QGIS API Documentation 3.37.0-Master (fdefdf9c27f)
layer.h
Go to the documentation of this file.
1/*
2 * libpal - Automated Placement of Labels Library
3 *
4 * Copyright (C) 2008 Maxence Laurent, MIS-TIC, HEIG-VD
5 * University of Applied Sciences, Western Switzerland
6 * http://www.hes-so.ch
7 *
8 * Contact:
9 * maxence.laurent <at> heig-vd <dot> ch
10 * or
11 * eric.taillard <at> heig-vd <dot> ch
12 *
13 * This file is part of libpal.
14 *
15 * libpal is free software: you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation, either version 3 of the License, or
18 * (at your option) any later version.
19 *
20 * libpal is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with libpal. If not, see <http://www.gnu.org/licenses/>.
27 *
28 */
29
30#ifndef PAL_LAYER_H_
31#define PAL_LAYER_H_
32
33#define SIP_NO_FILE
34
35
36#include "qgis_core.h"
37#include "pal.h" // for LineArrangementFlags enum
38#include "qgsgeos.h"
41#include <QMutex>
42#include <QLinkedList>
43#include <QHash>
44#include <fstream>
45
46class QgsLabelFeature;
47
48namespace pal
49{
50
51 class FeaturePart;
52
53 class Pal;
54 class LabelInfo;
55
62 class CORE_EXPORT Layer
63 {
64 friend class Pal;
65 friend class FeaturePart;
66
67 friend class Problem;
68
69 friend class LabelPosition;
70
71 public:
72
84 Layer( QgsAbstractLabelProvider *provider, const QString &name, Qgis::LabelPlacement arrangement, double defaultPriority, bool active, bool toLabel, Pal *pal );
85
86 virtual ~Layer();
87
91 int featureCount() { return mHashtable.size(); }
92
97 std::size_t maximumPointLabelCandidates() const
98 {
99 // when an extreme number of features exist in the layer, we limit the number of candidates
100 // to avoid the engine processing endlessly...
101 const int size = mHashtable.size();
102 if ( size > 1000 )
103 return static_cast< std::size_t >( mPal->globalCandidatesLimitPoint() > 0 ? std::min( mPal->globalCandidatesLimitPoint(), 4 ) : 4 );
104 else if ( size > 500 )
105 return static_cast< std::size_t >( mPal->globalCandidatesLimitPoint() > 0 ? std::min( mPal->globalCandidatesLimitPoint(), 6 ) : 6 );
106 else if ( size > 200 )
107 return static_cast< std::size_t >( mPal->globalCandidatesLimitPoint() > 0 ? std::min( mPal->globalCandidatesLimitPoint(), 8 ) : 8 );
108 else if ( size > 100 )
109 return static_cast< std::size_t >( mPal->globalCandidatesLimitPoint() > 0 ? std::min( mPal->globalCandidatesLimitPoint(), 12 ) : 12 );
110 else
111 return static_cast< std::size_t >( std::max( mPal->globalCandidatesLimitPoint(), 0 ) );
112 }
113
118 std::size_t maximumLineLabelCandidates() const
119 {
120 // when an extreme number of features exist in the layer, we limit the number of candidates
121 // to avoid the engine processing endlessly...
122 const int size = mHashtable.size();
123 if ( size > 1000 )
124 return static_cast< std::size_t >( mPal->globalCandidatesLimitLine() > 0 ? std::min( mPal->globalCandidatesLimitLine(), 5 ) : 5 );
125 else if ( size > 500 )
126 return static_cast< std::size_t >( mPal->globalCandidatesLimitLine() > 0 ? std::min( mPal->globalCandidatesLimitLine(), 10 ) : 10 );
127 else if ( size > 200 )
128 return static_cast< std::size_t >( mPal->globalCandidatesLimitLine() > 0 ? std::min( mPal->globalCandidatesLimitLine(), 20 ) : 20 );
129 else if ( size > 100 )
130 return static_cast< std::size_t >( mPal->globalCandidatesLimitLine() > 0 ? std::min( mPal->globalCandidatesLimitLine(), 40 ) : 40 );
131 else
132 return static_cast< std::size_t >( std::max( mPal->globalCandidatesLimitLine(), 0 ) );
133 }
134
140 {
141 // when an extreme number of features exist in the layer, we limit the number of candidates
142 // to avoid the engine processing endlessly...
143 const int size = mHashtable.size();
144 if ( size > 1000 )
145 return static_cast< std::size_t >( mPal->globalCandidatesLimitPolygon() > 0 ? std::min( mPal->globalCandidatesLimitPolygon(), 5 ) : 5 );
146 else if ( size > 500 )
147 return static_cast< std::size_t >( mPal->globalCandidatesLimitPolygon() > 0 ? std::min( mPal->globalCandidatesLimitPolygon(), 15 ) : 15 );
148 else if ( size > 200 )
149 return static_cast< std::size_t >( mPal->globalCandidatesLimitPolygon() > 0 ? std::min( mPal->globalCandidatesLimitPolygon(), 20 ) : 20 );
150 else if ( size > 100 )
151 return static_cast< std::size_t >( mPal->globalCandidatesLimitPolygon() > 0 ? std::min( mPal->globalCandidatesLimitPolygon(), 25 ) : 25 );
152 else
153 return static_cast< std::size_t >( std::max( mPal->globalCandidatesLimitPolygon(), 0 ) );
154 }
155
157 QgsAbstractLabelProvider *provider() const { return mProvider; }
158
162 QString name() const { return mName; }
163
168 Qgis::LabelPlacement arrangement() const { return mArrangement; }
169
173 bool isCurved() const { return mArrangement == Qgis::LabelPlacement::Curved || mArrangement == Qgis::LabelPlacement::PerimeterCurved; }
174
180 void setArrangement( Qgis::LabelPlacement arrangement ) { mArrangement = arrangement; }
181
192 void setActive( bool active ) { mActive = active; }
193
198 bool active() const { return mActive; }
199
207 void setLabelLayer( bool toLabel ) { mLabelLayer = toLabel; }
208
213 bool labelLayer() const { return mLabelLayer; }
214
220 QgsLabelObstacleSettings::ObstacleType obstacleType() const { return mObstacleType; }
221
228 void setObstacleType( QgsLabelObstacleSettings::ObstacleType obstacleType ) { mObstacleType = obstacleType; }
229
236 void setPriority( double priority );
237
243 double priority() const { return mDefaultPriority; }
244
250 void setMergeConnectedLines( bool merge ) { mMergeLines = merge; }
251
256 bool mergeConnectedLines() const { return mMergeLines; }
257
263 void setUpsidedownLabels( Qgis::UpsideDownLabelHandling ud ) { mUpsidedownLabels = ud; }
264
269 Qgis::UpsideDownLabelHandling upsidedownLabels() const { return mUpsidedownLabels; }
270
278 void setCentroidInside( bool forceInside ) { mCentroidInside = forceInside; }
279
285 bool centroidInside() const { return mCentroidInside; }
286
296 bool registerFeature( QgsLabelFeature *label );
297
299 void joinConnectedFeatures();
300
306 int connectedFeatureId( QgsFeatureId featureId ) const;
307
309 void chopFeaturesAtRepeatDistance();
310
311 protected:
313 QString mName;
314
316 std::deque< std::unique_ptr< FeaturePart > > mFeatureParts;
317
319 QList<FeaturePart *> mObstacleParts;
320
321 std::vector< geos::unique_ptr > mGeosObstacleGeometries;
322
323 Pal *mPal = nullptr;
324
326
330 bool mCentroidInside = false;
331
334
335 bool mMergeLines = false;
336
338
340 QHash< QgsFeatureId, QgsLabelFeature *> mHashtable;
341
342 QHash< QString, QVector<FeaturePart *> > mConnectedHashtable;
343 QHash< QgsFeatureId, int > mConnectedFeaturesIds;
344
345 QMutex mMutex;
346
348 void addFeaturePart( std::unique_ptr< FeaturePart > fpart, const QString &labelText = QString() );
349
351 void addObstaclePart( FeaturePart *fpart );
352
353 };
354
355} // end namespace pal
356
357
358#endif
LabelPlacement
Placement modes which determine how label candidates are generated for a feature.
Definition: qgis.h:914
@ Curved
Arranges candidates following the curvature of a line feature. Applies to line layers only.
@ PerimeterCurved
Arranges candidates following the curvature of a polygon's boundary. Applies to polygon layers only.
UpsideDownLabelHandling
Handling techniques for upside down labels.
Definition: qgis.h:1042
@ FlipUpsideDownLabels
Upside-down labels (90 <= angle < 270) are shown upright.
The QgsAbstractLabelProvider class is an interface class.
The QgsLabelFeature class describes a feature that should be used within the labeling engine.
ObstacleType
Valid obstacle types, which affect how features within the layer will act as obstacles for labels.
@ PolygonBoundary
Avoid placing labels over boundary of polygon (prefer placing outside or completely inside polygon)
Main class to handle feature.
Definition: feature.h:65
pal labeling engine
LabelPosition is a candidate feature label position.
Definition: labelposition.h:56
A set of features which influence the labeling process.
Definition: layer.h:63
QMutex mMutex
Definition: layer.h:345
void setUpsidedownLabels(Qgis::UpsideDownLabelHandling ud)
Sets how upside down labels will be handled within the layer.
Definition: layer.h:263
QHash< QString, QVector< FeaturePart * > > mConnectedHashtable
Definition: layer.h:342
std::deque< std::unique_ptr< FeaturePart > > mFeatureParts
List of feature parts.
Definition: layer.h:316
QList< FeaturePart * > mObstacleParts
List of obstacle parts.
Definition: layer.h:319
double mDefaultPriority
Definition: layer.h:325
QString name() const
Returns the layer's name.
Definition: layer.h:162
bool mLabelLayer
Definition: layer.h:329
QgsAbstractLabelProvider * provider() const
Returns pointer to the associated provider.
Definition: layer.h:157
std::size_t maximumPolygonLabelCandidates() const
Returns the maximum number of polygon label candidates to generate for features in this layer.
Definition: layer.h:139
bool active() const
Returns whether the layer is currently active.
Definition: layer.h:198
void setObstacleType(QgsLabelObstacleSettings::ObstacleType obstacleType)
Sets the obstacle type, which controls how features within the layer act as obstacles for labels.
Definition: layer.h:228
QgsAbstractLabelProvider * mProvider
Definition: layer.h:312
Qgis::LabelPlacement arrangement() const
Returns the layer's arrangement policy.
Definition: layer.h:168
std::size_t maximumPointLabelCandidates() const
Returns the maximum number of point label candidates to generate for features in this layer.
Definition: layer.h:97
bool mergeConnectedLines() const
Returns whether connected lines will be merged before labeling.
Definition: layer.h:256
void setMergeConnectedLines(bool merge)
Sets whether connected lines should be merged before labeling.
Definition: layer.h:250
void setActive(bool active)
Sets whether the layer is currently active.
Definition: layer.h:192
QHash< QgsFeatureId, int > mConnectedFeaturesIds
Definition: layer.h:343
Qgis::UpsideDownLabelHandling upsidedownLabels() const
Returns how upside down labels are handled within the layer.
Definition: layer.h:269
void setArrangement(Qgis::LabelPlacement arrangement)
Sets the layer's arrangement policy.
Definition: layer.h:180
QHash< QgsFeatureId, QgsLabelFeature * > mHashtable
Lookup table of label features (owned by the label feature provider that created them)
Definition: layer.h:340
void setLabelLayer(bool toLabel)
Sets whether the layer will be labeled.
Definition: layer.h:207
std::vector< geos::unique_ptr > mGeosObstacleGeometries
Definition: layer.h:321
int featureCount()
Returns the number of features in layer.
Definition: layer.h:91
QString mName
Definition: layer.h:313
Qgis::LabelPlacement mArrangement
Optional flags used for some placement methods.
Definition: layer.h:333
bool labelLayer() const
Returns whether the layer will be labeled or not.
Definition: layer.h:213
bool centroidInside() const
Returns whether labels placed at the centroid of features within the layer are forced to be placed in...
Definition: layer.h:285
bool isCurved() const
Returns true if the layer has curved labels.
Definition: layer.h:173
void setCentroidInside(bool forceInside)
Sets whether labels placed at the centroid of features within the layer are forced to be placed insid...
Definition: layer.h:278
QgsLabelObstacleSettings::ObstacleType obstacleType() const
Returns the obstacle type, which controls how features within the layer act as obstacles for labels.
Definition: layer.h:220
double priority() const
Returns the layer's priority, between 0 and 1.
Definition: layer.h:243
bool mActive
Definition: layer.h:328
std::size_t maximumLineLabelCandidates() const
Returns the maximum number of line label candidates to generate for features in this layer.
Definition: layer.h:118
Main Pal labeling class.
Definition: pal.h:83
Representation of a labeling problem.
Definition: problem.h:73
qint64 QgsFeatureId
64 bit feature ids negative numbers are used for uncommitted/newly added features
Definition: qgsfeatureid.h:28