MessageCompat
public
final
class
MessageCompat
extends Object
java.lang.Object | |
↳ | androidx.core.os.MessageCompat |
Helper for accessing features in Message
.
Summary
Public methods | |
---|---|
static
boolean
|
isAsynchronous(Message message)
Returns true if the message is asynchronous, meaning that it is not
subject to |
static
void
|
setAsynchronous(Message message, boolean async)
Sets whether the message is asynchronous, meaning that it is not
subject to |
Inherited methods | |
---|---|
Public methods
isAsynchronous
public static boolean isAsynchronous (Message message)
Returns true if the message is asynchronous, meaning that it is not
subject to Looper
synchronization barriers.
Parameters | |
---|---|
message |
Message |
Returns | |
---|---|
boolean |
True if the message is asynchronous. Always false prior to API 16. |
setAsynchronous
public static void setAsynchronous (Message message, 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 View.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.
This API has no effect prior to API 16.
Parameters | |
---|---|
message |
Message |
async |
boolean : True if the message is asynchronous. |