Abstract base class for objects which generate elevation profiles. More...
#include <qgsabstractprofilegenerator.h>
Public Member Functions | |
| virtual | ~QgsAbstractProfileGenerator () |
| virtual QgsFeedback * | feedback () const =0 |
Access to feedback object of the generator (may be nullptr) | |
| virtual Qgis::ProfileGeneratorFlags | flags () const |
| Returns flags which reflect how the profile generator operates. | |
| virtual bool | generateProfile (const QgsProfileGenerationContext &context=QgsProfileGenerationContext())=0 |
| Generate the profile (based on data stored in the class). | |
| virtual QString | sourceId () const =0 |
| Returns a unique identifier representing the source of the profile. | |
| virtual QgsAbstractProfileResults * | takeResults ()=0 |
| Takes results from the generator. | |
Detailed Description
Abstract base class for objects which generate elevation profiles.
The generation is typically done in a background thread, so it is necessary to keep all structures required for generating the profile away from the original profile source because it may change at any time.
Because the data needs to be copied (to avoid the need for locking), it is highly desirable to use copy-on-write where possible. This way, the overhead of copying (both memory and CPU) will be kept low. Qt containers and various Qt classes use implicit sharing.
The scenario will be:
- elevation profile job (doing preparation in the GUI thread) calls QgsAbstractProfileSource::createProfileGenerator() and gets an instance of this class. The instance is initialized at that point and should not need additional calls to the source.
- profile job (still in GUI thread) stores the generator for later use.
- profile job (in worker thread) calls QgsAbstractProfileGenerator::generateProfile()
- profile job (again in GUI thread) will check errors() and report them
- Since
- QGIS 3.26
Definition at line 415 of file qgsabstractprofilegenerator.h.
Constructor & Destructor Documentation
◆ ~QgsAbstractProfileGenerator()
|
virtualdefault |
Member Function Documentation
◆ feedback()
|
pure virtual |
Access to feedback object of the generator (may be nullptr)
Implemented in QgsMeshLayerProfileGenerator, QgsPointCloudLayerProfileGenerator, QgsRasterLayerProfileGenerator, and QgsVectorLayerProfileGenerator.
◆ flags()
|
virtual |
Returns flags which reflect how the profile generator operates.
Reimplemented in QgsPointCloudLayerProfileGenerator, and QgsRasterLayerProfileGenerator.
Definition at line 146 of file qgsabstractprofilegenerator.cpp.
◆ generateProfile()
|
pure virtual |
Generate the profile (based on data stored in the class).
Returns true if the profile was generated successfully (i.e. the generation was not canceled early).
Implemented in QgsMeshLayerProfileGenerator, QgsPointCloudLayerProfileGenerator, QgsRasterLayerProfileGenerator, and QgsVectorLayerProfileGenerator.
◆ sourceId()
|
pure virtual |
Returns a unique identifier representing the source of the profile.
For generators associated with a map layer the source ID will match the layer's QgsMapLayer::id(). Other (non-map-layer) sources will have a different unique ID with its own custom interpretation.gen
Implemented in QgsMeshLayerProfileGenerator, QgsPointCloudLayerProfileGenerator, QgsRasterLayerProfileGenerator, and QgsVectorLayerProfileGenerator.
◆ takeResults()
|
pure virtual |
Takes results from the generator.
Ownership is transferred to the caller.
Implemented in QgsMeshLayerProfileGenerator, QgsPointCloudLayerProfileGenerator, QgsRasterLayerProfileGenerator, and QgsVectorLayerProfileGenerator.
The documentation for this class was generated from the following files:
- /build/qgis-3.40.0+99sid/src/core/elevation/qgsabstractprofilegenerator.h
- /build/qgis-3.40.0+99sid/src/core/elevation/qgsabstractprofilegenerator.cpp
