Extensions

Extensions

designsystem-utilities provides various extensions and utilities functions as helpers. Usually the utilities functions are attached to the Companion object of a certain type.

Color

fromHex()

ℹ️ This an utility method in Color.Companion

Convert a hex value string to a Color

• If the conversion fails, fallbackColor will be returned
• If hexValue is null, fallbackColor will be returned
• If fallbackColor is not provided, Color.White will be returned

// valid values
val white = Color.fromHex("#ffffff")
val anotherWhite = Color.fromHex("#FFFFFFFF")

// exception
val exception = Color.fromHex("ffffff")

ifUnspecified()

Chain colors values until a color != Color.Unspecified is found.

val color = someColor.ifUnspecified(anotherColor).ifUnspecified(someOthercolor)

Dp

toRoundedShape()

Creates a RoundedCornerShape from a Dp value.

val shape = 8.dp.toRoundedShape()

String

String.empty, String.whitespace, String.questionMark

These are a series of extensions used to avoid using magic strings.

orEmpty()

Extensions for String? to return String.empty if the source is null.

val someString: String? = null
val empty = someString.orEmpty()

toAnnotatedString()

Used to covert a regular String to a AnnotedString.

val annotedString = "some string".toAnnotedString()

toColor()

Covert a String? to Color using Color.fromHex()

TypedArray

The library provides a series of extensions to TypedArray to:

1. More easily extract attributes in custom views
2. Bridge XML theme/attributes to compose Theme

The provided extensions are: getStringOrEmpty, getBooleanOrTrue, getBooleanOrFalse, getResourceIdOrNull, getComposeColor, getDp.

// example of usage inside a custom view `init` block
// the extensions provide a nice way to have fallback/default values
init {
  context.theme.obtainStyledAttributes(
    attrs,
    R.styleable.EverliButtonView,
    0, 0
  ).apply {
    try {
      text = getStringOrEmpty(R.styleable.EverliButtonView_text)
      variant = enumValueOfOrFallback(getInt(R.styleable.EverliButtonView_btnVariant, variant.ordinal), ButtonVariant.PRIMARY)
      isButtonEnabled = getBooleanOrTrue(R.styleable.EverliButtonView_enabled)
      useContextTheme = getBooleanOrFalse(R.styleable.EverliButtonView_useContextTheme)
      icon = getDrawable(R.styleable.EverliButtonView_btnIcon)
    } finally {
      recycle()
    }
  }
}

Using the extensions to extract `xml` theme attributes and convert them to `Compose`

context.obtainStyledAttributes(R.styleable.EverliTheme).use { ta ->
  val small = ta.getDp(R.styleable.EverliTheme_radiusSmall, density, DefaultRadiusTheme.small)
  val primary = ta.getComposeColor(R.styleable.EverliTheme_textColorPrimary, DefaultTextTheme.color.primary)
}