net.sf.saxon.trace

Class TraceEventMulticaster

public class TraceEventMulticaster extends Object implements TraceListener

A class which implements efficient and thread-safe multi-cast event dispatching for the TraceListener evants.

Grabbed from java.awt.AWTEventMulticaster

Field Summary
protected EventListenera
protected EventListenerb
Constructor Summary
protected TraceEventMulticaster(EventListener a, EventListener b)
Creates an event multicaster instance which chains listener-a with listener-b.
Method Summary
static TraceListeneradd(TraceListener a, TraceListener b)
Adds trace-listener-a with trace-listener-b and returns the resulting multicast listener.
protected static EventListeneraddInternal(EventListener a, EventListener b)
Returns the resulting multicast listener from adding listener-a and listener-b together.
voidclose()
Called at end
voidendCurrentItem(Item item)
Called when an item ceases to be the current item
voidenter(InstructionInfo element, XPathContext context)
Called when an element of the stylesheet gets processed
voidleave(InstructionInfo element)
Called after an element of the stylesheet got processed
voidopen()
Called at start
protected EventListenerremove(EventListener oldl)
Removes a listener from this multicaster and returns the resulting multicast listener.
static TraceListenerremove(TraceListener l, TraceListener oldl)
Removes the old trace-listener from trace-listener-l and returns the resulting multicast listener.
protected static EventListenerremoveInternal(EventListener l, EventListener oldl)
Returns the resulting multicast listener after removing the old listener from listener-l.
voidstartCurrentItem(Item item)
Called when an item becomes current

Field Detail

a

protected final EventListener a

b

protected final EventListener b

Constructor Detail

TraceEventMulticaster

protected TraceEventMulticaster(EventListener a, EventListener b)
Creates an event multicaster instance which chains listener-a with listener-b.

Parameters: a listener-a b listener-b

Method Detail

add

public static TraceListener add(TraceListener a, TraceListener b)
Adds trace-listener-a with trace-listener-b and returns the resulting multicast listener.

Parameters: a trace-listener-a b trace-listener-b

addInternal

protected static EventListener addInternal(EventListener a, EventListener b)
Returns the resulting multicast listener from adding listener-a and listener-b together. If listener-a is null, it returns listener-b; If listener-b is null, it returns listener-a If neither are null, then it creates and returns a new EventMulticaster instance which chains a with b.

Parameters: a event listener-a b event listener-b

close

public void close()
Called at end

endCurrentItem

public void endCurrentItem(Item item)
Called when an item ceases to be the current item

enter

public void enter(InstructionInfo element, XPathContext context)
Called when an element of the stylesheet gets processed

leave

public void leave(InstructionInfo element)
Called after an element of the stylesheet got processed

open

public void open()
Called at start

remove

protected EventListener remove(EventListener oldl)
Removes a listener from this multicaster and returns the resulting multicast listener.

Parameters: oldl the listener to be removed

remove

public static TraceListener remove(TraceListener l, TraceListener oldl)
Removes the old trace-listener from trace-listener-l and returns the resulting multicast listener.

Parameters: l trace-listener-l oldl the trace-listener being removed

removeInternal

protected static EventListener removeInternal(EventListener l, EventListener oldl)
Returns the resulting multicast listener after removing the old listener from listener-l. If listener-l equals the old listener OR listener-l is null, returns null. Else if listener-l is an instance of SaxonEventMulticaster, then it removes the old listener from it. Else, returns listener l.

Parameters: l the listener being removed from oldl the listener being removed

startCurrentItem

public void startCurrentItem(Item item)
Called when an item becomes current