Message

CREATOR

Creator<Message> CREATOR

arg1

int arg1

arg1 and arg2 are lower-cost alternatives to using setData() if you only need to store a few integer values.

arg2

int arg2

arg1 and arg2 are lower-cost alternatives to using setData() if you only need to store a few integer values.

obj

Object obj

An arbitrary object to send to the recipient. When using Messenger to send the message across processes this can only be non-null if it contains a Parcelable of a framework class (not one implemented by the application). For other data transfer use setData(Bundle).

Note that Parcelable objects here are not supported prior to the FROYO release.

replyTo

Messenger replyTo

Optional Messenger where replies to this message can be sent. The semantics of exactly how this is used are up to the sender and receiver.

sendingUid

int sendingUid

Optional field indicating the uid that sent the message. This is only valid for messages posted by a Messenger; otherwise, it will be -1.

what

int what

User-defined message code so that the recipient can identify what this message is about. Each Handler has its own name-space for message codes, so you do not need to worry about yours conflicting with other handlers.

Message

Message ()

Constructor (but the preferred way to get a Message is to call Message.obtain()).

copyFrom

void copyFrom (Message o)

Make this message like o. Performs a shallow copy of the data field. Does not copy the linked list fields, nor the timestamp or target/callback of the original message.

describeContents

int describeContents ()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(Parcel, int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.

getCallback

Runnable getCallback ()

Retrieve callback object that will execute when this message is handled. This object must implement Runnable. This is called by the target Handler that is receiving this Message to dispatch it. If not set, the message will be dispatched to the receiving Handler's handleMessage(Message).

getData

Bundle getData ()

Obtains a Bundle of arbitrary data associated with this event, lazily creating it if necessary. Set this value by calling setData(Bundle). Note that when transferring data across processes via Messenger, you will need to set your ClassLoader on the Bundle via Bundle.setClassLoader() so that it can instantiate your objects when you retrieve them.

getTarget

Handler getTarget ()

Retrieve the a Handler implementation that will receive this message. The object must implement Handler.handleMessage(). Each Handler has its own name-space for message codes, so you do not need to worry about yours conflicting with other handlers.

getWhen

long getWhen ()

Return the targeted delivery time of this message, in milliseconds.

isAsynchronous

boolean isAsynchronous ()

Returns true if the message is asynchronous, meaning that it is not subject to Looper synchronization barriers.

obtain

Message obtain (Handler h)

Same as obtain(), but sets the value for the target member on the Message returned.

obtain

Message obtain (Handler h, 
                int what)

Same as obtain(), but sets the values for both target and what members on the Message.

obtain

Message obtain (Handler h, 
                Runnable callback)

Same as obtain(Handler), but assigns a callback Runnable on the Message that is returned.

obtain

Message obtain (Message orig)

Same as obtain(), but copies the values of an existing message (including its target) into the new one.

obtain

Message obtain (Handler h, 
                int what, 
                int arg1, 
                int arg2, 
                Object obj)

Same as obtain(), but sets the values of the target, what, arg1, arg2, and obj members.

obtain

Message obtain (Handler h, 
                int what, 
                int arg1, 
                int arg2)

Same as obtain(), but sets the values of the target, what, arg1, and arg2 members.

obtain

Message obtain (Handler h, 
                int what, 
                Object obj)

Same as obtain(), but sets the values of the target, what, and obj members.

obtain

Message obtain ()

Return a new Message instance from the global pool. Allows us to avoid allocating new objects in many cases.

peekData

Bundle peekData ()

Like getData(), but does not lazily create the Bundle. A null is returned if the Bundle does not already exist. See getData() for further information on this.

recycle

void recycle ()

Return a Message instance to the global pool.

You MUST NOT touch the Message after calling this function because it has effectively been freed. It is an error to recycle a message that is currently enqueued or that is in the process of being delivered to a Handler.

sendToTarget

void sendToTarget ()

Sends this Message to the Handler specified by getTarget(). Throws a null pointer exception if this field has not been set.

setAsynchronous

void setAsynchronous (boolean async)

Sets whether the message is asynchronous, meaning that it is not subject to Looper synchronization barriers.

Certain operations, such as view invalidation, may introduce synchronization barriers into the Looper's message queue to prevent subsequent messages from being delivered until some condition is met. In the case of view invalidation, messages which are posted after a call to invalidate() are suspended by means of a synchronization barrier until the next frame is ready to be drawn. The synchronization barrier ensures that the invalidation request is completely handled before resuming.

Asynchronous messages are exempt from synchronization barriers. They typically represent interrupts, input events, and other signals that must be handled independently even while other work has been suspended.

Note that asynchronous messages may be delivered out of order with respect to synchronous messages although they are always delivered in order among themselves. If the relative order of these messages matters then they probably should not be asynchronous in the first place. Use with caution.

setData

void setData (Bundle data)

Sets a Bundle of arbitrary data values. Use arg1 and arg2 members as a lower cost way to send a few simple integer values, if you can.

setTarget

void setTarget (Handler target)

toString

String toString ()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

writeToParcel

void writeToParcel (Parcel dest, 
                int flags)

Flatten this object in to a Parcel.