ml::Hoverable Class Reference

Trait that adds mouse-hover and mouse-leave callbacks to any Core object. More...

#include <Malena/Traits/Interaction/Hoverable.h>

Inheritance diagram for ml::Hoverable:

Public Member Functions
void	onHover (std::function< void()> callback, bool overwrite=true)
	Register a no-argument callback invoked when the mouse enters this component's bounds.
void	onHover (std::function< void(const std::optional< sf::Event > &event)> callback, bool overwrite=true)
	Register a callback invoked when the mouse enters this component's bounds, receiving the raw SFML event.
void	onUnhover (std::function< void()> callback, bool overwrite=true)
	Register a no-argument callback invoked when the mouse leaves this component's bounds.
void	onUnhover (std::function< void(const std::optional< sf::Event > &event)> callback, bool overwrite=true)
	Register a callback invoked when the mouse leaves this component's bounds, receiving the raw SFML event.
virtual void	process (const std::string &key, const std::optional< sf::Event > &event)
	Invoke all callbacks registered for key.
template<typename ENUM_TYPE>
void	process (ENUM_TYPE eventName, const std::optional< sf::Event > &event)
	Invoke all callbacks registered for eventName.

Public Attributes
Core *	_selfCore = nullptr

Detailed Description

Trait that adds mouse-hover and mouse-leave callbacks to any Core object.

Hoverable is automatically inherited by every ml::Core object. The hover event fires once when the mouse cursor enters a component's bounds; the unhover event fires once when it leaves.

Usage

// Highlight on hover, restore on leave
myRect.onHover([&]{ myRect.setFillColor(sf::Color::Yellow); });
myRect.onUnhover([&]{ myRect.setFillColor(sf::Color::White); });
 
// With SFML event data
myRect.onHover([](const std::optional<sf::Event>& e){
    // e holds the MouseMoved event that triggered the enter
});

To unsubscribe:

myRect.unsubscribe(ml::Event::HOVER);
myRect.unsubscribe(ml::Event::UNHOVER);

See also

Clickable, Focusable, ml::Event::HOVER, ml::Event::UNHOVER, Unsubscribable

Definition at line 46 of file Hoverable.h.

Member Function Documentation

onHover() [1/2]

void ml::Hoverable::onHover	(	std::function< void()>	callback,
		bool	overwrite = true )

Register a no-argument callback invoked when the mouse enters this component's bounds.

Parameters

callback	Function invoked with no arguments on hover enter.
overwrite	When true, replaces any existing callback; when false, appends an additional one.

onHover() [2/2]

void ml::Hoverable::onHover	(	std::function< void(const std::optional< sf::Event > &event)>	callback,
		bool	overwrite = true )

Register a callback invoked when the mouse enters this component's bounds, receiving the raw SFML event.

Parameters

callback	Function invoked with the SFML event on hover enter.
overwrite	When true, replaces any existing callback; when false, appends an additional one.

onUnhover() [1/2]

void ml::Hoverable::onUnhover	(	std::function< void()>	callback,
		bool	overwrite = true )

Register a no-argument callback invoked when the mouse leaves this component's bounds.

Parameters

callback	Function invoked with no arguments on hover leave.
overwrite	When true, replaces any existing callback; when false, appends an additional one.

onUnhover() [2/2]

void ml::Hoverable::onUnhover	(	std::function< void(const std::optional< sf::Event > &event)>	callback,
		bool	overwrite = true )

Register a callback invoked when the mouse leaves this component's bounds, receiving the raw SFML event.

Parameters

callback	Function invoked with the SFML event on hover leave.
overwrite	When true, replaces any existing callback; when false, appends an additional one.

process() [1/2]

virtual void ml::EventReceiver::process ( const std::string & key, const std::optional< sf::Event > & event )

virtualinherited

Invoke all callbacks registered for key.

Called by framework dispatchers. key is the string produced by EnumKey::get(eventEnum).

Parameters

key	String key identifying the event.
event	SFML event forwarded to each callback.

process() [2/2]

template<typename ENUM_TYPE>

void ml::EventReceiver::process ( ENUM_TYPE eventName, const std::optional< sf::Event > & event )

inherited

Invoke all callbacks registered for eventName.

Template overload that accepts any enum value directly, converting to a string key via EnumKey::get() internally.

Template Parameters

ENUM_TYPE

Any enum type.

Parameters

eventName	The enum value identifying the event.
event	SFML event forwarded to each callback.

Member Data Documentation

_selfCore

Core* ml::EventReceiver::_selfCore = nullptr

inherited

The owning Core, stamped by Core's constructor.

Traits subscribe from inside their OWN constructors (ml::TextInput calls onFocus(), ComponentCore subscribes to CLICK/HOVER/DRAG), at which point the derived type does not exist yet. Recovering the Core by dynamic_cast there is undefined: Clang returns something usable, MSVC throws "Access violation - no RTTI data!" and aborts the process. Core sets this on every one of its EventReceiver subobjects before any derived constructor runs, so no RTTI is ever needed.

Definition at line 93 of file EventReceiver.h.

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

• Traits/Interaction/Hoverable.h