QGIS API Documentation  3.18.1-Zürich (202f1bf7e5)
qgslabelsearchtree.cpp
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1 /***************************************************************************
2  qgslabelsearchtree.cpp
3  ---------------------
4  begin : November 2010
5  copyright : (C) 2010 by Marco Hugentobler
6  email : marco dot hugentobler at sourcepole dot ch
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 #include "qgslabelsearchtree.h"
16 #include "labelposition.h"
17 
19 
21 
22 void QgsLabelSearchTree::label( const QgsPointXY &point, QList<QgsLabelPosition *> &posList ) const
23 {
24  QgsPointXY p( point );
25 
26  QList<QgsLabelPosition *> searchResults;
27  mSpatialIndex.intersects( QgsRectangle( p.x() - 0.1, p.y() - 0.1, p.x() + 0.1, p.y() + 0.1 ), [&searchResults]( const QgsLabelPosition * pos ) -> bool
28  {
29  searchResults.push_back( const_cast< QgsLabelPosition * >( pos ) );
30  return true;
31  } );
32 
33  //tolerance +-0.1 could be high in case of degree crs, so check if p is really contained in the results
34  posList.clear();
35  QList<QgsLabelPosition *>::const_iterator resultIt = searchResults.constBegin();
36  for ( ; resultIt != searchResults.constEnd(); ++resultIt )
37  {
38  if ( ( *resultIt )->labelGeometry.contains( &p ) )
39  {
40  posList.push_back( *resultIt );
41  }
42  }
43 }
44 
45 void QgsLabelSearchTree::labelsInRect( const QgsRectangle &r, QList<QgsLabelPosition *> &posList ) const
46 {
47  QList<QgsLabelPosition *> searchResults;
48  mSpatialIndex.intersects( r, [&searchResults]( const QgsLabelPosition * pos )->bool
49  {
50  searchResults.push_back( const_cast< QgsLabelPosition * >( pos ) );
51  return true;
52  } );
53 
54  posList.clear();
55  QList<QgsLabelPosition *>::const_iterator resultIt = searchResults.constBegin();
56  for ( ; resultIt != searchResults.constEnd(); ++resultIt )
57  {
58  if ( ( *resultIt )->labelGeometry.intersects( r ) )
59  {
60  posList.push_back( *resultIt );
61  }
62  }
63 }
64 
65 bool QgsLabelSearchTree::insertLabel( pal::LabelPosition *labelPos, QgsFeatureId featureId, const QString &layerName, const QString &labeltext, const QFont &labelfont, bool diagram, bool pinned, const QString &providerId, bool isUnplaced )
66 {
67  if ( !labelPos )
68  {
69  return false;
70  }
71 
72  QVector<QgsPointXY> cornerPoints;
73  cornerPoints.reserve( 4 );
74  double xMin = std::numeric_limits< double >::max();
75  double yMin = std::numeric_limits< double >::max();
76  double xMax = std::numeric_limits< double >::lowest();
77  double yMax = std::numeric_limits< double >::lowest();
78  for ( int i = 0; i < 4; ++i )
79  {
80  // we have to transform the bounding box to convert pre-rotated label positions back to real world locations
81  QPointF res = mTransform.map( QPointF( labelPos->getX( i ), labelPos->getY( i ) ) );
82  cornerPoints.push_back( QgsPointXY( res ) );
83  xMin = std::min( xMin, res.x() );
84  xMax = std::max( xMax, res.x() );
85  yMin = std::min( yMin, res.y() );
86  yMax = std::max( yMax, res.y() );
87  }
88 
89  const QgsRectangle bounds( xMin, yMin, xMax, yMax );
90  QgsGeometry labelGeometry( QgsGeometry::fromPolygonXY( QVector<QgsPolylineXY>() << cornerPoints ) );
91  std::unique_ptr< QgsLabelPosition > newEntry = qgis::make_unique< QgsLabelPosition >( featureId, labelPos->getAlpha() + mMapSettings.rotation(), cornerPoints, bounds,
92  labelPos->getWidth(), labelPos->getHeight(), layerName, labeltext, labelfont, labelPos->getUpsideDown(), diagram, pinned, providerId, labelGeometry, isUnplaced );
93  mSpatialIndex.insert( newEntry.get(), bounds );
94  mOwnedPositions.emplace_back( std::move( newEntry ) );
95 
96  if ( pal::LabelPosition *next = labelPos->nextPart() )
97  {
98  return insertLabel( next, featureId, layerName, labeltext, labelfont, diagram, pinned, providerId, isUnplaced );
99  }
100  return true;
101 }
102 
104 {
105  mMapSettings = settings;
106 
107  if ( !qgsDoubleNear( mMapSettings.rotation(), 0.0 ) )
108  {
109  // build a transform to convert points from real world to pre-rotated label positions
110  const QgsPointXY center = mMapSettings.visibleExtent().center();
111  mTransform = QTransform::fromTranslate( center.x(), center.y() );
112  mTransform.rotate( mMapSettings.rotation() );
113  mTransform.translate( -center.x(), -center.y() );
114  }
115  else
116  {
117  mTransform = QTransform();
118  }
119 }
120 
121 
123 {
124 
125 }
bool intersects(const QgsRectangle &bounds, const std::function< bool(T *data)> &callback) const
Performs an intersection check against the index, for data intersecting the specified bounds.
bool insert(T *data, const QgsRectangle &bounds)
Inserts new data into the spatial index, with the specified bounds.
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:124
static QgsGeometry fromPolygonXY(const QgsPolygonXY &polygon)
Creates a new geometry from a QgsPolygon.
Represents the calculated placement of a map label.
Q_DECL_DEPRECATED void clear()
Removes and deletes all the entries.
QgsLabelSearchTree()
Constructor for QgsLabelSearchTree.
void label(const QgsPointXY &p, QList< QgsLabelPosition * > &posList) const
Returns label position(s) at a given point.
void labelsInRect(const QgsRectangle &r, QList< QgsLabelPosition * > &posList) const
Returns label position(s) in given rectangle.
bool insertLabel(pal::LabelPosition *labelPos, QgsFeatureId featureId, const QString &layerName, const QString &labeltext, const QFont &labelfont, bool diagram=false, bool pinned=false, const QString &providerId=QString(), bool isUnplaced=false)
Inserts label position.
void setMapSettings(const QgsMapSettings &settings)
Sets the map settings associated with the labeling run.
The QgsMapSettings class contains configuration for rendering of the map.
QgsRectangle visibleExtent() const
Returns the actual extent derived from requested extent that takes takes output image size into accou...
double rotation() const
Returns the rotation of the resulting map image, in degrees clockwise.
A class to represent a 2D point.
Definition: qgspointxy.h:44
double y
Definition: qgspointxy.h:48
Q_GADGET double x
Definition: qgspointxy.h:47
A rectangle specified with double values.
Definition: qgsrectangle.h:42
QgsPointXY center() const SIP_HOLDGIL
Returns the center point of the rectangle.
Definition: qgsrectangle.h:230
LabelPosition is a candidate feature label position.
Definition: labelposition.h:56
double getAlpha() const
Returns the angle to rotate text (in rad).
double getHeight() const
double getWidth() const
LabelPosition * nextPart() const
Returns the next part of this label position (i.e.
double getX(int i=0) const
Returns the down-left x coordinate.
double getY(int i=0) const
Returns the down-left y coordinate.
bool getUpsideDown() const
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:316
qint64 QgsFeatureId
64 bit feature ids negative numbers are used for uncommitted/newly added features
Definition: qgsfeatureid.h:28