Font file abstract base class.

Write a class derived from COpenFontFile to manage a file with the font format supported by your DLL. The derived class must implement the virtual GetNearestFontInPixelsL() function. This function takes a font description and creates a COpenFont derived object if the description matches a typeface contained in the font file.

Derived classes must also load typeface attributes from the file into the protected typeface attribute array during construction. This array is what is searched when getting font attribute information see AddFaceL(), GetNearestFontHelper().

Writing derived classes construction:

Call the COpenFontFile constructor in the constructor for your derived object, passing it aUid and aFileName arguments. These values are the arguments passed when the constructor is called by COpenFontRasterizer::NewFontFileL().

A file may contain one or more typefaces. During construction the derived object should extract the information for each typeface and add it to this object's protected typeface attribute array see AddFaceL(). This process will probably leave under some conditions. It should therefore be implemented in a second phase constructor.

Writing derived classes implement the pure virtual functions:

Derived classes must also implement the two pure virtual functions GetNearestFontInPixelsL() and HasUnicodeCharacterL(). Information about these functions is provided in the definitions below. Information about deriving from this class is also provided in the API guide.

COpenFontRasterizer::NewFontFileL()

CWsScreenDevice::AddFile()