KJob Class Reference

The base class for all jobs. More...

#include <kjob.h>

Inheritance diagram for KJob:

List of all members.

Public Types
enum	{ NoError = 0, KilledJobError = 1, UserDefinedError = 100 }
enum	Capability { NoCapabilities = 0x0000, Killable = 0x0001, Suspendable = 0x0002 }
enum	KillVerbosity { Quietly, EmitResult }
enum	Unit { Bytes, Files, Directories }
Public Slots
bool	kill (KillVerbosity verbosity=Quietly)
bool	resume ()
bool	suspend ()
Signals
void	description (KJob *job, const QString &title, const QPair< QString, QString > &field1=qMakePair(QString(), QString()), const QPair< QString, QString > &field2=qMakePair(QString(), QString()))
void	finished (KJob *job)
void	infoMessage (KJob *job, const QString &plain, const QString &rich=QString())
void	percent (KJob *job, unsigned long percent)
void	processedAmount (KJob *job, KJob::Unit unit, qulonglong amount)
void	processedSize (KJob *job, qulonglong size)
void	result (KJob *job)
void	resumed (KJob *job)
void	speed (KJob *job, unsigned long speed)
void	suspended (KJob *job)
void	totalAmount (KJob *job, KJob::Unit unit, qulonglong amount)
void	totalSize (KJob *job, qulonglong size)
void	warning (KJob *job, const QString &plain, const QString &rich=QString())
Public Member Functions
	KJob (QObject *parent=0)
virtual	~KJob ()
Capabilities	capabilities () const
int	error () const
virtual QString	errorString () const
QString	errorText () const
bool	exec ()
bool	isAutoDelete () const
bool	isSuspended () const
unsigned long	percent () const
qulonglong	processedAmount (Unit unit) const
void	setAutoDelete (bool autodelete)
void	setUiDelegate (KJobUiDelegate *delegate)
virtual void	start ()=0
qulonglong	totalAmount (Unit unit) const
KJobUiDelegate *	uiDelegate () const
Protected Member Functions
	KJob (KJobPrivate &dd, QObject *parent)
virtual bool	doKill ()
virtual bool	doResume ()
virtual bool	doSuspend ()
void	emitPercent (qulonglong processedAmount, qulonglong totalAmount)
void	emitResult ()
void	emitSpeed (unsigned long speed)
void	setCapabilities (Capabilities capabilities)
void	setError (int errorCode)
void	setErrorText (const QString &errorText)
void	setPercent (unsigned long percentage)
void	setProcessedAmount (Unit unit, qulonglong amount)
void	setTotalAmount (Unit unit, qulonglong amount)
Protected Attributes
KJobPrivate *const	d_ptr

---

Detailed Description

The base class for all jobs.

For all jobs created in an application, the code looks like

 void SomeClass::methodWithAsynchronousJobCall()
 {
   KJob * job = someoperation( some parameters );
   connect( job, SIGNAL( result( KJob * ) ),
            this, SLOT( handleResult( KJob * ) ) );
   job->start();
 }

(other connects, specific to the job)

And handleResult is usually at least:

 void SomeClass::handleResult( KJob *job )
 {
   if ( job->error() )
       doSomething();
 }

With the synchronous interface the code looks like

 void SomeClass::methodWithSynchronousJobCall()
 {
   KJob *job = someoperation( some parameters );
   if ( !job->exec() )
   {
       // An error occurred
   }
   else
   {
       // Do something
   }
 }

Note:

: KJob and its subclasses is meant to be used in a fire-and-forget way. It's deleting itself when it has finished using deleteLater() so the job instance disappears after the next event loop run.

Definition at line 79 of file kjob.h.

---

Member Enumeration Documentation

anonymous enum

Enumerator:

NoError
KilledJobError
UserDefinedError

Definition at line 246 of file kjob.h.

enum KJob::Capability

Enumerator:

NoCapabilities
Killable
Suspendable

Definition at line 88 of file kjob.h.

enum KJob::KillVerbosity

Enumerator:

Quietly
EmitResult

Definition at line 162 of file kjob.h.

enum KJob::Unit

Enumerator:

Bytes
Files
Directories

Definition at line 86 of file kjob.h.

---

Constructor & Destructor Documentation

KJob::KJob

(

QObject *

parent = 0

)

[explicit]

Creates a new KJob object.

Parameters:

parent

the parent QObject

Definition at line 49 of file kjob.cpp.

KJob::~KJob

(

)

[virtual]

Destroys a KJob object.

Definition at line 65 of file kjob.cpp.

KJob::KJob	(	KJobPrivate &	dd,
		QObject *	parent
	)		[protected]

Definition at line 57 of file kjob.cpp.

---

Member Function Documentation

KJob::Capabilities KJob::capabilities

(

)

const

Returns the capabilities of this job.

Returns:

the capabilities that this job supports

See also:

setCapabilities()

Definition at line 94 of file kjob.cpp.

void KJob::description	(	KJob *	job,
		const QString &	title,
		const QPair< QString, QString > &	field1 = qMakePair(QString(), QString()),
		const QPair< QString, QString > &	field2 = qMakePair(QString(), QString())
	)		[signal]

Emitted to display general description of this job.

A description has a title and two optional fields which can be used to complete the description.

Examples of titles are "Copying", "Creating resource", etc. The fields of the description can be "Source" with an URL, and, "Destination" with an URL for a "Copying" description.

Parameters:

job	the job that emitted this signal
title	the general description of the job
field1	first field (localized name and value)
field2	second field (localized name and value)

bool KJob::doKill

(

)

[protected, virtual]

Aborts this job quietly.

This simply kills the job, no error reporting or job deletion should be involved.

Returns:

true if the operation is supported and succeeded, false otherwise

Definition at line 165 of file kjob.cpp.

bool KJob::doResume

(

)

[protected, virtual]

Resumes this job.

Returns:

true if the operation is supported and succeeded, false otherwise

Definition at line 175 of file kjob.cpp.

bool KJob::doSuspend

(

)

[protected, virtual]

Suspends this job.

Returns:

true if the operation is supported and succeeded, false otherwise

Definition at line 170 of file kjob.cpp.

void KJob::emitPercent	(	qulonglong	processedAmount,
		qulonglong	totalAmount
	)		[protected]

Utility function for inherited jobs.

Emits the percent signal if bigger than previous value, after calculating it from the parameters.

Parameters:

processedAmount	the processed amount
totalAmount	the total amount

See also:

percent()

Definition at line 318 of file kjob.cpp.

void KJob::emitResult

(

)

[protected]

Utility function to emit the result signal, and suicide this job.

It first notifies the observers to hide the progress for this job using the finished() signal.

Note:

: Deletes this job using deleteLater().

See also:

result()

finished()

Definition at line 300 of file kjob.cpp.

void KJob::emitSpeed

(

unsigned long

speed

)

[protected]

Utility function for inherited jobs.

Emits the speed signal and starts the timer for removing that info

Parameters:

speed

the speed in bytes/s

Definition at line 331 of file kjob.cpp.

int KJob::error

(

)

const

Returns the error code, if there has been an error.

Only call this method from the slot connected to result().

Returns:

the error code for this job, 0 if no error.

Definition at line 214 of file kjob.cpp.

QString KJob::errorString

(

)

const [virtual]

Converts an error code and a non-i18n error message into an error message in the current language.

The low level (non-i18n) error message (usually a url) is put into the translated error message using 1.

Example for errid == ERR_CANNOT_OPEN_FOR_READING:

   i18n( "Could not read\n%1" , errorText() );

Only call if error is not 0.

Returns:

the error message and if there is no error, a message telling the user that the app is broken, so check with error() whether there is an error

Definition at line 224 of file kjob.cpp.

QString KJob::errorText

(

)

const

Returns the error text if there has been an error.

Only call if error is not 0. This is really internal, better use errorString.

Returns:

a string to help understand the error, usually the url related to the error. Only valid if error() is not 0.

Definition at line 219 of file kjob.cpp.

bool KJob::exec

(

)

Executes the job synchronously.

This will start a nested QEventLoop internally. Nested event loop can be dangerous and can have unintended side effects, you should avoid calling exec() whenever you can and use the asyncronous interface of KJob instead.

Should you indeed call this method, you need to make sure that all callers are reentrant, so that events delivered by the inner event loop don't cause non-reentrant functions to be called, which usually wreaks havoc.

Note that the event loop started by this method does not process user input events, which means your user interface will effectivly be blocked. Other events like paint or network events are still being processed. The advantage of not processing user input events is that the chance of accidental reentrancy is greatly reduced. Still you should avoid calling this function.

Returns:

true if the job has been executed without error, false otherwise

Definition at line 186 of file kjob.cpp.

void KJob::finished

(

KJob *

job

)

[signal]

Emitted when the job is finished, in any case.

It is used to notify observers that the job is terminated and that progress can be hidden.

This is a private signal, it can't be emitted directly by subclasses of KJob, use emitResult() instead.

Client code is not supposed to connect to this signal, signal result should be used instead.

If you store a list of jobs and they might get killed silently, then you must connect to this instead of result().

Parameters:

job	the job that emitted this signal

See also:

result

void KJob::infoMessage	(	KJob *	job,
		const QString &	plain,
		const QString &	rich = QString()
	)		[signal]

Emitted to display state information about this job.

Examples of message are "Resolving host", "Connecting to host...", etc.

Parameters:

job	the job that emitted this signal
plain	the info message
rich	the rich text version of the message, or QString() is none is available

bool KJob::isAutoDelete

(

)

const

Returns whether this job automatically deletes itself once the job is finished.

Returns:

whether the job is deleted automatically after finishing.

Definition at line 352 of file kjob.cpp.

bool KJob::isSuspended

(

)

const

Returns if the job was suspended with the suspend() call.

Returns:

if the job was suspended

See also:

suspend() resume()

Definition at line 99 of file kjob.cpp.

bool KJob::kill

(

KillVerbosity

verbosity = Quietly

)

[slot]

Aborts this job.

This kills and deletes the job.

Parameters:

verbosity

if equals to EmitResult, Job will emit signal result and ask uiserver to close the progress window. verbosity is set to EmitResult for subjobs. Whether applications should call with Quietly or EmitResult depends on whether they rely on result being emitted or not. Please notice that if verbosity is set to Quietly, signal result will NOT be emitted.

Returns:

true if the operation is supported and succeeded, false otherwise

Definition at line 104 of file kjob.cpp.

void KJob::percent	(	KJob *	job,
		unsigned long	percent
	)		[signal]

Progress signal showing the overall progress of the job This is valid for any kind of job, and allows using a a progress bar very easily.

(see KProgressBar). Note that this signal is not emitted for finished jobs.

This is a private signal, it can't be emitted directly by subclasses of KJob, use emitPercent(), setPercent() setTotalAmount() or setProcessedAmount() instead.

Parameters:

job	the job that emitted this signal
percent	the percentage

unsigned long KJob::percent

(

)

const

Returns the overall progress of this job.

Returns:

the overall progress of this job

Definition at line 239 of file kjob.cpp.

qulonglong KJob::processedAmount

(

Unit

unit

)

const

Returns the processed amount of a given unit for this job.

Parameters:

unit	the unit of the requested amount

Returns:

the processed size

Definition at line 229 of file kjob.cpp.

void KJob::processedAmount	(	KJob *	job,
		KJob::Unit	unit,
		qulonglong	amount
	)		[signal]

Regularly emitted to show the progress of this job by giving the current amount.

The unit of this amount is sent too. It can be emitted several times if the job manages several different units.

This is a private signal, it can't be emitted directly by subclasses of KJob, use setProcessedAmount() instead.

Parameters:

job	the job that emitted this signal
unit	the unit of the processed amount
amount	the processed amount

void KJob::processedSize	(	KJob *	job,
		qulonglong	size
	)		[signal]

Regularly emitted to show the progress of this job (current data size in bytes for transfers, entries listed, etc.).

This is a private signal, it can't be emitted directly by subclasses of KJob, use setProcessedAmount() instead.

Parameters:

job	the job that emitted this signal
size	the processed size

void KJob::result

(

KJob *

job

)

[signal]

Emitted when the job is finished (except when killed with KJob::Quietly).

Use error to know if the job was finished with error.

This is a private signal, it can't be emitted directly by subclasses of KJob, use emitResult() instead.

Please connect to this signal instead of finished.

Parameters:

job	the job that emitted this signal

See also:

kill

bool KJob::resume

(

)

[slot]

Resumes this job.

Returns:

true if the operation is supported and succeeded, false otherwise

Definition at line 148 of file kjob.cpp.

void KJob::resumed

(

KJob *

job

)

[signal]

Emitted when the job is resumed.

This is a private signal, it can't be emitted directly by subclasses of KJob.

Parameters:

job	the job that emitted this signal

void KJob::setAutoDelete

(

bool

autodelete

)

set the auto-delete property of the job.

If autodelete is set to false the job will not delete itself once it is finished.

The default for any KJob is to automatically delete itself.

Parameters:

autodelete

set to false to disable automatic deletion of the job.

Definition at line 358 of file kjob.cpp.

void KJob::setCapabilities

(

Capabilities

capabilities

)

[protected]

Sets the capabilities for this job.

Parameters:

capabilities

are the capabilities supported by this job

See also:

capabilities()

Definition at line 52 of file AuthBackend.cpp.

void KJob::setError

(

int

errorCode

)

[protected]

Sets the error code.

It should be called when an error is encountered in the job, just before calling emitResult().

Parameters:

errorCode

the error code

See also:

emitResult()

Definition at line 244 of file kjob.cpp.

void KJob::setErrorText

(

const QString &

errorText

)

[protected]

Sets the error text.

It should be called when an error is encountered in the job, just before calling emitResult().

Parameters:

errorText

the error text

See also:

emitResult()

Definition at line 250 of file kjob.cpp.

void KJob::setPercent

(

unsigned long

percentage

)

[protected]

Sets the overall progress of the job.

The percent() signal is emitted if the value changed.

Parameters:

percentage

the new overall progress

Definition at line 290 of file kjob.cpp.

void KJob::setProcessedAmount	(	Unit	unit,
		qulonglong	amount
	)		[protected]

Sets the processed size.

The processedAmount() and percent() signals are emitted if the values changed. The percent() signal is emitted only for the progress unit.

Parameters:

unit	the unit of the new processed amount
amount	the new processed amount

Definition at line 256 of file kjob.cpp.

void KJob::setTotalAmount	(	Unit	unit,
		qulonglong	amount
	)		[protected]

Sets the total size.

The totalSize() and percent() signals are emitted if the values changed. The percent() signal is emitted only for the progress unit.

Parameters:

unit	the unit of the new total amount
amount	the new total amount

Definition at line 273 of file kjob.cpp.

void KJob::setUiDelegate

(

KJobUiDelegate *

delegate

)

Attach a UI delegate to this job.

If the job had another UI delegate, it's automatically deleted. Once attached to the job, the UI delegate will be deleted with the job.

Parameters:

delegate

the new UI delegate to use

See also:

KJobUiDelegate

Definition at line 74 of file kjob.cpp.

void KJob::speed	(	KJob *	job,
		unsigned long	speed
	)		[signal]

Emitted to display information about the speed of this job.

This is a private signal, it can't be emitted directly by subclasses of KJob, use emitSpeed() instead.

Parameters:

job	the job that emitted this signal
speed	the speed in bytes/s

virtual void KJob::start

(

)

[pure virtual]

Starts the job asynchronously.

When the job is finished, result() is emitted.

Warning: Never implement any synchronous workload in this method. This method should just trigger the job startup, not do any work itself. It is expected to be non-blocking.

This is the method all subclasses need to implement. It should setup and trigger the workload of the job. It should not do any work itself. This includes all signals and terminating the job, e.g. by emitResult(). The workload, which could be another method of the subclass, is to be triggered using the event loop, e.g. by code like:

 void ExampleJob::start()
 {
  QTimer::singleShot( 0, this, SLOT( doWork() ) );
 }

bool KJob::suspend

(

)

[slot]

Suspends this job.

The job should be kept in a state in which it is possible to resume it.

Returns:

true if the operation is supported and succeeded, false otherwise

Definition at line 131 of file kjob.cpp.

void KJob::suspended

(

KJob *

job

)

[signal]

Emitted when the job is suspended.

This is a private signal, it can't be emitted directly by subclasses of KJob.

Parameters:

job	the job that emitted this signal

void KJob::totalAmount	(	KJob *	job,
		KJob::Unit	unit,
		qulonglong	amount
	)		[signal]

Emitted when we know the amount the job will have to process.

The unit of this amount is sent too. It can be emitted several times if the job manages several different units.

This is a private signal, it can't be emitted directly by subclasses of KJob, use setTotalAmount() instead.

Parameters:

job	the job that emitted this signal
unit	the unit of the total amount
amount	the total amount

qulonglong KJob::totalAmount

(

Unit

unit

)

const

Returns the total amount of a given unit for this job.

Parameters:

unit	the unit of the requested amount

Returns:

the total size

Definition at line 234 of file kjob.cpp.

void KJob::totalSize	(	KJob *	job,
		qulonglong	size
	)		[signal]

Emitted when we know the size of this job (data size in bytes for transfers, number of entries for listings, etc).

This is a private signal, it can't be emitted directly by subclasses of KJob, use setTotalAmount() instead.

Parameters:

job	the job that emitted this signal
size	the total size

KJobUiDelegate * KJob::uiDelegate

(

)

const

Retrieves the delegate attached to this job.

Returns:

the delegate attached to this job, or 0 if there's no such delegate

Definition at line 89 of file kjob.cpp.

void KJob::warning	(	KJob *	job,
		const QString &	plain,
		const QString &	rich = QString()
	)		[signal]

Emitted to display a warning about this job.

Parameters:

job	the job that emitted this signal
plain	the warning message
rich	the rich text version of the message, or QString() is none is available

---

Member Data Documentation

KJobPrivate* const KJob::d_ptr [protected]

Definition at line 595 of file kjob.h.

---

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

• kjob.h
• AuthBackend.cpp
• kjob.cpp