class.rb

require 'java'
require 'jruby'
require 'jruby/compiler/java_signature'

##
# Convenience methods added to class when you want to be able to
# reify a Ruby class into a honest to goodness type.  Typically, it would look
# like:
# :call-seq:
#
# class Foo
#   java_signature '@org.foo.EventHandler(@org.foo.Priority.High) void foo(int)'
#   def foo(number)
#   end
#   become_java!
# end 
#
# Although this will still just be an instance of a IRubyObject versus a 
# specific type, you can still use this facility for:
#   1. Adding runtime annotations to methods
#   2. Making a class still reflectable from Java reflection APIs.
#
# Case #1 above is also a useful combination with implementing Java interfaces.
#
class Class
  JClass = java.lang.Class
  private_constant :JClass

  ##
  # java_signature will take the argument and annotate the method of the
  # same name with the Java type and annotation signatures.
  # 
  # :call-seq:
  #   java_signature '@Override void foo(int)'
  #   java_signature '@Override void foo(int foo, org.foo.Bar bar)'
  def java_signature(signature_source)
    signature = JRuby::JavaSignature.parse signature_source
    add_method_signature signature.name, signature.types

    annotations = signature.annotations
    add_method_annotation signature.name, annotations if annotations
  end
  
  ##
  # Generate a native Java class for this Ruby class. If dump_dir is specified,
  # dump the JVM bytecode there for inspection. If child_loader is false, do not
  # generate the class into its own classloader (use the parent's loader).
  # 
  # :call-seq:
  #   become_java!
  #   become_java!(dump_dir)
  #   become_java!(dump_dir, child_loader)
  #   become_java!(child_loader)
  #   become_java!(child_loader, dump_dir)
  def become_java!(*args)
    # stub moved to org.jruby.java.addons.ClassJavaAddons
  end if false
  
  ##
  # Get the native or reified (a la become_java!) class for this Ruby class.
  def java_class
    current = JRuby.reference0(self)
    while current
      reified = current.reified_class
      return reified if reified
      current = JRuby.reference0(current.super_class)
    end
    
    nil
  end if false # moved to org.jruby.java.addons.ClassJavaAddons
  
  def _anno_class(type)
    return type if type.kind_of? JClass
    if type.respond_to? :java_class
      type.java_class.to_java :object
    else
      raise TypeError, "expected a Java class, got #{type}"
    end
  end
  private :_anno_class
  
  ##
  # Add annotations to the named method. Annotations are specified as a Hash
  # from the annotation classes to Hashes of name/value pairs for their 
  # parameters. Please refrain from using this in favor of java_signature.
  # :call-seq:
  #
  #  add_method_annotation :foo, {java.lang.Override => {}}
  #
  def add_method_annotation(name, annotations = {})
    name = name.to_s; self_r = JRuby.reference0(self)

    annotations.each do |type, params|
      self_r.add_method_annotation(name, _anno_class(type), params || {})
    end
    
    nil
  end
  
  ##
  # Add annotations to the parameters of the named method. Annotations are
  # specified as a parameter-list-length Array of Hashes from annotation classes
  # to Hashes of name/value pairs for their parameters.
  def add_parameter_annotation(name, annotations = [])
    name = name.to_s; self_r = JRuby.reference0(self)
    
    annotations.each_with_index do |param_annos, i|
      for cls, params in param_annos
        params ||= {}
        self_r.add_parameter_annotation(name, i, _anno_class(cls), params)
      end
    end
    
    nil
  end
  
  ##
  # Add annotations to this class. Annotations are specified as a Hash of
  # annotation classes to Hashes of name/value pairs for their parameters.
  # :call-seq:
  #
  # add_class_annotation java.lang.TypeAnno => {"type" => @com.foo.GoodOne}
  #
  def add_class_annotations(annotations = {})
    self_r = JRuby.reference0(self)

    annotations.each do |type, params|
      self_r.add_class_annotation(_anno_class(type), params || {})
    end
    
    nil
  end

  ##
  # Add a Java signaturefor the named method. The signature is specified as
  # an array of Java classes where the first class specifies the return
  # type.
  # :call-seq:
  #
  # add_method_signature :foo, [:void, :int, java.lang.Thread]
  #
  def add_method_signature(name, classes)
    name = name.to_s; self_r = JRuby.reference0(self)
    types = classes.inject([]) { |arr, klass| arr << _anno_class(klass) }
    
    self_r.add_method_signature(name, types.to_java(JClass))
  end

  ##
  # java_field will take the argument and create a java field as defined
  # with the name, the Java type, and the annotation signatures.
  #
  # For advanced JVM integration, you can bind it to the corresponding instance
  # variable via instance_variable: true. This changes the semantics of the
  # corresponding variable to JVM semantics (freeze is not honored, @var.equals?(@var) may be false, etc)
  # 
  # :call-seq:
  #   java_field '@FXML int foo'
  #   java_field 'org.foo.Bar bar'
  def java_field(signature_source, instance_variable: false, to_java: nil)
    signature = JRuby::JavaSignature.parse "#{signature_source}()"

    add_field_signature signature.name, signature.return_type
    
    if instance_variable # request @ivar field binding
      opts = {unwrap: nil, type: signature.return_type}
      unless to_java == nil
        if to_java == false
          opts[:unwrap] = false
        elsif to_java.is_a? Java::JavaLang::Class or to_java.is_a? Class
          opts[:unwrap] = true
          opts[:type] = to_java
        else
          raise ArgumentError, "to_java must be either false, or a valid java class"
        end
      end
      JRuby.reference0(self).variable_table_manager.request_field_storage(
        signature.name,
          Class.__ensure_java_class(signature.return_type),
          opts[:unwrap], 
          Class.__ensure_java_class(opts[:type]))
    elsif to_java != nil
      raise ArgumentError, "to_java only affects java_field when instance_variable is true"
    end

    annotations = signature.annotations
    add_field_annotation signature.name, annotations if annotations
  end
  
  def self.__ensure_java_class(clz)
    if clz.is_a? java.lang.Class
      clz
    else
      clz.java_class
    end
  end

  class JavaConfig
    
    def initialize(class_config)
      @config = class_config
    end
    
    def dispatch(args={}, two=nil, **kwargs)
      unless two.nil?
        _dispatch(args, two)
      else
        kwargs.each { |k, v| _dispatch(k, v) }
        args.each { |k, v| _dispatch(k, v) } if args.is_a? Hash
      end
    end

    def include(*args)
      args.each {|method| @config.include(method) }
    end
    
    def exclude(*args)
      args.each {|method| @config.exclude(method) }
    end
    
    def extra_ctor(*types)
      config.extraCtors << types.map(&:to_java).to_java(java.lang.Class)
    end
    
    private
    def _dispatch(k, v)
      @config.renamedMethods.put(k.to_s.to_java, v.to_s.to_java)
    end
  end
  
  ##
  # A way to configure how become_java! classes are generated
  # Valid options:
  #  call_init: bool (default true)
  #  methods: :all/:explicit Only generate explicitly marked methods, or all methods on the proxy (default :all)
  #  ctors: :all/:explicit Only generate explicitly marked methods, or all methods on the proxy (default :all)
  #  java_constructable: bool Ensure the class is constructable from java (default true)
  #  ruby_constructable: bool Ensure the class is constructable from ruby (default true)
  #  ctor_name: Symbol method name of the java ctor. (default :initialize)
  #  proxy_dispatches: {Symbol (Java method) => Symbol (Ruby method)} Dispatches the keys to the values from the java proxy (default empty/identity)
  #  includes: List<Symbol> methods that would otherwise be excluded that you want to generate on the java proxy
  #  excludes: List<Symbol> methods that would otherwise be included that you do not want to generate on the java proxy
  #
  # Optional block arg methods:
  #  include (alias for :includes key)
  #  exclude (alias for :excludes key)
  #  dispatch (alias for :proxy_dispatches key)
  #
  # :call-seq:
  #   configure_java_class methods: :all
  #   configure_java_class methods: :explicit
  #   configure_java_class ctor_name: :my_java_init
  #   configure_java_class {|c| c.dispatch {initialize: :java_intialize} }
  #   configure_java_class proxy_dispatches: {initialize: :java_intialize}
  def configure_java_class(**kwargs, &blk)
    self_r = JRuby.reference0(self)
    config = self_r.class_config
    r_config = JavaConfig.new(config)
    kwargs.each do |k, v|
      case k.to_sym
      when :methods then
        raise ArgumentError, "methods expected :all or :explicit, got #{v.inspect}" unless [:all, :explicit].include? v
        config.allMethods = v == :all
      when :ctors then
        raise ArgumentError, "ctors expected :all or :explicit, got #{v.inspect}" unless [:all, :explicit].include? v
        config.allCtors = v == :all
      when :call_init then config.callInitialize = !!v
      when :java_constructable then config.javaConstructable = !!v
      when :ruby_constructable then config.rubyConstructable = !!v
      when :ctor_name then
          config.javaCtorMethodName = v.to_s
      when :proxy_dispatches then r_config.dispatch(v)
      when :includes then r_config.include(*v)
      when :excludes then r_config.exclude(*v)
      else
        warn "Java Class configuration option '#{k}' is not supported"
      end
    end
    r_config.instance_exec(r_config, &blk) if block_given?
    self_r.class_config = config
    kwargs
  end

  def java_annotation(anno)
    warn "java_annotation is deprecated. Use java_signature '@#{anno} ...' instead. Called from: #{caller.first}"
  end

  def add_field_signature(name, type)
    self_r = JRuby.reference0(self)

    java_return_type = _anno_class(type)

    self_r.add_field_signature(name, java_return_type.to_java(JClass))
  end

  def add_field_annotation(name, annotations = {})
    name = name.to_s; self_r = JRuby.reference0(self)

    annotations.each do |type, params|
      self_r.add_field_annotation(name, _anno_class(type), params || {})
    end

    nil
  end

end