processing options are changed
Make sure the algorithm dialogs use their own copy of algorithms,
instead of the copies owned by the processing registry. Opening
processing options triggers a full reload of providers, deleting
all existing algorithm instances from the registry first.
the original layer's feature
Otherwise python processFeature implementations may return a
modified shallow copy of this feature, which means that the
test for modifications fails, since we're comparing against
the same feature which was modified.
Fixes some python algorithms do not modify features when used
in-place mode.
Also exposes this capability to modeler - so that model algorithms
can use data defined parameters within their child algorithms.
TODO:
- tests
- setting the associated vector layer
A new widget which handles parameter values for child algorithms
within a model. Instead of the previous approach of requiring
individual widget wrappers to handle creation of a suitable
model widget, we do all this automatically for them.
This widget uses a stacked widget with a toolbutton to select
the parameter's source, instead of the previous combo box approach
(which didn't scale well for large models). I.e. users select
first whether the value is taken from a static value, a
model input, or an output from a different child algorithm. The
widget then changes appearance and behavior based on this
choice.
Additionally, a new option is present for all parameters
of using a "precalculated expression". This expression is
evaluated once before the child algorithm is executed
and used during the execution of that algorithm.
- Add abstract base class for Processing widget wrappers to c++
- Add wrapper factory interface to c++
- Make QgsProcessingGuiRegistry also register widget wrapper
factories, and be responsible for creation of new c++
processing widget wrapper instances
- Start on private c++ implementation of boolean widget wrapper,
including unit tests
When an algorithm has a distance parameter in meters/feet/etc (i.e.
non-geographic distances), show a combo box allowing choice of
unit type.
(We don't (and should never) expose this for distances in degrees --
it's up to users in this situation to choose a suitable local
projection and reproject their data to match. Refs: a recent
talk by @volaya)
