Class: QgsProcessingParameterDistance

A double numeric parameter for distance values.

Linked to a source layer or CRS parameter to determine what units the distance values are in.

The number of decimals places shown in a distance parameter’s widget can be specified by setting the parameter’s metadata. For example:

param = QgsProcessingParameterDistance( 'VAL', 'Threshold')
# only show two decimal places in parameter's widgets, not 6:
param.setMetadata( {'widget_wrapper':
  { 'decimals': 2 }
})

Added in version 3.2.

Class Hierarchy

Inheritance diagram of qgis.core.QgsProcessingParameterDistance

Base classes

QgsProcessingParameterNumber

A numeric parameter for processing algorithms.

QgsProcessingParameterDefinition

Base class for the definition of processing parameters.

Methods

defaultUnit

Returns the default distance unit for the parameter.

parentParameterName

Returns the name of the parent parameter, or an empty string if this is not set.

setDefaultUnit

Sets the default distance unit for the parameter.

setParentParameterName

Sets the name of the parent layer parameter.

class qgis.core.QgsProcessingParameterDistance[source]

Bases: QgsProcessingParameterNumber

__init__(name: str | None, description: str | None = '', defaultValue: Any = None, parentParameterName: str | None = '', optional: bool = False, minValue: float = -DBL_MAX + 1, maxValue: float = DBL_MAX)

Constructor for QgsProcessingParameterDistance.

Parameters:
  • name (Optional[str])

  • description (Optional[str] = '')

  • defaultValue (Any = None)

  • parentParameterName (Optional[str] = '')

  • optional (bool = False)

  • minValue (float = -DBL_MAX+1)

  • maxValue (float = DBL_MAX)

__init__(a0: QgsProcessingParameterDistance)
Parameters:

a0 (QgsProcessingParameterDistance)

defaultUnit(self) Qgis.DistanceUnit[source]

Returns the default distance unit for the parameter.

See also

setDefaultUnit()

Added in version 3.4.3.

Return type:

Qgis.DistanceUnit

parentParameterName(self) str[source]

Returns the name of the parent parameter, or an empty string if this is not set.

Return type:

str

setDefaultUnit(self, unit: Qgis.DistanceUnit)[source]

Sets the default distance unit for the parameter.

See also

defaultUnit()

Added in version 3.4.3.

Parameters:

unit (Qgis.DistanceUnit)

setParentParameterName(self, parentParameterName: str | None)[source]

Sets the name of the parent layer parameter. Use an empty string if this is not required.

Parameters:

parentParameterName (Optional[str])