Select first surface when hitting tab and none is selected in texture edit mode

src/Application/TextureMappingState.cpp

@@ -40,6 +40,8 @@ void TextureMappingState::onKeyPressed(Application * app, ofKeyEventArgs & args)
 				new SetNextSourceCmd(
 					app->getSurfaceManager()->getSelectedSurface(),
 					app->getGui()->getSourcesEditor()));
+		 }else{
+			app->getCmdManager()->exec(new SelNextSurfaceCmd(app->getSurfaceManager()));
 		 }
 		 break;
 	}

src/Application/TextureMappingState.h

@@ -8,6 +8,7 @@
 #include "SelPrevTexCoordCmd.h"
 #include "DeselectTexCoordCmd.h"
 #include "SetNextSourceCmd.h"
+#include "SelNextSurfaceCmd.h"
 
 namespace ofx {
 namespace piMapper {