Based on tickets/stackexchange posts/mailing list activity, this
seems to be a highly in demand tool which is fragile and error
prone when run via the SAGA Processing Plugin.
Port to a native tool to avoid this situation, and give a nice
optimised out-of-the-box tool.
Note that this is functionally a 1:1 clone of the SAGA tool. I've
verified that the outputs match SAGAs outputs, but any bugs
present in the SAGA implementation will also be present here.
Adds an API which an algorithm can implement to support auto-setting
parameter values. This is designed to handle the case
of eg an algorithm which does a file format translation, where
it's desirable to default the output parameter value to an input
parameter value with a different extension.
This can now be done by implementing autogenerateParameterValues
in the algorithm, eg:
def autogenerateParameterValues(self, existingParameters, changedParameter, mode):
if changedParameter == self.INPUT:
input_file = existingParameters.get(self.INPUT)
if input_file:
input_path = Path(input_file)
if input_path.exists():
# auto set output parameter to same as input but with 'qgs' extension
return {self.OUTPUT: input_path.with_suffix('.qgs').as_posix()}
return {}
Works for both toolbox and batch modes for algorithms
When a profile tool is already opened, the output of a procssing is
not added to its layer tree. This is because it relies on a
`QgsLayerTreeRegistryBridge`. Indeed, `QgsLayerTreeRegistryBridge`
listens to the `QgsProject::legendLayersAdded()` signal in order to
update the elevation profile tree view. However this signal is not
triggered by the current logic in `Postprocessing.py`because
`QgsProject::addMaplayer` is called with `addToLegend` set to
False. Then, the layer is added to the tree by calling
`QgsLayerTreeGroup::insertChildNode`.
This issue is fixed by creating a
`QgsLayerTreeRegistryBridge::InsertionPoint` to set the insertion
point and then calling `QgsProject::addMaplayer` with `addToLegend`
set to True.
