A very simple FileHandler which allows to preview arbitrary text in the
font which is defined in the opened file. The currently supported font file
formats are TrueType and PostScript Type-1. If a file has an extension of
.ttf it will be loaded as
a TrueType font, otherwise as a Type-1 font.
It loads the font and displays its main properties. The font style and size and the sample text can be modified.
The viewer will remember the sample text and the font size between different invocations.