Instead of just silently return "0", which is misleading and
can result in data corruption/incorrect analysis results. Better
to be safe and force callers to handle transformation errors
appropriately.
In this case we:
- raise QgsProcessingExceptions when the failed measurement is coming
from a processing tool, so that the user is forced to deal with the
issue and we aren't providing meaningless/misleading measurements
- report evaluation errors if the measurement is coming from a
QGIS expression, so the user must appropriately handle the situation
- for all other cases we currently just write a console error and
maintain the current behavior of treating the measurement length
as 0. TODO notes have been added to handle this cases better.
For multi-line labels, this allows use of either:
- HTML <p align="xxx"> attributes
- CSS "text-align: xxx"
- HTML <center>some text</center> tags
Supported alignments are left, right, center and justify
Horizontal alignment can be used in all contexts where
HTML text is rendered, EXCEPT for curved labels (since they
are restricted to single-line text)
Sponsored by City of Freiburg im Breisgau
...and other places HTML text formatting is accepted.
This allows use of CSS "word-spacing: 12" to increase the word
spacing in a section of HTML text. The word spacing is always
treated as being in point units.
See https://github.com/qgis/QGIS-Enhancement-Proposals/issues/299
Implements the API framework for setting advanced labeling engine
rules for a project, and implements 4 initial rule types:
- QgsLabelingEngineRuleMinimumDistanceLabelToFeature: prevents labels
being placed too *close* to features from a different layer
- QgsLabelingEngineRuleMaximumDistanceLabelToFeature: prevents labels
being placed too *far* from features from a different layer
- QgsLabelingEngineRuleMinimumDistanceLabelToLabel: prevents labels
being placed too close to labels from a different layer
- QgsLabelingEngineRuleAvoidLabelOverlapWithFeature: prevents labels
being placed overlapping features from a different layer
(note that the first 3 rules require a build based on GEOS >= 3.10,
they are not available for older GEOS builds)
Also implements a registry for storing available rule classes,
and serialization of rules and configuration in QGIS projects
`surfaceToPolygon` is only useful for `QgsCurvePolygon` which inherits
from `QgsSurface`. The next commit will introduce
`QgsPolyhedralSurface` which also inherits from `QgsSurface`. For
`QgsPolyhedralSurface`, it does not make sense to have
`surfaceToPolygon`.
By moving `surfaceToPolygon` definition in `QgsCurvePolygon` this
allows to keep the functionality.
