The EventQueue class implements a queue of Kanzi input events gathered by EventSource instances. More...

#include <kanzi/core.ui/platform/input/common/event_queue.hpp>

Public Types
typedef vector< UniqueEventPtr >	Container
	Event container type. More...

using	FilterFunction = function< Container::iterator(Container::iterator it)>
	Filter function type to pass to the applyFilter() method. More...

typedef function< ProcessingResult(InputEvent *)>	ProcessingFunction
	The event processing function type passed to processEvents() method. More...

enum	ProcessingResult { Continue, Stop }
	Specifies the results values of the event processing. More...

Public Member Functions
void	append (EventQueue &other)
	Moves the content of other event queue into this queue, and clears the other queue. More...

void	applyFilter (const FilterFunction &filter)
	Applies the given filter over the event queue. More...

Container::iterator	begin ()
	Returns an iterator to the first event in the event queue. More...

Container::const_iterator	cbegin () const
	Returns an iterator to the first event in the event queue. More...

Container::const_iterator	cend () const
	Returns an iterator to the element following the last event in the event queue. More...

void	clear ()
	Clears the event queue. More...

Container::iterator	end ()
	Returns an iterator to the element following the last event in the event queue. More...

	EventQueue ()
	Creates an event queue instance. More...

size_t	getEventCount () const
	Returns the number or events in the queue. More...

Container::iterator	insert (Container::iterator position, UniqueEventPtr &&event)
	Inserts the event into this queue before the given position. More...

bool	isEmpty () const
	Checks for empty queue. More...

Container::iterator	move (Container::iterator position, Container &container)
	Moves the container content into this queue before the given position. More...

void	processEvents (ProcessingFunction function)
	The method loops through the queue events and passes each event to the given function for processing. More...

void	push (UniqueEventPtr event)
	Pushes an event into the queue. More...

Container::iterator	remove (Container::iterator position)
	Removes the event at position from the event queue. More...

void	swap (EventQueue &other)
	Swaps this event queue with the given one. More...

Detailed Description

The EventQueue class implements a queue of Kanzi input events gathered by EventSource instances.

Events are low-level Kanzi messages translated from the host operating system, and incorporate input, application, and window management events. Different parts of Kanzi handle these events immediately, whereas other elements, such as InputManager, forward them to input manipulators, which in turn transform them into Kanzi messages.

You can add events to the queue only by using the push() method. The EventQueue takes ownership of the event.

Once the queue events are handled, you can remove them from the queue with the clear() method. It is recommended to clear the queue before or after swapping the queue.

Member Typedef Documentation

◆ Container

typedef vector<UniqueEventPtr> kanzi::EventQueue::Container

Event container type.

◆ ProcessingFunction

typedef function<ProcessingResult(InputEvent*)> kanzi::EventQueue::ProcessingFunction

The event processing function type passed to processEvents() method.

The function expects an InputEvent as argument and returns the result of the event processing.

◆ FilterFunction

using kanzi::EventQueue::FilterFunction = function<Container::iterator(Container::iterator it)>

Filter function type to pass to the applyFilter() method.

Parameters

it	The event queue container iterator to filter.

Returns: The event queue container iterator with which to continue. To skip an event, return the next iterator. To remove an event, call the remove() method with the iterator and return the iterator returned by the remove() method. To insert events in front of or after the processed event, call the move() method, and return the iterator relative to the iterator returned by the move() method. Use the prepend() or prependAndAdvance() functions to position the iterators to the processed event or after the processed event.

Since: Kanzi 3.9.0

Member Enumeration Documentation

◆ ProcessingResult

enum kanzi::EventQueue::ProcessingResult

Specifies the results values of the event processing.

Enumerator
Continue	Continue the event processing with the next event in the queue.
Stop	Exit the event processing loop.

Constructor & Destructor Documentation

◆ EventQueue()

kanzi::EventQueue::EventQueue ( )

explicit

Creates an event queue instance.

Member Function Documentation

◆ processEvents()

void kanzi::EventQueue::processEvents ( ProcessingFunction function )

The method loops through the queue events and passes each event to the given function for processing.

The return value of the function drives the event processing in this way:

EventQueue keeps processing the events for as long as Continue is returned.
The event processing stops when Stop is returned.
Parameters

function The function to process the queue events.

◆ push()

void kanzi::EventQueue::push ( UniqueEventPtr event )

Pushes an event into the queue.

Parameters

event The event to push into the queue.

◆ clear()

void kanzi::EventQueue::clear ( )

Clears the event queue.

◆ getEventCount()

size_t kanzi::EventQueue::getEventCount ( ) const

Returns the number or events in the queue.

Returns: The number of events in the queue.

◆ isEmpty()

bool kanzi::EventQueue::isEmpty ( ) const

Checks for empty queue.

Returns: true if the queue is empty.

◆ swap()

void kanzi::EventQueue::swap ( EventQueue & other )

Swaps this event queue with the given one.

Parameters

other The event queue with which to swap the events.

◆ append()

void kanzi::EventQueue::append ( EventQueue & other )

Moves the content of other event queue into this queue, and clears the other queue.

Parameters

other The event queue to move into this event queue.

◆ insert()

Container::iterator kanzi::EventQueue::insert	(	Container::iterator	position,
		UniqueEventPtr &&	event
	)

Inserts the event into this queue before the given position.

Parameters

position	The iterator before which to move the content.
event	The event to insert into the event queue.

Returns: The iterator pointing to the inserted event.

Since: Kanzi 3.9.0

◆ move()

Container::iterator kanzi::EventQueue::move	(	Container::iterator	position,
		Container &	container
	)

Moves the container content into this queue before the given position.

Parameters

position	The iterator before which to move the content.
container	The container to move into the event queue.

Returns: The iterator pointing to the first moved event. If the source is empty, returns position.

Since: Kanzi 3.9.0

◆ remove()

Container::iterator kanzi::EventQueue::remove ( Container::iterator position )

Removes the event at position from the event queue.

Parameters

position The iterator to the event to remove.

Returns: The iterator following the removed event.

Since: Kanzi 3.9.0

◆ begin()

Container::iterator kanzi::EventQueue::begin ( )

inline

Returns an iterator to the first event in the event queue.

Returns: The iterator to the first event. If the event queue is empty, the returned iterator is the same as the iterator returned by end().

Since: Kanzi 3.9.0

◆ end()

Container::iterator kanzi::EventQueue::end ( )

inline

Returns an iterator to the element following the last event in the event queue.

Returns: The iterator to the element following the last event.

Since: Kanzi 3.9.0

◆ cbegin()

Container::const_iterator kanzi::EventQueue::cbegin ( ) const

inline

Returns an iterator to the first event in the event queue.

Returns: The iterator to the first event. If the event queue is empty, the returned iterator is the same as the iterator returned by end().

Since: Kanzi 3.9.0

◆ cend()

Container::const_iterator kanzi::EventQueue::cend ( ) const

inline

Returns an iterator to the element following the last event in the event queue.

Returns: The iterator to the element following the last event.

Since: Kanzi 3.9.0

◆ applyFilter()

void kanzi::EventQueue::applyFilter ( const FilterFunction & filter )

Applies the given filter over the event queue.

Parameters

filter The filter object applied over the events from the queue.

Since: Kanzi 3.9.0

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

kanzi/core.ui/platform/input/common/event_queue.hpp

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ Container

◆ ProcessingFunction

◆ FilterFunction

Member Enumeration Documentation

◆ ProcessingResult

Constructor & Destructor Documentation

◆ EventQueue()

Member Function Documentation

◆ processEvents()

◆ push()

◆ clear()

◆ getEventCount()

◆ isEmpty()

◆ swap()

◆ append()

◆ insert()

◆ move()

◆ remove()

◆ begin()

◆ end()

◆ cbegin()

◆ cend()

◆ applyFilter()