Subgroup: Raster
Class: QgsRasterDataProvider¶
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class
qgis.core.
QgsRasterDataProvider
¶ Bases:
qgis._core.QgsDataProvider
,qgis._core.QgsRasterInterface
QgsRasterDataProvider(uri: str, options: QgsDataProvider.ProviderOptions = QgsDataProvider.ProviderOptions()) Constructor for QgsRasterDataProvider.
The
uri
argument gives a provider-specific uri indicating the underlying data source and it’s parameters.The
options
argument specifies generic provider options.Base class for raster data providers.
Methods
appendError
bandOffset
Read band offset for raster value bandScale
Read band scale for raster value block
Read block of data using given extent and size. buildPyramidList
Returns the raster layers pyramid list. buildPyramids
Create pyramid overviews childEvent
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 customEvent
dataTimestamp
Current time stamp of data source dataType
Returns data type for the band specified by number disconnectNotify
dpi
Returns the dpi of the output device. extent
getLegendGraphicFetcher
Returns a new image downloader for the raster legend. hasPyramids
Returns true if raster has at least one populated histogram. htmlMetadata
Returns metadata in a format suitable for feeding directly into a subset of the GUI raster properties “Metadata” tab. identify
identifyFormatFromName
identifyFormatLabel
identifyFormatName
identifyFormatToCapability
initHistogram
initStatistics
isEditable
Checks whether the provider is in editing mode, i.e. isSignalConnected
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 providerCapabilities
Returns flags containing the supported capabilities of the data provider. pyramidResamplingMethods
Returns a list of pyramid resampling method name and label pairs for given provider receivers
reload
Reload data (data could change) remove
Remove dataset sender
senderSignalIndex
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 */ setNoDataValue
Set no data value on created dataset setUseSourceNoDataValue
Sets the source nodata value usage setUserNoDataValue
sourceDataType
Returns source data type for the band specified by number, source data type may be shorter than dataType sourceHasNoDataValue
Returns true if source band has no data value sourceNoDataValue
Value representing no data value. stepHeight
Step height for raster iterations. stepWidth
Step width for raster iterations. subLayers
Returns the sublayers of this layer - useful for providers that manage their own layers, such as WMS * supportsLegendGraphic
Returns whether the provider supplies a legend graphic timerEvent
timestamp
Time stamp of data source in the moment when data/metadata were loaded by provider useSourceNoDataValue
Returns the source nodata value usage userNoDataValues
Returns a 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. Signals
statusChanged
Emit a message to be displayed on status bar, usually used by network providers (WMS,WCS) Attributes
NoProviderCapabilities
ReadLayerMetadata
WriteLayerMetadata
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NoProviderCapabilities
= 0¶
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class
ProviderCapabilities
¶ Bases:
sip.wrapper
QgsRasterDataProvider.ProviderCapabilities(Union[QgsRasterDataProvider.ProviderCapabilities, QgsRasterDataProvider.ProviderCapability]) QgsRasterDataProvider.ProviderCapabilities(QgsRasterDataProvider.ProviderCapabilities)
-
class
ProviderCapability
¶ Bases:
int
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ReadLayerMetadata
= 2¶
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WriteLayerMetadata
= 4¶
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appendError
()¶
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bandOffset
(self, bandNo: int) → float¶ Read band offset for raster value
New in version 2.3.
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bandScale
(self, bandNo: int) → float¶ Read band scale for raster value
New in version 2.3.
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block
(self, bandNo: int, boundingBox: QgsRectangle, width: int, height: int, feedback: QgsRasterBlockFeedback = None) → QgsRasterBlock¶ Read block of data using given extent and size.
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buildPyramidList
(self, overviewList: Iterable[int] = []) → List[QgsRasterPyramid]¶ Returns 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.
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buildPyramids
(self, pyramidList: object, resamplingMethod: str = '', format: QgsRaster.RasterPyramidsFormat = QgsRaster.PyramidsGTiff, configOptions: Iterable[str] = [], feedback: QgsRasterBlockFeedback = None) → str¶ Create pyramid overviews
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childEvent
()¶
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clone
(self) → QgsRasterInterface¶
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colorInterpretation
(self, bandNo: int) → int¶ Returns data type for the band specified by number
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colorInterpretationName
(self, bandNo: int) → str¶
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colorName
(self, colorInterpretation: int) → str¶
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colorTable
(self, bandNo: int) → List[QgsColorRampShader.ColorRampItem]¶
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connectNotify
()¶
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copyBaseSettings
(self, other: QgsRasterDataProvider)¶ Copy member variables from other raster data provider. Useful for implementation of clone() method in subclasses
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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
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customEvent
()¶
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dataTimestamp
(self) → QDateTime¶ Current time stamp of data source
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dataType
(self, bandNo: int) → Qgis.DataType¶ Returns data type for the band specified by number
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disconnectNotify
()¶
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dpi
(self) → int¶ Returns the dpi of the output device.
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extent
(self) → QgsRectangle¶
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getLegendGraphicFetcher
(self, mapSettings: QgsMapSettings) → QgsImageFetcher¶ Returns a new 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.
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hasPyramids
(self) → bool¶ Returns true if raster has at least one populated histogram.
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htmlMetadata
(self) → str¶ Returns metadata in a format suitable for feeding directly into a subset of the GUI raster properties “Metadata” tab.
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identify
(self, point: QgsPointXY, format: QgsRaster.IdentifyFormat, boundingBox: QgsRectangle = QgsRectangle(), width: int = 0, height: int = 0, dpi: int = 96) → QgsRasterIdentifyResult¶
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identifyFormatFromName
(formatName: str) → QgsRaster.IdentifyFormat¶
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identifyFormatLabel
(format: QgsRaster.IdentifyFormat) → str¶
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identifyFormatName
(format: QgsRaster.IdentifyFormat) → str¶
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identifyFormatToCapability
(format: QgsRaster.IdentifyFormat) → QgsRasterInterface.Capability¶
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initHistogram
()¶
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initStatistics
()¶
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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
New in version 3.0.
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isSignalConnected
()¶
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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.
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lastErrorFormat
(self) → str¶ Returns the format of the error text for the last error in this provider
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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.
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providerCapabilities
(self) → QgsRasterDataProvider.ProviderCapabilities¶ Returns flags containing the supported capabilities of the data provider.
New in version 3.0.
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pyramidResamplingMethods
(providerKey: str) → List[Tuple[str, str]]¶ Returns a list of pyramid resampling method name and label pairs for given provider
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receivers
()¶
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reload
(self) → bool¶ Reload data (data could change)
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remove
(self) → bool¶ Remove dataset
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sender
()¶
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senderSignalIndex
()¶
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setDpi
(self, dpi: int)¶ Sets the output device resolution.
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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
New in version 3.0.
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setError
()¶
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setNoDataValue
(self, bandNo: int, noDataValue: float) → bool¶ Set no data value on created dataset
Parameters: - bandNo – band number
- noDataValue – no data value
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setUseSourceNoDataValue
(self, bandNo: int, use: bool)¶ Sets the source nodata value usage
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setUserNoDataValue
(self, bandNo: int, noData: object)¶
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sourceDataType
(self, bandNo: int) → Qgis.DataType¶ Returns source data type for the band specified by number, source data type may be shorter than dataType
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sourceHasNoDataValue
(self, bandNo: int) → bool¶ Returns true if source band has no data value
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sourceNoDataValue
(self, bandNo: int) → float¶ Value representing no data value.
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statusChanged
¶ Emit a message to be displayed on status bar, usually used by network providers (WMS,WCS)
New in version 2.14: [signal]
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stepHeight
(self) → int¶ Step height for raster iterations.
See also
New in version 3.0.
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stepWidth
(self) → int¶ Step width for raster iterations.
See also
New in version 3.0.
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subLayers
(self) → List[str]¶ Returns the sublayers of this layer - useful for providers that manage their own layers, such as WMS *
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supportsLegendGraphic
(self) → bool¶ Returns whether the provider supplies a legend graphic
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timerEvent
()¶
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timestamp
(self) → QDateTime¶ Time stamp of data source in the moment when data/metadata were loaded by provider
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useSourceNoDataValue
(self, bandNo: int) → bool¶ Returns the source nodata value usage
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userNoDataValues
(self, bandNo: int) → object¶ Returns a list of user no data value ranges.
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userNoDataValuesContains
(self, bandNo: int, value: float) → bool¶ Returns true if user no data contains value
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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
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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
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write
(self, data: sip.voidptr, band: int, width: int, height: int, xOffset: int, yOffset: int) → bool¶
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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.
See also
Returns: true on success New in version 3.0.
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