Type Mappings

The types used for properties in .slint design markup each translate to specific types in C++. The follow table summarizes the entire mapping. The .slint types link to the Slint language reference:

| .slint Type | C++ Type | Note | | --- | --- | --- | | int | int | | | float | float | | | bool | bool | | | string | slint::SharedString | A reference-counted string type that uses UTF-8 encoding and can be easily converted to a std::string_view or a const char *. | | color | slint::Color | | | brush | slint::Brush | | | image | slint::Image | | | physical_length | float | The unit are physical pixels. | | length | float | At run-time, logical lengths are automatically translated to physical pixels using the device pixel ratio. | | duration | std::int64_t | At run-time, durations are always represented as signed 64-bit integers with millisecond precision. | | angle | float | The angle in degrees. | | relative-font-size | float | Relative font size factor that is multiplied with the Window.default-font-size and can be converted to a length. | | structure | A class of the same name | The order of the data member are in the same as in the slint declaration. | | anonymous object | A std::tuple | The fields are in alphabetical order. | | enum | An enum class | The values are always converted to CamelCase. The order of the values is the same as in the declaration. | | data-transfer | slint::DataTransfer | Data associated with a drag-drop transfer. | | styled-text | slint::StyledText | Styled text parsed from markdown or plain text. Use StyledText::from_markdown() or StyledText::from_plain_text() to create. | | Point | slint::LogicalPosition | A struct with x and y fields, representing logical coordinates. |

Structures

The Slint compiler generates a class with all data members in the same order for any user-defined, exported struct in the .slint code.

For example, this struct in a .slint file

export struct MyStruct {
    foo: int,
    bar: string,
}

slint

will generate the following type in C++:

class MyStruct {
public:
    int foo;
    slint::SharedString bar;
};

C++

Enums

The Slint compiler generates an enum class with all values in the same order and converted to camel case for any user-defined, exported enum in the .slint code.

For example, this enum in a .slint file

export enum MyEnum { alpha, beta-gamma, omicron }

slint

will generate the following type in C++:

enum class MyEnum { Alpha, BetaGamma, Omicron };

C++