I'd like the frame title background - the bar at the top - to be a constant height, regardless of whether I have a title only or a subtitle as well.
One reason is consistency - I don't like the jumps from slide to slide. Another is that I'm also placing a logo in the top-right corner, and I don't know how else to keep its position constant relative to the top right corner..
Right now I'm kludging it by adding an invisible subtitle the same colour as the background, but I would appreciate a more elegant solution!
\PassOptionsToPackage{demo}{graphicx}
\documentclass{beamer}
\usepackage[english]{babel}
\usetheme{Madrid}
\definecolor{myblue}{RGB}{44,80,109}
\setbeamercolor{frametitle}{fg=white, bg=myblue}
\usepackage{textpos}
\addtobeamertemplate{frametitle}{}{%
\begin{textblock*}{10mm}(.94\textwidth,-1.3cm)
\includegraphics[height=1cm,width=1cm]{logo}
\end{textblock*}}
\begin{document}
\begin{frame}{Title}{Subtitle}
\end{frame}
\begin{frame}{Title with no Subtitle}
\end{frame}
\begin{frame}{Title with no Subtitle}{\textcolor{myblue}{placeholder for subtitle}}
\end{frame}
\end{document}