Try to add fonts to GUI resources and add to font database from main window

sdrgui/mainwindow.cpp

@@ -27,6 +27,7 @@
 #include <QSysInfo>
 #include <QKeyEvent>
 #include <QResource>
+#include <QFontDatabase>
 
 #include <plugin/plugininstancegui.h>
 #include <plugin/plugininstancegui.h>
@@ -101,6 +102,13 @@ MainWindow::MainWindow(qtwebapp::LoggerWithFile *logger, const MainParser& parse
     m_instance = this;
 	m_settings.setAudioDeviceManager(m_dspEngine->getAudioDeviceManager());
 
+    QFontDatabase::addApplicationFont(":/LiberationSans-Regular.ttf");
+    QFontDatabase::addApplicationFont(":/LiberationMono-Regular.ttf");
+
+    QFont font("Liberation Sans");
+    font.setPointSize(9);
+    qApp->setFont(font);
+
 	ui->setupUi(this);
 	createStatusBar();
 

sdrgui/resources/res.qrc

@@ -93,5 +93,7 @@
     <file>load.png</file>
     <file>keyboard.png</file>
     <file>kill.png</file>
+    <file>LiberationMono-Regular.ttf</file>
+    <file>LiberationSans-Regular.ttf</file>
   </qresource>
 </RCC>