DemoActivity.kt

package io.kolumbus.demo

import android.app.Activity
import android.os.Bundle
import io.kolumbus.Kolumbus
import io.kolumbus.demo.model.Category
import io.kolumbus.demo.model.Product
import io.realm.Realm
import io.realm.RealmConfiguration
import io.realm.RealmList
import java.util.Random

class DemoActivity : Activity() {
	private val CATEGORIES_COUNT = 100
	private val MAX_LINKED_CATEGORIES = 50
	private val PRODUCTS_COUNT = 1000

	override fun onCreate(savedInstanceState: Bundle?) {
		super.onCreate(savedInstanceState)

		Realm.init(this)

		val realmConfiguration = RealmConfiguration.Builder()
				.deleteRealmIfMigrationNeeded()
				.build()
		Realm.setDefaultConfiguration(realmConfiguration)

		this.fillDatabase()

		with(Kolumbus) {
			explore(realmConfiguration)
			navigate(this@DemoActivity)
		}
	}

	private fun fillDatabase() {
		with(Realm.getDefaultInstance()) {
			executeTransaction {
				val random = Random()
				val categoriesCount = this.where(Category::class.java).count()
				val productsCount = this.where(Product::class.java).count()

				for (i in 1..CATEGORIES_COUNT) {
					with(createObject(Category::class.java, (categoriesCount + i).toInt())) {
						color = random.nextColor()
						name = "Category $id"
					}
				}

				for (i in 1..PRODUCTS_COUNT) {
					with(createObject(Product::class.java, (productsCount + i).toInt())) {
						categories = RealmList<Category>()

						for (j in 0 until random.nextInt(MAX_LINKED_CATEGORIES)) {
							val category = where(Category::class.java).equalTo("id", random.nextInt(CATEGORIES_COUNT - 1) + 1).findFirst()

							if (!(categories as RealmList<Category>).contains(category)) {
								(categories as RealmList<Category>).add(category)
							}
						}

						description = "<b>Lorem ipsum</b> dolor sit amet, <i>consectetur adipiscing</i> elit. <b><u>Maecenas mollis</u></b> eget nibh et condimentum."
						name = "Product $id"
					}
				}
			}

			close()
		}
	}
}

fun Random.nextColor(): String {
	fun Random.nextColorHex(): String {
		return Integer.toHexString(this.nextInt(256)).padStart(2, '0')
	}

	return "#${this.nextColorHex()}${this.nextColorHex()}${this.nextColorHex()}"
}