slint/api/sixtyfps-cpp/docs/generated_code.md

Generated code

As of now, only the last component of a .60 source is generated. It is planed to generate all exported components.

The SixtyFPS compiler called by the build system will generate a header file for the root .60 file. This header file will contain a class with the same name as the component.

This class will have the following public member functions:

• A default constructor and a destructor.
• A show function, which will show the component on the screen. Note that in order to render and react to user input, it's still necessary to spin the event loop, by calling sixtyfps::run_event_loop() or using the convenience fun function in this class.
• A hide function, which de-registers the component from the windowing system.
• A run convenience function, which will show the component and starts the event loop.
• for each properties:
  • A getter get_<property_name> returning the property type.
  • A setter set_<property_name> taking the new value of the property by const reference
• for each callbacks:
  • invoke_<callback_name> function which takes the callback argument as parameter and call the callback.
  • on_<callback_name> functin wich takes a functor as an argument and sets the callback handler for this callback. the functor must accept the type parameter of the callback

Example

Let's assume we have this code in our .60 file

SampleComponent := Window {
    property<int> counter;
    property<string> user_name;
    callback hello;
    // ... maybe more elements here
}

This will generate a header with the following contents (edited for documentation purpose)

#include <array>
#include <limits>
#include <sixtyfps.h>


class SampleComponent {
public:
    /// Contructor
    inline auto create () -> sixtyfps::ComponentHandle<MainWindow>;
    /// Destructor
    inline ~SampleComponent ();

    /// Show this component, and runs the event loop
    inline void run () const;

    /// Getter for the `counter` property
    inline int get_counter () const -> int;
    /// Setter for the `counter` property
    inline void set_counter (const int &value) const;

    /// Getter for the `user_name` property
    inline sixtyfps::SharedString get_user_name () const;
    /// Setter for the `user_name` property
    inline void set_user_name (const sixtyfps::SharedString &value) const;

    /// Call this function to call the `hello` callback
    inline void invoke_hello () const;
    /// Sets the callback handler for the `hello` callback.
    template<typename Functor> inline void on_hello (Functor && callback_handler) const;

private:
    /// private fields omitted
};