QGIS API Documentation
3.0.2-Girona (307d082)
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QgsTask task which runs a QgsProcessingAlgorithm in a background task. More...
#include <qgsprocessingalgrunnertask.h>
Signals | |
void | executed (bool successful, const QVariantMap &results) |
Emitted when the algorithm has finished execution. More... | |
Signals inherited from QgsTask | |
void | begun () |
Will be emitted by task to indicate its commencement. More... | |
void | progressChanged (double progress) |
Will be emitted by task when its progress changes. More... | |
void | statusChanged (int status) |
Will be emitted by task when its status changes. More... | |
void | taskCompleted () |
Will be emitted by task to indicate its successful completion. More... | |
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). More... | |
Public Member Functions | |
QgsProcessingAlgRunnerTask (const QgsProcessingAlgorithm *algorithm, const QVariantMap ¶meters, QgsProcessingContext &context, QgsProcessingFeedback *feedback=nullptr) | |
Constructor for QgsProcessingAlgRunnerTask. More... | |
void | cancel () override |
Notifies the task that it should terminate. More... | |
Public Member Functions inherited from QgsTask | |
QgsTask (const QString &description=QString(), QgsTask::Flags flags=AllFlags) | |
Constructor for QgsTask. More... | |
~QgsTask () override | |
void | addSubTask (QgsTask *subTask, const QgsTaskList &dependencies=QgsTaskList(), SubTaskDependency subTaskDependency=SubTaskIndependent) |
Adds a subtask to this task. More... | |
bool | canCancel () const |
Returns true if the task can be canceled. More... | |
QList< QgsMapLayer *> | dependentLayers () const |
Returns the list of layers on which the task depends. More... | |
QString | description () const |
Returns the task's description. More... | |
Flags | flags () const |
Returns the flags associated with the task. More... | |
void | hold () |
Places the task on hold. More... | |
bool | isActive () const |
Returns true if the task is active, ie it is not complete and has not been canceled. More... | |
double | progress () const |
Returns the task's progress (between 0.0 and 100.0) More... | |
void | setDependentLayers (const QList< QgsMapLayer *> &dependentLayers) |
Sets a list of layers on which the task depends. More... | |
TaskStatus | status () const |
Returns the current task status. More... | |
void | unhold () |
Releases the task from being held. More... | |
bool | waitForFinished (unsigned long timeout=30000) |
Blocks the current thread until the task finishes or a maximum of timeout milliseconds. More... | |
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). More... | |
bool | run () override |
Performs the task's operation. More... | |
Protected Member Functions inherited from QgsTask | |
bool | isCanceled () const |
Will return true if task should terminate ASAP. More... | |
Additional Inherited Members | |
Public Types inherited from QgsTask | |
enum | Flag { CanCancel = 1 << 1, AllFlags = CanCancel } |
Task flags. More... | |
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. More... | |
QgsTask task which runs a QgsProcessingAlgorithm in a background task.
Definition at line 35 of file qgsprocessingalgrunnertask.h.
QgsProcessingAlgRunnerTask::QgsProcessingAlgRunnerTask | ( | const QgsProcessingAlgorithm * | algorithm, |
const QVariantMap & | parameters, | ||
QgsProcessingContext & | context, | ||
QgsProcessingFeedback * | feedback = nullptr |
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Constructor for QgsProcessingAlgRunnerTask.
Takes an algorithm, algorithm parameters and processing context.
Definition at line 25 of file qgsprocessingalgrunnertask.cpp.
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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.
Reimplemented from QgsTask.
Definition at line 41 of file qgsprocessingalgrunnertask.cpp.
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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.
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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 68 of file qgsprocessingalgrunnertask.cpp.
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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 47 of file qgsprocessingalgrunnertask.cpp.