Subgroup: Raster

Class: QgsRasterDataProvider¶

class qgis.core.QgsRasterDataProvider¶

Bases: qgis._core.QgsDataProvider, qgis._core.QgsRasterInterface

Base class for raster data providers.

Methods

appendError

bandCount Get number of bands

bandOffset Read band offset for raster value

bandScale Read band scale for raster value

bandStatistics Get band statistics.

block Read block of data using given extent and size.

blockSignals

buildPyramidList Accessor for the raster layers pyramid list.

buildPyramids Create pyramid overviews

capabilities Returns a bitmask containing the supported capabilities

capabilitiesString Returns the above in friendly format.

childEvent

children

clone

colorInterpretation Returns data type for the band specified by number

colorInterpretationName

colorName

colorTable

connectNotify

copyBaseSettings Copy member variables from other raster data provider.

create Creates a new dataset with mDataSourceURI

crs Returns the coordinate system for the data source.

cumulativeCut Find values for cumulative pixel count cut.

customEvent

dataSourceUri Get the data source specification.

dataTimestamp Current time stamp of data source

dataType Returns data type for the band specified by number

dataTypeSize

deleteLater

description Return description

disconnect

disconnectNotify

dpi Returns the dpi of the output device.

dumpObjectInfo

dumpObjectTree

dynamicPropertyNames

enterUpdateMode Enter update mode.

error Get current status error.

event

eventFilter

extent

fileRasterFilters Return raster file filter string

fileVectorFilters Return vector file filter string

findChild findChild(self, Tuple, name: str = ‘’, options: Union[Qt.FindChildOptions, Qt.FindChildOption] = Qt.FindChildrenRecursively) -> QObject

findChildren findChildren(self, Tuple, name: str = ‘’, options: Union[Qt.FindChildOptions, Qt.FindChildOption] = Qt.FindChildrenRecursively) -> List[QObject]

generateBandName helper function to create zero padded band names

getLegendGraphicFetcher Get an image downloader for the raster legend

hasHistogram Returns true if histogram is available (cached, already calculated)

hasPyramids Returns true if raster has at least one populated histogram.

hasStatistics Returns true if histogram is available (cached, already calculated).

histogram Get histogram.

htmlMetadata Get metadata in a format suitable for feeding directly into a subset of the GUI raster properties “Metadata” tab.

identify

identifyFormatFromName

identifyFormatLabel

identifyFormatName

identifyFormatToCapability

inherits

initHistogram

initStatistics

input Current input

installEventFilter

invalidateConnections Invalidate connections corresponding to specified name

isEditable Checks whether the provider is in editing mode, i.e.

isSignalConnected

isValid Returns true if this is a valid layer.

isWidgetType

isWindowType

killTimer

lastError Returns the verbose error text for the last error in this provider

lastErrorFormat Returns the format of the error text for the last error in this provider

lastErrorTitle Returns the caption error text for the last error in this provider

leaveUpdateMode Leave update mode.

metaObject

moveToThread

name Return a provider name

objectName

on Is on/off

parent

property

providerProperty Get the current value of a certain provider property.

pyqtConfigure Each keyword argument is either the name of a Qt property or a Qt signal.

pyramidResamplingMethods Returns a list of pyramid resampling method name and label pairs

readXml Sets base class members from xml.

receivers

reload Reload data (data could change)

reloadData Reloads the data from the source.

remove Remove dataset

removeEventFilter

sender

senderSignalIndex

setDataSourceUri Set the data source specification.

setDpi Sets the output device resolution.

setEditable Turns on/off editing mode of the provider.

setError

setInput It makes no sense to set input on provider */

setLayerOrder Reorder the list of layer names to be rendered by this provider

setListening Set whether the provider will listen to datasource notifications If set, the provider will issue notify signals.

setNoDataValue Set no data value on created dataset

setObjectName

setOn Set on/off

setParent

setProperty

setProviderProperty Allows setting arbitrary properties on the provider.

setSubLayerVisibility Set the visibility of the given sublayer name

setSubsetString Set the subset string used to create a subset of features in the layer.

setUri Set the data source specification.

setUseSourceNoDataValue Set source nodata value usage

setUserNoDataValue

signalsBlocked

sourceDataType Returns source data type for the band specified by number,

sourceHasNoDataValue Return true if source band has no data value

sourceInput Get source / raw input, the first in pipe, usually provider.

sourceNoDataValue Value representing no data value.

startTimer

stepHeight Step height for raster iterations.

stepWidth Step width for raster iterations.

subLayerCount return the number of layers for the current data source

subLayerStyles Sub-layer styles for each sub-layer handled by this provider,

subLayers Returns the sublayers of this layer - useful for providers that manage

subsetString Returns the subset definition string (typically sql) currently in use by the layer and used by the provider to limit the feature set.

supportsLegendGraphic Returns whether the provider supplies a legend graphic

supportsSubsetString Returns true if the provider supports setting of subset strings.

thread

timerEvent

timestamp Time stamp of data source in the moment when data/metadata were loaded by provider

tr

updateExtents Update the extents of the layer.

uri Get the data source specification.

useSourceNoDataValue Get source nodata value usage

userNoDataValues Get list of user no data value ranges

userNoDataValuesContains Returns true if user no data contains value

validateCreationOptions Validates creation options for a specific dataset and destination format.

validatePyramidsConfigOptions Validates pyramid creation options for a specific dataset and destination format

write

writeBlock Writes pixel data from a raster block into the provider data source.

writeXml Write base class members to xml.

xBlockSize Get block size

xSize Get raster size

yBlockSize

ySize

Attributes

BuildPyramids

Create

CustomData

Database

Dir

EvaluateDefaultValues

File

Identify

IdentifyFeature

IdentifyHtml

IdentifyText

IdentifyValue

Net

NoCapabilities

NoDataCapabilities

Remove

SUBLAYER_SEPARATOR

Size

dataChanged This is emitted whenever an asynchronous operation has finished

destroyed destroyed(self, QObject = None) [signal]

fullExtentCalculated This is emitted whenever the worker thread has fully calculated the PostGIS extents for this layer, and its event has been received by this provider.

notify Emitted when datasource issues a notification

objectNameChanged objectNameChanged(self, str) [signal]

staticMetaObject

statusChanged Emit a message to be displayed on status bar, usually used by network providers (WMS,WCS)

appendError()¶

bandOffset(self, bandNo: int) → float¶: Read band offset for raster value

New in version 2.3.

bandScale(self, bandNo: int) → float¶: Read band scale for raster value

New in version 2.3.

block(self, bandNo: int, boundingBox: QgsRectangle, width: int, height: int, feedback: QgsRasterBlockFeedback = None) → QgsRasterBlock¶: Read block of data using given extent and size.

buildPyramidList(self, overviewList: Iterable[int] = []) → List[QgsRasterPyramid]¶

Accessor for the raster layers pyramid list.

Parameters:	overviewList – used to construct the pyramid list (optional), when empty the list is defined by the provider.

A pyramid list defines the POTENTIAL pyramids that can be in a raster. To know which of the pyramid layers ACTUALLY exists you need to look at the existsFlag member in each struct stored in the list.

buildPyramids(self, pyramidList: object, resamplingMethod: str = '', format: QgsRaster.RasterPyramidsFormat = QgsRaster.PyramidsGTiff, configOptions: Iterable[str] = [], feedback: QgsRasterBlockFeedback = None) → str¶: Create pyramid overviews

childEvent()¶

clone(self) → QgsRasterInterface¶

colorInterpretation(self, bandNo: int) → int¶: Returns data type for the band specified by number

colorInterpretationName(self, bandNo: int) → str¶

colorName(self, colorInterpretation: int) → str¶

colorTable(self, bandNo: int) → List[QgsColorRampShader.ColorRampItem]¶

connectNotify()¶

copyBaseSettings(self, other: QgsRasterDataProvider)¶: Copy member variables from other raster data provider. Useful for implementation of clone() method in subclasses

create(providerKey: str, uri: str, format: str, nBands: int, type: Qgis.DataType, width: int, height: int, crs: QgsCoordinateReferenceSystem, createOptions: Iterable[str] = []) → Tuple[QgsRasterDataProvider, float]¶: Creates a new dataset with mDataSourceURI

customEvent()¶

dataTimestamp(self) → QDateTime¶: Current time stamp of data source

dataType(self, bandNo: int) → Qgis.DataType¶: Returns data type for the band specified by number

disconnectNotify()¶

dpi(self) → int¶: Returns the dpi of the output device.

extent(self) → QgsRectangle¶

getLegendGraphicFetcher(self, mapSettings: QgsMapSettings) → QgsImageFetcher¶

Get an image downloader for the raster legend

Parameters:	mapSettings – map settings for legend providers supporting

contextual legends.

Returns:	a download handler or null if the provider does not support

legend at all. Ownership of the returned object is transferred to caller.

New in version 2.8.

hasPyramids(self) → bool¶: Returns true if raster has at least one populated histogram.

htmlMetadata(self) → str¶: Get metadata in a format suitable for feeding directly into a subset of the GUI raster properties “Metadata” tab.

identify(self, point: QgsPointXY, format: QgsRaster.IdentifyFormat, boundingBox: QgsRectangle = QgsRectangle(), width: int = 0, height: int = 0, dpi: int = 96) → QgsRasterIdentifyResult¶

identifyFormatFromName(formatName: str) → QgsRaster.IdentifyFormat¶

identifyFormatLabel(format: QgsRaster.IdentifyFormat) → str¶

identifyFormatName(format: QgsRaster.IdentifyFormat) → str¶

identifyFormatToCapability(format: QgsRaster.IdentifyFormat) → QgsRasterInterface.Capability¶

initHistogram()¶

initStatistics()¶

isEditable(self) → bool¶: Checks whether the provider is in editing mode, i.e. raster write operations will be accepted. By default providers are not editable. Use setEditable() method to enable/disable editing.

See also

setEditable()

New in version 3.0.

isSignalConnected()¶

lastError(self) → str¶

Returns the verbose error text for the last error in this provider

If an operation returns 0 (e.g. draw()), this function returns the text of the error associated with the failure. Interactive users of this provider can then, for example, call a QMessageBox to display the contents.

lastErrorFormat(self) → str¶: Returns the format of the error text for the last error in this provider

lastErrorTitle(self) → str¶

Returns the caption error text for the last error in this provider

If an operation returns 0 (e.g. draw()), this function returns the text of the error associated with the failure. Interactive users of this provider can then, for example, call a QMessageBox to display the contents.

pyramidResamplingMethods(providerKey: str) → List[Tuple[str, str]]¶: Returns a list of pyramid resampling method name and label pairs for given provider

receivers()¶

reload(self) → bool¶: Reload data (data could change)

remove(self) → bool¶: Remove dataset

sender()¶

senderSignalIndex()¶

setDpi(self, dpi: int)¶: Sets the output device resolution.

setEditable(self, enabled: bool) → bool¶

Turns on/off editing mode of the provider. When in editing mode, it is possible to overwrite data of the provider using writeBlock() calls.

Returns:	true if the switch to/from editing mode was successful

Note

Only some providers support editing mode and even those may fail to turn the underlying data source into editing mode, so it is necessary to check the return value whether the operation was successful.

See also

isEditable()

New in version 3.0.

setError()¶

setInput(self, input: QgsRasterInterface) → bool¶: It makes no sense to set input on provider */

setNoDataValue(self, bandNo: int, noDataValue: float) → bool¶

Set no data value on created dataset

Parameters:	bandNo – band number noDataValue – no data value

setUseSourceNoDataValue(self, bandNo: int, use: bool)¶: Set source nodata value usage

setUserNoDataValue(self, bandNo: int, noData: object)¶

sourceDataType(self, bandNo: int) → Qgis.DataType¶: Returns source data type for the band specified by number, source data type may be shorter than dataType

sourceHasNoDataValue(self, bandNo: int) → bool¶: Return true if source band has no data value

sourceNoDataValue(self, bandNo: int) → float¶: Value representing no data value.

statusChanged¶: Emit a message to be displayed on status bar, usually used by network providers (WMS,WCS)

New in version 2.14: [signal]

stepHeight(self) → int¶: Step height for raster iterations.

See also

stepWidth()

New in version 3.0.

stepWidth(self) → int¶: Step width for raster iterations.

See also

stepHeight()

New in version 3.0.

subLayers(self) → List[str]¶: Returns the sublayers of this layer - useful for providers that manage their own layers, such as WMS *

supportsLegendGraphic(self) → bool¶: Returns whether the provider supplies a legend graphic

timerEvent()¶

timestamp(self) → QDateTime¶: Time stamp of data source in the moment when data/metadata were loaded by provider

useSourceNoDataValue(self, bandNo: int) → bool¶: Get source nodata value usage

userNoDataValues(self, bandNo: int) → object¶: Get list of user no data value ranges

userNoDataValuesContains(self, bandNo: int, value: float) → bool¶: Returns true if user no data contains value

validateCreationOptions(self, createOptions: Iterable[str], format: str) → str¶: Validates creation options for a specific dataset and destination format.

Note

used by GDAL provider only

Note

see also validateCreationOptionsFormat() in gdal provider for validating options based on format only

validatePyramidsConfigOptions(self, pyramidsFormat: QgsRaster.RasterPyramidsFormat, configOptions: Iterable[str], fileFormat: str) → str¶: Validates pyramid creation options for a specific dataset and destination format

Note

used by GDAL provider only

write(self, data: sip.voidptr, band: int, width: int, height: int, xOffset: int, yOffset: int) → bool¶

writeBlock(self, block: QgsRasterBlock, band: int, xOffset: int = 0, yOffset: int = 0) → bool¶

Writes pixel data from a raster block into the provider data source.

This will override previously stored pixel values. It is assumed that cells in the passed raster block are aligned with the cells of the data source. If raster block does not cover the whole area of the data source, only a subset of pixels covered by the raster block will be overwritten. By default, writing of raster data starts from the first cell of the raster - it is possible to set offset in pixels by specifying non-zero xOffset and yOffset values.

Writing is supported only by some data providers. Provider has to be in editing mode in order to allow write operations.