add subtitles

projektor.sty

@@ -69,3 +69,48 @@
 
 % Pas de préfix pour les figures
 \RequirePackage[figurename=]{caption}
+
+% Support des sous-titres
+\makeatletter
+\newcommand\startsubtitle{
+    \renewcommand{\metropolis@frametitlestrut@start}{
+        \rule{0pt}{1ex +
+            \totalheightof{
+                \ifcsdef{metropolis@frametitleformat}{\metropolis@frametitleformat X}{X}
+            }
+        }
+    }
+    \renewcommand{\metropolis@frametitlestrut@end}{
+        \rule[-3ex]{0pt}{\metropolis@frametitle@padding}
+    }
+}
+
+\newcommand\stopsubtitle{
+    \renewcommand{\metropolis@frametitlestrut@start}{
+        \rule{0pt}{\metropolis@frametitle@padding +
+            \totalheightof{
+                \ifcsdef{metropolis@frametitleformat}{\metropolis@frametitleformat X}{X}
+            }
+        }
+    }
+    \renewcommand{\metropolis@frametitlestrut@end}{
+        \rule[-\metropolis@frametitle@padding]{0pt}{\metropolis@frametitle@padding}
+    }
+}
+\makeatother
+
+\setbeamercolor{framesubtitle}{fg=white}
+\setbeamerfont{framesubtitle}{series=\mdseries}
+\addtobeamertemplate{frametitle}{
+    \ifx\insertframesubtitle\empty\else
+        \startsubtitle
+    \fi
+}{
+    \ifx\insertframesubtitle\empty\else
+        \vspace{-4ex}
+        \usebeamerfont{framesubtitle}
+        \usebeamercolor[fg]{framesubtitle}
+        \insertframesubtitle
+        \stopsubtitle
+    \fi
+}