added backup file functionallity

3 files changed, 73 insertions, 20 deletions

diff --git a/src/dialog.cpp b/src/dialog.cpp
index def152c..38711c3 100644
--- a/src/dialog.cpp
+++ b/src/dialog.cpp
@@ -26,7 +26,7 @@ Dialog::Dialog(QWidget *parent)
     QRect desktopRect = QApplication::desktop()->availableGeometry(this);
     oldCenter_ = desktopRect.center();
     centerTimer_ = new QTimer(this);
-    connect(centerTimer_, SIGNAL(timeout()), this, SLOT(on_centerTimer()));
+    connect(centerTimer_, SIGNAL(timeout()), this, SLOT(onCenterTimer()));
     centerTimer_->start(1000);
 }
 
@@ -228,7 +228,7 @@ void Dialog::setTheme() {
 	ui->label_r->setStyleSheet(label_r_style);
 }
 
-void Dialog::on_centerTimer() {
+void Dialog::onCenterTimer() {
     if (!autoStartEntry_.isEmpty()) {
         if (this->selectSession(autoStartEntry_)) {
             this->on_treeView_activated(ui->treeView->selectionModel()->currentIndex());
@@ -248,29 +248,51 @@ void Dialog::on_centerTimer() {
 }
 
 void Dialog::addSessionsAfterDownload(QNetworkReply* reply) {
+	QString filename = "/tmp/vmchooser2.xml";
+	QString backup_filename = "/tmp/vmchooser2_backup.xml";
+
 	if (reply->error() != QNetworkReply::NoError) {
-		qDebug() << "Error reading from URL: " << reply->error();
-		return;
-	}
+		if (debugMode) {
+			qDebug() << "Error reading from URL: " << reply->error();
+		}
 
-	QString xml_doc(reply->readAll());
+		QFile backup_file(backup_filename);
+
+		if (!backup_file.open(QIODevice::ReadOnly)) {
+			if (debugMode) {
+				qDebug() << "Cannot read backup file " << backup_filename << " either";
+			}
+			return;
+		}
 
-	QFile file("/tmp/vmchooser2.xml");
-	if (!file.open(QIODevice::WriteOnly)) {
 		if (debugMode) {
-			qDebug() << "Could not write XML to /tmp";
+			qDebug() << "Used backup file " << backup_filename;
 		}
-		return;
-	}
 
-	QByteArray data = xml_doc.toUtf8();
+		backup_file.close();
+		this->addItems(VSession::readXmlFile(backup_filename), QCoreApplication::instance()->translate("Dialog", "Virtual Sessions"));
 
-	if (file.write(data) != data.length()) {
-		return;
-	}
+	} else {
 
-	file.close();
+		QString xml_doc(reply->readAll());
+		QFile file(filename);
+
+		if (!file.open(QIODevice::WriteOnly)) {
+			if (debugMode) {
+				qDebug() << "Could not write XML to " << filename;
+			}
+			return;
+		}
+
+		QByteArray data = xml_doc.toUtf8();
+
+		if (file.write(data) != data.length()) {
+			return;
+		}
+
+		file.close();
+	}
 
-	this->addItems(VSession::readXmlFile(file.fileName()), QCoreApplication::instance()->translate("Dialog", "Virtual Sessions"));
+	this->addItems(VSession::readXmlFile(filename), QCoreApplication::instance()->translate("Dialog", "Virtual Sessions"));
 }
 
diff --git a/src/dialog.h b/src/dialog.h
index 7e9b1d5..4627a8e 100644
--- a/src/dialog.h
+++ b/src/dialog.h
@@ -45,7 +45,7 @@ class Dialog : public QDialog {
     void on_pushButtonStart_clicked();
     void on_pushButtonAbort_clicked();
     void on_treeView_activated(QModelIndex index);
-    void on_centerTimer();
+    void onCenterTimer();
 
   public slots:
     void addSessionsAfterDownload(QNetworkReply* reply);
diff --git a/src/vsession.cpp b/src/vsession.cpp
index 8134bc6..9d3cadb 100644
--- a/src/vsession.cpp
+++ b/src/vsession.cpp
@@ -305,6 +305,10 @@ QList<Session*> VSession::readXmlFile(const QString& filepath) {
 
     QDomDocument doc;
     QFile file(filepath);
+    QString backup_filename = "/tmp/vmchooser2_backup.xml";
+   	QFile backup_file(backup_filename);
+
+
     if (!file.open(QIODevice::ReadOnly)) {
         if (debugMode) {
         	qDebug() << "Cannot read file: " << file.fileName();
@@ -315,9 +319,36 @@ QList<Session*> VSession::readXmlFile(const QString& filepath) {
     	if (debugMode) {
     		qDebug() << "XML file not valid: " << file.fileName();
     	}
-        file.close();
-        return retval;
+
+    	file.close();
+
+    	// try to use backup file
+    	if (!backup_file.open(QIODevice::ReadOnly)) {
+			if (debugMode) {
+				qDebug() << "Cannot read backup file " << backup_filename << " either";
+			}
+			return retval;
+		}
+
+		if (!doc.setContent(&backup_file)) {
+			if (debugMode) {
+				qDebug() << "XML file not valid: " << backup_file.fileName();
+			}
+			backup_file.close();
+			return retval;
+		}
+
+		if (debugMode) {
+			qDebug() << "Used backup file " << backup_filename;
+		}
+
+		backup_file.close();
+    } else {
+    	// file is valid --> create backup file
+		QFile::remove(backup_filename);
+		QFile::copy(filepath, backup_filename);
     }
+
     file.close();
 
     QString dirName(QFileInfo(filepath).dir().absolutePath());