Class: QgsRasterBlockFeedback¶

Feedback object tailored for raster block reading.

Class Hierarchy¶

Base classes¶

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

Methods

`appendError`	Appends an error message to the stored list of errors.
`errors`	Returns a list of any errors encountered while retrieving the raster block.
`isPreviewOnly`	Whether the raster provider should return only data that are already available without waiting for full result.
`renderContext`	Returns the render context of the associated block reading
`renderPartialOutput`	Whether our painter is drawing to a temporary image used just by this layer
`setPreviewOnly`	set flag whether the block request is for preview purposes only
`setRenderContext`	Sets the render context of the associated block reading
`setRenderPartialOutput`	Set whether our painter is drawing to a temporary image used just by this layer

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsRasterBlockFeedback. See the FAQ for more details.

onNewData

May be emitted by raster data provider to indicate that some partial data are available and a new preview image may be produced

class qgis.core.QgsRasterBlockFeedback[source]¶

Bases: QgsFeedback

__init__(parent: QObject | None = None)

Construct a new raster block feedback object

Parameters:: parent (Optional[QObject] = None)

appendError(self, error: str | None)[source]¶

Appends an error message to the stored list of errors. Should be called whenever an error is encountered while retrieving a raster block.

See also

errors()

Added in version 3.8.0.

Parameters:: error (Optional[str])

errors(self) → List[str][source]¶

Returns a list of any errors encountered while retrieving the raster block.

See also

appendError()

Added in version 3.8.0.

Return type:: List[str]

isPreviewOnly(self) → bool[source]¶

Whether the raster provider should return only data that are already available without waiting for full result. By default this flag is not enabled.

See also

setPreviewOnly()

Return type:: bool

virtual onNewData(self)[source]¶: May be emitted by raster data provider to indicate that some partial data are available and a new preview image may be produced

renderContext(self) → QgsRenderContext[source]¶

Returns the render context of the associated block reading

See also

setRenderContext()

Added in version 3.24.0.