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Finally add forgotten SIP file
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wonder-sk committed Jul 24, 2016
1 parent 940883b commit 963ff9210893db2a352e327eb12bba4521cd01b3
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  1. +43 −0 python/core/qgsfeedback.sip
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/** 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:
* - if the worker thread uses an event loop (e.g. for network communication), the code can
* make a queued connection to cancelled() signal and handle the cancellation in its slot.
* - if the worker thread does not use an event loop, it can poll isCancelled() method regularly
* to see if the operation should be cancelled.
* 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 3.0
class QgsFeedback : QObject
#include <qgsfeedback.h>

//! Construct a feedback object
QgsFeedback( QObject* parent /TransferThis/ = nullptr );

virtual ~QgsFeedback();

//! Tells the internal routines that the current operation should be cancelled. This should be run by the main thread
void cancel();

//! Tells whether the operation has been cancelled already
bool isCancelled() const;

//! Internal routines can connect to this signal if they use event loop
void cancelled();


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