QGIS API Documentation 3.27.0-Master (f261cc1f8b)
Public Types | Public Member Functions | Protected Member Functions | List of all members
QgsVectorWarperTask Class Reference

A task for warping a vector layer in a background thread. More...

#include <qgsvectorwarper.h>

Inheritance diagram for QgsVectorWarperTask:
Inheritance graph

Public Types

enum class  Result { Success , Canceled , Error }
 Task results. More...
- Public Types inherited from QgsTask
enum  Flag {
  CanCancel = 1 << 1 , CancelWithoutPrompt = 1 << 2 , Hidden = 1 << 3 , Silent = 1 << 4 ,
  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 ,
 Status of tasks. More...

Public Member Functions

 QgsVectorWarperTask (QgsGcpTransformerInterface::TransformMethod method, const QList< QgsGcpPoint > &points, const QgsCoordinateReferenceSystem &destinationCrs, QgsVectorLayer *layer, const QString &fileName)
 Constructor for QgsVectorWarperTask. More...
void cancel () override
 Notifies the task that it should terminate. More...
QString errorMessage () const
 Returns the descriptive error message, if an error occurred. More...
Result result () const
 Returns the result of running the task. 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...
virtual void cancel ()
 Notifies the task that it should terminate. 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...
qint64 elapsedTime () const
 Returns the elapsed time since the task commenced, in milliseconds. 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...
void setDescription (const QString &description)
 Sets the task's description. More...
TaskStatus status () const
 Returns the current task status. More...
void unhold ()
 Releases the task from being held. More...
bool waitForFinished (int timeout=30000)
 Blocks the current thread until the task finishes or a maximum of timeout milliseconds. More...

Protected Member Functions

bool run () override
 Performs the task's operation. More...
- Protected Member Functions inherited from QgsTask
virtual void finished (bool result)
 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 isCanceled () const
 Will return true if task should terminate ASAP. More...
virtual bool run ()=0
 Performs the task's operation. More...

Additional Inherited Members

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

Detailed Description

A task for warping a vector layer in a background thread.

QGIS 3.26

Definition at line 84 of file qgsvectorwarper.h.

Member Enumeration Documentation

◆ Result

enum class QgsVectorWarperTask::Result

Task results.


Warping completed successfully.


Task was canceled before completion.


An error occurred while warping.

Definition at line 107 of file qgsvectorwarper.h.

Constructor & Destructor Documentation

◆ QgsVectorWarperTask()

QgsVectorWarperTask::QgsVectorWarperTask ( QgsGcpTransformerInterface::TransformMethod  method,
const QList< QgsGcpPoint > &  points,
const QgsCoordinateReferenceSystem destinationCrs,
QgsVectorLayer layer,
const QString &  fileName 

Constructor for QgsVectorWarperTask.

methodtransformation method
pointsGCP point list
destinationCrsdestination layer CRS
layersource layer
fileNamefilename for destination layer

Definition at line 95 of file qgsvectorwarper.cpp.

Member Function Documentation

◆ cancel()

void QgsVectorWarperTask::cancel ( )

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

Reimplemented from QgsTask.

Definition at line 114 of file qgsvectorwarper.cpp.

◆ errorMessage()

QString QgsVectorWarperTask::errorMessage ( ) const

Returns the descriptive error message, if an error occurred.

Definition at line 122 of file qgsvectorwarper.h.

◆ result()

Result QgsVectorWarperTask::result ( ) const

Returns the result of running the task.

Definition at line 117 of file qgsvectorwarper.h.

◆ run()

bool QgsVectorWarperTask::run ( )

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 122 of file qgsvectorwarper.cpp.

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