new feature: support for underlined text

src/window.cpp

@@ -87,6 +87,7 @@ Window::Window(size_t startx,
 		itsBorder(border),
 		itsHistory(0),
 		itsBoldCounter(0),
+		itsUnderlineCounter(0),
 		itsReverseCounter(0),
 		itsAltCharsetCounter(0)
 {
@@ -137,6 +138,7 @@ Window::Window(const Window &w) : itsWindow(dupwin(w.itsWindow)),
 				itsBorder(w.itsBorder),
 				itsHistory(w.itsHistory),
 				itsBoldCounter(w.itsBoldCounter),
+				itsUnderlineCounter(w.itsUnderlineCounter),
 				itsReverseCounter(w.itsReverseCounter),
 				itsAltCharsetCounter(w.itsAltCharsetCounter)
 {
@@ -328,6 +330,11 @@ void Window::Bold(bool bold_state) const
 	(bold_state ? wattron : wattroff)(itsWindow, A_BOLD);
 }
 
+void Window::Underline(bool underline_state) const
+{
+	(underline_state ? wattron : wattroff)(itsWindow, A_UNDERLINE);
+}
+
 void Window::Reverse(bool reverse_state) const
 {
 	(reverse_state ? wattron : wattroff)(itsWindow, A_REVERSE);
@@ -745,6 +752,13 @@ Window &Window::operator<<(Format format)
 			if (--itsBoldCounter <= 0)
 				Bold((itsBoldCounter = 0));
 			break;
+		case fmtUnderline:
+			Underline(++itsUnderlineCounter);
+			break;
+		case fmtUnderlineEnd:
+			if (--itsUnderlineCounter <= 0)
+				Underline((itsUnderlineCounter = 0));
+			break;
 		case fmtReverse:
 			Reverse(++itsReverseCounter);
 			break;