Subgroup: Map

Class: QgsMapRendererCustomPainterJob

class qgis.core.QgsMapRendererCustomPainterJob

Bases: qgis._core.QgsMapRendererJob

Job implementation that renders everything sequentially using a custom painter.

Also supports synchronous rendering in main thread for cases when rendering in background is not an option because of some technical limitations (e.g. printing to printer on some platforms).

New in version 2.4: Methods

cancel
cancelWithoutBlocking
childEvent
connectNotify
customEvent
disconnectNotify
isActive
isSignalConnected
receivers
renderSynchronously Render the map synchronously in this thread.
sender
senderSignalIndex
start
takeLabelingResults
timerEvent
usedCachedLabels
waitForFinished
waitForFinishedWithEventLoop Wait for the job to be finished - and keep the thread’s event loop running while waiting.

Signals

Attributes

cancel(self)
cancelWithoutBlocking(self)
childEvent()
connectNotify()
customEvent()
disconnectNotify()
isActive(self) → bool
isSignalConnected()
receivers()
renderSynchronously(self)

Render the map synchronously in this thread. The function does not return until the map is completely rendered.

This is an alternative to ordinary API (using start() + waiting for finished() signal). Users are discouraged to use this method unless they have a strong reason for doing it. The synchronous rendering blocks the main thread, making the application unresponsive. Also, it is not possible to cancel rendering while it is in progress.

sender()
senderSignalIndex()
start(self)
takeLabelingResults(self) → QgsLabelingResults
timerEvent()
usedCachedLabels(self) → bool
waitForFinished(self)
waitForFinishedWithEventLoop(self, flags: Union[QEventLoop.ProcessEventsFlags, QEventLoop.ProcessEventsFlag] = QEventLoop.AllEvents)

Wait for the job to be finished - and keep the thread’s event loop running while waiting.

With a call to waitForFinished(), the waiting is done with a synchronization primitive and does not involve processing of messages. That may cause issues to code which requires some events to be handled in the main thread. Some plugins hooking into the rendering pipeline may require this in order to work properly - for example, OpenLayers plugin which uses a QWebPage in the main thread.

Ideally the “wait for finished” method should not be used at all. The code triggering rendering should not need to actively wait for rendering to finish.