QGIS API Documentation 3.29.0-Master (ade4f0cf0f)
qgslabelsink.h
Go to the documentation of this file.
1/***************************************************************************
2 qgslabelsink.h
3 -------------------
4 begin : January 2014
5 copyright : (C) 2014 by Marco Hugentobler
6 email : marco at sourcepole dot ch
7 ***************************************************************************/
8
9/***************************************************************************
10 * *
11 * This program is free software; you can redistribute it and/or modify *
12 * it under the terms of the GNU General Public License as published by *
13 * the Free Software Foundation; either version 2 of the License, or *
14 * (at your option) any later version. *
15 * *
16 ***************************************************************************/
17
18#ifndef QGSLABELSINK_H
19#define QGSLABELSINK_H
20
21#define SIP_NO_FILE
22
25
28
38{
39 public:
40 virtual ~QgsLabelSink() = default;
41
47 virtual void drawLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings ) = 0;
48
57 virtual void drawUnplacedLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings )
58 {
59 Q_UNUSED( layerId );
60 Q_UNUSED( context )
61 Q_UNUSED( label );
62 Q_UNUSED( settings );
63 return;
64 }
65};
66
75{
76 public:
79
80 void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
81 void drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
82
83 private:
84 QgsLabelSink *mLabelSink = nullptr;
85};
86
95{
96 public:
99
104 Q_DECL_DEPRECATED void reinit( QgsVectorLayer *layer );
105
106 void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
107 void drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
108
110 QgsVectorLayerLabelProvider *createProvider( QgsVectorLayer *layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings ) override;
111
112 private:
113 QgsLabelSink *mLabelSink = nullptr;
114};
115
116
117
118#endif // QGSLABELSINK_H
QgsMapLayer * layer() const
Returns the associated layer, or nullptr if no layer is associated with the provider.
QString providerId() const
Returns provider ID - useful in case there is more than one label provider within a layer (e....
Implements a derived label provider for use with QgsLabelSink.
Definition: qgslabelsink.h:75
void drawUnplacedLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw an unplaced label.
void drawLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw this label at the position determined by the labeling engine.
QgsLabelSinkProvider(QgsVectorLayer *layer, const QString &providerId, QgsLabelSink *sink, const QgsPalLayerSettings *settings)
Creates a rule based label sink provider which will draw/register labels in sink.
Abstract base class that can be used to intercept rendered labels from a labeling / rendering job.
Definition: qgslabelsink.h:38
virtual void drawUnplacedLabel(const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings)
The drawLabel method is called for each unplaced label.
Definition: qgslabelsink.h:57
virtual void drawLabel(const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings)=0
The drawLabel method is called for each label that is being drawn.
virtual ~QgsLabelSink()=default
Contains settings for how a map layer will be labeled.
Contains information about the context of a rendering operation.
Label provider for rule based labeling.
Implements a derived label provider for rule based labels for use with QgsLabelSink.
Definition: qgslabelsink.h:95
void drawLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw this label at the position determined by the labeling engine.
Q_DECL_DEPRECATED void reinit(QgsVectorLayer *layer)
Reinitialize the subproviders with QgsLabelSinkProviders.
QgsVectorLayerLabelProvider * createProvider(QgsVectorLayer *layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings) override
Creates a QgsRuleBasedLabelSinkProvider.
void drawUnplacedLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw an unplaced label.
QgsRuleBasedLabelSinkProvider(const QgsRuleBasedLabeling &rules, QgsVectorLayer *layer, QgsLabelSink *sink)
Creates a rule based label sink provider which will draw/register labels in sink.
Rule based labeling for a vector layer.
The QgsVectorLayerLabelProvider class implements a label provider for vector layers.
const QgsPalLayerSettings & settings() const
Returns the layer's settings.
Represents a vector layer which manages a vector based data sets.
LabelPosition is a candidate feature label position.
Definition: labelposition.h:56