scalafx.event.EventTarget.scala Maven / Gradle / Ivy
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*
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package scalafx.event
import javafx.event as jfxe
import scalafx.Includes.*
import scalafx.delegate.SFXDelegate
import scalafx.event.subscriptions.Subscription
import scala.language.implicitConversions
object EventTarget {
implicit def sfxEventTarget2jfx(v: EventTarget): jfxe.EventTarget = if (v != null) v.delegate else null
}
/**
* Wraps a $JFX $URL0 $FC]].
*
* @define FC EventTarget
* @define URL0 [[https://docs.oracle.com/javase/8/javafx/api/javafx/event/EventTarget.html
* @define JFX JavaFX
* @define ORIGINALDOC Original Documentation]].
*/
abstract class EventTarget(override val delegate: jfxe.EventTarget)
extends SFXDelegate[jfxe.EventTarget] {
/**
* Construct an event dispatch chain for this target. The event dispatch
* chain contains event dispatchers which might be interested in processing
* of events targeted at this `EventTarget`. This event target is
* not automatically added to the chain, so if it wants to process events,
* it needs to add an `EventDispatcher` for itself to the chain.
*
* In the case the event target is part of some hierarchy, the chain for it
* is usually built from event dispatchers collected from the root of the
* hierarchy to the event target.
*
* The event dispatch chain is constructed by modifications to the provided
* initial event dispatch chain. The returned chain should have the initial
* chain at its end so the dispatchers should be prepended to the initial
* chain.
*
* The caller shouldn't assume that the initial chain remains unchanged nor
* that the returned value will reference a different chain.
*
* @param tail the initial chain to build from
* @return the resulting event dispatch chain for this target
* @see $URL0#buildEventDispatchChain $ORIGINALDOC
*/
def buildEventDispatchChain(tail: EventDispatchChain): EventDispatchChain =
delegate.buildEventDispatchChain(tail)
/**
* Registers an event handler. The handler is called when the node receives an Event of the specified type during
* the bubbling phase of event delivery.
*
* Example of handling mouse events
* {{{
* pane.handleEvent(MouseEvent.Any) {
* me: MouseEvent => {
* me.eventType match {
* case MouseEvent.MousePressed => ...
* case MouseEvent.MouseDragged => ...
* case _ => {}
* }
* }
* }
* }}}
* or
* {{{
* pane.handleEvent(MouseEvent.Any) { () => println("Some mouse event handled") }
* }}}
*
* @param eventType type of events that will be handled.
* @param handler code handling the event, see examples above.
* @tparam J type JavaFX delegate of the event
* @tparam S ScalaFX type for `J` type wrapper.
* @return Returns a subscription that can be used to cancel/remove this event handler
*/
def handleEvent[J <: jfxe.Event, S <: Event with SFXDelegate[J]](eventType: EventType[J])(handler: HandlerMagnet[
J,
S
]): Subscription = {
handler(eventType)
}
/**
* Registers an event filter. Registered event filters get an event before any associated event handlers.
*
* Example of filtering mouse events
* {{{
* pane.filterEvent(MouseEvent.Any) {
* me: MouseEvent => {
* me.eventType match {
* case MouseEvent.MousePressed => {
* ...
* }
* case MouseEvent.MouseDragged => {
* ...
* }
* case _ => {
* ...
* }
* }
* }
* }
* }}}
* or
* {{{
* pane.filterEvent(MouseEvent.Any) { () => println("Some mouse event handled") }
* }}}
*
* @param eventType type of events that will be handled.
* @param filter code handling the event, see examples above.
* @tparam J type JavaFX delegate of the event
* @tparam S ScalaFX type for `J` type wrapper.
*/
def filterEvent[J <: jfxe.Event, S <: Event with SFXDelegate[J]](eventType: EventType[J])(filter: FilterMagnet[J, S])
: Subscription = {
filter(eventType)
}
/**
* Trait implementing [[http://spray.io/blog/2012-12-13-the-magnet-pattern/ Magnet Pattern]]
* to avoid compilation error "ambiguous reference to overloaded definition"
*/
sealed trait FilterMagnet[J <: jfxe.Event, S <: SFXDelegate[J]] {
protected val eventFilter: jfxe.EventHandler[J]
def apply(eventType: EventType[J]): Subscription = {
EventTarget.this.addEventFilter(eventType.delegate, eventFilter)
new Subscription {
def cancel(): Unit = {
EventTarget.this.removeEventFilter(eventType.delegate, eventFilter)
}
}
}
}
/**
* Companion object implementing Magnet Pattern [[http://spray.io/blog/2012-12-13-the-magnet-pattern/ Magnet Pattern]]
* to avoid compilation error "ambiguous reference to overloaded definition"
*/
object FilterMagnet {
implicit def fromParen[J <: jfxe.Event, S <: Event with SFXDelegate[J]](op: () => Unit): FilterMagnet[J, S] = {
new FilterMagnet[J, S] {
override val eventFilter: jfxe.EventHandler[J] = new jfxe.EventHandler[J] {
def handle(event: J): Unit = {
op()
}
}
}
}
implicit def fromEvent[J <: jfxe.Event, S <: Event with SFXDelegate[J]](op: S => Unit)(implicit
jfx2sfx: J => S
): FilterMagnet[J, S] = {
new FilterMagnet[J, S] {
override val eventFilter: jfxe.EventHandler[J] = new jfxe.EventHandler[J] {
def handle(event: J): Unit = {
op(jfx2sfx(event))
}
}
}
}
}
/**
* Trait implementing [[http://spray.io/blog/2012-12-13-the-magnet-pattern/ Magnet Pattern]]
* to avoid compilation error "ambiguous reference to overloaded definition"
*/
sealed trait HandlerMagnet[J <: jfxe.Event, S <: SFXDelegate[J]] {
protected val eventHandler: jfxe.EventHandler[J]
def apply(eventType: EventType[J]): Subscription = {
EventTarget.this.addEventHandler(eventType.delegate, eventHandler)
new Subscription {
def cancel(): Unit = {
EventTarget.this.removeEventHandler(eventType.delegate, eventHandler)
}
}
}
}
/**
* Companion object implementing Magnet Pattern [[http://spray.io/blog/2012-12-13-the-magnet-pattern/ Magnet Pattern]]
* to avoid compilation error "ambiguous reference to overloaded definition"
*/
object HandlerMagnet {
implicit def fromParen[J <: jfxe.Event, S <: Event with SFXDelegate[J]](op: () => Unit): HandlerMagnet[J, S] = {
new HandlerMagnet[J, S] {
override val eventHandler: jfxe.EventHandler[J] = new jfxe.EventHandler[J] {
def handle(event: J): Unit = {
op()
}
}
}
}
implicit def fromEvent[J <: jfxe.Event, S <: Event with SFXDelegate[J]](op: S => Unit)(implicit
jfx2sfx: J => S
): HandlerMagnet[J, S] = {
new HandlerMagnet[J, S] {
override val eventHandler: jfxe.EventHandler[J] = new jfxe.EventHandler[J] {
def handle(event: J): Unit = {
op(jfx2sfx(event))
}
}
}
}
}
}