Class: Vips::Object

Inherits:

GObject::GObject

• Object
• GObject::GObject
• Vips::Object

Defined in:

lib/vips/object.rb

Direct Known Subclasses

Connection, Image, Interpolate, MutableImage, Operation, Region

Defined Under Namespace

Modules: ObjectLayout Classes: ManagedStruct, Struct

Instance Attribute Summary

Attributes inherited from GObject::GObject

#ptr, #references

Class Method Summary

• .print_all ⇒ Object

  print all active VipsObjects, with their reference counts.

Instance Method Summary

• #get(name) ⇒ Object
• #get_pspec(name) ⇒ Object

  return a pspec, or nil …

• #get_typeof(name) ⇒ Object

  return a gtype, 0 on not found.

• #get_typeof_error(name) ⇒ Object

  return a gtype, raise an error on not found.

• #set(name, value) ⇒ Object
• #signal_connect(name, handler = nil, &block) ⇒ Object

Methods inherited from GObject::GObject

#ffi_managed_struct, ffi_managed_struct, #ffi_struct, ffi_struct, #initialize

Constructor Details

This class inherits a constructor from GObject::GObject

Class Method Details

.print_all ⇒ Object

print all active VipsObjects, with their reference counts. Handy for debugging ruby-vips.

# File 'lib/vips/object.rb', line 168

def self.print_all
  GC.start
  Vips.vips_object_print_all
end

Instance Method Details

#get(name) ⇒ Object

# File 'lib/vips/object.rb', line 233

def get name
  gtype = get_typeof_error name
  gvalue = GObject::GValue.alloc
  gvalue.init gtype
  GObject.g_object_get_property self, name, gvalue
  result = gvalue.get
  gvalue.unset

  GLib.logger.debug("Vips::Object.get") { "#{name} == #{result}" }

  result
end

#get_pspec(name) ⇒ Object

return a pspec, or nil … nil wil leave a message in the error log which you must clear

# File 'lib/vips/object.rb', line 202

def get_pspec name
  ppspec = GObject::GParamSpecPtr.new
  argument_class = Vips::ArgumentClassPtr.new
  argument_instance = Vips::ArgumentInstancePtr.new

  result = Vips.vips_object_get_argument self, name,
    ppspec, argument_class, argument_instance
  return nil if result != 0

  ppspec[:value]
end

#get_typeof(name) ⇒ Object

return a gtype, 0 on not found

# File 'lib/vips/object.rb', line 223

def get_typeof name
  pspec = get_pspec name
  unless pspec
    Vips.vips_error_clear
    return 0
  end

  pspec[:value_type]
end

#get_typeof_error(name) ⇒ Object

return a gtype, raise an error on not found

Raises:

• (Vips::Error)

# File 'lib/vips/object.rb', line 215

def get_typeof_error name
  pspec = get_pspec name
  raise Vips::Error unless pspec

  pspec[:value_type]
end

#set(name, value) ⇒ Object

# File 'lib/vips/object.rb', line 246

def set name, value
  GLib.logger.debug("Vips::Object.set") { "#{name} = #{value}" }

  gtype = get_typeof_error name
  gvalue = GObject::GValue.alloc
  gvalue.init gtype
  gvalue.set value
  GObject.g_object_set_property self, name, gvalue
  gvalue.unset
end

#signal_connect(name, handler = nil, &block) ⇒ Object

Raises:

• (Vips::Error)

# File 'lib/vips/object.rb', line 257

def signal_connect name, handler = nil, &block
  marshal = MARSHAL_ALL[name.to_sym]
  raise Vips::Error, "unsupported signal #{name}" if marshal.nil?

  if block
    # our block as a Proc
    prc = block
  elsif handler
    # We assume the hander is a Proc (perhaps we should test)
    prc = handler
  else
    raise Vips::Error, "must supply either block or handler"
  end

  # The marshal function will make a closure with the right type signature
  # for the selected signal
  callback = marshal.call(prc)

  # we need to make sure this is not GCd while self is alive
  @references << callback

  GObject.g_signal_connect_data(self, name.to_s, callback, nil, nil, 0)
end