Class TraceEventMulticaster

java.lang.Object
net.sf.saxon.trace.TraceEventMulticaster
All Implemented Interfaces:
EventListener, TraceListener

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 Details

  • Constructor Details

    • 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 Details

    • 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
    • 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 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
    • 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