class Job
attr_reader :name
def initialize(name)
@name = name
end
def get_time_required
0.0
end
end
class SubJob1 < Job
def initialize
super('sub job 1')
end
def get_time_required
1.0 # 1 minute to add flour and sugar
end
end
class SubJob2 < Job
def initialize
super('sub job 2')
end
def get_time_required
3.0 # Mix for 3 minutes
end
end
class CompositeJob < Job
def initialize(name)
super(name)
@sub_jobs = []
end
def add_sub_job(job)
@sub_jobs << job
end
def remove_sub_job(job)
@sub_jobs.delete(job)
end
def get_time_required
time=0.0
@sub_jobs.each {|job| time += job.get_time_required}
time
end
end
class MakeCakeJob < CompositeJob
def initialize
super('Make cake')
add_sub_job( SubJob1.new )
add_sub_job( SubJob2.new )
end
end