ml::Scrollable Class Reference

Trait that adds mouse-wheel and raw mouse-button callbacks to any Core object. More...

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

Inheritance diagram for ml::Scrollable:

Public Member Functions
void	onMouseMoved (std::function< void()> callback, bool overwrite=true)
	Register a no-argument callback invoked whenever the mouse moves anywhere in the window.
void	onMouseMoved (std::function< void(const std::optional< sf::Event > &)> callback, bool overwrite=true)
	Register a callback invoked whenever the mouse moves anywhere in the window, receiving the raw SFML event.
void	onMousePressed (std::function< void()> callback, bool overwrite=true)
	Register a no-argument callback invoked when a mouse button is pressed anywhere in the window.
void	onMousePressed (std::function< void(const std::optional< sf::Event > &)> callback, bool overwrite=true)
	Register a callback invoked when a mouse button is pressed, receiving the raw SFML event.
void	onMouseReleased (std::function< void()> callback, bool overwrite=true)
	Register a no-argument callback invoked when a mouse button is released anywhere in the window.
void	onMouseReleased (std::function< void(const std::optional< sf::Event > &)> callback, bool overwrite=true)
	Register a callback invoked when a mouse button is released, receiving the raw SFML event.
void	onScroll (std::function< void()> callback, bool overwrite=true)
	Register a no-argument callback invoked when the mouse wheel is scrolled while the cursor is over this component.
void	onScroll (std::function< void(const std::optional< sf::Event > &)> callback, bool overwrite=true)
	Register a callback invoked when the mouse wheel is scrolled while the cursor is over this component, receiving the 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-wheel and raw mouse-button callbacks to any Core object.

Scrollable is automatically inherited by every ml::Core object. It exposes four event hooks covering the mouse wheel and the low-level mouse button press/release cycle (before click logic is applied):

Callback	Fires when
onScroll	Mouse wheel is scrolled while the cursor is over this component
onMouseMoved	Mouse moves anywhere in the window (all components receive this)
onMousePressed	Mouse button is pressed (raw — before click logic)
onMouseReleased	Mouse button is released (raw — before click logic)

Usage

// Scroll a list view on wheel
listView.onScroll([&](const std::optional<sf::Event>& e){
    if (auto* w = e->getIf<sf::Event::MouseWheelScrolled>())
        offset -= w->delta * scrollSpeed;
});
 
// Track raw press/release for custom drag logic
handle.onMousePressed([]{ dragging = true; });
handle.onMouseReleased([]{ dragging = false; });

To unsubscribe:

myComp.unsubscribe(ml::Event::SCROLL);
myComp.unsubscribe(ml::Event::MOUSE_MOVED);

See also

Clickable, Draggable, ml::Event::SCROLL, ml::Event::MOUSE_MOVED, ml::Event::MOUSE_PRESSED, ml::Event::MOUSE_RELEASED, Unsubscribable

Definition at line 54 of file Scrollable.h.

Member Function Documentation

onMouseMoved() [1/2]

void ml::Scrollable::onMouseMoved	(	std::function< void()>	callback,
		bool	overwrite = true )

Register a no-argument callback invoked whenever the mouse moves anywhere in the window.

Unlike onHover, this fires for every component regardless of whether the cursor is over it.

Parameters

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

onMouseMoved() [2/2]

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

Register a callback invoked whenever the mouse moves anywhere in the window, receiving the raw SFML event.

Parameters

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

onMousePressed() [1/2]

void ml::Scrollable::onMousePressed	(	std::function< void()>	callback,
		bool	overwrite = true )

Register a no-argument callback invoked when a mouse button is pressed anywhere in the window.

This fires before click logic is evaluated. Prefer onClick for standard click handling.

Parameters

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

onMousePressed() [2/2]

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

Register a callback invoked when a mouse button is pressed, receiving the raw SFML event.

Parameters

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

onMouseReleased() [1/2]

void ml::Scrollable::onMouseReleased	(	std::function< void()>	callback,
		bool	overwrite = true )

Register a no-argument callback invoked when a mouse button is released anywhere in the window.

This fires before click logic is evaluated. Prefer onClick for standard click handling.

Parameters

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

onMouseReleased() [2/2]

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

Register a callback invoked when a mouse button is released, receiving the raw SFML event.

Parameters

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

onScroll() [1/2]

void ml::Scrollable::onScroll	(	std::function< void()>	callback,
		bool	overwrite = true )

Register a no-argument callback invoked when the mouse wheel is scrolled while the cursor is over this component.

Parameters

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

onScroll() [2/2]

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

Register a callback invoked when the mouse wheel is scrolled while the cursor is over this component, receiving the SFML event.

Parameters

callback	Function invoked with the SFML event on scroll.
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/Scrollable.h