QGIS API Documentation 3.27.0-Master (f261cc1f8b)
qgsvectorlayerlabelprovider.h
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1/***************************************************************************
2 qgsvectorlayerlabelprovider.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 QGSVECTORLAYERLABELPROVIDER_H
17#define QGSVECTORLAYERLABELPROVIDER_H
18
19#define SIP_NO_FILE
20
21#include "qgis_core.h"
22#include "qgslabelingengine.h"
23#include "qgsrenderer.h"
24#include "qgstextrenderer.h"
25#include "qgspallabeling.h"
26
29class QgsSymbol;
30
42{
43 public:
44
47 const QString &providerId,
48 bool withFeatureLoop,
49 const QgsPalLayerSettings *settings,
50 const QString &layerName = QString() );
51
54 const QgsFields &fields,
56 const QString &providerId,
57 const QgsPalLayerSettings *settings,
58 QgsMapLayer *layer,
59 const QString &layerName = QString() );
60
62
63 QList<QgsLabelFeature *> labelFeatures( QgsRenderContext &context ) override;
64
65 void drawLabelBackground( QgsRenderContext &context, pal::LabelPosition *label ) const override;
66 void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
67 void drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
68 void startRender( QgsRenderContext &context ) override;
69 void stopRender( QgsRenderContext &context ) override;
70
71 // new virtual methods
72
79 virtual bool prepare( QgsRenderContext &context, QSet<QString> &attributeNames );
80
95 virtual QList< QgsLabelFeature * > registerFeature( const QgsFeature &feature, QgsRenderContext &context, const QgsGeometry &obstacleGeometry = QgsGeometry(), const QgsSymbol *symbol = nullptr );
96
106 static QgsGeometry getPointObstacleGeometry( QgsFeature &fet, QgsRenderContext &context, const QgsSymbolList &symbols );
107
112 const QgsPalLayerSettings &settings() const;
113
120 void setFields( const QgsFields &fields ) { mFields = fields; }
121
122 protected:
124 void init();
126 void drawLabelPrivate( pal::LabelPosition *label, QgsRenderContext &context, QgsPalLayerSettings &tmpLyr, QgsTextRenderer::TextPart drawType, double dpiRatio = 1.0 ) const;
127
128 protected:
133
134 QgsFeatureRenderer *mRenderer = nullptr;
135
136 // these are needed only if using own renderer loop
137
143 std::unique_ptr<QgsAbstractFeatureSource> mSource;
144
146 QList<QgsLabelFeature *> mLabels;
147
148 private:
149
150 friend class TestQgsLabelingEngine;
151 void drawCallout( QgsRenderContext &context, pal::LabelPosition *label ) const;
152};
153
154#endif // QGSVECTORLAYERLABELPROVIDER_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 drawUnplacedLabel(QgsRenderContext &context, pal::LabelPosition *label) const
Draw an unplaced label.
virtual void stopRender(QgsRenderContext &context)
To be called after rendering is complete.
virtual void drawLabel(QgsRenderContext &context, pal::LabelPosition *label) const =0
Draw this label at the position determined by the labeling engine.
virtual void drawLabelBackground(QgsRenderContext &context, pal::LabelPosition *label) const
Draw the background for the specified label.
virtual void startRender(QgsRenderContext &context)
To be called before rendering of labels begins.
This class represents a coordinate reference system (CRS).
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
Container of fields for a vector layer.
Definition: qgsfields.h:45
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:125
Base class for all map layer types.
Definition: qgsmaplayer.h:73
Contains settings for how a map layer will be labeled.
Contains information about the context of a rendering operation.
Abstract base class for all rendered symbols.
Definition: qgssymbol.h:93
TextPart
Components of text.
The QgsVectorLayerLabelProvider class implements a label provider for vector layers.
QgsCoordinateReferenceSystem mCrs
Layer's CRS.
QList< QgsLabelFeature * > mLabels
List of generated.
QgsWkbTypes::GeometryType mLayerGeometryType
Geometry type of layer.
QgsPalLayerSettings mSettings
Layer's labeling configuration.
std::unique_ptr< QgsAbstractFeatureSource > mSource
Layer's feature source.
void setFields(const QgsFields &fields)
Sets fields of this label provider.
Represents a vector layer which manages a vector based data sets.
GeometryType
The geometry types are used to group QgsWkbTypes::Type in a coarse way.
Definition: qgswkbtypes.h:141
LabelPosition is a candidate feature label position.
Definition: labelposition.h:56
QList< QgsSymbol * > QgsSymbolList
Definition: qgsrenderer.h:44
const QgsCoordinateReferenceSystem & crs