HandlerCompat

Added in 1.1.0

class HandlerCompat

Helper for accessing features in Handler.

Summary

Public functions
java-static Handler

Create a new Handler whose posted messages and runnables are not subject to synchronization barriers such as display vsync.
java-static Handler
createAsync(looper: Looper, callback: Handler.Callback)

Create a new Handler whose posted messages and runnables are not subject to synchronization barriers such as display vsync.
java-static Boolean
hasCallbacks(handler: Handler, r: Runnable)

Checks if there are any pending posts of messages with callback r in the message queue.
java-static Boolean
postDelayed(handler: Handler, r: Runnable, token: Any?, delayMillis: Long)

Causes the Runnable r to be added to the message queue, to be run after the specified amount of time elapses.

Public functions

createAsync

Added in 1.1.0
java-static fun createAsync(looper: Looper): Handler

Create a new Handler whose posted messages and runnables are not subject to synchronization barriers such as display vsync.

Messages sent to an async handler are guaranteed to be ordered with respect to one another, but not necessarily with respect to messages from other Handlers.

Parameters
looper: Looper

the Looper that the new Handler should be bound to
Returns
Handler

a new async Handler instance
See also
createAsync

to create an async Handler with custom message handling. Compatibility behavior:

  • SDK 28 and above, this method matches platform behavior.
  • SDK 27 and earlier, this method attempts to call the platform API via reflection, but may fail and return a synchronous handler instance.
createAsync

createAsync

Added in 1.1.0
java-static fun createAsync(looper: Looper, callback: Handler.Callback): Handler

Create a new Handler whose posted messages and runnables are not subject to synchronization barriers such as display vsync.

Messages sent to an async handler are guaranteed to be ordered with respect to one another, but not necessarily with respect to messages from other Handlers.

Parameters
looper: Looper

the Looper that the new Handler should be bound to
callback: Handler.Callback

callback to send events to
Returns
Handler

a new async Handler instance
See also
createAsync

to create an async Handler without custom message handling. Compatibility behavior:

  • SDK 28 and above, this method matches platform behavior.
  • SDK 27 and earlier, this method attempts to call the platform API via reflection, but may fail and return a synchronous handler instance.
createAsync

hasCallbacks

Added in 1.6.0
java-static fun hasCallbacks(handler: Handler, r: Runnable): Boolean

Checks if there are any pending posts of messages with callback r in the message queue. Compatibility behavior:

  • SDK 29 and above, this method matches platform behavior.
  • SDK 28 and earlier, this method attempts to call the platform API via reflection, but will throw an unchecked exception if the method has been altered from the AOSP implementation and cannot be called. This is unlikely, but there is no safe fallback case for this method and we must throw an exception as a result.
Parameters
handler: Handler

handler on which to call the method
r: Runnable

callback to look for in the message queue
Returns
Boolean

true if the callback is in the message queue
See also
hasCallbacks

postDelayed

Added in 1.1.0
java-static fun postDelayed(handler: Handler, r: Runnable, token: Any?, delayMillis: Long): Boolean

Causes the Runnable r to be added to the message queue, to be run after the specified amount of time elapses. The runnable will be run on the thread to which this handler is attached. The time-base is uptimeMillis. Time spent in deep sleep will add an additional delay to execution.

Parameters
handler: Handler

handler to use for posting the runnable.
r: Runnable

The Runnable that will be executed.
token: Any?

An instance which can be used to cancel r via removeCallbacksAndMessages.
delayMillis: Long

The delay (in milliseconds) until the Runnable will be executed.
Returns
Boolean

Returns true if the Runnable was successfully placed in to the message queue. Returns false on failure, usually because the looper processing the message queue is exiting. Note that a result of true does not mean the Runnable will be processed -- if the looper is quit before the delivery time of the message occurs then the message will be dropped.
See also
postDelayed