AndyObtiva/glimmer-dsl-libui

require 'glimmer-dsl-libui'

class LazyTable
  Contact = Struct.new(:name, :email, :phone, :city, :state)
  
  include Glimmer::LibUI::Application
  
  NAMES_FIRST = %w[
    Liam Noah William James Oliver Benjamin Elijah Lucas Mason Logan Alexander Ethan Jacob Michael Daniel Henry Jackson Sebastian
    Aiden Matthew Samuel David Joseph Carter Owen Wyatt John Jack Luke Jayden Dylan Grayson Levi Isaac Gabriel Julian Mateo
    Anthony Jaxon Lincoln Joshua Christopher Andrew Theodore Caleb Ryan Asher Nathan Thomas Leo Isaiah Charles Josiah Hudson
    Christian Hunter Connor Eli Ezra Aaron Landon Adrian Jonathan Nolan Jeremiah Easton Elias Colton Cameron Carson Robert Angel
    Maverick Nicholas Dominic Jaxson Greyson Adam Ian Austin Santiago Jordan Cooper Brayden Roman Evan Ezekiel Xaviar Jose Jace
    Jameson Leonardo Axel Everett Kayden Miles Sawyer Jason Emma Olivia Bartholomew Corey Danielle Eva Felicity
  ]
  
  NAMES_LAST = %w[
    Smith Johnson Williams Brown Jones Miller Davis Wilson Anderson Taylor George Harrington Iverson Jackson Korby Levinson
  ]
  
  CITIES = [
    'Bellesville', 'Lombardia', 'Steepleton', 'Deerenstein', 'Schwartz', 'Hollandia', 'Saint Pete', 'Grandville', 'London',
    'Berlin', 'Elktown', 'Paris', 'Garrison', 'Muncy', 'St Louis',
  ]
  
  STATES = [ 'AK', 'AL', 'AR', 'AZ', 'CA', 'CO', 'CT', 'DC', 'DE', 'FL', 'GA',
             'HI', 'IA', 'ID', 'IL', 'IN', 'KS', 'KY', 'LA', 'MA', 'MD', 'ME',
             'MI', 'MN', 'MO', 'MS', 'MT', 'NC', 'ND', 'NE', 'NH', 'NJ', 'NM',
             'NV', 'NY', 'OH', 'OK', 'OR', 'PA', 'RI', 'SC', 'SD', 'TN', 'TX',
             'UT', 'VA', 'VT', 'WA', 'WI', 'WV', 'WY']
             
  before_body do
    contact_count = 1_000_000
    # Make sure to pass Enumerator::Lazy constructor size (2nd) argument as it gets used by Glimmer DSL for LibUI
    # to determine the number of rows in the table before generating all its data
    @contacts = Enumerator::Lazy.new(contact_count.times, contact_count) do |yielder, index|
      number = index + 1
      first_name = NAMES_FIRST.sample
      last_name = NAMES_LAST.sample
      phone = 10.times.map { rand(10) }.yield_self { |numbers| [numbers[0..2], numbers[3..5], numbers[6..9]].map(&:join).join('-') }
      city = CITIES.sample
      state = STATES.sample
      
      # Data will get lazy loaded into the table as the user scrolls through.
      # After data is built, it is cached long-term, till updating table `cell_rows`.
      yielder << Contact.new("#{first_name} #{last_name}", "#{first_name.downcase}#{number}@#{last_name.downcase}.com", phone, city, state)
    end
  end
  
  body {
    window("1,000,000 Lazy Loaded Contacts", 600, 700) {
      margined true
      
      table {
        text_column('Name')
        text_column('Email')
        text_column('Phone')
        text_column('City')
        text_column('State')
        
        cell_rows @contacts
      }
    }
  }
end

LazyTable.launch