DefaultTask (SciJava Common 2.93.0 API)

java.lang.Object
- org.scijava.task.DefaultTask

All Implemented Interfaces:

Cancelable, Named, Task
```
public class DefaultTask
extends Object
implements Task
```
Default implementation of Task. Throughout the task (or job), Task.setProgressValue(long) can be called to inform how the job is progressing. Asynchronous case: - A job (runnable) is sent for execution to the linked ThreadService. It reports status updates via the linked EventService. A TaskEvent is sent before the job is started and when finished. In the asynchronous case, upon task cancellation (Cancelable.cancel(String) call), the runnable associated to the ThreadService is attempted to be stopped by calling Future.cancel(boolean). This default behaviour can be supplemented by an additional custom callback which can be set in Task.setCancelCallBack(Runnable). Synchronous case: - A job that reports its status in between calls of Task.start(), and Task.finish(). It also reports its status via the linked EventService. Start and finish calls allow publishing proper TaskEvent to subscribers (with the EventService). Upon cancellation of a synchronous task, it is the responsibility of the synchronous task to handle its own cancellation through a custom callback which can be set via Task.setCancelCallBack(Runnable).

Author:

Curtis Rueden, Nicolas Chiaruttini

Constructor Summary

Constructors
Constructor and Description

DefaultTask(ThreadService threadService, EventService eventService)
Creates a new task.

Constructors
Constructor and Description
`DefaultTask(ThreadService threadService, EventService eventService)` Creates a new task.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`cancel(String reason)` Cancels the operation execution, with the given reason for doing so.
`void`	`finish()` reports that the task is finished - synchronous job
`Runnable`	`getCancelCallBack()` Returns the current cancel callback runnable, This can be used to concatenate callbacks in order, for instance, to ask for a user confirmation before cancelling the task
`String`	`getCancelReason()` Gets a message describing why the operation was canceled.
`String`	`getName()` Gets the name of the object.
`long`	`getProgressMaximum()` Gets the number of steps the task performs in total.
`long`	`getProgressValue()` Gets the step the task is currently performing.
`String`	`getStatusMessage()` Gets a status message describing what the task is currently doing.
`boolean`	`isCanceled()` Gets whether the operation has been canceled.
`boolean`	`isDone()` Checks whether the task has completed.
`void`	`run(Runnable r)` Starts running the task - asynchronous job
`void`	`setCancelCallBack(Runnable r)` If the task is cancelled (external call to `Cancelable.cancel(String)`), the input runnable argument should be executed by task implementors.
`void`	`setName(String name)` Sets the name of the object.
`void`	`setProgressMaximum(long max)` Sets the total number of steps.
`void`	`setProgressValue(long step)` Sets the current step.
`void`	`setStatusMessage(String status)` Sets the status message.
`void`	`start()` reports that the task is started - synchronous job
`void`	`waitFor()` Waits for the task to complete - asynchronous job

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DefaultTask
```
public DefaultTask(ThreadService threadService,
                   EventService eventService)
```
    Creates a new task.
    
    Parameters:
    
    threadService - Service to use for launching the task in its own thread. Required.
    
    eventService - Service to use for reporting status updates as TaskEvents. May be null, in which case no events are reported.
- Method Detail
  - run
```
public void run(Runnable r)
```
    Description copied from interface: Task
    
    Starts running the task - asynchronous job
    
    Specified by:
    
    run in interface Task
  - waitFor
```
public void waitFor()
             throws InterruptedException,
                    ExecutionException
```
    Description copied from interface: Task
    
    Waits for the task to complete - asynchronous job
    
    Specified by:
    
    waitFor in interface Task
    
    Throws:
    
    InterruptedException - if the task is interrupted.
    
    ExecutionException - if the task throws an exception while running.
  - start
```
public void start()
```
    Description copied from interface: Task
    
    reports that the task is started - synchronous job
    
    Specified by:
    
    start in interface Task
  - finish
```
public void finish()
```
    Description copied from interface: Task
    
    reports that the task is finished - synchronous job
    
    Specified by:
    
    finish in interface Task
  - isDone
```
public boolean isDone()
```
    Description copied from interface: Task
    
    Checks whether the task has completed.
    
    Specified by:
    
    isDone in interface Task
  - getStatusMessage
```
public String getStatusMessage()
```
    Description copied from interface: Task
    
    Gets a status message describing what the task is currently doing.
    
    Specified by:
    
    getStatusMessage in interface Task
  - getProgressValue
```
public long getProgressValue()
```
    Description copied from interface: Task
    
    Gets the step the task is currently performing.
    
    Specified by:
    
    getProgressValue in interface Task
    
    Returns:
    
    A value between 0 and Task.getProgressMaximum() inclusive.
    
    See Also:
    
    Task.getProgressMaximum()
  - getProgressMaximum
```
public long getProgressMaximum()
```
    Description copied from interface: Task
    
    Gets the number of steps the task performs in total.
    
    Specified by:
    
    getProgressMaximum in interface Task
    
    Returns:
    
    Total number of steps the task will perform, or 0 if unknown.
    
    See Also:
    
    Task.getProgressValue()
  - setStatusMessage
```
public void setStatusMessage(String status)
```
    Description copied from interface: Task
    
    Sets the status message. Called by task implementors.
    
    Specified by:
    
    setStatusMessage in interface Task
    
    Parameters:
    
    status - The message to set.
    
    See Also:
    
    Task.getStatusMessage()
  - setProgressValue
```
public void setProgressValue(long step)
```
    Description copied from interface: Task
    
    Sets the current step. Called by task implementors.
    
    Specified by:
    
    setProgressValue in interface Task
    
    Parameters:
    
    step - The step vaule to set.
    
    See Also:
    
    Task.getProgressValue()
  - setProgressMaximum
```
public void setProgressMaximum(long max)
```
    Description copied from interface: Task
    
    Sets the total number of steps. Called by task implementors.
    
    Specified by:
    
    setProgressMaximum in interface Task
    
    Parameters:
    
    max - The step count to set.
    
    See Also:
    
    Task.getProgressMaximum()
  - isCanceled
```
public boolean isCanceled()
```
    Description copied from interface: Cancelable
    
    Gets whether the operation has been canceled.
    
    Specified by:
    
    isCanceled in interface Cancelable
  - cancel
```
public void cancel(String reason)
```
    Description copied from interface: Cancelable
    
    Cancels the operation execution, with the given reason for doing so.
    This method merely sets the operation status to canceled; it cannot necessarily stop the operation itself. That is, it is the responsibility of each individual operation to check Cancelable.isCanceled() in a timely manner during execution, and stop doing whatever it is doing if the flag has been tripped.
    
    Specified by:
    
    cancel in interface Cancelable
    
    Parameters:
    
    reason - A message describing why the operation is being canceled.
  - setCancelCallBack
```
public void setCancelCallBack(Runnable r)
```
    Description copied from interface: Task
    
    If the task is cancelled (external call to Cancelable.cancel(String)), the input runnable argument should be executed by task implementors.
    
    Specified by:
    
    setCancelCallBack in interface Task
    
    Parameters:
    
    r - : should be executed if this task is cancelled through Cancelable.cancel(String)
  - getCancelCallBack
```
public Runnable getCancelCallBack()
```
    Description copied from interface: Task
    
    Returns the current cancel callback runnable, This can be used to concatenate callbacks in order, for instance, to ask for a user confirmation before cancelling the task
    
    Specified by:
    
    getCancelCallBack in interface Task
  - getCancelReason
```
public String getCancelReason()
```
    Description copied from interface: Cancelable
    
    Gets a message describing why the operation was canceled.
    
    Specified by:
    
    getCancelReason in interface Cancelable
    
    Returns:
    
    The reason for cancelation, which may be null if no reason was given, or if the operation was not in fact canceled.
  - getName
```
public String getName()
```
    Description copied from interface: Named
    
    Gets the name of the object.
    
    Specified by:
    
    getName in interface Named
  - setName
```
public void setName(String name)
```
    Description copied from interface: Named
    
    Sets the name of the object.
    
    Specified by:
    
    setName in interface Named

Class DefaultTask

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DefaultTask

Method Detail

run

waitFor

start

finish

isDone

getStatusMessage

getProgressValue

getProgressMaximum

setStatusMessage

setProgressValue

setProgressMaximum

isCanceled

cancel

setCancelCallBack

getCancelCallBack

getCancelReason

getName

setName