The layer expression context (which is required for aggregate
calculation to work) was not being added to the context used
by vector layer feature iterators.
Fix#15930
Allows setting symbols other map item sizes to Map Units in Meters. This allows setting the size always in meters, regardless of what the underlying map units are (e.g. they can be it geographic degrees). The size in meters is calculated based on the current project ellipsoid setting and a projection of the distances in meters at the center of the current map extent.
The dialogs are parented to the main window, which means sip
transfers the ownership to the main window - and they are
never deleted as a result. This results in various error
messages caused by the widgets hanging around forever
and listening out for various signals they are connected to.
By initializing the prototype of the algorithm stored in the
provider we allow shortcuts like directly querying the parameter
definitions from the provider's prototype (instead of having
to create a new instance and manually initialize it first)
parameters to an algorithm
QgsProcessingAlgorithm::addParameter() has a new createOuput
argument (true by default).
If the createOutput argument is true, then a corresponding
output definition will also be created (and added to the
algorithm) where appropriate. E.g. when adding a
QgsProcessingParameterVectorDestination and createOutput is
true, then a QgsProcessingOutputVectorLayer output will be
created and added to the algorithm. There is no need to call
addOutput() to manually add a corresponding output for this
vector. If createOutput is false then this automatic output
creation will not occur.
This should simplify declaration of outputs for algorithms
as it avoids the need to manually declare these corresponding
outputs.
This partially reverts commit c7c52442f71a6a17ea1ad97e741b2b4b6d51f698.
Causes a race condition which results in random crashes while
using the categorised symbol renderer.
The intent behind the original commit is unknown
while rendering has already been started for a particular symbol instance
Relates to a random but frequent crash which occurs when using the
categorised symbol renderer - tracked down to a race condition
in which multiple concurrent calls to startRender() are performed
on a single symbol instance.
