QgsTask task which runs a QgsProcessingAlgorithm in a background task. More...

#include <qgsprocessingalgrunnertask.h>

Inheritance diagram for QgsProcessingAlgRunnerTask:

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Signals
void	executed (bool successful, const QVariantMap &results)
	Emitted when the algorithm has finished execution.

Signals inherited from QgsTask
void	begun ()
	Will be emitted by task to indicate its commencement.

void	progressChanged (double progress)
	Will be emitted by task when its progress changes.

void	statusChanged (int status)
	Will be emitted by task when its status changes.

void	taskCompleted ()
	Will be emitted by task to indicate its successful completion.

void	taskTerminated ()
	Will be emitted by task if it has terminated for any reason other then completion (e.g., when a task has been canceled or encountered an internal error).

Public Member Functions
	QgsProcessingAlgRunnerTask (const QgsProcessingAlgorithm algorithm, const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback feedback=nullptr, QgsTask::Flags flags=QgsTask::CanCancel)
	Constructor for QgsProcessingAlgRunnerTask.

bool	algorithmCanceled ()
	Returns `true` if the algorithm was canceled.

void	cancel () override
	Notifies the task that it should terminate.

Public Member Functions inherited from QgsTask
	QgsTask (const QString &description=QString(), QgsTask::Flags flags=AllFlags)
	Constructor for QgsTask.

	~QgsTask () override

void	addSubTask (QgsTask *subTask, const QgsTaskList &dependencies=QgsTaskList(), SubTaskDependency subTaskDependency=SubTaskIndependent)
	Adds a subtask to this task.

bool	canCancel () const
	Returns `true` if the task can be canceled.

QList< QgsMapLayer * >	dependentLayers () const
	Returns the list of layers on which the task depends.

QString	description () const
	Returns the task's description.

qint64	elapsedTime () const
	Returns the elapsed time since the task commenced, in milliseconds.

Flags	flags () const
	Returns the flags associated with the task.

void	hold ()
	Places the task on hold.

bool	isActive () const
	Returns `true` if the task is active, ie it is not complete and has not been canceled.

double	progress () const
	Returns the task's progress (between 0.0 and 100.0)

void	setDependentLayers (const QList< QgsMapLayer * > &dependentLayers)
	Sets a list of layers on which the task depends.

void	setDescription (const QString &description)
	Sets the task's description.

TaskStatus	status () const
	Returns the current task status.

void	unhold ()
	Releases the task from being held.

bool	waitForFinished (int timeout=30000)
	Blocks the current thread until the task finishes or a maximum of timeout milliseconds.

Protected Member Functions
void	finished (bool result) override
	If the task is managed by a QgsTaskManager, this will be called after the task has finished (whether through successful completion or via early termination).

bool	run () override
	Performs the task's operation.

Protected Member Functions inherited from QgsTask
bool	isCanceled () const
	Will return `true` if task should terminate ASAP.

Additional Inherited Members
Public Types inherited from QgsTask
enum	Flag { CanCancel = 1 << 1 , CancelWithoutPrompt = 1 << 2 , Hidden = 1 << 3 , Silent = 1 << 4 , AllFlags = CanCancel }
	Task flags. More...

typedef QFlags< Flag >	Flags

enum	SubTaskDependency { SubTaskIndependent = 0 , ParentDependsOnSubTask }
	Controls how subtasks relate to their parent task. More...

enum	TaskStatus { Queued , OnHold , Running , Complete , Terminated }
	Status of tasks. More...

Protected Slots inherited from QgsTask
void	setProgress (double progress)
	Sets the task's current progress.

Detailed Description

QgsTask task which runs a QgsProcessingAlgorithm in a background task.

Definition at line 34 of file qgsprocessingalgrunnertask.h.

Constructor & Destructor Documentation

◆ QgsProcessingAlgRunnerTask()

QgsProcessingAlgRunnerTask::QgsProcessingAlgRunnerTask	(	const QgsProcessingAlgorithm *	algorithm,
		const QVariantMap &	parameters,
		QgsProcessingContext &	context,
		QgsProcessingFeedback *	feedback = `nullptr`,
		QgsTask::Flags	flags = `QgsTask::CanCancel`
	)

Constructor for QgsProcessingAlgRunnerTask.

Takes an algorithm, algorithm parameters and processing context.

Since QGIS 3.26, the flags argument allows control over task flags.

Definition at line 25 of file qgsprocessingalgrunnertask.cpp.

Member Function Documentation

◆ algorithmCanceled()

bool QgsProcessingAlgRunnerTask::algorithmCanceled ( )

inline

Returns true if the algorithm was canceled.

Since: QGIS 3.26

Definition at line 59 of file qgsprocessingalgrunnertask.h.

◆ cancel()

void QgsProcessingAlgRunnerTask::cancel ( )

overridevirtual

Notifies the task that it should terminate.

Calling this is not guaranteed to immediately end the task, rather it sets the isCanceled() flag which task subclasses can check and terminate their operations at an appropriate time. Any subtasks owned by this task will also be canceled. Derived classes must ensure that the base class implementation is called from any overridden version.

See also: isCanceled()

Reimplemented from QgsTask.

Definition at line 53 of file qgsprocessingalgrunnertask.cpp.

◆ executed

void QgsProcessingAlgRunnerTask::executed	(	bool	successful,
		const QVariantMap &	results
	)

signal

Emitted when the algorithm has finished execution.

If the algorithm completed execution without errors then successful will be true. The results argument contains the results reported by the algorithm.

◆ finished()

void QgsProcessingAlgRunnerTask::finished ( bool result )

overrideprotectedvirtual

If the task is managed by a QgsTaskManager, this will be called after the task has finished (whether through successful completion or via early termination).

The result argument reflects whether the task was successfully completed or not. This method is always called from the main thread, so it is safe to create widgets and perform other operations which require the main thread. However, the GUI will be blocked for the duration of this method so tasks should avoid performing any lengthy operations here.

Reimplemented from QgsTask.

Definition at line 81 of file qgsprocessingalgrunnertask.cpp.

◆ run()

bool QgsProcessingAlgRunnerTask::run ( )

overrideprotectedvirtual

Performs the task's operation.

This method will be called when the task commences (ie via calling start() ), and subclasses should implement the operation they wish to perform in the background within this method.

A task must return a boolean value to indicate whether the task was completed successfully or terminated before completion.

Implements QgsTask.

Definition at line 60 of file qgsprocessingalgrunnertask.cpp.

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

/build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/processing/qgsprocessingalgrunnertask.h
/build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/processing/qgsprocessingalgrunnertask.cpp

Signals

Public Member Functions

Protected Member Functions

Additional Inherited Members