QGIS API Documentation  2.18.3-Las Palmas (77b8c3d)
Signals | Public Member Functions | List of all members
QgsFeedback Class Reference

Base class for feedback objects to be used for cancellation of something running in a worker thread. More...

#include <qgsfeedback.h>

Inheritance diagram for QgsFeedback:
Inheritance graph
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Signals

void cancelled ()
 Internal routines can connect to this signal if they use event loop. More...
 

Public Member Functions

 QgsFeedback (QObject *parent=nullptr)
 Construct a feedback object. More...
 
virtual ~QgsFeedback ()
 
void cancel ()
 Tells the internal routines that the current operation should be cancelled. This should be run by the main thread. More...
 
bool isCancelled () const
 Tells whether the operation has been cancelled already. More...
 
- Public Member Functions inherited from QObject
 QObject (QObject *parent)
 
 QObject (QObject *parent, const char *name)
 
virtual  ~QObject ()
 
bool blockSignals (bool block)
 
QObjectchild (const char *objName, const char *inheritsClass, bool recursiveSearch) const
 
const QObjectList & children () const
 
const char * className () const
 
bool connect (const QObject *sender, const char *signal, const char *method, Qt::ConnectionType type) const
 
void deleteLater ()
 
void destroyed (QObject *obj)
 
bool disconnect (const QObject *receiver, const char *method)
 
bool disconnect (const char *signal, const QObject *receiver, const char *method)
 
void dumpObjectInfo ()
 
void dumpObjectTree ()
 
QList< QByteArraydynamicPropertyNames () const
 
virtual bool event (QEvent *e)
 
virtual bool eventFilter (QObject *watched, QEvent *event)
 
findChild (const QString &name) const
 
QList< T > findChildren (const QRegExp &regExp) const
 
QList< T > findChildren (const QString &name) const
 
bool inherits (const char *className) const
 
void insertChild (QObject *object)
 
void installEventFilter (QObject *filterObj)
 
bool isA (const char *className) const
 
bool isWidgetType () const
 
void killTimer (int id)
 
virtual const QMetaObjectmetaObject () const
 
void moveToThread (QThread *targetThread)
 
const char * name () const
 
const char * name (const char *defaultName) const
 
QString objectName () const
 
QObjectparent () const
 
QVariant property (const char *name) const
 
void removeChild (QObject *object)
 
void removeEventFilter (QObject *obj)
 
void setName (const char *name)
 
void setObjectName (const QString &name)
 
void setParent (QObject *parent)
 
bool setProperty (const char *name, const QVariant &value)
 
bool signalsBlocked () const
 
int startTimer (int interval)
 
QThreadthread () const
 

Additional Inherited Members

- Static Public Member Functions inherited from QObject
bool connect (const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type)
 
bool connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type)
 
bool disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *method)
 
bool disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method)
 
QString tr (const char *sourceText, const char *disambiguation, int n)
 
QString trUtf8 (const char *sourceText, const char *disambiguation, int n)
 
- Protected Member Functions inherited from QObject
bool checkConnectArgs (const char *signal, const QObject *object, const char *method)
 
virtual void childEvent (QChildEvent *event)
 
virtual void connectNotify (const char *signal)
 
virtual void customEvent (QEvent *event)
 
virtual void disconnectNotify (const char *signal)
 
int receivers (const char *signal) const
 
QObjectsender () const
 
int senderSignalIndex () const
 
virtual void timerEvent (QTimerEvent *event)
 
- Static Protected Member Functions inherited from QObject
QByteArray normalizeSignalSlot (const char *signalSlot)
 
- Properties inherited from QObject
 objectName
 

Detailed Description

Base class for feedback objects to be used for cancellation of something running in a worker thread.

The class may be used as is or it may be subclassed for extended functionality for a particular operation (e.g. report progress or pass some data for preview).

When cancel() is called, the internal code has two options to check for cancellation state:

The class is meant to be created and destroyed in the main thread.

For map rendering, the object may be created in constructor of a QgsMapLayerRenderer subclass and available with QgsMapLayerRenderer::feedback() method. When a map rendering job gets cancelled, the cancel() method is called on the feedback object of all layers.

Note
added in QGIS 2.18

Definition at line 40 of file qgsfeedback.h.

Constructor & Destructor Documentation

QgsFeedback::QgsFeedback ( QObject parent = nullptr)
inline

Construct a feedback object.

Definition at line 45 of file qgsfeedback.h.

virtual QgsFeedback::~QgsFeedback ( )
inlinevirtual

Definition at line 50 of file qgsfeedback.h.

Member Function Documentation

void QgsFeedback::cancel ( )
inline

Tells the internal routines that the current operation should be cancelled. This should be run by the main thread.

Definition at line 53 of file qgsfeedback.h.

void QgsFeedback::cancelled ( )
signal

Internal routines can connect to this signal if they use event loop.

bool QgsFeedback::isCancelled ( ) const
inline

Tells whether the operation has been cancelled already.

Definition at line 62 of file qgsfeedback.h.


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