Beautify TextureMappingMode code

src/Application/Modes/TextureMappingMode.cpp

@@ -85,31 +85,27 @@ void TextureMappingMode::onKeyPressed(Application * app, ofKeyEventArgs & args){
 	switch(args.key){
 
 	 case OF_KEY_LEFT:
-		 if(app->getSurfaceManager()->getSelectedSurface() == 0){
-			return;
+		 if(app->getSurfaceManager()->getSelectedSurface() != 0){
+			moveSelection(app, ofVec2f(-moveStep, 0.0f));
 		 }
-		 moveSelection(app, ofVec2f(-moveStep, 0.0f));
 		 break;
 
 	 case OF_KEY_RIGHT:
-		 if(app->getSurfaceManager()->getSelectedSurface() == 0){
-			return;
+		 if(app->getSurfaceManager()->getSelectedSurface() != 0){
+			moveSelection(app, ofVec2f(moveStep, 0.0f));
 		 }
-		 moveSelection(app, ofVec2f(moveStep, 0.0f));
 		 break;
 
 	 case OF_KEY_UP:
-		 if(app->getSurfaceManager()->getSelectedSurface() == 0){
-			return;
+		 if(app->getSurfaceManager()->getSelectedSurface() != 0){
+			moveSelection(app, ofVec2f(0.0f, -moveStep));
 		 }
-		 moveSelection(app, ofVec2f(0.0f, -moveStep));
 		 break;
 
 	 case OF_KEY_DOWN:
-		 if(app->getSurfaceManager()->getSelectedSurface() == 0){
-			return;
+		 if(app->getSurfaceManager()->getSelectedSurface() != 0){
+			moveSelection(app, ofVec2f(0.0f, moveStep));
 		 }
-		 moveSelection(app, ofVec2f(0.0f, moveStep));
 		 break;
 
 	 case '>':