QGIS API Documentation 3.39.0-Master (be2050b798e)
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qgsvectorlayerdiagramprovider.h
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1/***************************************************************************
2 qgsvectorlayerdiagramprovider.h
3 --------------------------------------
4 Date : September 2015
5 Copyright : (C) 2015 by Martin Dobias
6 Email : wonder dot sk at gmail dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15
16#ifndef QGSVECTORLAYERDIAGRAMPROVIDER_H
17#define QGSVECTORLAYERDIAGRAMPROVIDER_H
18
19#define SIP_NO_FILE
20
21#include "qgis_core.h"
22#include "qgslabelingengine.h"
23#include "qgslabelfeature.h"
24#include "qgsdiagramrenderer.h"
25
34{
35 public:
37 QgsDiagramLabelFeature( const QgsFeature &feature, geos::unique_ptr geometry, QSizeF size )
38 : QgsLabelFeature( feature.id(), std::move( geometry ), size )
39 {
41 }
42
43};
44
45
47
57{
58 public:
59
61 explicit QgsVectorLayerDiagramProvider( QgsVectorLayer *layer, bool ownFeatureLoop = true );
62
65
66 QList<QgsLabelFeature *> labelFeatures( QgsRenderContext &context ) override;
67
68 void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
69
70 // new virtual methods
71
78 virtual bool prepare( const QgsRenderContext &context, QSet<QString> &attributeNames );
79
92 virtual void registerFeature( QgsFeature &feature, QgsRenderContext &context, const QgsGeometry &obstacleGeometry = QgsGeometry() );
93
99 void setClipFeatureGeometry( const QgsGeometry &geometry );
100
101 protected:
103 void init();
105 QgsLabelFeature *registerDiagram( const QgsFeature &feat, QgsRenderContext &context, const QgsGeometry &obstacleGeometry = QgsGeometry() );
106
107 protected:
108
112 QgsDiagramRenderer *mDiagRenderer = nullptr;
113
114 // these are needed only if using own renderer loop
115
121 QgsAbstractFeatureSource *mSource = nullptr;
124
126 QList<QgsLabelFeature *> mFeatures;
127
128 std::unique_ptr< QgsExpressionContextScope > mLayerScope;
129
131};
132
133#endif // QGSVECTORLAYERDIAGRAMPROVIDER_H
Base class that can be used for any class that is capable of returning features.
The QgsAbstractLabelProvider class is an interface class.
virtual QList< QgsLabelFeature * > labelFeatures(QgsRenderContext &context)=0
Returns list of label features (they are owned by the provider and thus deleted on its destruction)
virtual void drawLabel(QgsRenderContext &context, pal::LabelPosition *label) const =0
Draw this label at the position determined by the labeling engine.
This class represents a coordinate reference system (CRS).
Class that adds extra information to QgsLabelFeature for labeling of diagrams.
QgsDiagramLabelFeature(const QgsFeature &feature, geos::unique_ptr geometry, QSizeF size)
Create label feature, takes ownership of the geometry instance.
Stores the settings for rendering of all diagrams for a layer.
Evaluates and returns the diagram settings relating to a diagram for a specific feature.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition qgsfeature.h:58
Container of fields for a vector layer.
Definition qgsfields.h:46
A geometry is the spatial representation of a feature.
The QgsLabelFeature class describes a feature that should be used within the labeling engine.
QSizeF size(double angle=0.0) const
Size of the label (in map units).
void setFeature(const QgsFeature &feature)
Sets the original feature associated with this label.
GEOSGeometry * geometry() const
Gets access to the associated geometry.
QgsFeature feature() const
Returns the original feature associated with this label.
QgsFeatureId id() const
Identifier of the label (unique within the parent label provider)
Contains information about the context of a rendering operation.
The QgsVectorLayerDiagramProvider class implements support for diagrams within the labeling engine.
QgsDiagramLayerSettings mSettings
Diagram layer settings.
bool mOwnsSource
Whether layer's feature source is owned.
QgsCoordinateReferenceSystem mLayerCrs
Layer's CRS.
QList< QgsLabelFeature * > mFeatures
List of generated label features (owned by the provider)
std::unique_ptr< QgsExpressionContextScope > mLayerScope
Represents a vector layer which manages a vector based data sets.
LabelPosition is a candidate feature label position.