OpenType Add-on Library

In order to help users work with the OpenType information, a new add-on library has been provided with two functions. The first is a dialog which provides information about a selected typeface file. The second is a Layout Developer file which allows users to examine the glyphs available in a given font file.

OpenType fonts contain, as you now know, feature tables which can be grouped according to script and language. The FOM fTypeface object provides methods to find information out about the available features, languages and scripts, but outside of code it is helpful to know what is available. For this reason the Feature Table Viewer dialog is provided as part of the OpenType add-on library. Selecting this in the menu will pop open the following dialog. It is not necessary to have a document open to do this.

There are four sections to this dialog:

• The top drop-down lets the user select the typeface they wish to view. This is the standard list of typefaces in Layout Developer.

• When a typeface is selected, a list of available scripts is provided. By default, ‘default’ is selected. This will provide a list of all feature tables available in the typeface (in the ‘Features available’ box’). Selecting a specific script will cause the languages and ‘Features available’ panels to update according to what is available.

• Selecting a script value (which isn’t ‘—Default—’) will update the language panel. This panel lists those languages which are supported in the typeface for that script. As with selecting a script, the ‘Features available’ panel will update.

• The ‘Features available’ panel will provide a list of those feature tables which are in the typeface for the selected script and language. You might notice that the list is longer than the options provided by other applications, but all tables can be used within Layout Developer.

The library also provides a Layout Developer document which lets the user see glyphs which are available in a selected typeface. The menu option in the library will open the document. When opened, a dialog is presented which allows the user to select the typeface and the glyph range to view. The glyphs are presented in a tabular format with their number which can then be used with the fFormatting.outputGlyphs() method.