com.datagis.com4j

Class GenericNativeWindow.NativeWindowEventDispatcher

java.lang.Object

com.datagis.com4j.GenericNativeWindow.NativeWindowEventDispatcher

All Implemented Interfaces:

InvocationHandler

Enclosing class:

GenericNativeWindow<T extends com4j.Com4jObject,E extends ComEventListener>

protected class GenericNativeWindow.NativeWindowEventDispatcher
extends Object
implements InvocationHandler

The class NativeWindowEventDispatcher implements a custom layer to handle native window events as defined in NativeWindowListener.

Basically, this class provides its own private implementation of a NativeWindowListener, which is implemented as a import java.lang.reflect.Proxy object. This is due to the the actual native event interface, which is specified by the generic parameter E, being known only at runtime. Furthermore, this class itself is also the proxy's InvocationHandler.

Each invocation of any of the event handler methods is then forwarded to all registered event listeners. Between the invocation and forwarding, a new NativeWindowEvent object is created, including the parameters passed from the native side, which is in turn passed to the registered listeners.

Since:

TEJ1.0

Author:

Carsten Klein

Field Summary

Fields

Modifier and Type	Field and Description
protected GenericNativeWindow.EventInvocationCache	eventInvocationCache This HashMap derived cache provides fast mapping between the name of an event method invoked on the native event interface and the corresponding method to be invoked on a registered NativeWindowListener together with the event id.
protected List<NativeWindowListener>	listeners Stores all listeners that have registered to receive native window events.
protected Class<E>	nativeEventInterface The native COM event interface.
protected E	nativeEventProxy A reference to the proxy object receiving native COM events.

Constructor Summary

Constructors

Constructor and Description
NativeWindowEventDispatcher(Class<E> eventInterface) Create a NativeWindowEventDispatcher object.

Method Summary

Modifier and Type	Method and Description
void	addNativeWindowListener(NativeWindowListener listener) Adds the specified native window listener to receive window events from the underlying native window.
NativeWindowListener[]	getNativeWindowListeners() Returns an array of all the native window listeners registered on this GenericNativeWindow instance.
Object	invoke(Object proxy, Method method, Object[] args) The InvocationHandler implementation.
boolean	isNativeWindowListener(NativeWindowListener listener) Indicates whether the specified native window listener listener is registered on this GenericNativeWindow instance.
void	removeNativeWindowListener(NativeWindowListener listener) Removes the specified native window listener, so that it no longer receives window events from the underlying native window.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

listeners

protected List<NativeWindowListener> listeners

Stores all listeners that have registered to receive native window events.

eventInvocationCache

protected GenericNativeWindow.EventInvocationCache eventInvocationCache

This HashMap derived cache provides fast mapping between the name of an event method invoked on the native event interface and the corresponding method to be invoked on a registered NativeWindowListener together with the event id.

nativeEventInterface

protected Class<E extends ComEventListener> nativeEventInterface

The native COM event interface. This interface is passed through the sole constructor of this class. It is used to create the native event listener proxy as well as for registering that listener with method addComEventListener. Since native registering is done lazily after the first NativeWindowListener has registered, the native event interface is kept in this field.

nativeEventProxy

protected E extends ComEventListener nativeEventProxy

A reference to the proxy object receiving native COM events.

Constructor Detail

NativeWindowEventDispatcher

public NativeWindowEventDispatcher(Class<E> eventInterface)

Create a NativeWindowEventDispatcher object.

Parameters:

eventInterface - the native event interface used to receive native COM events

Method Detail

addNativeWindowListener

public void addNativeWindowListener(NativeWindowListener listener)

Adds the specified native window listener to receive window events from the underlying native window. If listener is null, no exception is thrown and no action is performed.

Parameters:

listener - the native window listener to be added

See Also:

removeNativeWindowListener(com.datagis.com4j.NativeWindowListener), getNativeWindowListeners(), NativeWindowListener, NativeWindowAdapter

removeNativeWindowListener

public void removeNativeWindowListener(NativeWindowListener listener)

Removes the specified native window listener, so that it no longer receives window events from the underlying native window. This method performs no action, nor does it throw an exception, if either the listener specified by the argument is null or was not previously added to this GenericNativeWindowinstance.

Parameters:

listener - the native window listener to be removed

See Also:

addNativeWindowListener(com.datagis.com4j.NativeWindowListener), getNativeWindowListeners(), NativeWindowListener, NativeWindowAdapter

getNativeWindowListeners

public NativeWindowListener[] getNativeWindowListeners()

Returns an array of all the native window listeners registered on this GenericNativeWindow instance.

Returns:

all of this native window's NativeWindowListener s or an empty array if no native window listeners are currently registered

See Also:

addNativeWindowListener(com.datagis.com4j.NativeWindowListener), removeNativeWindowListener(com.datagis.com4j.NativeWindowListener)

isNativeWindowListener

public boolean isNativeWindowListener(NativeWindowListener listener)

Indicates whether the specified native window listener listener is registered on this GenericNativeWindow instance.

Parameters:

listener - the native window listener to test

Returns:

true if the specified native window listener listener is registered with this GenericNativeWindow instance; false otherwise.

See Also:

addNativeWindowListener(com.datagis.com4j.NativeWindowListener), removeNativeWindowListener(com.datagis.com4j.NativeWindowListener), getNativeWindowListeners()

invoke

public Object invoke(Object proxy,
                     Method method,
                     Object[] args)
              throws Throwable

The InvocationHandler implementation. Invoked each time, a method on nativeEventProxy is invoked.

Specified by:

invoke in interface InvocationHandler

Parameters:

proxy - the proxy instance that the method was invoked on

method - the Method instance corresponding to the interface method invoked on the proxy instance

args - an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments

Returns:

the value to return from the method invocation on the proxy instance

Throws:

Throwable - the exception to throw from the method invocation on the proxy instance

See Also:

InvocationHandler, Proxy