WebMessagePort

public abstract class WebMessagePort
extends Object

The Java representation of the HTML5 message ports. A Message port represents one endpoint of a Message Channel. In Android webview, there is no separate Message Channel object. When a message channel is created, both ports are tangled to each other and started, and then returned in a MessagePort array, see createWebMessageChannel() for creating a message channel. When a message port is first created or received via transfer, it does not have a WebMessageCallback to receive web messages. The messages are queued until a WebMessageCallback is set. A message port should be closed when it is not used by the embedder application anymore. A closed port cannot be transferred or cannot be reopened to send messages. Close can be called multiple times. When a port is transferred to JS, it cannot be used to send or receive messages at the Java side anymore. Different from HTML5 Spec, a port cannot be transferred if one of these has ever happened: i. a message callback was set, ii. a message was posted on it. A transferred port cannot be closed by the application, since the ownership is also transferred. It is possible to transfer both ports of a channel to JS, for example for communication between subframes.

Summary

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long millis, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. final void wait(long millis) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed. final void wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object.

Public methods

void close ()

void postMessage (WebMessage message)

void setWebMessageCallback (WebMessagePort.WebMessageCallback callback, 
                Handler handler)

void setWebMessageCallback (WebMessagePort.WebMessageCallback callback)