Class TraceEventMulticaster

  • All Implemented Interfaces:
    java.util.EventListener, TraceListener

    public class TraceEventMulticaster
    extends java.lang.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

      Fields 
      Modifier and Type Field Description
      protected java.util.EventListener a  
      protected java.util.EventListener b  
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected TraceEventMulticaster​(java.util.EventListener a, java.util.EventListener b)
      Creates an event multicaster instance which chains listener-a with listener-b.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static TraceListener add​(TraceListener a, TraceListener b)
      Adds trace-listener-a with trace-listener-b and returns the resulting multicast listener.
      protected static java.util.EventListener addInternal​(java.util.EventListener a, java.util.EventListener b)
      Returns the resulting multicast listener from adding listener-a and listener-b together.
      void close()
      Called at end
      void endCurrentItem​(Item item)
      Called when an item ceases to be the current item
      void enter​(InstructionInfo element, XPathContext context)
      Called when an element of the stylesheet gets processed
      void leave​(InstructionInfo element)
      Called after an element of the stylesheet got processed
      void open()
      Called at start
      protected java.util.EventListener remove​(java.util.EventListener oldl)
      Removes a listener from this multicaster and returns the resulting multicast listener.
      static TraceListener remove​(TraceListener l, TraceListener oldl)
      Removes the old trace-listener from trace-listener-l and returns the resulting multicast listener.
      protected static java.util.EventListener removeInternal​(java.util.EventListener l, java.util.EventListener oldl)
      Returns the resulting multicast listener after removing the old listener from listener-l.
      void startCurrentItem​(Item item)
      Called when an item becomes current
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • a

        protected final java.util.EventListener a
      • b

        protected final java.util.EventListener b
    • Constructor Detail

      • TraceEventMulticaster

        protected TraceEventMulticaster​(java.util.EventListener a,
                                        java.util.EventListener b)
        Creates an event multicaster instance which chains listener-a with listener-b.
        Parameters:
        a - listener-a
        b - listener-b
    • Method Detail

      • remove

        protected java.util.EventListener remove​(java.util.EventListener oldl)
        Removes a listener from this multicaster and returns the resulting multicast listener.
        Parameters:
        oldl - the listener to be removed
      • open

        public void open()
        Called at start
        Specified by:
        open in interface TraceListener
      • close

        public void close()
        Called at end
        Specified by:
        close in interface TraceListener
      • enter

        public void enter​(InstructionInfo element,
                          XPathContext context)
        Called when an element of the stylesheet gets processed
        Specified by:
        enter in interface TraceListener
        Parameters:
        element - gives information about the instruction being executed, and about the context in which it is executed. This object is mutable, so if information from the InstructionInfo is to be retained, it must be copied.
      • leave

        public void leave​(InstructionInfo element)
        Called after an element of the stylesheet got processed
        Specified by:
        leave in interface TraceListener
        Parameters:
        element - gives the same information that was supplied to the enter method, though it is not necessarily the same object. Note that the line number of the instruction is that of the start tag in the source stylesheet, not the line number of the end tag.
      • startCurrentItem

        public void startCurrentItem​(Item item)
        Called when an item becomes current
        Specified by:
        startCurrentItem in interface TraceListener
        Parameters:
        item - the new current item. Item objects are not mutable; it is safe to retain a reference to the Item for later use.
      • endCurrentItem

        public void endCurrentItem​(Item item)
        Called when an item ceases to be the current item
        Specified by:
        endCurrentItem in interface TraceListener
        Parameters:
        item - the item that was current, whose processing is now complete. This will represent the same underlying item as the corresponding startCurrentItem() call, though it will not necessarily be the same actual object.
      • 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
      • 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
      • addInternal

        protected static java.util.EventListener addInternal​(java.util.EventListener a,
                                                             java.util.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
      • removeInternal

        protected static java.util.EventListener removeInternal​(java.util.EventListener l,
                                                                java.util.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