";
-            
-        } else if (fi.size() == 0) {
-            
-            QMessageBox::critical(0, tr("File is empty"),
-                                  tr("<b>File is empty</b><p>File \"%1\" is empty").arg(path));
-            path = "";
-        }                
-    }
-
-    if (path != "") {
-        settings.setValue(settingsKey,
-                          QFileInfo(path).absoluteDir().canonicalPath());
-    }
-    
-    return path;
-}
-
-QString
-FileFinder::getSaveFileName(FileType type, QString fallbackLocation)
-{
-    QString settingsKey;
-    QString lastPath = fallbackLocation;
-    
-    QString title = tr("Select file");
-    QString filter = tr("All files (*.*)");
-
-    switch (type) {
-
-    case SessionFile:
-        settingsKey = "savesessionpath";
-        title = tr("Select a session file");
-        filter = tr("Sonic Visualiser session files (*.sv)\nAll files (*.*)");
-        break;
-
-    case AudioFile:
-        settingsKey = "saveaudiopath";
-        title = "Select an audio file";
-        title = tr("Select a file to export to");
-        filter = tr("WAV audio files (*.wav)\nAll files (*.*)");
-        break;
-
-    case LayerFile:
-        settingsKey = "savelayerpath";
-        title = tr("Select a file to export to");
-        filter = tr("Sonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nRDF/Turtle files (%1)\nMIDI files (*.mid)\nText files (*.txt)\nAll files (*.*)").arg(RDFExporter::getSupportedExtensions());
-        break;
-
-    case LayerFileNoMidi:
-        settingsKey = "savelayerpath";
-        title = tr("Select a file to export to");
-        filter = tr("Sonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nRDF/Turtle files (%1)\nText files (*.txt)\nAll files (*.*)").arg(RDFExporter::getSupportedExtensions());
-        break;
-
-    case SessionOrAudioFile:
-        std::cerr << "ERROR: Internal error: FileFinder::getSaveFileName: SessionOrAudioFile cannot be used here" << std::endl;
-        abort();
-
-    case ImageFile:
-        settingsKey = "saveimagepath";
-        title = tr("Select a file to export to");
-        filter = tr("Portable Network Graphics files (*.png)\nAll files (*.*)");
-        break;
-
-    case AnyFile:
-        std::cerr << "ERROR: Internal error: FileFinder::getSaveFileName: AnyFile cannot be used here" << std::endl;
-        abort();
-    };
-
-    if (lastPath == "") {
-        char *home = getenv("HOME");
-        if (home) lastPath = home;
-        else lastPath = ".";
-    } else if (QFileInfo(lastPath).isDir()) {
-        lastPath = QFileInfo(lastPath).canonicalPath();
-    } else {
-        lastPath = QFileInfo(lastPath).absoluteDir().canonicalPath();
-    }
-
-    QSettings settings;
-    settings.beginGroup("FileFinder");
-    lastPath = settings.value(settingsKey, lastPath).toString();
-
-    QString path = "";
-
-    // Use our own QFileDialog instead of static functions, as we may
-    // need to adjust the file extension based on the selected filter
-
-    QFileDialog dialog;
-    dialog.setFilters(filter.split('\n'));
-    dialog.setWindowTitle(title);
-    dialog.setDirectory(lastPath);
-
-    dialog.setAcceptMode(QFileDialog::AcceptSave);
-    dialog.setFileMode(QFileDialog::AnyFile);
-    dialog.setConfirmOverwrite(false); // we'll do that
-        
-    if (type == SessionFile) {
-        dialog.setDefaultSuffix("sv");
-    } else if (type == AudioFile) {
-        dialog.setDefaultSuffix("wav");
-    } else if (type == ImageFile) {
-        dialog.setDefaultSuffix("png");
-    }
-
-    bool good = false;
-
-    while (!good) {
-
-        path = "";
-        
-        if (!dialog.exec()) break;
-        
-        QStringList files = dialog.selectedFiles();
-        if (files.empty()) break;
-        path = *files.begin();
-        
-        QFileInfo fi(path);
-
-        std::cerr << "type = " << type << ", suffix = " << fi.suffix().toStdString() << std::endl;
-        
-        if ((type == LayerFile || type == LayerFileNoMidi)
-            && fi.suffix() == "") {
-            QString expectedExtension;
-            QString selectedFilter = dialog.selectedFilter();
-            if (selectedFilter.contains(".svl")) {
-                expectedExtension = "svl";
-            } else if (selectedFilter.contains(".txt")) {
-                expectedExtension = "txt";
-            } else if (selectedFilter.contains(".csv")) {
-                expectedExtension = "csv";
-            } else if (selectedFilter.contains(".mid")) {
-                expectedExtension = "mid";
-            } else if (selectedFilter.contains(".ttl")) {
-                expectedExtension = "ttl";
-            }
-            std::cerr << "expected extension = " << expectedExtension.toStdString() << std::endl;
-            if (expectedExtension != "") {
-                path = QString("%1.%2").arg(path).arg(expectedExtension);
-                fi = QFileInfo(path);
-            }
-        }
-        
-        if (fi.isDir()) {
-            QMessageBox::critical(0, tr("Directory selected"),
-                                  tr("<b>Directory selected</b><p>File \"%1\" is a directory").arg(path));
-            continue;
-        }
-        
-        if (fi.exists()) {
-            if (QMessageBox::question(0, tr("File exists"),
-                                      tr("<b>File exists</b><p>The file \"%1\" already exists.\nDo you want to overwrite it?").arg(path),
-                                      QMessageBox::Ok,
-                                      QMessageBox::Cancel) != QMessageBox::Ok) {
-                continue;
-            }
-        }
-        
-        good = true;
-    }
-        
-    if (path != "") {
-        settings.setValue(settingsKey,
-                          QFileInfo(path).absoluteDir().canonicalPath());
-    }
-    
-    return path;
-}
-
-void
-FileFinder::registerLastOpenedFilePath(FileType type, QString path)
-{
-    QString settingsKey;
-
-    switch (type) {
-    case SessionFile:
-        settingsKey = "sessionpath";
-        break;
-
-    case AudioFile:
-        settingsKey = "audiopath";
-        break;
-
-    case LayerFile:
-        settingsKey = "layerpath";
-        break;
-
-    case LayerFileNoMidi:
-        settingsKey = "layerpath";
-        break;
-
-    case SessionOrAudioFile:
-        settingsKey = "lastpath";
-        break;
-
-    case ImageFile:
-        settingsKey = "imagepath";
-        break;
-
-    case AnyFile:
-        settingsKey = "lastpath";
-        break;
-    }
-
-    if (path != "") {
-        QSettings settings;
-        settings.beginGroup("FileFinder");
-        path = QFileInfo(path).absoluteDir().canonicalPath();
-        settings.setValue(settingsKey, path);
-        settings.setValue("lastpath", path);
-    }
-}
-    
-QString
-FileFinder::find(FileType type, QString location, QString lastKnownLocation)
-{
-    if (FileSource::canHandleScheme(location)) {
-        if (FileSource(location).isAvailable()) {
-            std::cerr << "FileFinder::find: ok, it's available... returning" << std::endl;
-            return location;
-        }
-    }
-
-    if (QFileInfo(location).exists()) return location;
-
-    QString foundAt = "";
-
-    if ((foundAt = findRelative(location, lastKnownLocation)) != "") {
-        return foundAt;
-    }
-
-    if ((foundAt = findRelative(location, m_lastLocatedLocation)) != "") {
-        return foundAt;
-    }
-
-    return locateInteractive(type, location);
-}
-
-QString
-FileFinder::findRelative(QString location, QString relativeTo)
-{
-    if (relativeTo == "") return "";
-
-    std::cerr << "Looking for \"" << location.toStdString() << "\" next to \""
-              << relativeTo.toStdString() << "\"..." << std::endl;
-
-    QString fileName;
-    QString resolved;
-
-    if (FileSource::isRemote(location)) {
-        fileName = QUrl(location).path().section('/', -1, -1,
-                                                 QString::SectionSkipEmpty);
-    } else {
-        if (QUrl(location).scheme() == "file") {
-            location = QUrl(location).toLocalFile();
-        }
-        fileName = QFileInfo(location).fileName();
-    }
-
-    if (FileSource::isRemote(relativeTo)) {
-        resolved = QUrl(relativeTo).resolved(fileName).toString();
-        if (!FileSource(resolved).isAvailable()) resolved = "";
-        std::cerr << "resolved: " << resolved.toStdString() << std::endl;
-    } else {
-        if (QUrl(relativeTo).scheme() == "file") {
-            relativeTo = QUrl(relativeTo).toLocalFile();
-        }
-        resolved = QFileInfo(relativeTo).dir().filePath(fileName);
-        if (!QFileInfo(resolved).exists() ||
-            !QFileInfo(resolved).isFile() ||
-            !QFileInfo(resolved).isReadable()) {
-            resolved = "";
-        }
-    }
-            
-    return resolved;
-}
-
-QString
-FileFinder::locateInteractive(FileType type, QString thing)
-{
-    QString question;
-    if (type == AudioFile) {
-        question = tr("<b>File not found</b><p>Audio file \"%1\" could not be opened.\nDo you want to locate it?");
-    } else {
-        question = tr("<b>File not found</b><p>File \"%1\" could not be opened.\nDo you want to locate it?");
-    }
-
-    QString path = "";
-    bool done = false;
-
-    while (!done) {
-
-        int rv = QMessageBox::question
-            (0, 
-             tr("Failed to open file"),
-             question.arg(thing),
-             tr("Locate file..."),
-             tr("Use URL..."),
-             tr("Cancel"),
-             0, 2);
-        
-        switch (rv) {
-
-        case 0: // Locate file
-
-            if (QFileInfo(thing).dir().exists()) {
-                path = QFileInfo(thing).dir().canonicalPath();
-            }
-            
-            path = getOpenFileName(type, path);
-            done = (path != "");
-            break;
-
-        case 1: // Use URL
-        {
-            bool ok = false;
-            path = QInputDialog::getText
-                (0, tr("Use URL"),
-                 tr("Please enter the URL to use for this file:"),
-                 QLineEdit::Normal, "", &ok);
-
-            if (ok && path != "") {
-                if (FileSource(path).isAvailable()) {
-                    done = true;
-                } else {
-                    QMessageBox::critical
-                        (0, tr("Failed to open location"),
-                         tr("<b>Failed to open location</b><p>URL \"%1\" could not be opened").arg(path));
-                    path = "";
-                }
-            }
-            break;
-        }
-
-        case 2: // Cancel
-            path = "";
-            done = true;
-            break;
-        }
-    }
-
-    if (path != "") m_lastLocatedLocation = path;
-    return path;
-}
-
-
diff -r 44f391ec2172 -r 3228b7913aa4 widgets/FileFinder.h
--- a/widgets/FileFinder.h	Fri Mar 27 13:10:01 2009 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,58 +0,0 @@
-/* -*- 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.
-*/
-
-#ifndef _FILE_FINDER_H_
-#define _FILE_FINDER_H_
-
-#include <QString>
-#include <QObject>
-
-class FileFinder : public QObject
-{
-    Q_OBJECT
-
-public:
-    virtual ~FileFinder();
-
-    enum FileType {
-        SessionFile,
-        AudioFile,
-        LayerFile,
-        LayerFileNoMidi,
-        SessionOrAudioFile,
-        ImageFile,
-        AnyFile
-    };
-
-    QString getOpenFileName(FileType type, QString fallbackLocation = "");
-    QString getSaveFileName(FileType type, QString fallbackLocation = "");
-    void registerLastOpenedFilePath(FileType type, QString path);
-
-    QString find(FileType type, QString location, QString lastKnownLocation = "");
-
-    static FileFinder *getInstance();
-
-protected:
-    FileFinder();
-    static FileFinder *m_instance;
-
-    QString findRelative(QString location, QString relativeTo);
-    QString locateInteractive(FileType type, QString thing);
-
-    QString m_lastLocatedLocation;
-};
-
-#endif
-
diff -r 44f391ec2172 -r 3228b7913aa4 widgets/ImageDialog.cpp
--- a/widgets/ImageDialog.cpp	Fri Mar 27 13:10:01 2009 +0000
+++ b/widgets/ImageDialog.cpp	Fri Mar 27 16:25:52 2009 +0000
@@ -29,7 +29,7 @@
 #include "ProgressDialog.h"
 
 #include "data/fileio/FileSource.h"
-#include "FileFinder.h"
+#include "InteractiveFileFinder.h"
 
 #include <iostream>
 
@@ -228,7 +228,7 @@
 ImageDialog::browseClicked()
 {
     QString file =
-        FileFinder::getInstance()->getOpenFileName(FileFinder::ImageFile);
+        InteractiveFileFinder::getInstance()->getOpenFileName(FileFinder::ImageFile);
 
     if (file != "") {
         setImage(file);
diff -r 44f391ec2172 -r 3228b7913aa4 widgets/InteractiveFileFinder.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widgets/InteractiveFileFinder.cpp	Fri Mar 27 16:25:52 2009 +0000
@@ -0,0 +1,514 @@
+/* -*- 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 "InteractiveFileFinder.h"
+#include "data/fileio/FileSource.h"
+#include "data/fileio/AudioFileReaderFactory.h"
+#include "data/fileio/DataFileReaderFactory.h"
+#include "rdf/RDFImporter.h"
+#include "rdf/RDFExporter.h"
+
+#include <QFileInfo>
+#include <QMessageBox>
+#include <QFileDialog>
+#include <QInputDialog>
+#include <QImageReader>
+#include <QSettings>
+
+#include <iostream>
+
+InteractiveFileFinder 
+InteractiveFileFinder::m_instance;
+
+InteractiveFileFinder::InteractiveFileFinder() :
+    m_lastLocatedLocation("")
+{
+    std::cerr << "Registering interactive file finder" << std::endl;
+    FileFinder::registerFileFinder(this);
+}
+
+InteractiveFileFinder::~InteractiveFileFinder()
+{
+}
+
+QString
+InteractiveFileFinder::getOpenFileName(FileType type, QString fallbackLocation)
+{
+    QString settingsKey;
+    QString lastPath = fallbackLocation;
+    
+    QString title = tr("Select file");
+    QString filter = tr("All files (*.*)");
+
+    switch (type) {
+
+    case SessionFile:
+        settingsKey = "sessionpath";
+        title = tr("Select a session file");
+        filter = tr("Sonic Visualiser session files (*.sv)\nRDF files (%1)\nAll files (*.*)").arg(RDFImporter::getKnownExtensions());
+        break;
+
+    case AudioFile:
+        settingsKey = "audiopath";
+        title = "Select an audio file";
+        filter = tr("Audio files (%1)\nAll files (*.*)")
+            .arg(AudioFileReaderFactory::getKnownExtensions());
+        break;
+
+    case LayerFile:
+        settingsKey = "layerpath";
+        filter = tr("All supported files (%1 %2)\nSonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nSpace-separated .lab files (*.lab)\nRDF files (%2)\nMIDI files (*.mid)\nText files (*.txt)\nAll files (*.*)")
+            .arg(DataFileReaderFactory::getKnownExtensions())
+            .arg(RDFImporter::getKnownExtensions());
+        break;
+
+    case LayerFileNoMidi:
+        settingsKey = "layerpath";
+        filter = tr("All supported files (%1 %2)\nSonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nSpace-separated .lab files (*.lab)\nRDF files (%2)\nText files (*.txt)\nAll files (*.*)")
+            .arg(DataFileReaderFactory::getKnownExtensions())
+            .arg(RDFImporter::getKnownExtensions());
+        break;
+
+    case SessionOrAudioFile:
+        settingsKey = "lastpath";
+        filter = tr("All supported files (*.sv %1 %2)\nSonic Visualiser session files (*.sv)\nAudio files (%2)\nRDF files (%1)\nAll files (*.*)")
+            .arg(RDFImporter::getKnownExtensions())
+            .arg(AudioFileReaderFactory::getKnownExtensions());
+        break;
+
+    case ImageFile:
+        settingsKey = "imagepath";
+        {
+            QStringList fmts;
+            QList<QByteArray> formats = QImageReader::supportedImageFormats();
+            for (QList<QByteArray>::iterator i = formats.begin();
+                 i != formats.end(); ++i) {
+                fmts.push_back(QString("*.%1")
+                               .arg(QString::fromLocal8Bit(*i).toLower()));
+            }
+            filter = tr("Image files (%1)\nAll files (*.*)").arg(fmts.join(" "));
+        }
+        break;
+
+    case AnyFile:
+        settingsKey = "lastpath";
+        filter = tr("All supported files (*.sv %1 %2 %3)\nSonic Visualiser session files (*.sv)\nAudio files (%1)\nLayer files (%2)\nRDF files (%3)\nAll files (*.*)")
+            .arg(AudioFileReaderFactory::getKnownExtensions())
+            .arg(DataFileReaderFactory::getKnownExtensions())
+            .arg(RDFImporter::getKnownExtensions());
+        break;
+    };
+
+    if (lastPath == "") {
+        char *home = getenv("HOME");
+        if (home) lastPath = home;
+        else lastPath = ".";
+    } else if (QFileInfo(lastPath).isDir()) {
+        lastPath = QFileInfo(lastPath).canonicalPath();
+    } else {
+        lastPath = QFileInfo(lastPath).absoluteDir().canonicalPath();
+    }
+
+    QSettings settings;
+    settings.beginGroup("FileFinder");
+    lastPath = settings.value(settingsKey, lastPath).toString();
+
+    QString path = "";
+
+    // Use our own QFileDialog just for symmetry with getSaveFileName below
+
+    QFileDialog dialog;
+    dialog.setFilters(filter.split('\n'));
+    dialog.setWindowTitle(title);
+    dialog.setDirectory(lastPath);
+
+    dialog.setAcceptMode(QFileDialog::AcceptOpen);
+    dialog.setFileMode(QFileDialog::ExistingFile);
+    
+    if (dialog.exec()) {
+        QStringList files = dialog.selectedFiles();
+        if (!files.empty()) path = *files.begin();
+        
+        QFileInfo fi(path);
+        
+        if (!fi.exists()) {
+            
+            QMessageBox::critical(0, tr("File does not exist"),
+                                  tr("<b>File not found</b><p>File \"%1\" does not exist").arg(path));
+            path = "";
+            
+        } else if (!fi.isReadable()) {
+            
+            QMessageBox::critical(0, tr("File is not readable"),
+                                  tr("<b>File is not readable</b><p>File \"%1\" can not be read").arg(path));
+            path = "";
+            
+        } else if (fi.isDir()) {
+            
+            QMessageBox::critical(0, tr("Directory selected"),
+                                  tr("<b>Directory selected</b><p>File \"%1\" is a directory").arg(path));
+            path = "";
+
+        } else if (!fi.isFile()) {
+            
+            QMessageBox::critical(0, tr("Non-file selected"),
+                                  tr("<b>Not a file</b><p>Path \"%1\" is not a file").arg(path));
+            path = "";
+            
+        } else if (fi.size() == 0) {
+            
+            QMessageBox::critical(0, tr("File is empty"),
+                                  tr("<b>File is empty</b><p>File \"%1\" is empty").arg(path));
+            path = "";
+        }                
+    }
+
+    if (path != "") {
+        settings.setValue(settingsKey,
+                          QFileInfo(path).absoluteDir().canonicalPath());
+    }
+    
+    return path;
+}
+
+QString
+InteractiveFileFinder::getSaveFileName(FileType type, QString fallbackLocation)
+{
+    QString settingsKey;
+    QString lastPath = fallbackLocation;
+    
+    QString title = tr("Select file");
+    QString filter = tr("All files (*.*)");
+
+    switch (type) {
+
+    case SessionFile:
+        settingsKey = "savesessionpath";
+        title = tr("Select a session file");
+        filter = tr("Sonic Visualiser session files (*.sv)\nAll files (*.*)");
+        break;
+
+    case AudioFile:
+        settingsKey = "saveaudiopath";
+        title = "Select an audio file";
+        title = tr("Select a file to export to");
+        filter = tr("WAV audio files (*.wav)\nAll files (*.*)");
+        break;
+
+    case LayerFile:
+        settingsKey = "savelayerpath";
+        title = tr("Select a file to export to");
+        filter = tr("Sonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nRDF/Turtle files (%1)\nMIDI files (*.mid)\nText files (*.txt)\nAll files (*.*)").arg(RDFExporter::getSupportedExtensions());
+        break;
+
+    case LayerFileNoMidi:
+        settingsKey = "savelayerpath";
+        title = tr("Select a file to export to");
+        filter = tr("Sonic Visualiser Layer XML files (*.svl)\nComma-separated data files (*.csv)\nRDF/Turtle files (%1)\nText files (*.txt)\nAll files (*.*)").arg(RDFExporter::getSupportedExtensions());
+        break;
+
+    case SessionOrAudioFile:
+        std::cerr << "ERROR: Internal error: InteractiveFileFinder::getSaveFileName: SessionOrAudioFile cannot be used here" << std::endl;
+        abort();
+
+    case ImageFile:
+        settingsKey = "saveimagepath";
+        title = tr("Select a file to export to");
+        filter = tr("Portable Network Graphics files (*.png)\nAll files (*.*)");
+        break;
+
+    case AnyFile:
+        std::cerr << "ERROR: Internal error: InteractiveFileFinder::getSaveFileName: AnyFile cannot be used here" << std::endl;
+        abort();
+    };
+
+    if (lastPath == "") {
+        char *home = getenv("HOME");
+        if (home) lastPath = home;
+        else lastPath = ".";
+    } else if (QFileInfo(lastPath).isDir()) {
+        lastPath = QFileInfo(lastPath).canonicalPath();
+    } else {
+        lastPath = QFileInfo(lastPath).absoluteDir().canonicalPath();
+    }
+
+    QSettings settings;
+    settings.beginGroup("FileFinder");
+    lastPath = settings.value(settingsKey, lastPath).toString();
+
+    QString path = "";
+
+    // Use our own QFileDialog instead of static functions, as we may
+    // need to adjust the file extension based on the selected filter
+
+    QFileDialog dialog;
+    dialog.setFilters(filter.split('\n'));
+    dialog.setWindowTitle(title);
+    dialog.setDirectory(lastPath);
+
+    dialog.setAcceptMode(QFileDialog::AcceptSave);
+    dialog.setFileMode(QFileDialog::AnyFile);
+    dialog.setConfirmOverwrite(false); // we'll do that
+        
+    if (type == SessionFile) {
+        dialog.setDefaultSuffix("sv");
+    } else if (type == AudioFile) {
+        dialog.setDefaultSuffix("wav");
+    } else if (type == ImageFile) {
+        dialog.setDefaultSuffix("png");
+    }
+
+    bool good = false;
+
+    while (!good) {
+
+        path = "";
+        
+        if (!dialog.exec()) break;
+        
+        QStringList files = dialog.selectedFiles();
+        if (files.empty()) break;
+        path = *files.begin();
+        
+        QFileInfo fi(path);
+
+        std::cerr << "type = " << type << ", suffix = " << fi.suffix().toStdString() << std::endl;
+        
+        if ((type == LayerFile || type == LayerFileNoMidi)
+            && fi.suffix() == "") {
+            QString expectedExtension;
+            QString selectedFilter = dialog.selectedFilter();
+            if (selectedFilter.contains(".svl")) {
+                expectedExtension = "svl";
+            } else if (selectedFilter.contains(".txt")) {
+                expectedExtension = "txt";
+            } else if (selectedFilter.contains(".csv")) {
+                expectedExtension = "csv";
+            } else if (selectedFilter.contains(".mid")) {
+                expectedExtension = "mid";
+            } else if (selectedFilter.contains(".ttl")) {
+                expectedExtension = "ttl";
+            }
+            std::cerr << "expected extension = " << expectedExtension.toStdString() << std::endl;
+            if (expectedExtension != "") {
+                path = QString("%1.%2").arg(path).arg(expectedExtension);
+                fi = QFileInfo(path);
+            }
+        }
+        
+        if (fi.isDir()) {
+            QMessageBox::critical(0, tr("Directory selected"),
+                                  tr("<b>Directory selected</b><p>File \"%1\" is a directory").arg(path));
+            continue;
+        }
+        
+        if (fi.exists()) {
+            if (QMessageBox::question(0, tr("File exists"),
+                                      tr("<b>File exists</b><p>The file \"%1\" already exists.\nDo you want to overwrite it?").arg(path),
+                                      QMessageBox::Ok,
+                                      QMessageBox::Cancel) != QMessageBox::Ok) {
+                continue;
+            }
+        }
+        
+        good = true;
+    }
+        
+    if (path != "") {
+        settings.setValue(settingsKey,
+                          QFileInfo(path).absoluteDir().canonicalPath());
+    }
+    
+    return path;
+}
+
+void
+InteractiveFileFinder::registerLastOpenedFilePath(FileType type, QString path)
+{
+    QString settingsKey;
+
+    switch (type) {
+    case SessionFile:
+        settingsKey = "sessionpath";
+        break;
+
+    case AudioFile:
+        settingsKey = "audiopath";
+        break;
+
+    case LayerFile:
+        settingsKey = "layerpath";
+        break;
+
+    case LayerFileNoMidi:
+        settingsKey = "layerpath";
+        break;
+
+    case SessionOrAudioFile:
+        settingsKey = "lastpath";
+        break;
+
+    case ImageFile:
+        settingsKey = "imagepath";
+        break;
+
+    case AnyFile:
+        settingsKey = "lastpath";
+        break;
+    }
+
+    if (path != "") {
+        QSettings settings;
+        settings.beginGroup("FileFinder");
+        path = QFileInfo(path).absoluteDir().canonicalPath();
+        settings.setValue(settingsKey, path);
+        settings.setValue("lastpath", path);
+    }
+}
+    
+QString
+InteractiveFileFinder::find(FileType type, QString location, QString lastKnownLocation)
+{
+    if (FileSource::canHandleScheme(location)) {
+        if (FileSource(location).isAvailable()) {
+            std::cerr << "InteractiveFileFinder::find: ok, it's available... returning" << std::endl;
+            return location;
+        }
+    }
+
+    if (QFileInfo(location).exists()) return location;
+
+    QString foundAt = "";
+
+    if ((foundAt = findRelative(location, lastKnownLocation)) != "") {
+        return foundAt;
+    }
+
+    if ((foundAt = findRelative(location, m_lastLocatedLocation)) != "") {
+        return foundAt;
+    }
+
+    return locateInteractive(type, location);
+}
+
+QString
+InteractiveFileFinder::findRelative(QString location, QString relativeTo)
+{
+    if (relativeTo == "") return "";
+
+    std::cerr << "Looking for \"" << location.toStdString() << "\" next to \""
+              << relativeTo.toStdString() << "\"..." << std::endl;
+
+    QString fileName;
+    QString resolved;
+
+    if (FileSource::isRemote(location)) {
+        fileName = QUrl(location).path().section('/', -1, -1,
+                                                 QString::SectionSkipEmpty);
+    } else {
+        if (QUrl(location).scheme() == "file") {
+            location = QUrl(location).toLocalFile();
+        }
+        fileName = QFileInfo(location).fileName();
+    }
+
+    if (FileSource::isRemote(relativeTo)) {
+        resolved = QUrl(relativeTo).resolved(fileName).toString();
+        if (!FileSource(resolved).isAvailable()) resolved = "";
+        std::cerr << "resolved: " << resolved.toStdString() << std::endl;
+    } else {
+        if (QUrl(relativeTo).scheme() == "file") {
+            relativeTo = QUrl(relativeTo).toLocalFile();
+        }
+        resolved = QFileInfo(relativeTo).dir().filePath(fileName);
+        if (!QFileInfo(resolved).exists() ||
+            !QFileInfo(resolved).isFile() ||
+            !QFileInfo(resolved).isReadable()) {
+            resolved = "";
+        }
+    }
+            
+    return resolved;
+}
+
+QString
+InteractiveFileFinder::locateInteractive(FileType type, QString thing)
+{
+    QString question;
+    if (type == AudioFile) {
+        question = tr("<b>File not found</b><p>Audio file \"%1\" could not be opened.\nDo you want to locate it?");
+    } else {
+        question = tr("<b>File not found</b><p>File \"%1\" could not be opened.\nDo you want to locate it?");
+    }
+
+    QString path = "";
+    bool done = false;
+
+    while (!done) {
+
+        int rv = QMessageBox::question
+            (0, 
+             tr("Failed to open file"),
+             question.arg(thing),
+             tr("Locate file..."),
+             tr("Use URL..."),
+             tr("Cancel"),
+             0, 2);
+        
+        switch (rv) {
+
+        case 0: // Locate file
+
+            if (QFileInfo(thing).dir().exists()) {
+                path = QFileInfo(thing).dir().canonicalPath();
+            }
+            
+            path = getOpenFileName(type, path);
+            done = (path != "");
+            break;
+
+        case 1: // Use URL
+        {
+            bool ok = false;
+            path = QInputDialog::getText
+                (0, tr("Use URL"),
+                 tr("Please enter the URL to use for this file:"),
+                 QLineEdit::Normal, "", &ok);
+
+            if (ok && path != "") {
+                if (FileSource(path).isAvailable()) {
+                    done = true;
+                } else {
+                    QMessageBox::critical
+                        (0, tr("Failed to open location"),
+                         tr("<b>Failed to open location</b><p>URL \"%1\" could not be opened").arg(path));
+                    path = "";
+                }
+            }
+            break;
+        }
+
+        case 2: // Cancel
+            path = "";
+            done = true;
+            break;
+        }
+    }
+
+    if (path != "") m_lastLocatedLocation = path;
+    return path;
+}
+
+
diff -r 44f391ec2172 -r 3228b7913aa4 widgets/InteractiveFileFinder.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widgets/InteractiveFileFinder.h	Fri Mar 27 16:25:52 2009 +0000
@@ -0,0 +1,51 @@
+/* -*- 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.
+*/
+
+#ifndef _INTERACTIVE_FILE_FINDER_H_
+#define _INTERACTIVE_FILE_FINDER_H_
+
+#include "data/fileio/FileFinder.h"
+
+#include <QString>
+#include <QObject>
+
+class InteractiveFileFinder : public QObject,
+                              public FileFinder
+{
+    Q_OBJECT
+
+public:
+    virtual ~InteractiveFileFinder();
+
+    QString getOpenFileName(FileType type, QString fallbackLocation = "");
+    QString getSaveFileName(FileType type, QString fallbackLocation = "");
+    void registerLastOpenedFilePath(FileType type, QString path);
+
+    QString find(FileType type, QString location, QString lastKnownLocation = "");
+
+    static InteractiveFileFinder *getInstance() { return &m_instance; }
+
+protected:
+    InteractiveFileFinder();
+    static InteractiveFileFinder m_instance;
+
+    QString findRelative(QString location, QString relativeTo);
+    QString locateInteractive(FileType type, QString thing);
+
+    QString m_lastLocatedLocation;
+};
+
+#endif
+
diff -r 44f391ec2172 -r 3228b7913aa4 widgets/widgets.pro
--- a/widgets/widgets.pro	Fri Mar 27 13:10:01 2009 +0000
+++ b/widgets/widgets.pro	Fri Mar 27 16:25:52 2009 +0000
@@ -21,7 +21,7 @@
            CommandHistory.h \
            CSVFormatDialog.h \
            Fader.h \
-           FileFinder.h \
+           InteractiveFileFinder.h \
            IconLoader.h \
            ImageDialog.h \
            ItemEditDialog.h \
@@ -58,7 +58,7 @@
            CommandHistory.cpp \
            CSVFormatDialog.cpp \
            Fader.cpp \
-           FileFinder.cpp \
+           InteractiveFileFinder.cpp \
            IconLoader.cpp \
            ImageDialog.cpp \
            ItemEditDialog.cpp \