Separate font and font size

If the font is not available but the OS is supported, OSFont will be empty but OSFontSize will have the value of the system font size. Also, FONTEXIST was made into a separate function.

README.md

@@ -8,7 +8,7 @@ Graphical user interfaces developed with MATLAB often lack the look and feel of
 
 ## Usage
 
-`[OSFont, OSFontSize] = getOSfont(OS, OSVersion)` returns the name and size (in points) of the system UI font of operating system `OS` in version `OSVersion`. If the system UI font is not available to MATLAB, it is replaced by a similar font and a warning is issued. If the OS is not supported, or if the selected font is not available, `OSFont` and `OSFontSize` are returned empty.
+`[OSFont, OSFontSize] = getOSfont(OS, OSVersion)` returns the name and size (in points) of the system UI font of operating system `OS` in version `OSVersion`. If the system UI font is not available to MATLAB, it is replaced by a similar font and a warning is issued. If the OS is not supported, `OSFONT` and `OSFONTSIZE` are returned empty. `OSFONT` is also returned empty if the selected font is not available.
 
 `OS` is a character vector containing the name of the operating system in lowercase letters. The following operating systems are supported:
 
@@ -32,9 +32,11 @@ catch
    OSVersion = [];
 end
 [OSFont, OSFontSize] = getOSfont(OS, OSVersion);
+% if returned empty, fall back on factory settings
 if isempty(OSFont)
-   % default to factory settings
-   OSFont     = get(groot, 'factoryUicontrolFontName');
+   OSFont = get(groot, 'factoryUicontrolFontName');
+end
+if isempty(OSFontSize)
    OSFontSize = get(groot, 'factoryUicontrolFontSize');
 end
 ```

fontexist.m

@@ -0,0 +1,19 @@
+function bool = fontexist(font)
+%FONTEXIST Check existence of font.
+%   FONTEXIST(FONT) returns TRUE if FONT is an available system font.
+
+% Created 2016-01-05 by Jorg C. Woehl
+% 2016-12-16 (JCW): Converted to standalone function, comments added.
+
+% input: empty character array, or nonempty character vector
+assert(ischar(font) && (isrow(font) || isempty(font)),...
+    'fontexist:IncorrectInputType', 'Input must be an empty character array or a nonempty character vector.');
+if isempty(font)
+    % reduce to simplest empty type
+    font = '';
+end
+
+idx = find(strcmpi(listfonts, font), 1);
+bool = ~isempty(idx);
+
+end

getOSfont.m

@@ -4,8 +4,8 @@
 %   size (in points) of the user interface (UI) font of operating system OS
 %   in version OSVERSION. If the system UI font is not available to MATLAB,
 %   it is replaced by a similar font and a warning is issued. If the OS is
-%   not supported, or if the selected font is not available, OSFONT and
-%   OSFONTSIZE are returned empty.
+%   not supported, OSFONT and OSFONTSIZE are returned empty. OSFONT is also
+%   returned empty if the selected font is not available.
 %
 %   OS is a character vector containing the name of the operating system in
 %   lowercase letters. The following operating systems are supported:
@@ -29,9 +29,11 @@
 %      OSVersion = [];
 %   end
 %   [OSFont, OSFontSize] = getOSfont(OS, OSVersion);
+%   % if returned empty, fall back on factory settings
 %   if isempty(OSFont)
-%      % default to factory settings
-%      OSFont     = get(groot, 'factoryUicontrolFontName');
+%      OSFont = get(groot, 'factoryUicontrolFontName');
+%   end
+%   if isempty(OSFontSize)
 %      OSFontSize = get(groot, 'factoryUicontrolFontSize');
 %   end
 %
@@ -40,6 +42,7 @@
 % Created 2016-01-05 by Jorg C. Woehl
 % 2016-12-05 (JCW): Converted to standalone function, comments added.
 % 2016-12-08 (JCW): Input arguments added.
+% 2016-12-19 (JCW): Font and font size treated separately.
 
 %% Input argument validation
 
@@ -48,8 +51,10 @@
     'Input 1 must be an empty character array or a nonempty character vector.');
 % convert to all lowercase if necessary
 OS = lower(OS);
-
-if ~isempty(OS)
+if isempty(OS)
+    % reduce to simplest empty type
+    OS = '';
+else
     % input 2: (nonempty) numeric vector containing finite real non-negative "integers"
     assert(isnumeric(OSVersion) && isvector(OSVersion) && all(isfinite(OSVersion))...
         && isreal(OSVersion) && all(OSVersion == round(OSVersion)) && all(OSVersion >= 0),...
@@ -60,6 +65,7 @@
 %% Determine system UI font
 
 font = '';
+fontSize = [];
 
 % supported operating systems
 switch OS
@@ -147,23 +153,12 @@
         end
 end
 
-% check if the selected font exists, otherwise return empty variables
+OSFontSize = fontSize;
+% check if the selected font exists
 if fontexist(font)
     OSFont = font;
-    OSFontSize = fontSize;
 else
     OSFont = '';
-    OSFontSize = [];
-end
-
 end
 
-%% is font available on system?
-
-function bool = fontexist(font)
-
-% find first occurrence of font in list of all fonts on the system
-idx = find(strcmpi(listfonts, font), 1);
-bool = ~isempty(idx);
-
 end