ove::lvgl::EventMixin< Derived > Class Template Reference

CRTP mixin that adds type-safe LVGL event registration to widget classes. More...

#include <lvgl.hpp>

Public Member Functions
template<detail::StatelessCallable F>
Derived &	on (lv_event_code_t code, F &&fn)
	Registers a stateless callback for the given event code.
template<auto MemFn, typename T >
Derived &	on (lv_event_code_t code, T *instance)
	Registers a member function pointer as an event callback — zero-cost trampoline.
template<detail::StatelessCallable F>
Derived &	on_click (F &&fn)
	Registers a stateless click callback (shorthand for on(LV_EVENT_CLICKED, fn)).
template<auto MemFn, typename T >
Derived &	on_click (T *instance)
	Registers a member function click callback.
template<detail::StatelessCallable F>
Derived &	on_value_changed (F &&fn)
	Registers a stateless value-changed callback (shorthand for on(LV_EVENT_VALUE_CHANGED, fn)).
template<auto MemFn, typename T >
Derived &	on_value_changed (T *instance)
	Registers a member function value-changed callback.

Detailed Description

template<typename Derived>
class ove::lvgl::EventMixin< Derived >

CRTP mixin that adds type-safe LVGL event registration to widget classes.

Provides overloaded on() methods for:

• Stateless (non-capturing) lambdas and function pointers, registered directly as LVGL callbacks without any indirection.
• Member function pointers as non-type template parameters, using a zero-cost trampoline that reads the instance from the LVGL user-data slot.

Convenience wrappers on_click() and on_value_changed() cover the most common event codes.

Template Parameters

Derived

The concrete widget class inheriting this mixin. Must expose a get() method returning lv_obj_t*.

Member Function Documentation

on() [1/2]

template<typename Derived >

template<detail::StatelessCallable F>

Derived & ove::lvgl::EventMixin< Derived >::on ( lv_event_code_t  code, F &&  fn  )

inline

Registers a stateless callback for the given event code.

Only participates in overload resolution when F satisfies detail::StatelessCallable (i.e., non-capturing lambda or function pointer).

Template Parameters

F	Callable type satisfying detail::StatelessCallable.

Parameters

[in]	code	Event code to listen for (e.g., LV_EVENT_CLICKED).
[in]	fn	Callback function; stored as a raw function pointer.

Returns

Reference to the derived object for method chaining.

on() [2/2]

template<typename Derived >

template<auto MemFn, typename T >

Derived & ove::lvgl::EventMixin< Derived >::on ( lv_event_code_t  code, T *  instance  )

inline

Registers a member function pointer as an event callback — zero-cost trampoline.

The instance pointer is stored in the LVGL user-data slot and recovered inside the inline trampoline lambda. No heap allocation is needed.

Template Parameters

MemFn	Non-type template parameter: pointer to member function with signature void T::fn(lv_event_t*).
T	Class type that owns MemFn.

Parameters

[in]	code	Event code to listen for.
[in]	instance	Pointer to the object on which MemFn will be called.

Returns

Reference to the derived object for method chaining.

on_click() [1/2]

template<typename Derived >

template<detail::StatelessCallable F>

Derived & ove::lvgl::EventMixin< Derived >::on_click ( F &&  fn )

inline

Registers a stateless click callback (shorthand for on(LV_EVENT_CLICKED, fn)).

Template Parameters

F	Callable type satisfying detail::StatelessCallable.

Parameters

[in]

fn

Callback function invoked on click.

Returns

Reference to the derived object for method chaining.

on_click() [2/2]

template<typename Derived >

template<auto MemFn, typename T >

Derived & ove::lvgl::EventMixin< Derived >::on_click ( T *  instance )

inline

Registers a member function click callback.

Template Parameters

MemFn	Non-type member function pointer.
T	Class type owning MemFn.

Parameters

[in]

instance

Pointer to the instance on which MemFn is called.

Returns

Reference to the derived object for method chaining.

on_value_changed() [1/2]

template<typename Derived >

template<detail::StatelessCallable F>

Derived & ove::lvgl::EventMixin< Derived >::on_value_changed ( F &&  fn )

inline

Registers a stateless value-changed callback (shorthand for on(LV_EVENT_VALUE_CHANGED, fn)).

Template Parameters

F	Callable type satisfying detail::StatelessCallable.

Parameters

[in]

fn

Callback function invoked when the widget value changes.

Returns

Reference to the derived object for method chaining.

on_value_changed() [2/2]

template<typename Derived >

template<auto MemFn, typename T >

Derived & ove::lvgl::EventMixin< Derived >::on_value_changed ( T *  instance )

inline

Registers a member function value-changed callback.

Template Parameters

MemFn	Non-type member function pointer.
T	Class type owning MemFn.

Parameters

[in]

instance

Pointer to the instance on which MemFn is called.

Returns

Reference to the derived object for method chaining.

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The documentation for this class was generated from the following file:

• bindings/cpp/ove/lvgl.hpp