QGIS API Documentation  3.20.0-Odense (decaadbb31)
qgsvectorlayerlabelprovider.cpp
Go to the documentation of this file.
1 /***************************************************************************
2  qgsvectorlayerlabelprovider.cpp
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 
17 
18 #include "qgsgeometry.h"
19 #include "qgslabelsearchtree.h"
20 #include "qgspallabeling.h"
21 #include "qgstextlabelfeature.h"
22 #include "qgsvectorlayer.h"
24 #include "qgsrenderer.h"
25 #include "qgspolygon.h"
26 #include "qgslinestring.h"
27 #include "qgsmultipolygon.h"
28 #include "qgslogger.h"
30 #include "qgsmaskidprovider.h"
31 #include "qgstextcharacterformat.h"
32 #include "qgstextfragment.h"
33 #include "qgslabelingresults.h"
34 
35 #include "feature.h"
36 #include "labelposition.h"
37 #include "callouts/qgscallout.h"
38 #include "qgssymbol.h"
39 #include "qgsmarkersymbol.h"
40 
41 #include "pal/layer.h"
42 
43 #include <QPicture>
44 #include <QTextDocument>
45 #include <QTextFragment>
46 
47 using namespace pal;
48 
49 QgsVectorLayerLabelProvider::QgsVectorLayerLabelProvider( QgsVectorLayer *layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings, const QString &layerName )
50  : QgsAbstractLabelProvider( layer, providerId )
51  , mSettings( settings ? * settings : QgsPalLayerSettings() ) // TODO: all providers should have valid settings?
52  , mLayerGeometryType( layer->geometryType() )
53  , mRenderer( layer->renderer() )
54  , mFields( layer->fields() )
55  , mCrs( layer->crs() )
56 {
57  mName = layerName.isEmpty() ? layer->id() : layerName;
58 
59  if ( withFeatureLoop )
60  {
61  mSource = std::make_unique<QgsVectorLayerFeatureSource>( layer );
62  }
63 
64  init();
65 }
66 
67 QgsVectorLayerLabelProvider::QgsVectorLayerLabelProvider( QgsWkbTypes::GeometryType geometryType, const QgsFields &fields, const QgsCoordinateReferenceSystem &crs, const QString &providerId, const QgsPalLayerSettings *settings, QgsMapLayer *layer, const QString &layerName )
68  : QgsAbstractLabelProvider( layer, providerId )
69  , mSettings( settings ? * settings : QgsPalLayerSettings() ) // TODO: all providers should have valid settings?
70  , mLayerGeometryType( geometryType )
71  , mRenderer( nullptr )
72  , mFields( fields )
73  , mCrs( crs )
74 {
75  mName = layerName.isEmpty() ? layer->id() : layerName;
76 
77  init();
78 }
79 
81 {
83  mFlags = Flags();
84  if ( mSettings.drawLabels )
85  mFlags |= DrawLabels;
86  if ( mSettings.displayAll )
92 
93  mPriority = 1 - mSettings.priority / 10.0; // convert 0..10 --> 1..0
94 
96  {
97  //override obstacle type to treat any intersection of a label with the point symbol as a high cost conflict
99  }
100  else
101  {
103  }
104 
106 }
107 
108 
110 {
111  qDeleteAll( mLabels );
112 }
113 
114 
115 bool QgsVectorLayerLabelProvider::prepare( QgsRenderContext &context, QSet<QString> &attributeNames )
116 {
117  const QgsMapSettings &mapSettings = mEngine->mapSettings();
118 
119  return mSettings.prepare( context, attributeNames, mFields, mapSettings, mCrs );
120 }
121 
123 {
125  mSettings.startRender( context );
126 }
127 
129 {
131  mSettings.stopRender( context );
132 }
133 
135 {
136  if ( !mSource )
137  {
138  // we have created the provider with "own feature loop" == false
139  // so it is assumed that prepare() has been already called followed by registerFeature() calls
140  return mLabels;
141  }
142 
143  QSet<QString> attrNames;
144  if ( !prepare( ctx, attrNames ) )
145  return QList<QgsLabelFeature *>();
146 
147  if ( mRenderer )
148  mRenderer->startRender( ctx, mFields );
149 
150  QgsRectangle layerExtent = ctx.extent();
153 
154  QgsFeatureRequest request;
155  request.setFilterRect( layerExtent );
156  request.setSubsetOfAttributes( attrNames, mFields );
157  QgsFeatureIterator fit = mSource->getFeatures( request );
158 
160  ctx.expressionContext().appendScope( symbolScope );
161  QgsFeature fet;
162  while ( fit.nextFeature( fet ) )
163  {
164  QgsGeometry obstacleGeometry;
165  const QgsSymbol *symbol = nullptr;
166  if ( mRenderer )
167  {
168  QgsSymbolList symbols = mRenderer->originalSymbolsForFeature( fet, ctx );
169  if ( !symbols.isEmpty() && fet.geometry().type() == QgsWkbTypes::PointGeometry )
170  {
171  //point feature, use symbol bounds as obstacle
172  obstacleGeometry = QgsVectorLayerLabelProvider::getPointObstacleGeometry( fet, ctx, symbols );
173  }
174  if ( !symbols.isEmpty() )
175  {
176  symbol = symbols.at( 0 );
177  symbolScope = QgsExpressionContextUtils::updateSymbolScope( symbol, symbolScope );
178  }
179  }
180  ctx.expressionContext().setFeature( fet );
181  registerFeature( fet, ctx, obstacleGeometry, symbol );
182  }
183 
184  if ( ctx.expressionContext().lastScope() == symbolScope )
185  delete ctx.expressionContext().popScope();
186 
187  if ( mRenderer )
188  mRenderer->stopRender( ctx );
189 
190  return mLabels;
191 }
192 
193 void QgsVectorLayerLabelProvider::registerFeature( const QgsFeature &feature, QgsRenderContext &context, const QgsGeometry &obstacleGeometry, const QgsSymbol *symbol )
194 {
195  QgsLabelFeature *label = nullptr;
196 
197  mSettings.registerFeature( feature, context, &label, obstacleGeometry, symbol );
198  if ( label )
199  mLabels << label;
200 }
201 
203 {
204  if ( !fet.hasGeometry() || fet.geometry().type() != QgsWkbTypes::PointGeometry )
205  return QgsGeometry();
206 
207  bool isMultiPoint = fet.geometry().constGet()->nCoordinates() > 1;
208  std::unique_ptr< QgsAbstractGeometry > obstacleGeom;
209  if ( isMultiPoint )
210  obstacleGeom = std::make_unique< QgsMultiPolygon >();
211 
212  // for each point
213  for ( int i = 0; i < fet.geometry().constGet()->nCoordinates(); ++i )
214  {
215  QRectF bounds;
216  QgsPoint p = fet.geometry().constGet()->vertexAt( QgsVertexId( i, 0, 0 ) );
217  double x = p.x();
218  double y = p.y();
219  double z = 0; // dummy variable for coordinate transforms
220 
221  //transform point to pixels
222  if ( context.coordinateTransform().isValid() )
223  {
224  try
225  {
226  context.coordinateTransform().transformInPlace( x, y, z );
227  }
228  catch ( QgsCsException & )
229  {
230  return QgsGeometry();
231  }
232  }
233  context.mapToPixel().transformInPlace( x, y );
234 
235  QPointF pt( x, y );
236  const auto constSymbols = symbols;
237  for ( QgsSymbol *symbol : constSymbols )
238  {
239  if ( symbol->type() == Qgis::SymbolType::Marker )
240  {
241  if ( bounds.isValid() )
242  bounds = bounds.united( static_cast< QgsMarkerSymbol * >( symbol )->bounds( pt, context, fet ) );
243  else
244  bounds = static_cast< QgsMarkerSymbol * >( symbol )->bounds( pt, context, fet );
245  }
246  }
247 
248  //convert bounds to a geometry
249  QVector< double > bX;
250  bX << bounds.left() << bounds.right() << bounds.right() << bounds.left();
251  QVector< double > bY;
252  bY << bounds.top() << bounds.top() << bounds.bottom() << bounds.bottom();
253  std::unique_ptr< QgsLineString > boundLineString = std::make_unique< QgsLineString >( bX, bY );
254 
255  //then transform back to map units
256  //TODO - remove when labeling is refactored to use screen units
257  for ( int i = 0; i < boundLineString->numPoints(); ++i )
258  {
259  QgsPointXY point = context.mapToPixel().toMapCoordinates( static_cast<int>( boundLineString->xAt( i ) ),
260  static_cast<int>( boundLineString->yAt( i ) ) );
261  boundLineString->setXAt( i, point.x() );
262  boundLineString->setYAt( i, point.y() );
263  }
264  if ( context.coordinateTransform().isValid() )
265  {
266  try
267  {
268  boundLineString->transform( context.coordinateTransform(), QgsCoordinateTransform::ReverseTransform );
269  }
270  catch ( QgsCsException & )
271  {
272  return QgsGeometry();
273  }
274  }
275  boundLineString->close();
276 
277  if ( context.coordinateTransform().isValid() )
278  {
279  // coordinate transforms may have resulted in nan coordinates - if so, strip these out
280  boundLineString->filterVertices( []( const QgsPoint & point )->bool
281  {
282  return std::isfinite( point.x() ) && std::isfinite( point.y() );
283  } );
284  if ( !boundLineString->isRing() )
285  return QgsGeometry();
286  }
287 
288  std::unique_ptr< QgsPolygon > obstaclePolygon = std::make_unique< QgsPolygon >();
289  obstaclePolygon->setExteriorRing( boundLineString.release() );
290 
291  if ( isMultiPoint )
292  {
293  static_cast<QgsMultiPolygon *>( obstacleGeom.get() )->addGeometry( obstaclePolygon.release() );
294  }
295  else
296  {
297  obstacleGeom = std::move( obstaclePolygon );
298  }
299  }
300 
301  return QgsGeometry( std::move( obstacleGeom ) );
302 }
303 
305 {
306  if ( !mSettings.drawLabels )
307  return;
308 
309  // render callout
311  {
312  drawCallout( context, label );
313  }
314 }
315 
316 void QgsVectorLayerLabelProvider::drawCallout( QgsRenderContext &context, pal::LabelPosition *label ) const
317 {
318  bool enabled = mSettings.callout()->enabled();
320  {
321  context.expressionContext().setOriginalValueVariable( enabled );
323  }
324  if ( enabled )
325  {
326  QgsMapToPixel xform = context.mapToPixel();
327  xform.setMapRotation( 0, 0, 0 );
328  QPointF outPt = xform.transform( label->getX(), label->getY() ).toQPointF();
329  QgsPointXY outPt2 = xform.transform( label->getX() + label->getWidth(), label->getY() + label->getHeight() );
330  QRectF rect( outPt.x(), outPt.y(), outPt2.x() - outPt.x(), outPt2.y() - outPt.y() );
331 
333  g.transform( xform.transform() );
334  QgsCallout::QgsCalloutContext calloutContext;
335  calloutContext.allFeaturePartsLabeled = label->getFeaturePart()->feature()->labelAllParts();
336  calloutContext.originalFeatureCrs = label->getFeaturePart()->feature()->originalFeatureCrs();
337  mSettings.callout()->render( context, rect, label->getAlpha() * 180 / M_PI, g, calloutContext );
338 
339  const QList< QgsCalloutPosition > renderedPositions = calloutContext.positions();
340 
341  for ( QgsCalloutPosition position : renderedPositions )
342  {
343  position.layerID = mLayerId;
344  position.featureId = label->getFeaturePart()->featureId();
345  position.providerID = mProviderId;
346  mEngine->results()->mLabelSearchTree->insertCallout( position );
347  }
348  }
349 }
350 
352 {
353  if ( !mSettings.drawLabels )
354  return;
355 
356  QgsTextLabelFeature *lf = dynamic_cast<QgsTextLabelFeature *>( label->getFeaturePart()->feature() );
357 
358  // Copy to temp, editable layer settings
359  // these settings will be changed by any data defined values, then used for rendering label components
360  // settings may be adjusted during rendering of components
361  QgsPalLayerSettings tmpLyr( mSettings );
362 
363  // apply any previously applied data defined settings for the label
364  const QMap< QgsPalLayerSettings::Property, QVariant > &ddValues = lf->dataDefinedValues();
365 
366  //font
367  QFont dFont = lf->definedFont();
368  QgsDebugMsgLevel( QStringLiteral( "PAL font tmpLyr: %1, Style: %2" ).arg( tmpLyr.format().font().toString(), tmpLyr.format().font().styleName() ), 4 );
369  QgsDebugMsgLevel( QStringLiteral( "PAL font definedFont: %1, Style: %2" ).arg( dFont.toString(), dFont.styleName() ), 4 );
370 
371  QgsTextFormat format = tmpLyr.format();
372  format.setFont( dFont );
373 
374  // size has already been calculated and stored in the defined font - this calculated size
375  // is in pixels
376  format.setSize( dFont.pixelSize() );
378  tmpLyr.setFormat( format );
379 
381  {
382  //calculate font alignment based on label quadrant
383  switch ( label->getQuadrant() )
384  {
385  case LabelPosition::QuadrantAboveLeft:
386  case LabelPosition::QuadrantLeft:
387  case LabelPosition::QuadrantBelowLeft:
389  break;
390  case LabelPosition::QuadrantAbove:
391  case LabelPosition::QuadrantOver:
392  case LabelPosition::QuadrantBelow:
394  break;
395  case LabelPosition::QuadrantAboveRight:
396  case LabelPosition::QuadrantRight:
397  case LabelPosition::QuadrantBelowRight:
399  break;
400  }
401  }
402 
403  // update tmpLyr with any data defined text style values
404  QgsPalLabeling::dataDefinedTextStyle( tmpLyr, ddValues );
405 
406  // update tmpLyr with any data defined text buffer values
407  QgsPalLabeling::dataDefinedTextBuffer( tmpLyr, ddValues );
408 
409  // update tmpLyr with any data defined text mask values
410  QgsPalLabeling::dataDefinedTextMask( tmpLyr, ddValues );
411 
412  // update tmpLyr with any data defined text formatting values
413  QgsPalLabeling::dataDefinedTextFormatting( tmpLyr, ddValues );
414 
415  // update tmpLyr with any data defined shape background values
416  QgsPalLabeling::dataDefinedShapeBackground( tmpLyr, ddValues );
417 
418  // update tmpLyr with any data defined drop shadow values
419  QgsPalLabeling::dataDefinedDropShadow( tmpLyr, ddValues );
420 
421  // Render the components of a label in reverse order
422  // (backgrounds -> text)
423 
424  // render callout
426  {
427  drawCallout( context, label );
428  }
429 
431  {
432  QgsTextFormat format = tmpLyr.format();
433 
434  if ( tmpLyr.format().background().enabled() && tmpLyr.format().background().type() != QgsTextBackgroundSettings::ShapeMarkerSymbol ) // background shadows not compatible with marker symbol backgrounds
435  {
437  }
438  else if ( tmpLyr.format().buffer().enabled() )
439  {
441  }
442  else
443  {
445  }
446 
447  tmpLyr.setFormat( format );
448  }
449 
450  if ( tmpLyr.format().background().enabled() )
451  {
452  drawLabelPrivate( label, context, tmpLyr, QgsTextRenderer::Background );
453  }
454 
455  if ( tmpLyr.format().buffer().enabled() )
456  {
457  drawLabelPrivate( label, context, tmpLyr, QgsTextRenderer::Buffer );
458  }
459 
460  drawLabelPrivate( label, context, tmpLyr, QgsTextRenderer::Text );
461 
462  // add to the results
463  QString labeltext = label->getFeaturePart()->feature()->labelText();
464  mEngine->results()->mLabelSearchTree->insertLabel( label, label->getFeaturePart()->featureId(), mLayerId, labeltext, dFont, false, lf->hasFixedPosition(), mProviderId );
465 }
466 
468 {
469  QgsTextLabelFeature *lf = dynamic_cast<QgsTextLabelFeature *>( label->getFeaturePart()->feature() );
470 
471  QgsTextFormat format = mSettings.format();
472  if ( mSettings.drawLabels
475  {
476  QgsPalLayerSettings tmpLyr( mSettings );
477  format = tmpLyr.format();
479  tmpLyr.setFormat( format );
480  drawLabelPrivate( label, context, tmpLyr, QgsTextRenderer::Text );
481  }
482 
483  // add to the results
484  QString labeltext = label->getFeaturePart()->feature()->labelText();
485  mEngine->results()->mLabelSearchTree->insertLabel( label, label->getFeaturePart()->featureId(), mLayerId, labeltext, format.font(), false, lf->hasFixedPosition(), mProviderId, true );
486 }
487 
489 {
490  // NOTE: this is repeatedly called for multi-part labels
491  QPainter *painter = context.painter();
492 
493  // features are pre-rotated but not scaled/translated,
494  // so we only disable rotation here. Ideally, they'd be
495  // also pre-scaled/translated, as suggested here:
496  // https://github.com/qgis/QGIS/issues/20071
497  QgsMapToPixel xform = context.mapToPixel();
498  xform.setMapRotation( 0, 0, 0 );
499 
500  QPointF outPt = xform.transform( label->getX(), label->getY() ).toQPointF();
501 
502  if ( mEngine->engineSettings().testFlag( QgsLabelingEngineSettings::DrawLabelRectOnly ) ) // TODO: this should get directly to labeling engine
503  {
504  //debugging rect
505  if ( drawType != QgsTextRenderer::Text )
506  return;
507 
508  QgsPointXY outPt2 = xform.transform( label->getX() + label->getWidth(), label->getY() + label->getHeight() );
509  QRectF rect( 0, 0, outPt2.x() - outPt.x(), outPt2.y() - outPt.y() );
510  painter->save();
511  painter->setRenderHint( QPainter::Antialiasing, false );
512  painter->translate( QPointF( outPt.x(), outPt.y() ) );
513  painter->rotate( -label->getAlpha() * 180 / M_PI );
514 
515  if ( label->conflictsWithObstacle() )
516  {
517  painter->setBrush( QColor( 255, 0, 0, 100 ) );
518  painter->setPen( QColor( 255, 0, 0, 150 ) );
519  }
520  else
521  {
522  painter->setBrush( QColor( 0, 255, 0, 100 ) );
523  painter->setPen( QColor( 0, 255, 0, 150 ) );
524  }
525 
526  painter->drawRect( rect );
527  painter->restore();
528 
529  if ( label->nextPart() )
530  drawLabelPrivate( label->nextPart(), context, tmpLyr, drawType, dpiRatio );
531 
532  return;
533  }
534 
535  QgsTextRenderer::Component component;
536  component.dpiRatio = dpiRatio;
537  component.origin = outPt;
538  component.rotation = label->getAlpha();
539 
540  if ( drawType == QgsTextRenderer::Background )
541  {
542  // get rotated label's center point
543  QPointF centerPt( outPt );
544  QgsPointXY outPt2 = xform.transform( label->getX() + label->getWidth() / 2,
545  label->getY() + label->getHeight() / 2 );
546 
547  double xc = outPt2.x() - outPt.x();
548  double yc = outPt2.y() - outPt.y();
549 
550  double angle = -component.rotation;
551  double xd = xc * std::cos( angle ) - yc * std::sin( angle );
552  double yd = xc * std::sin( angle ) + yc * std::cos( angle );
553 
554  centerPt.setX( centerPt.x() + xd );
555  centerPt.setY( centerPt.y() + yd );
556 
557  component.center = centerPt;
558 
559  // convert label size to render units
560  double labelWidthPx = context.convertToPainterUnits( label->getWidth(), QgsUnitTypes::RenderMapUnits, QgsMapUnitScale() );
561  double labelHeightPx = context.convertToPainterUnits( label->getHeight(), QgsUnitTypes::RenderMapUnits, QgsMapUnitScale() );
562 
563  component.size = QSizeF( labelWidthPx, labelHeightPx );
564 
565  QgsTextRenderer::drawBackground( context, component, tmpLyr.format(), QgsTextDocument(), QgsTextRenderer::Label );
566  }
567 
568  else if ( drawType == QgsTextRenderer::Buffer
569  || drawType == QgsTextRenderer::Text )
570  {
571 
572  // TODO: optimize access :)
573  QgsTextLabelFeature *lf = static_cast<QgsTextLabelFeature *>( label->getFeaturePart()->feature() );
574  QString txt = lf->text( label->getPartId() );
575  QFontMetricsF *labelfm = lf->labelFontMetrics();
576 
577  if ( auto *lMaskIdProvider = context.maskIdProvider() )
578  {
579  int maskId = lMaskIdProvider->maskId( label->getFeaturePart()->layer()->provider()->layerId(),
580  label->getFeaturePart()->layer()->provider()->providerId() );
581  context.setCurrentMaskId( maskId );
582  }
583 
584  //add the direction symbol if needed
585  if ( !txt.isEmpty() && tmpLyr.placement == QgsPalLayerSettings::Line &&
586  tmpLyr.lineSettings().addDirectionSymbol() )
587  {
588  bool prependSymb = false;
589  QString symb = tmpLyr.lineSettings().rightDirectionSymbol();
590 
591  if ( label->getReversed() )
592  {
593  prependSymb = true;
594  symb = tmpLyr.lineSettings().leftDirectionSymbol();
595  }
596 
597  if ( tmpLyr.lineSettings().reverseDirectionSymbol() )
598  {
599  if ( symb == tmpLyr.lineSettings().rightDirectionSymbol() )
600  {
601  prependSymb = true;
602  symb = tmpLyr.lineSettings().leftDirectionSymbol();
603  }
604  else
605  {
606  prependSymb = false;
607  symb = tmpLyr.lineSettings().rightDirectionSymbol();
608  }
609  }
610 
611  switch ( tmpLyr.lineSettings().directionSymbolPlacement() )
612  {
614  prependSymb = true;
615  symb = symb + QStringLiteral( "\n" );
616  break;
617 
619  prependSymb = false;
620  symb = QStringLiteral( "\n" ) + symb;
621  break;
622 
624  break;
625  }
626 
627  if ( prependSymb )
628  {
629  txt.prepend( symb );
630  }
631  else
632  {
633  txt.append( symb );
634  }
635  }
636 
640  else if ( tmpLyr.multilineAlign == QgsPalLayerSettings::MultiRight )
644 
645  QgsTextRenderer::Component component;
646  component.origin = outPt;
647  component.rotation = label->getAlpha();
648 
649  QgsTextDocument document;
650  if ( !tmpLyr.format().allowHtmlFormatting() || tmpLyr.placement == QgsPalLayerSettings::Curved )
651  {
652  const QgsTextCharacterFormat c = lf->characterFormat( label->getPartId() );
653  const QStringList multiLineList = QgsPalLabeling::splitToLines( txt, tmpLyr.wrapChar, tmpLyr.autoWrapLength, tmpLyr.useMaxLineLengthForAutoWrap );
654  for ( const QString &line : multiLineList )
655  document.append( QgsTextBlock( QgsTextFragment( line, c ) ) );
656  }
657  else
658  {
659  document = lf->document();
660  }
661 
662  QgsTextRenderer::drawTextInternal( drawType, context, tmpLyr.format(), component, document, labelfm,
664 
665  }
666  if ( label->nextPart() )
667  drawLabelPrivate( label->nextPart(), context, tmpLyr, drawType, dpiRatio );
668 }
669 
671 {
672  return mSettings;
673 }
@ NeverShow
Never show unplaced labels, regardless of the engine setting.
@ Marker
Marker symbol.
virtual int nCoordinates() const
Returns the number of nodes contained in the geometry.
virtual QgsPoint vertexAt(QgsVertexId id) const =0
Returns the point corresponding to a specified vertex id.
The QgsAbstractLabelProvider class is an interface class.
QgsLabelObstacleSettings::ObstacleType mObstacleType
Type of the obstacle of feature geometries.
QString mName
Name of the layer.
virtual void stopRender(QgsRenderContext &context)
To be called after rendering is complete.
QgsMapLayer * layer() const
Returns the associated layer, or nullptr if no layer is associated with the provider.
QString mLayerId
Associated layer's ID, if applicable.
QgsPalLayerSettings::UpsideDownLabels mUpsidedownLabels
How to handle labels that would be upside down.
double mPriority
Default priority of labels.
const QgsLabelingEngine * mEngine
Associated labeling engine.
Flags mFlags
Flags altering drawing and registration of features.
virtual void startRender(QgsRenderContext &context)
To be called before rendering of labels begins.
@ DrawAllLabels
Whether all features will be labelled even though overlaps occur.
@ MergeConnectedLines
Whether adjacent lines (with the same label text) should be merged.
@ DrawLabels
Whether the labels should be rendered.
@ CentroidMustBeInside
Whether location of centroid must be inside of polygons.
QString layerId() const
Returns ID of associated layer, or empty string 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....
QgsPalLayerSettings::Placement mPlacement
Placement strategy.
QString mProviderId
Associated provider ID (one layer may have multiple providers, e.g. in rule-based labeling)
bool valueAsBool(int key, const QgsExpressionContext &context, bool defaultValue=false, bool *ok=nullptr) const
Calculates the current value of the property with the specified key and interprets it as an boolean.
Represents the calculated placement of a map label callout line.
Contains additional contextual information about the context in which a callout is being rendered.
Definition: qgscallout.h:245
bool allFeaturePartsLabeled
true if all parts of associated feature were labeled
Definition: qgscallout.h:248
QList< QgsCalloutPosition > positions() const
Returns the list of rendered callout positions.
Definition: qgscallout.h:282
QgsCoordinateReferenceSystem originalFeatureCrs
Contains the CRS of the original feature associated with this callout.
Definition: qgscallout.h:255
void render(QgsRenderContext &context, const QRectF &rect, const double angle, const QgsGeometry &anchor, QgsCalloutContext &calloutContext)
Renders the callout onto the specified render context.
Definition: qgscallout.cpp:148
@ OrderBelowIndividualLabels
Render callouts below their individual associated labels, some callouts may be drawn over other label...
Definition: qgscallout.h:106
@ OrderBelowAllLabels
Render callouts below all labels.
Definition: qgscallout.h:105
virtual DrawOrder drawOrder() const
Returns the desired drawing order (stacking) to use while rendering this callout.
Definition: qgscallout.cpp:143
bool enabled() const
Returns true if the the callout is enabled.
Definition: qgscallout.h:318
This class represents a coordinate reference system (CRS).
bool isShortCircuited() const
Returns true if the transform short circuits because the source and destination are equivalent.
@ ReverseTransform
Transform from destination to source CRS.
QgsRectangle transformBoundingBox(const QgsRectangle &rectangle, TransformDirection direction=ForwardTransform, bool handle180Crossover=false) const SIP_THROW(QgsCsException)
Transforms a rectangle from the source CRS to the destination CRS.
void transformInPlace(double &x, double &y, double &z, TransformDirection direction=ForwardTransform) const SIP_THROW(QgsCsException)
Transforms an array of x, y and z double coordinates in place, from the source CRS to the destination...
bool isValid() const
Returns true if the coordinate transform is valid, ie both the source and destination CRS have been s...
Custom exception class for Coordinate Reference System related exceptions.
Definition: qgsexception.h:66
Single scope for storing variables and functions for use within a QgsExpressionContext.
static QgsExpressionContextScope * updateSymbolScope(const QgsSymbol *symbol, QgsExpressionContextScope *symbolScope=nullptr)
Updates a symbol scope related to a QgsSymbol to an expression context.
QgsExpressionContextScope * popScope()
Removes the last scope from the expression context and return it.
void setOriginalValueVariable(const QVariant &value)
Sets the original value variable value for the context.
QgsExpressionContextScope * lastScope()
Returns the last scope added to the context.
void appendScope(QgsExpressionContextScope *scope)
Appends a scope to the end of the context.
void setFeature(const QgsFeature &feature)
Convenience function for setting a feature for the context.
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
virtual void stopRender(QgsRenderContext &context)
Must be called when a render cycle has finished, to allow the renderer to clean up.
virtual void startRender(QgsRenderContext &context, const QgsFields &fields)
Must be called when a new render cycle is started.
Definition: qgsrenderer.cpp:94
virtual QgsSymbolList originalSymbolsForFeature(const QgsFeature &feature, QgsRenderContext &context) const
Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbol...
This class wraps a request for features to a vector layer (or directly its vector data provider).
QgsFeatureRequest & setSubsetOfAttributes(const QgsAttributeList &attrs)
Set a subset of attributes that will be fetched.
QgsFeatureRequest & setFilterRect(const QgsRectangle &rectangle)
Sets the rectangle from which features will be taken.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
QgsGeometry geometry
Definition: qgsfeature.h:67
bool hasGeometry() const
Returns true if the feature has an associated geometry.
Definition: qgsfeature.cpp:205
Container of fields for a vector layer.
Definition: qgsfields.h:45
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:124
const QgsAbstractGeometry * constGet() const SIP_HOLDGIL
Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.
QgsWkbTypes::GeometryType type
Definition: qgsgeometry.h:127
static std::unique_ptr< QgsAbstractGeometry > fromGeos(const GEOSGeometry *geos)
Create a geometry from a GEOSGeometry.
Definition: qgsgeos.cpp:1175
The QgsLabelFeature class describes a feature that should be used within the labeling engine.
QgsCoordinateReferenceSystem originalFeatureCrs() const
Returns the original layer CRS of the feature associated with the label.
bool hasFixedPosition() const
Whether the label should use a fixed position instead of being automatically placed.
QString labelText() const
Text of the label.
GEOSGeometry * geometry() const
Gets access to the associated geometry.
bool labelAllParts() const
Returns true if all parts of the feature should be labeled.
bool reverseDirectionSymbol() const
Returns true if direction symbols should be reversed.
DirectionSymbolPlacement directionSymbolPlacement() const
Returns the placement for direction symbols.
QString leftDirectionSymbol() const
Returns the string to use for left direction arrows.
@ SymbolLeftRight
Place direction symbols on left/right of label.
@ SymbolAbove
Place direction symbols on above label.
@ SymbolBelow
Place direction symbols on below label.
QString rightDirectionSymbol() const
Returns the string to use for right direction arrows.
bool addDirectionSymbol() const
Returns true if '<' or '>' (or custom strings set via leftDirectionSymbol and rightDirectionSymbol) w...
bool mergeLines() const
Returns true if connected line features with identical label text should be merged prior to generatin...
ObstacleType type() const
Returns how features act as obstacles for labels.
bool testFlag(Flag f) const
Test whether a particular flag is enabled.
Flags flags() const
Gets flags of the labeling engine.
@ DrawUnplacedLabels
Whether to render unplaced labels as an indicator/warning for users.
@ DrawLabelRectOnly
Whether to only draw the label rect and not the actual label text (used for unit tests)
QColor unplacedLabelColor() const
Returns the color to use when rendering unplaced labels.
const QgsLabelingEngineSettings & engineSettings() const
Gets associated labeling engine settings.
const QgsMapSettings & mapSettings() const
Gets associated map settings.
QgsLabelingResults * results() const
For internal use by the providers.
Base class for all map layer types.
Definition: qgsmaplayer.h:70
QString id() const
Returns the layer's unique ID, which is used to access this layer from QgsProject.
The QgsMapSettings class contains configuration for rendering of the map.
Perform transforms between map coordinates and device coordinates.
Definition: qgsmaptopixel.h:39
void setMapRotation(double degrees, double cx, double cy)
Set map rotation in degrees (clockwise)
QgsPointXY toMapCoordinates(int x, int y) const
Transform device coordinates to map (world) coordinates.
QgsPointXY transform(const QgsPointXY &p) const
Transform the point p from map (world) coordinates to device coordinates.
Definition: qgsmaptopixel.h:82
void transformInPlace(double &x, double &y) const
Transforms device coordinates to map coordinates.
Struct for storing maximum and minimum scales for measurements in map units.
A marker symbol type, for rendering Point and MultiPoint geometries.
Multi polygon geometry collection.
static QStringList splitToLines(const QString &text, const QString &wrapCharacter, int autoWrapLength=0, bool useMaxLineLengthWhenAutoWrapping=true)
Splits a text string to a list of separate lines, using a specified wrap character (wrapCharacter).
Contains settings for how a map layer will be labeled.
void setFormat(const QgsTextFormat &format)
Sets the label text formatting settings, e.g., font settings, buffer settings, etc.
void startRender(QgsRenderContext &context)
Prepares the label settings for rendering.
bool displayAll
If true, all features will be labelled even when overlaps occur.
QString wrapChar
Wrapping character string.
QgsPropertyCollection & dataDefinedProperties()
Returns a reference to the label's property collection, used for data defined overrides.
QgsCoordinateTransform ct
bool drawLabels
Whether to draw labels for this layer.
QgsCallout * callout() const
Returns the label callout renderer, responsible for drawing label callouts.
void registerFeature(const QgsFeature &f, QgsRenderContext &context, QgsLabelFeature **labelFeature=nullptr, QgsGeometry obstacleGeometry=QgsGeometry(), const QgsSymbol *symbol=nullptr)
Register a feature for labeling.
@ Curved
Arranges candidates following the curvature of a line feature. Applies to line layers only.
@ Line
Arranges candidates parallel to a generalised line representing the feature or parallel to a polygon'...
bool centroidInside
true if centroid positioned labels must be placed inside their corresponding feature polygon,...
int priority
Label priority.
@ MultiJustify
Justified.
MultiLineAlign multilineAlign
Horizontal alignment of multi-line labels.
@ CalloutDraw
Show callout.
const QgsLabelLineSettings & lineSettings() const
Returns the label line settings, which contain settings related to how the label engine places and fo...
const QgsLabelObstacleSettings & obstacleSettings() const
Returns the label obstacle settings.
bool prepare(QgsRenderContext &context, QSet< QString > &attributeNames, const QgsFields &fields, const QgsMapSettings &mapSettings, const QgsCoordinateReferenceSystem &crs)
Prepare for registration of features.
const QgsTextFormat & format() const
Returns the label text formatting settings, e.g., font settings, buffer settings, etc.
UpsideDownLabels upsidedownLabels
Controls whether upside down labels are displayed and how they are handled.
int autoWrapLength
If non-zero, indicates that label text should be automatically wrapped to (ideally) the specified num...
Qgis::UnplacedLabelVisibility unplacedVisibility() const
Returns the layer's unplaced label visibility.
bool useMaxLineLengthForAutoWrap
If true, indicates that when auto wrapping label text the autoWrapLength length indicates the maximum...
void stopRender(QgsRenderContext &context)
Finalises the label settings after use.
A class to represent a 2D point.
Definition: qgspointxy.h:59
double y
Definition: qgspointxy.h:63
Q_GADGET double x
Definition: qgspointxy.h:62
QPointF toQPointF() const
Converts a point to a QPointF.
Definition: qgspointxy.h:169
Point geometry type, with support for z-dimension and m-values.
Definition: qgspoint.h:49
Q_GADGET double x
Definition: qgspoint.h:52
double y
Definition: qgspoint.h:53
bool isActive(int key) const override
Returns true if the collection contains an active property with the specified key.
A rectangle specified with double values.
Definition: qgsrectangle.h:42
Contains information about the context of a rendering operation.
QPainter * painter()
Returns the destination QPainter for the render operation.
QgsExpressionContext & expressionContext()
Gets the expression context.
const QgsMapToPixel & mapToPixel() const
Returns the context's map to pixel transform, which transforms between map coordinates and device coo...
void setCurrentMaskId(int id)
Stores a mask id as the "current" one.
double convertToPainterUnits(double size, QgsUnitTypes::RenderUnit unit, const QgsMapUnitScale &scale=QgsMapUnitScale()) const
Converts a size from the specified units to painter units (pixels).
QgsCoordinateTransform coordinateTransform() const
Returns the current coordinate transform for the context.
const QgsRectangle & extent() const
When rendering a map layer, calling this method returns the "clipping" extent for the layer (in the l...
const QgsMaskIdProvider * maskIdProvider() const
Returns the mask id provider attached to the context.
Abstract base class for all rendered symbols.
Definition: qgssymbol.h:38
bool enabled() const
Returns whether the background is enabled.
ShapeType type() const
Returns the type of background shape (e.g., square, ellipse, SVG).
Represents a block of text consisting of one or more QgsTextFragment objects.
Definition: qgstextblock.h:36
bool enabled() const
Returns whether the buffer is enabled.
Stores information relating to individual character formatting.
Represents a document consisting of one or more QgsTextBlock objects.
void append(const QgsTextBlock &block)
Appends a block to the document.
Container for all settings relating to text rendering.
Definition: qgstextformat.h:41
void setColor(const QColor &color)
Sets the color that text will be rendered in.
void setSize(double size)
Sets the size for rendered text.
void setFont(const QFont &font)
Sets the font used for rendering text.
QgsTextBackgroundSettings & background()
Returns a reference to the text background settings.
bool allowHtmlFormatting() const
Returns true if text should be treated as a HTML document and HTML tags should be used for formatting...
void setSizeUnit(QgsUnitTypes::RenderUnit unit)
Sets the units for the size of rendered text.
QgsTextShadowSettings & shadow()
Returns a reference to the text drop shadow settings.
QFont font() const
Returns the font used for rendering text.
QgsTextBufferSettings & buffer()
Returns a reference to the text buffer settings.
Stores a fragment of text along with formatting overrides to be used when rendering the fragment.
Class that adds extra information to QgsLabelFeature for text labels.
const QMap< QgsPalLayerSettings::Property, QVariant > & dataDefinedValues() const
Gets data-defined values.
QgsTextDocument document() const
Returns the document for the label.
QFont definedFont()
Font to be used for rendering.
QgsTextCharacterFormat characterFormat(int partId) const
Returns the character format corresponding to the specified label part.
QString text(int partId) const
Returns the text component corresponding to a specified label part.
QFontMetricsF * labelFontMetrics()
Metrics of the font for rendering.
@ AlignTop
Align to top.
TextPart
Components of text.
@ Text
Text component.
@ Buffer
Buffer component.
@ Background
Background shape.
HAlignment
Horizontal alignment.
@ AlignLeft
Left align.
@ AlignRight
Right align.
@ AlignCenter
Center align.
@ AlignJustify
Justify align.
@ Label
Label-specific draw mode.
bool enabled() const
Returns whether the shadow is enabled.
void setShadowPlacement(QgsTextShadowSettings::ShadowPlacement placement)
Sets the placement for the drop shadow.
@ ShadowBuffer
Draw shadow under buffer.
@ ShadowShape
Draw shadow under background shape.
@ ShadowLowest
Draw shadow below all text components.
@ ShadowText
Draw shadow under text.
QgsTextShadowSettings::ShadowPlacement shadowPlacement() const
Returns the placement for the drop shadow.
@ RenderPixels
Pixels.
Definition: qgsunittypes.h:171
@ RenderMapUnits
Map units.
Definition: qgsunittypes.h:170
void stopRender(QgsRenderContext &context) override
To be called after rendering is complete.
QgsCoordinateReferenceSystem mCrs
Layer's CRS.
void drawLabelPrivate(pal::LabelPosition *label, QgsRenderContext &context, QgsPalLayerSettings &tmpLyr, QgsTextRenderer::TextPart drawType, double dpiRatio=1.0) const
Internal label drawing method.
virtual bool prepare(QgsRenderContext &context, QSet< QString > &attributeNames)
Prepare for registration of features.
void drawUnplacedLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw an unplaced label.
QList< QgsLabelFeature * > mLabels
List of generated.
QgsVectorLayerLabelProvider(QgsVectorLayer *layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings, const QString &layerName=QString())
Convenience constructor to initialize the provider from given vector layer.
void startRender(QgsRenderContext &context) override
To be called before rendering of labels begins.
const QgsPalLayerSettings & settings() const
Returns the layer's settings.
static QgsGeometry getPointObstacleGeometry(QgsFeature &fet, QgsRenderContext &context, const QgsSymbolList &symbols)
Returns the geometry for a point feature which should be used as an obstacle for labels.
QgsWkbTypes::GeometryType mLayerGeometryType
Geometry type of layer.
QgsPalLayerSettings mSettings
Layer's labeling configuration.
std::unique_ptr< QgsAbstractFeatureSource > mSource
Layer's feature source.
virtual void registerFeature(const QgsFeature &feature, QgsRenderContext &context, const QgsGeometry &obstacleGeometry=QgsGeometry(), const QgsSymbol *symbol=nullptr)
Register a feature for labeling as one or more QgsLabelFeature objects stored into mLabels.
QList< QgsLabelFeature * > labelFeatures(QgsRenderContext &context) override
Returns list of label features (they are owned by the provider and thus deleted on its destruction)
void init()
initialization method - called from constructors
void drawLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw this label at the position determined by the labeling engine.
void drawLabelBackground(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw the background for the specified label.
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
QgsFeatureId featureId() const
Returns the unique ID of the feature.
Definition: feature.cpp:161
Layer * layer()
Returns the layer that feature belongs to.
Definition: feature.cpp:156
QgsLabelFeature * feature()
Returns the parent feature.
Definition: feature.h:94
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
bool getReversed() const
Quadrant getQuadrant() const
bool conflictsWithObstacle() const
Returns whether the position is marked as conflicting with an obstacle feature.
double getWidth() const
LabelPosition * nextPart() const
Returns the next part of this label position (i.e.
FeaturePart * getFeaturePart() const
Returns the feature corresponding to this labelposition.
int getPartId() const
double getX(int i=0) const
Returns the down-left x coordinate.
double getY(int i=0) const
Returns the down-left y coordinate.
QgsAbstractLabelProvider * provider() const
Returns pointer to the associated provider.
Definition: layer.h:166
double ANALYSIS_EXPORT angle(QgsPoint *p1, QgsPoint *p2, QgsPoint *p3, QgsPoint *p4)
Calculates the angle between two segments (in 2 dimension, z-values are ignored)
Definition: MathUtils.cpp:786
As part of the API refactoring and improvements which landed in the Processing API was substantially reworked from the x version This was done in order to allow much of the underlying Processing framework to be ported into c
#define QgsDebugMsgLevel(str, level)
Definition: qgslogger.h:39
QList< QgsSymbol * > QgsSymbolList
Definition: qgsrenderer.h:43
const QgsCoordinateReferenceSystem & crs
Utility class for identifying a unique vertex within a geometry.