Task Class Reference

An abstract base class for objects that represent tasks to be executed by a TaskProcessor. More...

#include <Task.h++>

Inheritance diagram for Task:

Signals
void	statusUpdated (const QString &status)
	Emitted whenever updateStatus() is called. More...
void	finished ()
	Emitted when the task has finished executing. More...
void	cancelled ()
	Emitted when the task has been cancelled. More...

Public Member Functions
virtual	~Task ()
	Destructor. More...
int	id () const
	Returns the unique ID that was assigned to this task. More...
bool	isRunning () const
	Tests if the task is currently executing. More...
bool	isCancelling () const
	Tests if the task is currently cancelling. More...
bool	isCancelled () const
	Tests if the task has been cancelled. More...
bool	isFailed () const
	Tests if the task has failed. More...
bool	isBackground () const
	Tests if the task is a background task. More...
QString	error () const
	Returns the error message reported by this task upon failure, if any. More...
void	setTimeout (int seconds)
	Sets the task's timeout, in seconds. More...
qint64	executionTime () const
	Returns the amount of time the task spent executing, or 0 if the task has not finished executing. More...

Static Public Attributes
static const int	DEFAULT_TIMEOUT
	The default timeout interval, in seconds. More...

Protected Member Functions
	Task (bool background=false)
	Constructs a new Task of the given type. More...
virtual void	execute ()=0
	Executes the task. More...
virtual bool	cancel ()
	Attempts to cancel the task. More...
void	setCancelled ()
	Marks the task as cancelled. More...
void	fail (QString error=QString())
	Marks the task as failed, with an optional error message. More...
void	updateStatus (const QString &text)
	Updates the status of the task. More...

Friends
class	TaskProcessor

Detailed Description

An abstract base class for objects that represent tasks to be executed by a TaskProcessor.

Author

Mark Lindner

Constructor & Destructor Documentation

~Task()

virtual ~Task ( )

virtual

Destructor.

Task()

Task ( bool  background = false )

protected

Constructs a new Task of the given type.

Parameters

background

Whether this is a "background" task that continues executing indefinitely.

Member Function Documentation

cancel()

virtual bool cancel ( )

protectedvirtual

Attempts to cancel the task.

Some tasks may not be cancellable. The default implementation is a no-op that returns false.

Parameters

<b>true</b>

if the task was successfully cancelled, false otherwise.

Reimplemented in ExternalCommandTask.

cancelled

void cancelled ( )

signal

Emitted when the task has been cancelled.

error()

QString error ( ) const

inline

Returns the error message reported by this task upon failure, if any.

execute()

virtual void execute ( )

protectedpure virtual

Executes the task.

The actual work of the task must be implemented in this method.

Implemented in ExternalCommandTask.

executionTime()

qint64 executionTime

(

)

const

Returns the amount of time the task spent executing, or 0 if the task has not finished executing.

fail()

void fail ( QString  error = QString() )

protected

Marks the task as failed, with an optional error message.

finished

void finished ( )

signal

Emitted when the task has finished executing.

id()

int id ( ) const

inline

Returns the unique ID that was assigned to this task.

isBackground()

bool isBackground ( ) const

inline

Tests if the task is a background task.

isCancelled()

bool isCancelled ( ) const

inline

Tests if the task has been cancelled.

isCancelling()

bool isCancelling ( ) const

inline

Tests if the task is currently cancelling.

isFailed()

bool isFailed ( ) const

inline

Tests if the task has failed.

isRunning()

bool isRunning ( ) const

inline

Tests if the task is currently executing.

setCancelled()

void setCancelled ( )

protected

Marks the task as cancelled.

setTimeout()

void setTimeout

(

int

seconds

)

Sets the task's timeout, in seconds.

statusUpdated

void statusUpdated ( const QString &  status )

signal

Emitted whenever updateStatus() is called.

updateStatus()

void updateStatus ( const QString &  text )

protected

Updates the status of the task.

See statusUpdated().

Friends And Related Function Documentation

TaskProcessor

friend class TaskProcessor

friend

Member Data Documentation

DEFAULT_TIMEOUT

const int DEFAULT_TIMEOUT

static

The default timeout interval, in seconds.

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The documentation for this class was generated from the following file:

• Task.h++