org.androidannotations.annotations

Annotation Type UiThread

@Retention(value=CLASS)
 @Target(value=METHOD)
public @interface UiThread

Should be used on method that must be run in the Ui thread

The annotated method MUST return void and MAY contain parameters.

The generated code is based on a local Handler instance.

Delay

Sometimes you may want to delay execution of a Ui thread method. To do so, you should use the delay() field.

Example :

 @EBean
 public class MyBean {
 
        @UiThread(delay = 2000)
        void uiThreadTask() {
                // ...
        }
 }
 

Execution flow

Prior to 3.0, UiThread annotated method calls was always added in the handler execution queue to ensure that execution was done in Ui thread. In 3.0, we kept the same behavior for compatibility purpose.

But, if you want to optimize UiThread calls, you may want to change propagation() value to REUSE. In this configuration, the code will make a direct call to the method if current thread is already Ui thread. If not, we're falling back to handler call.

Example :

 @EBean
 public class MyBean {
 
        @UiThread
        void uiThreadTask() {
                // This code is executed via the handler
                // The following method will be directly executed instead of using
                // handler
                uiThreadTaskReused();
        }
 
        @UiThread(propagation = REUSE)
        void uiThreadTaskReused() {
                // ...
        }
 }
 

Cancellation

You can cancel UiThread tasks if you provide an id (which cannot be an empty string) with the id() parameter. Please note tasks which use REUSE propagation() cannot have an id hence cannot be cancelled. To cancel all UiThread tasks with a given id, call UiThreadExecutor#cancelAll(String).

Example :

 @EBean
 public class MyBean {
 
        @UiThread(id = "myId")
        void uiThreadTask() {
                // do sg
        }
 }
 
 ...
 
 UiThreadExecutor.cancelAll("myId");
 

See Also:

Background, Handler, UiThreadExecutor.cancelAll(String)

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
long	delay The delay of the execution in milliseconds.
String	id Identifier for cancellation.
UiThread.Propagation	propagation If propagation is UiThread.Propagation.REUSE, the method will check first if it is inside the UI thread already.

Element Detail

delay

public abstract long delay

The delay of the execution in milliseconds.

Returns:

the delay of the execution

Default:

0L

propagation

public abstract UiThread.Propagation propagation

If propagation is UiThread.Propagation.REUSE, the method will check first if it is inside the UI thread already. If so, it will directly call the method instead of using the handler. The default value is UiThread.Propagation.ENQUEUE, which will always call the handler. When using a non-zero delay the propagation parameter is ignored.

Returns:

UiThread.Propagation.ENQUEUE to always call the handler, UiThread.Propagation.REUSE, to check whether it is already on the UI thread

Default:

org.androidannotations.annotations.UiThread.Propagation.ENQUEUE

id

public abstract String id

Identifier for cancellation. To cancel all tasks having a specified id:

 UiThreadExecutor.cancelAll("my_background_id");
 

Returns:

the id for cancellation

Default:

""