class Alda::Event

The class of elements of Alda::EventList#events.

Attributes

container[RW]

The Alda::EventContainer object that contains it. It may be nil if there is not a container containing it, especially probably when it itself is an Alda::EventContainer.

parent[RW]

The Alda::EventList object that contains it.

Note that it may not be directly contained, but with an Alda::EventContainer object in the middle.

Public Instance Methods

event == other → true or false click to toggle source

Whether it is equal to other. To be overriden.

Note that parent and container should not be taken into account when comparing two events.

Calls superclass method

# File lib/alda-rb/event.rb, line 94
def == other
  super
end

detach_from_parent(except = []) click to toggle source

Delete itself (or its topmost container if it has) from its parent. If it is not at its parent‘s end, raises Alda::OrderError.

Here is a list of cases where the method is invoked:

Using the sequence sugar when operating an Alda::EventList.
Using Alda::EventContainer#/ to create chords or parts of multiple instruments.
Using dot accessor of Alda::Part. See Alda::Part#method_missing.
Using the inline lisp sugar. See Alda::InlineLisp.

This method needs invoking in these cases because if an event is created using Alda::EventList sugars (see Alda::EventList#method_missing), it is automatically pushed to its parent. However, the cases above requires the event be contained in another object.

The parameter except specifies an Array of classes. If parent is an instance of any of the classes in except, the method does nothing.

# File lib/alda-rb/event.rb, line 67
def detach_from_parent except = []
  event = self
  event = event.container while event.container
  if @parent && except.none? { @parent.is_a? _1 } && event != (got = @parent.events.pop)
    raise Alda::OrderError.new event, got
  end
end

is_event_of?(klass) → true or false click to toggle source

Whether it is an event of the given class (klass). By default, this is the same as +is_a?(klass)+. It is overridden in Alda::EventContainer.

# File lib/alda-rb/event.rb, line 82
def is_event_of? klass
  is_a? klass
end

on_contained() click to toggle source

The callback invoked when it is contained in an Alda::EventContainer. It is overridden in Alda::InlineLisp and Alda::EventList. It is called in Alda::EventContainer#on_containing.

class Alda::Note
  def on_contained
    super
    puts 'a note contained'
  end
end
Alda::Score.new { c } # => outputs "a note contained"

# File lib/alda-rb/event.rb, line 30
def on_contained
end

to_alda_code() → String click to toggle source

Converts to alda code. To be overridden in subclasses.

# File lib/alda-rb/event.rb, line 38
def to_alda_code
  ''
end