java: Add documentation generation.

Makefile.am

@@ -522,6 +522,10 @@ java-clean:
 	rm -f $(JINT)/*.class
 	rm -f $(JJAR)
 	rm -f $(JLIB)
+	rm -rf $(JDIR)/doxy/
+
+java-doc:
+	$(AM_v_at)cd $(JDIR) && doxygen Doxyfile
 
 BUILD_EXTRA += java-build
 INSTALL_EXTRA += java-install

bindings/java/org/sigrok/core/classes/classes.i

@@ -7,11 +7,36 @@
   }
 %}
 
-/* Import interfaces. */
+/* Documentation & importing interfaces. */
 %pragma(java) jniclassimports=%{
-  import org.sigrok.core.interfaces.LogCallback;
+/**
-  import org.sigrok.core.interfaces.DatafeedCallback;
+ * @mainpage API Reference
-  import org.sigrok.core.interfaces.SourceCallback;
+ * 
+ * Introduction
+ * ------------
+ * 
+ * The sigrok-java API provides an object-oriented Java interface to the
+ * functionality in libsigrok. It is built on top of the sigrok++ C++ API.
+ * 
+ * Getting started
+ * ---------------
+ * 
+ * Usage of the sigrok-java API needs to begin with a call to Context.create().
+ * This will create the global libsigrok context and returns a Context object.
+ * Methods on this object provide access to the hardware drivers, input and
+ * output formats supported by the library, as well as means of creating other
+ * objects such as sessions and triggers.
+ * 
+ * Error handling
+ * --------------
+ * 
+ * When any libsigrok C API call returns an error, an Error exception is raised,
+ * which provides access to the error code and description.
+ */
+
+import org.sigrok.core.interfaces.LogCallback;
+import org.sigrok.core.interfaces.DatafeedCallback;
+import org.sigrok.core.interfaces.SourceCallback;
 %}
 
 /* Map Java FileDescriptor objects to int fds */