comparison framework/SVFileReader.cpp @ 140:9ccaa8fd9b9f

* Add code to identify (usually) the type of an XML file that contains
  either SV session or layer data, and use it to permit loading files
  with plain .xml extension that contain complete uncompression sessions

 
 SVFileReaderPaneCallback::~SVFileReaderPaneCallback()
 {
 }
 
+
+class SVFileIdentifier : public QXmlDefaultHandler
+{
+public:
+    SVFileIdentifier() :
+        m_inSv(false),
+        m_inData(false),
+        m_type(SVFileReader::UnknownFileType)
+    { }
+    virtual ~SVFileIdentifier() { }
+
+    void parse(QXmlInputSource &source) {
+        QXmlSimpleReader reader;
+        reader.setContentHandler(this);
+        reader.setErrorHandler(this);
+        reader.parse(source);
+    }
+
+    SVFileReader::FileType getType() const { return m_type; }
+
+    virtual bool startElement(const QString &,
+			      const QString &,
+			      const QString &qName,
+			      const QXmlAttributes& atts)
+    {
+        QString name = qName.toLower();
+
+        // SV session files have an sv element containing a data
+        // element containing a model element with mainModel="true".
+
+        // If the sv element is present but the rest does not satisfy,
+        // then it's (probably) an SV layer file.
+
+        // Otherwise, it's of unknown type.
+
+        if (name == "sv") {
+            m_inSv = true;
+            if (m_type == SVFileReader::UnknownFileType) {
+                m_type = SVFileReader::SVLayerFile;
+            }
+            return true;
+        } else if (name == "data") {
+            if (!m_inSv) return true;
+            m_inData = true;
+        } else if (name == "model") {
+            if (!m_inData) return true;
+            if (atts.value("mainModel").trimmed() == "true") {
+                if (m_type == SVFileReader::SVLayerFile) {
+                    m_type = SVFileReader::SVSessionFile;
+                    return false; // done
+                }
+            }
+        }
+        return true;
+    }
+
+    virtual bool endElement(const QString &,
+			    const QString &,
+			    const QString &qName)
+    {
+        QString name = qName.toLower();
+
+        if (name == "sv") {
+            if (m_inSv) {
+                m_inSv = false;
+                return false; // done
+            }
+        } else if (name == "data") {
+            if (m_inData) {
+                m_inData = false;
+                return false; // also done, nothing after the first
+                              // data element is of use here
+            }
+        }
+        return true;
+    }
+
+private:
+    bool m_inSv;
+    bool m_inData;
+    SVFileReader::FileType m_type;
+};
+
+
+SVFileReader::FileType
+SVFileReader::identifyXmlFile(QString path)
+{
+    QFile file(path);
+    SVFileIdentifier identifier;
+    QXmlInputSource source(&file);
+    identifier.parse(source);
+    return identifier.getType();
+}
+
+    
+