1 files changed, 40 insertions, 25 deletions
diff --git a/sqlitebackend.h b/sqlitebackend.h
index 4dfd2f9..52faedc 100644
--- a/sqlitebackend.h
+++ b/sqlitebackend.h
@@ -16,86 +16,101 @@ enum TagChange {
 class Tag
 {
 public:
+    Tag() : valid(false) {}
     Tag(long long int id, QString name, qreal anchor_x, qreal anchor_y, QByteArray metadata);
-    Tag();
     Tag(long long int id, const Tag &other);
 
+    bool isValid() { return valid; }
+
     long long int id;
     QString name;
     QPointF anchor;
     QVariantMap metadata;
+
+private:
+    bool valid;
 };
 
 class SQLiteSaveFile : public QObject
 {
     Q_OBJECT
 public:
-    explicit SQLiteSaveFile(QObject *parent = nullptr, QString filename = ":memory:");
-    bool connect();
-    bool isOpen() { return m_isOpen; }
+    explicit SQLiteSaveFile(QObject *parent = nullptr);
 
     QList<Tag> getAllTags();
 
-    QByteArray getImage();
+    const QByteArray &getImage() const { return m_image; };
 
     bool updateTag(Tag tag);
     bool deleteTag(Tag tag);
     bool createTag(Tag tag);
 
+    bool isMemory() { return m_memory; } /* backend db points to temporary memory db */
+    bool isDirty() { return m_dirty; } /* backend db was changed since opening */
+    bool isOpen() { return m_open; } /* backend db is open */
+
     bool setMeta(const QString &key, const QVariant &value);
     bool setMeta(std::initializer_list<QPair<QString, QVariant>> metas);
-    QVariant getMeta(const QString &key);
+    const QVariant getMeta(const QString &key) const;
 
-    QString errorString() { return lastErrorString; }
+    const QString &errorString() const { return m_lastErrorString; }
     enum Error {
         NoError = 0,
+        FileNotFoundError,
         SQLiteError,
         ImageOpenError,
-        ImageReadError
+        ImageReadError,
+        MaxError
     };
-    inline const static QString errorNames[] =  {
+    inline const static QString errorNames[MaxError] =  {
                 [NoError] = "No Error",
+                [FileNotFoundError] = "File not found",
                 [SQLiteError] = "Database Error",
                 [ImageOpenError] = "Error Opening Image",
                 [ImageReadError] = "Error Reading Image"
             };
 
     Error error();
-    void resetError() { lastError = NoError; lastErrorString = QString(); }
+    void resetError() const { m_lastError = NoError; m_lastErrorString = QString(); }
 
 public slots:
     /** Save this project file under a new name. This changes the backend database this project file object points to, and copies all data.
      * Callers can continue to use the same project file object afterwards.
      */
     bool saveAs(const QString &filename);
+    bool open(const QString &filename);
     bool reloadImageFromDisk();
-    bool loadImageFromDisk(const QString &filename);
+    bool loadImageFromDisk(const QString &m_filename);
     bool clearNew();
 
 signals:
     void tagChange(TagChange change, const Tag &tag);
     void fileReload();
-    void fileIOError(Error e, QString errorName, QString description);
+    void fileIOError(Error e, QString errorName, QString description) const;
 
 private:
+    bool connect();
     bool initDb(bool setCreationDate=true);
     bool runSql(QString query, std::initializer_list<QVariant> bindings={});
 
     bool setMetaLocked(const QString &key, const QVariant &value);
     bool setMetaLocked(std::initializer_list<QPair<QString, QVariant>> metas);
-    QVariant getMetaLocked(const QString &key);
-
-    void setError(Error e, QString desc) { lastError = e; lastErrorString = desc; fileIOError(e, errorNames[e], desc); }
-    bool setDatabaseError(const QSqlQuery &q);
-    bool setDatabaseError(const QSqlDatabase &db);
-
-    Error lastError;
-    QString lastErrorString;
-    QSqlDatabase db;
-    QMutex dbMut;
-    QString filename;
-    QByteArray imageData;
-    bool m_isOpen;
+    const QVariant getMetaLocked(const QString &key) const;
+
+    void setError(Error e, QString desc) const { m_lastError = e; m_lastErrorString = desc; fileIOError(e, errorNames[e], desc); }
+    bool setDatabaseError(const QSqlQuery &q) const;
+    bool setDatabaseError(const QSqlDatabase &m_db) const;
+
+    mutable Error m_lastError;
+    mutable QString m_lastErrorString;
+    QSqlDatabase m_db;
+    mutable QMutex m_dbMut;
+    QString m_filename;
+    QByteArray m_image;
+
+    bool m_open;
+    bool m_dirty;
+    bool m_memory;
 };