private fun initializeEmojiCategoriesPreferred() {
        emojiItemViewList = EmojiCategoryTransformer().transform(initializeEmojiCategoryList())
    }

    private fun initializeEmojiCategoryList(): List<Category> {
        return listOf(
            ActivitiesCategory(getString(R.string.activitiesCategoryTitle)),
            AnimalsNatureCategory(getString(R.string.animalsAndNatureTitle)),
            FoodDrinkCategory(getString(R.string.foodAndDrinkTitle)),
            FlagsCategory(getString(R.string.flagsTitle)),
            ObjectsCategory(getString(R.string.objectsTitle)),
            SmileysPeopleCategory(getString(R.string.smileysAndPeopleTitle)),
            SymbolsCategory(getString(R.string.symbolsTitle)),
            TravelPlacesCategory(getString(R.string.travelAndPlacesTitle))
        )
    }

    private fun showEmojiDialog() {
        EmojiPickerDialog.Builder(this@MainActivity, emojiItemViewList)
            .dismissWithAnimation(true)
            .title(getString(R.string.emojiDialogTitle))
            .cancelable(true)
            .listener(object : EmojiClickListener {
                override fun emojiClicked(unicode: EmojiItemView) {
                    selectedEmoji.text = unicode.value
                    selectedEmojiName.text = unicode.name
                }
            }).build().show()
    }