Merge lp:~schwann/gallery-app/gallery-previewmanager-refactor into lp:gallery-app

[Günter Schwann]

Refactor PreviewManager to save thumbnails in $HOME/.cache/thumbnails (LP: 1089655)

Refactor PreviewManager.
Fixes bug LP 1089655
Saves the thumbnails in $HOME/.cache/thumbnails
Thumbnail creation is now closer to the freedesktop standard

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[Olivier Tilloy (osomon)]

411 + * \brief PreviewManager::saveThumbnail saves the thumbnail in an save way

You mean "in a safe way", right?

review: Needs Fixing

[Olivier Tilloy (osomon)]

474 + QString previewDir = m_thumbnailDir + levelName + "/";

In some places you’re using "/", and in other places QDir::separator(). It would be good to make this consistent (I’d go for the latter, for portability).

[Olivier Tilloy (osomon)]

Apart from the two comments above, the changeset looks good to me.

review: Approve

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FAILED: Continuous integration, rev:685
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PASSED: Continuous integration, rev:685
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=== modified file 'src/database/database.cpp'
--- src/database/database.cpp	2013-06-03 15:18:06 +0000
+++ src/database/database.cpp	2013-06-05 09:11:06 +0000
@@ -44,7 +44,7 @@
         QDir dir;
         bool createOk = dir.mkpath(m_databaseDirectory);
         if (!createOk)
-            qWarning() << "Unanble to create DB directory" << m_databaseDirectory;
+            qWarning() << "Unable to create DB directory" << m_databaseDirectory;
     }
 
     album_table_ = new AlbumTable(this, this);
@@ -156,7 +156,7 @@
     for (;; version++) {
         // Check for the existence of an updated db file.
         // Filename format is n.sql, where n is the schema version number.
-        QFile file(get_sql_dir() + "/" + QString::number(version) + ".sql");
+        QFile file(get_sql_dir() + QDir::separator() + QString::number(version) + ".sql");
         if (!file.exists())
             return;
 

=== modified file 'src/gallery-manager.cpp'
--- src/gallery-manager.cpp	2013-06-03 15:18:06 +0000
+++ src/gallery-manager.cpp	2013-06-05 09:11:06 +0000
@@ -71,6 +71,8 @@
 
 void GalleryManager::post_init()
 {
+    Q_ASSERT(resource_);
+
     if (!collections_initialised)
     {
         qDebug() << "Opening" << resource_->picturesDirectory() << "...";
@@ -85,13 +87,11 @@
         media_collection_ = new MediaCollection(mediaDir);
         album_collection_ = new AlbumCollection();
         event_collection_ = new EventCollection();
-        preview_manager_ = new PreviewManager();
-
-        gallery_standard_image_provider_->setPreviewManager(preview_manager_);
-        gallery_thumbnail_image_provider_->setPreviewManager(preview_manager_);
 
         collections_initialised = true;
 
+        initPreviewManager();
+
         qDebug() << "Opened" << resource_->picturesDirectory();
     }
 }
@@ -125,3 +125,38 @@
     delete preview_manager_;
     preview_manager_ = NULL;
 }
+
+/*!
+ * \brief GalleryManager::initPreviewManager creates the PreviewManager,
+ * assigns it to all needed objects and creates all signal slot connection.
+ */
+void GalleryManager::initPreviewManager()
+{
+    Q_ASSERT(resource_);
+    Q_ASSERT(media_collection_);
+    Q_ASSERT(gallery_standard_image_provider_);
+    Q_ASSERT(gallery_thumbnail_image_provider_);
+
+    if (preview_manager_)
+        return;
+
+    preview_manager_ = new PreviewManager(resource_->thumbnailDirectory(),
+                                          media_collection_);
+
+    gallery_standard_image_provider_->setPreviewManager(preview_manager_);
+    gallery_thumbnail_image_provider_->setPreviewManager(preview_manager_);
+
+    // Monitor MediaCollection for all new MediaSources
+    QObject::connect(media_collection_,
+                     SIGNAL(contents_altered(const QSet<DataObject*>*,const QSet<DataObject*>*)),
+                     preview_manager_,
+                     SLOT(on_media_added_removed(const QSet<DataObject*>*,const QSet<DataObject*>*)));
+
+    QObject::connect(media_collection_,
+                     SIGNAL(destroying(const QSet<DataObject*>*)),
+                     preview_manager_,
+                     SLOT(on_media_destroying(const QSet<DataObject*>*)));
+
+    // Verify previews for all existing added MediaSources
+    preview_manager_->onMediaAddedRemoved(&media_collection_->GetAsSet(), NULL);
+}

=== modified file 'src/gallery-manager.h'
--- src/gallery-manager.h	2013-06-03 15:18:06 +0000
+++ src/gallery-manager.h	2013-06-05 09:11:06 +0000
@@ -69,6 +69,8 @@
     GalleryManager(const GalleryManager&);
     void operator=(const GalleryManager&);
 
+    void initPreviewManager();
+
     static GalleryManager* gallery_mgr_;
 
     bool collections_initialised;

=== modified file 'src/media/media-monitor.cpp'
--- src/media/media-monitor.cpp	2013-02-25 10:16:29 +0000
+++ src/media/media-monitor.cpp	2013-06-05 09:11:06 +0000
@@ -65,8 +65,8 @@
 
     QStringList difference = subtract_manifest(new_manifest, manifest_);
     for (int i = 0; i < difference.size(); i++)
-        notify_media_item_added(target_directory_.absolutePath() + "/" +
-                                difference.at(i));
+        notify_media_item_added(target_directory_.absolutePath() +
+                                QDir::separator() + difference.at(i));
 
     manifest_ = new_manifest;
 }

=== modified file 'src/media/media-source.cpp'
--- src/media/media-source.cpp	2013-05-28 13:50:03 +0000
+++ src/media/media-source.cpp	2013-06-05 09:11:06 +0000
@@ -85,9 +85,9 @@
  * \brief MediaSource::preview_file
  * \return
  */
-QFileInfo MediaSource::preview_file() const
+QString MediaSource::preview_file() const
 {
-    return GalleryManager::instance()->preview_manager()->PreviewFileFor(file_);
+    return GalleryManager::instance()->preview_manager()->previewFileName(file_);
 }
 
 /*!
@@ -96,7 +96,7 @@
  */
 QUrl MediaSource::preview_path() const
 {
-    return QUrl::fromLocalFile(preview_file().absoluteFilePath());
+    return QUrl::fromLocalFile(preview_file());
 }
 
 /*!
@@ -112,9 +112,9 @@
  * \brief MediaSource::thumbnail_file
  * \return
  */
-QFileInfo MediaSource::thumbnail_file() const
+QString MediaSource::thumbnail_file() const
 {
-    return GalleryManager::instance()->preview_manager()->ThumbnailFileFor(file_);
+    return GalleryManager::instance()->preview_manager()->thumbnailFileName(file_);
 }
 
 /*!
@@ -123,7 +123,7 @@
  */
 QUrl MediaSource::thumbnail_path() const
 {
-    return QUrl::fromLocalFile(thumbnail_file().absoluteFilePath());
+    return QUrl::fromLocalFile(thumbnail_file());
 }
 
 /*!

=== modified file 'src/media/media-source.h'
--- src/media/media-source.h	2013-03-29 11:21:18 +0000
+++ src/media/media-source.h	2013-06-05 09:11:06 +0000
@@ -82,11 +82,11 @@
     QUrl path() const;
     virtual QUrl gallery_path() const;
 
-    QFileInfo preview_file() const;
+    QString preview_file() const;
     QUrl preview_path() const;
     virtual QUrl gallery_preview_path() const;
 
-    QFileInfo thumbnail_file() const;
+    QString thumbnail_file() const;
     QUrl thumbnail_path() const;
     virtual QUrl gallery_thumbnail_path() const;
 

=== modified file 'src/media/preview-manager.cpp'
--- src/media/preview-manager.cpp	2013-05-28 13:50:03 +0000
+++ src/media/preview-manager.cpp	2013-06-05 09:11:06 +0000
@@ -17,51 +17,51 @@
  * Jim Nelson <[e-mail]>
  */
 
+#include <QCryptographicHash>
 #include <QDir>
 #include <QMutexLocker>
 
 #include "preview-manager.h"
 #include "media-collection.h"
 #include "photo/photo.h"
-#include "gallery-manager.h"
 
-const int PreviewManager::PREVIEW_WIDTH_MAX = 360;
-const int PreviewManager::PREVIEW_HEIGHT_MAX = 360;
 // FIXME adapt to different sizes. This is fixed size for the demo device
-const int PreviewManager::THUMBNAIL_SIZE = 216;
+const int PreviewManager::PREVIEW_SIZE = 360; // in pixel
+const int PreviewManager::THUMBNAIL_SIZE = 216; // in pixel
 const int PreviewManager::PREVIEW_QUALITY = 70;
 const char* PreviewManager::PREVIEW_FILE_FORMAT = "JPEG";
-const char* PreviewManager::PREVIEW_FILE_EXT = "JPG";
-const QString PreviewManager::PREVIEW_DIR = ".thumbs";
+const char* PreviewManager::PREVIEW_FILE_EXT = ".jpg";
+const QString PreviewManager::PREVIEW_DIR = "preview";
+const QString PreviewManager::THUMBNAIL_DIR = "square";
 
-QMutex PreviewManager::createMutex_;
+QMutex PreviewManager::m_createMutex;
 
 /*!
  * \brief PreviewManager::PreviewManager
  */
-PreviewManager::PreviewManager()
+PreviewManager::PreviewManager(const QString &thumbnailDirectory,
+                               MediaCollection *mediaCollection, QObject *parent)
+    : QObject(parent),
+      m_thumbnailDir(thumbnailDirectory),
+      m_mediaCollection(mediaCollection)
 {
-    // Monitor MediaCollection for all new MediaSources
-    QObject::connect(GalleryManager::instance()->media_collection(),
-                     SIGNAL(contents_altered(const QSet<DataObject*>*,const QSet<DataObject*>*)),
-                     this,
-                     SLOT(on_media_added_removed(const QSet<DataObject*>*,const QSet<DataObject*>*)));
-
-    QObject::connect(GalleryManager::instance()->media_collection(),
-                     SIGNAL(destroying(const QSet<DataObject*>*)),
-                     this,
-                     SLOT(on_media_destroying(const QSet<DataObject*>*)));
-
-    // Verify previews for all existing added MediaSources
-    on_media_added_removed(&GalleryManager::instance()->media_collection()->GetAsSet(), NULL);
+    Q_ASSERT(m_mediaCollection);
+
+    if (m_thumbnailDir.right(1) != QDir::separator())
+        m_thumbnailDir += QDir::separator();
+
+    // create the thumbnail directory if not already present
+    QDir dir;
+    dir.mkpath(m_thumbnailDir + PREVIEW_DIR);
+    dir.mkpath(m_thumbnailDir + THUMBNAIL_DIR);
 }
 
 /*!
- * \brief PreviewManager::on_media_added_removed
+ * \brief PreviewManager::onMediaAddedRemoved
  * \param added
  * \param removed
  */
-void PreviewManager::on_media_added_removed(const QSet<DataObject*>* added,
+void PreviewManager::onMediaAddedRemoved(const QSet<DataObject*>* added,
                                             const QSet<DataObject*>* removed)
 {
     if (added != NULL) {
@@ -70,7 +70,7 @@
             MediaSource* source = qobject_cast<MediaSource*>(object);
 
             QObject::connect(source, SIGNAL(data_altered()),
-                             this, SLOT(on_media_data_altered()), Qt::UniqueConnection);
+                             this, SLOT(updatePreview()), Qt::UniqueConnection);
         }
     }
 
@@ -79,76 +79,73 @@
         foreach (object, *removed) {
             MediaSource* source = qobject_cast<MediaSource*>(object);
             QObject::disconnect(source, SIGNAL(data_altered()),
-                                this, SLOT(on_media_data_altered()));
+                                this, SLOT(updatePreview()));
         }
     }
 }
 
 /*!
- * \brief PreviewManager::on_media_destroying
+ * \brief PreviewManager::onMediaDestroying
  * \param destroying
  */
-void PreviewManager::on_media_destroying(const QSet<DataObject*>* destroying)
+void PreviewManager::onMediaDestroying(const QSet<DataObject*>* destroying)
 {
     if (destroying != NULL) {
         DataObject* object;
         foreach (object, *destroying)
-            DestroyPreview(qobject_cast<MediaSource*>(object));
+            destroyPreviews(qobject_cast<MediaSource*>(object));
     }
 }
 
 /*!
- * \brief PreviewManager::on_media_data_altered
+ * \brief PreviewManager::updatePreview
  */
-void PreviewManager::on_media_data_altered()
+void PreviewManager::updatePreview()
 {
     QObject* object = QObject::sender();
     MediaSource* source = qobject_cast<MediaSource*>(object);
 
-    ensure_preview_for_media(source->file(), true);
-}
-
-/*!
- * \brief PreviewManager::PreviewFileFor
- * \param file
- * \return
- */
-QFileInfo PreviewManager::PreviewFileFor(const QFileInfo& file)
-{
-    return QFileInfo(file.dir(), PREVIEW_DIR + "/" + file.completeBaseName() + "_th." + PREVIEW_FILE_EXT);
-}
-
-/*!
- * \brief PreviewManager::ThumbnailFileFor
- * \param file
- * \return
- */
-QFileInfo PreviewManager::ThumbnailFileFor(const QFileInfo& file)
-{
-    return QFileInfo(file.dir(), PREVIEW_DIR + "/" + file.completeBaseName() + "_th_s." + PREVIEW_FILE_EXT);
-}
-
-/*!
- * \brief PreviewManager::ensure_preview_for_media
+    ensurePreview(source->file(), true);
+}
+
+/*!
+ * \brief PreviewManager::previewFileName
+ * \param file
+ * \return
+ */
+QString PreviewManager::previewFileName(const QFileInfo& file) const
+{
+    return thumbnailFileName(file.canonicalFilePath(), PREVIEW_DIR);
+}
+
+/*!
+ * \brief PreviewManager::thumbnailFileName
+ * \param file
+ * \return
+ */
+QString PreviewManager::thumbnailFileName(const QFileInfo& file) const
+{
+    return thumbnailFileName(file.canonicalFilePath(), THUMBNAIL_DIR);
+}
+
+/*!
+ * \brief PreviewManager::ensurePreview
  * \param file
  * \param regen
  * \return
  */
-bool PreviewManager::ensure_preview_for_media(QFileInfo file, bool regen)
+bool PreviewManager::ensurePreview(QFileInfo file, bool regen)
 {
-    QMutexLocker locker(&createMutex_);
-
-    // create the thumbnail directory if not already present
-    file.dir().mkdir(PREVIEW_DIR);
+    QMutexLocker locker(&m_createMutex);
 
     // If preview file exists, considered valid (unless we're regenerating it).
-    QFileInfo preview = PreviewFileFor(file);
-    QFileInfo thumbnail = ThumbnailFileFor(file);
+    QString preview = previewFileName(file);
+    QString thumbnail = thumbnailFileName(file);
 
     QImage thumbMaster;
-    if (!preview.exists() || regen) {
-        Photo* photo = GalleryManager::instance()->media_collection()->photoFromFileinfo(file);
-        QSize previewSize(PREVIEW_WIDTH_MAX, PREVIEW_WIDTH_MAX);
+    if (updateNeeded(file, QFileInfo(preview)) || regen) {
+        Photo* photo = m_mediaCollection->photoFromFileinfo(file);
+        QSize previewSize(PREVIEW_SIZE, PREVIEW_SIZE);
         QImage fullsized(photo->Image(true, previewSize));
         if (fullsized.isNull()) {
             qDebug() << "Unable to generate fullsized image for " << file.filePath() << "not generating preview";
@@ -159,34 +156,34 @@
         // these values are replicated in the QML so that the preview will fill each
         // grid cell, cropping down to the center of the image if necessary
         QImage scaled = (fullsized.height() > fullsized.width())
-                ? fullsized.scaledToWidth(PREVIEW_WIDTH_MAX, Qt::SmoothTransformation)
-                : fullsized.scaledToHeight(PREVIEW_HEIGHT_MAX, Qt::SmoothTransformation);
+                ? fullsized.scaledToWidth(PREVIEW_SIZE, Qt::SmoothTransformation)
+                : fullsized.scaledToHeight(PREVIEW_SIZE, Qt::SmoothTransformation);
 
         if (scaled.isNull()) {
             qDebug() << "Unable to scale " << file.filePath() << "for preview";
             return false;
         }
 
-        if (!scaled.save(preview.filePath(), PREVIEW_FILE_FORMAT, PREVIEW_QUALITY)) {
-            qDebug("Unable to save preview %s", qPrintable(preview.filePath()));
+        if (!saveThumbnail(scaled, preview)) {
+            qDebug("Unable to save preview %s", qPrintable(preview));
             return false;
         }
         thumbMaster = scaled;
     }
 
-    if (!thumbnail.exists() || regen) {
+    if (updateNeeded(file, QFileInfo(thumbnail)) || regen) {
         if (thumbMaster.isNull()) {
-            thumbMaster.load(preview.filePath());
+            thumbMaster.load(preview);
             if (thumbMaster.isNull()) {
                 qDebug("Unable load preview image for %s, not generating thumbnail",
-                       qPrintable(preview.filePath()));
+                       qPrintable(preview));
                 return false;
             }
         }
 
-        QImage square = generate_Thumbnail(thumbMaster);
-        if (!square.save(thumbnail.filePath(), PREVIEW_FILE_FORMAT, PREVIEW_QUALITY)) {
-            qDebug("Unable to save preview %s", qPrintable(thumbnail.filePath()));
+        QImage square = generateThumbnail(thumbMaster);
+        if (!saveThumbnail(square, thumbnail)) {
+            qDebug("Unable to save preview %s", qPrintable(thumbnail));
             return false;
         }
     }
@@ -195,25 +192,44 @@
 }
 
 /*!
- * \brief PreviewManager::DestroyPreview
+ * \brief PreviewManager::saveThumbnail saves the thumbnail in a safe way
+ * The image is written to a temporary file, and then moved (the move is atomic)
+ * \param image thumbnail to save
+ * \param fileName filename of the thumbnail
+ * \return true, if saving the file was successful
+ */
+bool PreviewManager::saveThumbnail(const QImage &image, const QString &fileName) const
+{
+    QString temporaryName(fileName+".tmp");
+    bool ok;
+    ok = image.save(temporaryName, PREVIEW_FILE_FORMAT, PREVIEW_QUALITY);
+    if (!ok)
+        return false;
+
+    QFile thumbnail(temporaryName);
+    return thumbnail.rename(fileName);
+}
+
+/*!
+ * \brief PreviewManager::destroyPreviews
  * \param media
  */
-void PreviewManager::DestroyPreview(MediaSource* media)
+void PreviewManager::destroyPreviews(MediaSource* media)
 {
-    QString filename = PreviewFileFor(media->file()).filePath();
+    QString filename = previewFileName(media->file());
     if (!QFile::remove(filename))
         qDebug("Unable to remove preview %s", qPrintable(filename));
-    filename = ThumbnailFileFor(media->file()).filePath();
+    filename = thumbnailFileName(media->file());
     if (!QFile::remove(filename))
         qDebug("Unable to remove thumbnail %s", qPrintable(filename));
 }
 
 /*!
- * \brief PreviewManager::generate_Thumbnail
+ * \brief PreviewManager::generateThumbnail
  * \param master
  * \return
  */
-QImage PreviewManager::generate_Thumbnail(const QImage &master) const
+QImage PreviewManager::generateThumbnail(const QImage &master) const
 {
     int xOffset = 0;
     int yOffset = 0;
@@ -230,3 +246,33 @@
     QImage thumbnail = square.scaled(THUMBNAIL_SIZE, THUMBNAIL_SIZE);
     return thumbnail;
 }
+
+/*!
+ * \brief PreviewManager::thumbnailFileName generates the file name for a given
+ * file and it's level (size/type)
+ * \param fileName full filename URI (file:///directory/file.name.png)
+ * \param levelName correclates to the sub directory inside of the thumbnail directory
+ * \return full filePath of the thumbnail
+ */
+QString PreviewManager::thumbnailFileName(const QString &fileName,
+                                          const QString &levelName) const
+{
+    QCryptographicHash md5(QCryptographicHash::Md5);
+    md5.addData(QUrl::fromLocalFile(fileName).toEncoded());
+    QString previewDir = m_thumbnailDir + levelName + QDir::separator();
+    return QString(previewDir + md5.result().toHex() + PREVIEW_FILE_EXT);
+}
+
+/*!
+ * \brief PreviewManager::updateNeeded checks if the thumbnail needs to be (re-)created
+ * \param mediaFile the original photo/video
+ * \param previewFile the preview file
+ * \return true if the thumbnail needs to be created
+ */
+bool PreviewManager::updateNeeded(const QFileInfo &mediaFile, const QFileInfo &previewFile) const
+{
+    if (!previewFile.exists())
+        return true;
+
+    return mediaFile.lastModified() > previewFile.lastModified();
+}

=== modified file 'src/media/preview-manager.h'
--- src/media/preview-manager.h	2013-05-28 13:50:03 +0000
+++ src/media/preview-manager.h	2013-06-05 09:11:06 +0000
@@ -28,43 +28,60 @@
 
 class QImage;
 class DataObject;
+class MediaCollection;
 class MediaSource;
 
 /*!
- * \brief The PreviewManager class
+ * \brief The PreviewManager class creates and removes thumbnails
+ *
+ * The thumbnail storage and creation is inspired by
+ * http://specifications.freedesktop.org/thumbnail-spec/thumbnail-spec-latest.html
+ * But it uses jpeg (for performance),
+ * uses different sizes,
+ * not the standard sub directoy name (because of the sizes),
+ * does not save any meta information in the thumbnails,
+ * does not use the fail directory
  */
 class PreviewManager : public QObject
 {
     Q_OBJECT
 
 public:
-    static const int PREVIEW_WIDTH_MAX;
-    static const int PREVIEW_HEIGHT_MAX;
+    static const int PREVIEW_SIZE;
     static const int THUMBNAIL_SIZE;
     static const int PREVIEW_QUALITY;
     static const char* PREVIEW_FILE_FORMAT;
     static const char* PREVIEW_FILE_EXT;
 
     static const QString PREVIEW_DIR;
-
-    PreviewManager();
-
-    static QFileInfo PreviewFileFor(const QFileInfo& file);
-    static QFileInfo ThumbnailFileFor(const QFileInfo& file);
-
-    bool ensure_preview_for_media(QFileInfo file, bool regen = false);
+    static const QString THUMBNAIL_DIR;
+
+    PreviewManager(const QString& thumbnailDirectory, MediaCollection *mediaCollection,
+                   QObject* parent = 0);
+
+    QString previewFileName(const QFileInfo& file) const;
+    QString thumbnailFileName(const QFileInfo& file) const;
+
+    bool ensurePreview(QFileInfo file, bool regen = false);
+
+public slots:
+    void onMediaAddedRemoved(const QSet<DataObject*>* added,
+                                const QSet<DataObject*>* removed);
+    void onMediaDestroying(const QSet<DataObject*>* destroying);
 
 private slots:
-    void on_media_added_removed(const QSet<DataObject*>* added,
-                                const QSet<DataObject*>* removed);
-    void on_media_destroying(const QSet<DataObject*>* destroying);
-    void on_media_data_altered();
+    void updatePreview();
 
 private:
-    void DestroyPreview(MediaSource* media);
-    QImage generate_Thumbnail(const QImage& master) const;
+    bool saveThumbnail(const QImage& image, const QString& fileName) const;
+    void destroyPreviews(MediaSource* media);
+    QImage generateThumbnail(const QImage& master) const;
+    QString thumbnailFileName(const QString& fileName, const QString& levelName) const;
+    bool updateNeeded(const QFileInfo& mediaFile, const QFileInfo& previewFile) const;
 
-    static QMutex createMutex_;
+    static QMutex m_createMutex;
+    QString m_thumbnailDir;
+    MediaCollection *m_mediaCollection;
 };
 
 #endif  // GALLERY_PREVIEW_MANAGER_H_

=== modified file 'src/qml/gallery-standard-image-provider.cpp'
--- src/qml/gallery-standard-image-provider.cpp	2013-05-28 13:50:03 +0000
+++ src/qml/gallery-standard-image-provider.cpp	2013-06-05 09:11:06 +0000
@@ -39,7 +39,7 @@
 
 // fully load previews into memory when requested
 const int SCALED_LOAD_FLOOR_DIM_PIXELS =
-        qMax(PreviewManager::PREVIEW_WIDTH_MAX, PreviewManager::PREVIEW_HEIGHT_MAX);
+        qMax(PreviewManager::PREVIEW_SIZE, PreviewManager::PREVIEW_SIZE);
 
 /*!
  * \brief GalleryStandardImageProvider::GalleryStandardImageProvider
@@ -100,7 +100,7 @@
 
     QUrl url(id);
     QFileInfo photoFile(url.path());
-    m_previewManager->ensure_preview_for_media(photoFile);
+    m_previewManager->ensurePreview(photoFile);
 
     CachedImage* cachedImage = claim_cached_image_entry(id, loggingStr);
     Q_ASSERT(cachedImage != NULL);
@@ -178,7 +178,7 @@
         // remove CachedImage before prepending to FIFO
         fifo_.removeOne(id);
     } else {
-        cachedImage = new CachedImage(id);
+        cachedImage = new CachedImage(id, idToFile(id));
         cache_.insert(id, cachedImage);
         LOG_IMAGE_STATUS("new-cache-entry ");
     }
@@ -392,11 +392,40 @@
 }
 
 /*!
+ * \brief GalleryStandardImageProvider::idToFile
+ * \param id
+ * \return
+ */
+QString GalleryStandardImageProvider::idToFile(const QString& id) const
+{
+    if (!m_previewManager) {
+        qWarning() << Q_FUNC_INFO << "no PreviewManager set";
+        return QString();
+    }
+
+    QUrl url = QUrl(id);
+    QString fileName = url.path();
+
+    //Get our item value from our query by it's key.
+    QUrlQuery url_query(url);
+    url_query.hasQueryItem(GalleryStandardImageProvider::SIZE_KEY);
+    QString value = url_query.queryItemValue(GalleryStandardImageProvider::SIZE_KEY);
+
+    if (value == "1") {
+        fileName = m_previewManager->previewFileName(fileName);
+    }
+
+    return fileName;
+}
+
+/*!
  * \brief GalleryStandardImageProvider::CachedImage::CachedImage
- * \param id
+ * \param id the full URI of the image
+ * \param fileName the filename for the URI (can be the file itself or the preview)
  */
-GalleryStandardImageProvider::CachedImage::CachedImage(const QString& id)
-    : id_(id), uri_(id), file_(idToFile(id)), hasOrientation_(false),
+GalleryStandardImageProvider::CachedImage::CachedImage(const QString& id,
+                                                       const QString& filename)
+    : id_(id), uri_(id), file_(filename), hasOrientation_(false),
       orientation_(TOP_LEFT_ORIGIN), inUseCount_(0), byteCount_(0)
 {
     QUrlQuery query(uri_);
@@ -414,30 +443,6 @@
 }
 
 /*!
- * \brief GalleryStandardImageProvider::CachedImage::idToFile
- * \param id
- * \return
- */
-QString GalleryStandardImageProvider::CachedImage::idToFile(const QString& id)
-{
-    QUrl url = QUrl(id);
-    QString fileName = url.path();
-
-    //Get our item value from our query by it's key.
-    QUrlQuery url_query(url);
-    url_query.hasQueryItem(GalleryStandardImageProvider::SIZE_KEY);
-    QString value = url_query.queryItemValue(GalleryStandardImageProvider::SIZE_KEY);
-
-    if (value == "1")
-    {
-        QFileInfo thumbnailFile = PreviewManager::PreviewFileFor(fileName);
-        fileName = thumbnailFile.absoluteFilePath();
-    }
-
-    return fileName;
-}
-
-/*!
  * \brief GalleryStandardImageProvider::CachedImage::storeImage
  * Importand: the following should only be called when imageMutex_ is locked
  * \param image

=== modified file 'src/qml/gallery-standard-image-provider.h'
--- src/qml/gallery-standard-image-provider.h	2013-05-28 13:50:03 +0000
+++ src/qml/gallery-standard-image-provider.h	2013-06-05 09:11:06 +0000
@@ -95,9 +95,7 @@
         int inUseCount_;
         uint byteCount_;
 
-        CachedImage(const QString& id);
-
-        static QString idToFile(const QString& id);
+        CachedImage(const QString& id, const QString& filename);
 
         void storeImage(const QImage& image, const QSize& fullSize, Orientation orientation);
         bool isFullSized() const;
@@ -123,6 +121,8 @@
     void release_cached_image_entry(CachedImage* cachedImage, uint bytesLoaded,
                                     long* currentCachedBytes, int* currentCacheEntries);
 
+    QString idToFile(const QString& id) const;
+
     //Allow our test access to private variables.
     friend class tst_GalleryStandardImageProvider;
 };

=== modified file 'src/qml/gallery-thumbnail-image-provider.cpp'
--- src/qml/gallery-thumbnail-image-provider.cpp	2013-05-28 13:50:03 +0000
+++ src/qml/gallery-thumbnail-image-provider.cpp	2013-06-05 09:11:06 +0000
@@ -69,10 +69,9 @@
 
     QUrl url(id);
     QFileInfo photoFile(url.path());
-    m_previewManager->ensure_preview_for_media(photoFile);
+    m_previewManager->ensurePreview(photoFile);
 
-    QFileInfo thumbnailFile = m_previewManager->ThumbnailFileFor(photoFile);
-    QString fileName = thumbnailFile.absoluteFilePath();
+    QString fileName = m_previewManager->thumbnailFileName(photoFile);
 
     QImage thumbnail;
     thumbnail.load(fileName);

=== modified file 'src/util/resource.cpp'
--- src/util/resource.cpp	2013-06-03 15:18:06 +0000
+++ src/util/resource.cpp	2013-06-05 09:11:06 +0000
@@ -25,6 +25,7 @@
 #include <QStandardPaths>
 
 const QLatin1String Resource::DATABASE_DIR = QLatin1String("database");
+const QLatin1String Resource::THUMBNAIL_DIR = QLatin1String("thumbnails");
 
 /*!
  * \brief Resource::Resource
@@ -35,6 +36,7 @@
 Resource::Resource(const QString &pictureDir, QQuickView *view)
     : m_pictureDirectory(pictureDir),
       m_databaseDirectory(""),
+      m_thumbnailDirectory(""),
       m_view(view),
       m_maxTextureSize(0)
 {
@@ -83,6 +85,23 @@
 }
 
 /*!
+ * \brief Resource::thumbnailDirectory returns the base directory of the thumbnails
+ * \return
+ */
+const QString &Resource::thumbnailDirectory() const
+{
+    if (m_thumbnailDirectory.isEmpty()) {
+        if (m_pictureDirectory == QStandardPaths::writableLocation(QStandardPaths::PicturesLocation)) {
+            m_thumbnailDirectory = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) +
+                    QDir::separator() + THUMBNAIL_DIR;
+        } else {
+            m_thumbnailDirectory = m_pictureDirectory + QDir::separator() + "." + THUMBNAIL_DIR;
+        }
+    }
+    return m_thumbnailDirectory;
+}
+
+/*!
  * \brief maxTextureSize
  * \return max texture size provided by OpenGL
  */

=== modified file 'src/util/resource.h'
--- src/util/resource.h	2013-06-03 15:18:06 +0000
+++ src/util/resource.h	2013-06-05 09:11:06 +0000
@@ -37,6 +37,7 @@
 
     const QString &picturesDirectory() const;
     const QString &databaseDirectory() const;
+    const QString &thumbnailDirectory() const;
 
     int maxTextureSize() const;
     void setView(QQuickView* view);
@@ -44,11 +45,14 @@
 private:
     QString m_pictureDirectory;
     mutable QString m_databaseDirectory;
+    mutable QString m_thumbnailDirectory;
     QQuickView* m_view;
     mutable int m_maxTextureSize;
 
     // Path to database, relative to application data path.
     static const QLatin1String DATABASE_DIR;
+    // Path to database, relative to application cache path.
+    static const QLatin1String THUMBNAIL_DIR;
 
     friend class tst_Resource;
 };

=== added directory 'tests/autopilot/gallery_app/data/.thumbnails'
=== added directory 'tests/autopilot/gallery_app/data/.thumbnails/preview'
=== added file 'tests/autopilot/gallery_app/data/.thumbnails/preview/b117f754f46e254a434a73c9f4501853.jpg'
Binary files tests/autopilot/gallery_app/data/.thumbnails/preview/b117f754f46e254a434a73c9f4501853.jpg	1970-01-01 00:00:00 +0000 and tests/autopilot/gallery_app/data/.thumbnails/preview/b117f754f46e254a434a73c9f4501853.jpg	2013-06-05 09:11:06 +0000 differ
=== added file 'tests/autopilot/gallery_app/data/.thumbnails/preview/e3034181bd65a2f1b1e8fa3ec1961bed.jpg'
Binary files tests/autopilot/gallery_app/data/.thumbnails/preview/e3034181bd65a2f1b1e8fa3ec1961bed.jpg	1970-01-01 00:00:00 +0000 and tests/autopilot/gallery_app/data/.thumbnails/preview/e3034181bd65a2f1b1e8fa3ec1961bed.jpg	2013-06-05 09:11:06 +0000 differ
=== added directory 'tests/autopilot/gallery_app/data/.thumbnails/square'
=== added file 'tests/autopilot/gallery_app/data/.thumbnails/square/b117f754f46e254a434a73c9f4501853.jpg'
Binary files tests/autopilot/gallery_app/data/.thumbnails/square/b117f754f46e254a434a73c9f4501853.jpg	1970-01-01 00:00:00 +0000 and tests/autopilot/gallery_app/data/.thumbnails/square/b117f754f46e254a434a73c9f4501853.jpg	2013-06-05 09:11:06 +0000 differ
=== added file 'tests/autopilot/gallery_app/data/.thumbnails/square/e3034181bd65a2f1b1e8fa3ec1961bed.jpg'
Binary files tests/autopilot/gallery_app/data/.thumbnails/square/e3034181bd65a2f1b1e8fa3ec1961bed.jpg	1970-01-01 00:00:00 +0000 and tests/autopilot/gallery_app/data/.thumbnails/square/e3034181bd65a2f1b1e8fa3ec1961bed.jpg	2013-06-05 09:11:06 +0000 differ
=== removed directory 'tests/autopilot/gallery_app/data/.thumbs'
=== removed file 'tests/autopilot/gallery_app/data/.thumbs/sample01_th.JPG'
Binary files tests/autopilot/gallery_app/data/.thumbs/sample01_th.JPG	2013-03-28 10:35:15 +0000 and tests/autopilot/gallery_app/data/.thumbs/sample01_th.JPG	1970-01-01 00:00:00 +0000 differ
=== removed file 'tests/autopilot/gallery_app/data/.thumbs/sample01_th_s.JPG'
Binary files tests/autopilot/gallery_app/data/.thumbs/sample01_th_s.JPG	2013-03-28 10:35:15 +0000 and tests/autopilot/gallery_app/data/.thumbs/sample01_th_s.JPG	1970-01-01 00:00:00 +0000 differ
=== removed file 'tests/autopilot/gallery_app/data/.thumbs/sample02_th.JPG'
Binary files tests/autopilot/gallery_app/data/.thumbs/sample02_th.JPG	2013-03-28 10:35:15 +0000 and tests/autopilot/gallery_app/data/.thumbs/sample02_th.JPG	1970-01-01 00:00:00 +0000 differ
=== removed file 'tests/autopilot/gallery_app/data/.thumbs/sample02_th_s.JPG'
Binary files tests/autopilot/gallery_app/data/.thumbs/sample02_th_s.JPG	2013-03-28 10:35:15 +0000 and tests/autopilot/gallery_app/data/.thumbs/sample02_th_s.JPG	1970-01-01 00:00:00 +0000 differ
=== modified file 'tests/unittests/gallerystandardimageprovider/CMakeLists.txt'
--- tests/unittests/gallerystandardimageprovider/CMakeLists.txt	2013-05-28 13:50:03 +0000
+++ tests/unittests/gallerystandardimageprovider/CMakeLists.txt	2013-06-05 09:11:06 +0000
@@ -10,11 +10,16 @@
     ${GSTLIB_INCLUDE_DIRS}
     )
 
+QT_WRAP_CPP(gallerystandardimageprovider GALLERYSTANDARDIMAGEPROVIDIER_MOCS
+    ${gallery_src_SOURCE_DIR}/media/preview-manager.h
+    )
+
 add_executable(gallerystandardimageprovider
     tst_gallerystandardimageprovidertest.cpp
     preview-manager.cpp
     photometa-data.cpp
     ${gallery_src_SOURCE_DIR}/qml/gallery-standard-image-provider.cpp
+    ${GALLERYSTANDARDIMAGEPROVIDIER_MOCS}
     )
 
 qt5_use_modules(gallerystandardimageprovider Quick Test)
@@ -25,6 +30,6 @@
     TIMEOUT ${CTEST_TESTING_TIMEOUT}
     ENVIRONMENT "QT_QPA_PLATFORM=minimal"
     )
-target_link_libraries(gallerystandardimageprovider 
+target_link_libraries(gallerystandardimageprovider
     ${GSTLIB_LDFLAGS}
     )

=== added directory 'tests/unittests/gallerystandardimageprovider/media'
=== added file 'tests/unittests/gallerystandardimageprovider/media/media-collection.h'
--- tests/unittests/gallerystandardimageprovider/media/media-collection.h	1970-01-01 00:00:00 +0000
+++ tests/unittests/gallerystandardimageprovider/media/media-collection.h	2013-06-05 09:11:06 +0000
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2013 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * 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/>.
+ */
+
+#ifndef GALLERY_MEDIA_COLLECTION_H_
+#define GALLERY_MEDIA_COLLECTION_H_
+
+#include <QDir>
+
+class MediaCollection
+{
+public:
+    MediaCollection(const QDir& directory) {Q_UNUSED(directory);}
+};
+
+#endif

=== modified file 'tests/unittests/gallerystandardimageprovider/preview-manager.cpp'
--- tests/unittests/gallerystandardimageprovider/preview-manager.cpp	2013-05-28 13:50:03 +0000
+++ tests/unittests/gallerystandardimageprovider/preview-manager.cpp	2013-06-05 09:11:06 +0000
@@ -21,14 +21,20 @@
 #include <QDir>
 
 #include "media/preview-manager.h"
-
-const int PreviewManager::PREVIEW_WIDTH_MAX = 360;
-const int PreviewManager::PREVIEW_HEIGHT_MAX = 360;
-
+#include "media/media-collection.h"
+
+const int PreviewManager::PREVIEW_SIZE = 360;
 const QString PreviewManager::PREVIEW_DIR = ".thumbs";
 const char* PreviewManager::PREVIEW_FILE_EXT = "JPG";
 
-bool PreviewManager::ensure_preview_for_media(QFileInfo file, bool regen)
+PreviewManager::PreviewManager(const QString &thumbnailDirectory,
+                               MediaCollection *mediaCollection, QObject *parent)
+{
+    Q_UNUSED(thumbnailDirectory);
+    Q_UNUSED(mediaCollection)
+}
+
+bool PreviewManager::ensurePreview(QFileInfo file, bool regen)
 {
     file = QFileInfo();
     regen = false;
@@ -36,22 +42,20 @@
     return regen;
 }
 
-void PreviewManager::on_media_added_removed(const QSet<DataObject *> *, const QSet<DataObject *> *)
-{
-
-}
-
-void PreviewManager::on_media_destroying(const QSet<DataObject *> *)
-{
-
-}
-
-void PreviewManager::on_media_data_altered()
-{
-
-}
-
-QFileInfo PreviewManager::PreviewFileFor(const QFileInfo &file)
-{
-    return QFileInfo(file.dir(), PREVIEW_DIR + "/" + file.completeBaseName() + "_th." + PREVIEW_FILE_EXT);
+void PreviewManager::onMediaAddedRemoved(const QSet<DataObject *> *, const QSet<DataObject *> *)
+{
+}
+
+void PreviewManager::onMediaDestroying(const QSet<DataObject *> *)
+{
+}
+
+void PreviewManager::updatePreview()
+{
+}
+
+QString PreviewManager::previewFileName(const QFileInfo &file) const
+{
+    return QString(file.absolutePath() + QDir::separator() + PREVIEW_DIR +
+                   QDir::separator() + file.completeBaseName() + "_th." + PREVIEW_FILE_EXT);
 }

=== modified file 'tests/unittests/gallerystandardimageprovider/tst_gallerystandardimageprovidertest.cpp'
--- tests/unittests/gallerystandardimageprovider/tst_gallerystandardimageprovidertest.cpp	2013-05-28 13:50:03 +0000
+++ tests/unittests/gallerystandardimageprovider/tst_gallerystandardimageprovidertest.cpp	2013-06-05 09:11:06 +0000
@@ -19,11 +19,14 @@
  */
 
 #include <QtTest/QtTest>
+#include <QDir>
 #include <QFileInfo>
 #include <QUrl>
 
 #include "qml/gallery-standard-image-provider.h"
 #include "media/preview-manager.h"
+#include "media/media-collection.h"
+#include "gallery-manager.h"
 
 class tst_GalleryStandardImageProvider : public QObject
 {
@@ -33,8 +36,8 @@
 
 private slots:
     void ToURL();
-    void Fullsize();
-    void Thumbnail();
+    void idToFile_data();
+    void idToFile();
 
 private:
     GalleryStandardImageProvider gallery_standard_image_provider;
@@ -54,18 +57,27 @@
     QCOMPARE(url, expect);
 }
 
-void tst_GalleryStandardImageProvider::Fullsize()
+void tst_GalleryStandardImageProvider::idToFile_data()
 {
-    QString id = "/home/user/Pictures/logo.jpg?size_level=0&orientation=1";
-    QString fileName = "/home/user/Pictures/logo.jpg";
-    QCOMPARE(GalleryStandardImageProvider::CachedImage::idToFile(id), fileName);
+    QTest::addColumn<QString>("id");
+    QTest::addColumn<QString>("fileName");
+
+    QTest::newRow("FullSize") << "/home/user/Pictures/logo.jpg?size_level=0&orientation=1" <<
+                                 "/home/user/Pictures/logo.jpg";
+    QTest::newRow("Thumbnail") << "/home/user/Pictures/logo.jpg?size_level=1&orientation=1" <<
+                                 "/home/user/Pictures/.thumbs/logo_th.JPG";
 }
 
-void tst_GalleryStandardImageProvider::Thumbnail()
+void tst_GalleryStandardImageProvider::idToFile()
 {
-    QString id = "/home/user/Pictures/logo.jpg?size_level=1&orientation=1";
-    QString fileName = "/home/user/Pictures/.thumbs/logo_th.JPG";
-    QCOMPARE(GalleryStandardImageProvider::CachedImage::idToFile(id), fileName);
+    QFETCH(QString, id);
+    QFETCH(QString, fileName);
+
+    MediaCollection mediaCollection(QDir("/home/user/Pictures"));
+    PreviewManager previewManager("/home/user/thumbnails", &mediaCollection);
+    GalleryStandardImageProvider provider;
+    provider.setPreviewManager(&previewManager);
+    QCOMPARE(provider.idToFile(id), fileName);
 }
 
 QTEST_MAIN(tst_GalleryStandardImageProvider);

=== modified file 'tests/unittests/gallerythumbnailimageprovider/CMakeLists.txt'
--- tests/unittests/gallerythumbnailimageprovider/CMakeLists.txt	2013-05-28 13:50:03 +0000
+++ tests/unittests/gallerythumbnailimageprovider/CMakeLists.txt	2013-06-05 09:11:06 +0000
@@ -10,10 +10,15 @@
     ${GSTLIB_INCLUDE_DIRS}
     )
 
+QT_WRAP_CPP(gallerythumbnailimageprovider GALLERYTHUMBNAILIMAGEPROVIDIER_MOCS
+    ${gallery_src_SOURCE_DIR}/media/preview-manager.h
+    )
+
 add_executable(gallerythumbnailimageprovider
     tst_gallerythumbnailimageprovider.cpp
     preview-manager.cpp
     ${gallery_src_SOURCE_DIR}/qml/gallery-thumbnail-image-provider.cpp
+    ${GALLERYTHUMBNAILIMAGEPROVIDIER_MOCS}
     )
 
 qt5_use_modules(gallerythumbnailimageprovider Quick Test)

=== added directory 'tests/unittests/gallerythumbnailimageprovider/media'
=== added file 'tests/unittests/gallerythumbnailimageprovider/media/media-collection.h'
--- tests/unittests/gallerythumbnailimageprovider/media/media-collection.h	1970-01-01 00:00:00 +0000
+++ tests/unittests/gallerythumbnailimageprovider/media/media-collection.h	2013-06-05 09:11:06 +0000
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2013 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * 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/>.
+ */
+
+#ifndef GALLERY_MEDIA_COLLECTION_H_
+#define GALLERY_MEDIA_COLLECTION_H_
+
+#include <QDir>
+
+class MediaCollection
+{
+public:
+    MediaCollection(const QDir& directory) {Q_UNUSED(directory);}
+};
+
+#endif

=== modified file 'tests/unittests/gallerythumbnailimageprovider/preview-manager.cpp'
--- tests/unittests/gallerythumbnailimageprovider/preview-manager.cpp	2013-05-28 13:50:03 +0000
+++ tests/unittests/gallerythumbnailimageprovider/preview-manager.cpp	2013-06-05 09:11:06 +0000
@@ -25,7 +25,14 @@
 const QString PreviewManager::PREVIEW_DIR = ".thumbs";
 const char* PreviewManager::PREVIEW_FILE_EXT = "JPG";
 
-bool PreviewManager::ensure_preview_for_media(QFileInfo file, bool regen)
+PreviewManager::PreviewManager(const QString &thumbnailDirectory,
+                               MediaCollection *mediaCollection, QObject *parent)
+{
+    Q_UNUSED(thumbnailDirectory);
+    Q_UNUSED(mediaCollection)
+}
+
+bool PreviewManager::ensurePreview(QFileInfo file, bool regen)
 {
     file = QFileInfo();
     regen = false;
@@ -33,21 +40,20 @@
     return regen;
 }
 
-void PreviewManager::on_media_added_removed(const QSet<DataObject *> *, const QSet<DataObject *> *)
-{
-
-}
-
-void PreviewManager::on_media_destroying(const QSet<DataObject *> *)
-{
-
-}
-
-void PreviewManager::on_media_data_altered()
-{
-
-}
-
-QFileInfo PreviewManager::ThumbnailFileFor(const QFileInfo& file) {
-  return QFileInfo(file.dir(), PREVIEW_DIR + "/" + file.completeBaseName() + "_th_s." + PREVIEW_FILE_EXT);
+void PreviewManager::onMediaAddedRemoved(const QSet<DataObject *> *, const QSet<DataObject *> *)
+{
+}
+
+void PreviewManager::onMediaDestroying(const QSet<DataObject *> *)
+{
+}
+
+void PreviewManager::updatePreview()
+{
+}
+
+QString PreviewManager::thumbnailFileName(const QFileInfo& file) const
+{
+  return QString(file.absolutePath() + PREVIEW_DIR + QDir::separator() +
+                 file.completeBaseName() + "_th_s." + PREVIEW_FILE_EXT);
 }

=== modified file 'tests/unittests/resource/tst_resource.cpp'
--- tests/unittests/resource/tst_resource.cpp	2013-06-03 13:08:17 +0000
+++ tests/unittests/resource/tst_resource.cpp	2013-06-05 09:11:06 +0000
@@ -30,6 +30,7 @@
 private slots:
     void picturesDirectory();
     void databaseDirectory();
+    void thumbnailDirectory();
     void maxTextureSize();
 };
 
@@ -46,7 +47,8 @@
 void tst_Resource::databaseDirectory()
 {
     Resource resource("", 0);
-    QString dbDir = QStandardPaths::writableLocation(QStandardPaths::DataLocation) + "/" + Resource::DATABASE_DIR;
+    QString dbDir = QStandardPaths::writableLocation(QStandardPaths::DataLocation) +
+            QDir::separator() + Resource::DATABASE_DIR;
     QCOMPARE(resource.databaseDirectory(), dbDir);
 
     QString picDir("/some/where/else");
@@ -55,6 +57,19 @@
     QCOMPARE(resource2.databaseDirectory(), dbDir);
 }
 
+void tst_Resource::thumbnailDirectory()
+{
+    Resource resource("", 0);
+    QString dbDir = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) +
+            QDir::separator() + Resource::THUMBNAIL_DIR;
+    QCOMPARE(resource.thumbnailDirectory(), dbDir);
+
+    QString picDir("/some/where/else");
+    Resource resource2(picDir, 0);
+    dbDir = picDir + "/." + Resource::THUMBNAIL_DIR;
+    QCOMPARE(resource2.thumbnailDirectory(), dbDir);
+}
+
 void tst_Resource::maxTextureSize()
 {
     Resource resource("", 0);