* generator/DESIGN: Document what the different classes do

svn path=/trunk/gtk-sharp/; revision=36140

generator/DESIGN

@@ -0,0 +1,86 @@
+Main Program
+------------
+
+CodeGenerator: Static class. Contains Main
+GenerationInfo: Stores info passed in on the command line, such as the
+                assembly name and glue library name. Passed to
+                IGeneratable.Generate().
+Parser: Reads the foo-api.xml file and creates IGeneratable objects
+Statistics: Static class. Used by other classes to keep statistics on
+            generated classes
+SymbolTable: Static class. Keeps track of the type hierarchy and the
+             mappings between C types and IGeneratable classes
+
+
+IGeneratables
+-------------
+The IGeneratable interface is implemented by all classes that
+represent types.
+
+GenBase: Abstract base class for any api.xml element that will have
+         its own generated .cs file
+    CallbackGen: Handles <callback> elements by creating a public
+                 delegate type for the public API (in NAME.cs), and an
+                 internal type that wraps that delegate, to be passed
+                 as the actual unmanaged callback (in
+                 NAMESPACESharp.NAMENative.cs)
+    ClassBase: Abstract base class for types that will be converted
+               to C# classes, structs, or interfaces
+        ClassGen: Handles <class> elements (static classes)
+        InterfaceGen: Handles <interface> elements
+        ObjectGen: Handles <object> elements
+        OpaqueGen: Handles <boxed> and <struct> elements with the
+                   "opaque" flag (by creating C# classes)
+        StructBase: Abstract base class for types that will be
+                    translated to C# structs.
+            BoxedGen: Handles non-opaque <boxed> elements
+            StructGen: Handles non-opaque <struct> elements
+    EnumGen: Handles <enum> elements.
+
+The remaining IGeneratable classes don't generate output files
+themselves, they are just used to generate references to their
+corresponding types in method signatures and the like.
+
+ByRefGen: Handles struct types that must be passed into C code by
+          reference (at the moment, only GValue/GLib.Value)
+CustomMarshalerGen: Handles types that need custom marshalling.
+                    (Currently unused?)
+GStringGen: Handles conversion between GString and System.String
+ManualGen: Handles types that must be manually marshalled between
+           managed and unmanaged code (by handwritten classes such
+           as GLib.List)
+    GObjectGen: Handles GObjects
+SimpleGen: Handles types that can be simply converted from an
+           unmanaged type to a managed type (usually IntPtr)
+    ConstStringGen: Handles conversion between "const char *" and
+                    System.String
+        StringGen: Handles conversion between non-const "char *" and
+                   System.String
+TimeTGen: Handles conversion between time_t and System.DateTime
+
+AliasGen: Handles <alias> elements. "Generates" type aliases by
+          ignoring them (eg, outputting "Gdk.Rectangle" wherever the
+          API calls for a GtkAllocation).
+
+
+Other code-generating classes used by IGeneratables
+---------------------------------------------------
+
+Ctor: Handles <constructor> elements
+Field: Handle <field> elements (only used by StructBase, not
+       ClassBase)
+Method: Handle <method> elements
+Property: Handles <property> elements
+    ChildProperty: Handles <childprop> elements
+Signal: Handles <signal> elements
+
+ImportSignature: Represents a signature for an unmanaged method
+ManagedCallString: Represents a call to a managed method from a
+                   method that has unmanaged data
+MethodBody: shared by Ctor and Method
+Parameter: Represents the parameters to a method
+SignalHandler: Used by Signal. Like CallbackGen, this creates an
+               internal type to wrap a signal-handler delegate.
+Signature: Represents the signature of a method
+VMSignature: Used by Signal. Represents the signature of a virtual
+             method.