Structs and Enums in Slint

Structs

Use the struct keyword to define named data structures.

Example:

export struct Player {
    name: string,
    score: int,
}

export component Example {
    in-out property<Player> player: { name: "Foo", score: 100 };
}

• Default values: all fields are set to their type’s default value.

Anonymous Structures

You can declare anonymous structs inline using:

{ field1: type1, field2: type2 }

Initialize them with:

{ field1: value1, field2: value2 }

Example:

export component Example {
    in-out property<{name: string, score: int}> player: { name: "Foo", score: 100 };
    in-out property<{a: int, }> foo: { a: 3 };
}

• Trailing commas are allowed in type declarations and initializers.

Enums

Use the enum keyword to define enumerations.

Example:

export enum CardSuit { clubs, diamonds, hearts, spade }

export component Example {
    in-out property<CardSuit> card: spade;
    out property<bool> is-clubs: card == CardSuit.clubs;
}

• Enum values are accessed as EnumName.value (e.g., CardSuit.spade).
• The enum name can be omitted if:
  • The property is of that enum type.
  • The return value of a callback is of that enum type.
• Default value of an enum type is always its first value.