QGIS API Documentation  3.21.0-Master (5b68dc587e)
qgsvectorfieldsymbollayer.cpp
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1 /***************************************************************************
2  qgsvectorfieldsymbollayer.cpp
3  -----------------------------
4  begin : Octorer 25, 2011
5  copyright : (C) 2011 by Marco Hugentobler
6  email : marco dot hugentobler 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 
19 #include "qgsvectorlayer.h"
20 #include "qgsunittypes.h"
21 #include "qgssymbollayerutils.h"
22 #include "qgslinesymbol.h"
23 
25 {
26  setSubSymbol( new QgsLineSymbol() );
27 }
28 
30 
32 {
34  mDistanceUnit = unit;
35 }
36 
38 {
39  if ( QgsMarkerSymbolLayer::outputUnit() == mDistanceUnit )
40  {
41  return mDistanceUnit;
42  }
44 }
45 
47 {
49  mDistanceMapUnitScale = scale;
50 }
51 
53 {
54  if ( QgsMarkerSymbolLayer::mapUnitScale() == mDistanceMapUnitScale )
55  {
56  return mDistanceMapUnitScale;
57  }
58  return QgsMapUnitScale();
59 }
60 
61 QgsSymbolLayer *QgsVectorFieldSymbolLayer::create( const QVariantMap &properties )
62 {
64  if ( properties.contains( QStringLiteral( "x_attribute" ) ) )
65  {
66  symbolLayer->setXAttribute( properties[QStringLiteral( "x_attribute" )].toString() );
67  }
68  if ( properties.contains( QStringLiteral( "y_attribute" ) ) )
69  {
70  symbolLayer->setYAttribute( properties[QStringLiteral( "y_attribute" )].toString() );
71  }
72  if ( properties.contains( QStringLiteral( "distance_unit" ) ) )
73  {
74  symbolLayer->setDistanceUnit( QgsUnitTypes::decodeRenderUnit( properties[QStringLiteral( "distance_unit" )].toString() ) );
75  }
76  if ( properties.contains( QStringLiteral( "distance_map_unit_scale" ) ) )
77  {
78  symbolLayer->setDistanceMapUnitScale( QgsSymbolLayerUtils::decodeMapUnitScale( properties[QStringLiteral( "distance_map_unit_scale" )].toString() ) );
79  }
80  if ( properties.contains( QStringLiteral( "scale" ) ) )
81  {
82  symbolLayer->setScale( properties[QStringLiteral( "scale" )].toDouble() );
83  }
84  if ( properties.contains( QStringLiteral( "vector_field_type" ) ) )
85  {
86  symbolLayer->setVectorFieldType( static_cast< VectorFieldType >( properties[QStringLiteral( "vector_field_type" )].toInt() ) );
87  }
88  if ( properties.contains( QStringLiteral( "angle_orientation" ) ) )
89  {
90  symbolLayer->setAngleOrientation( static_cast< AngleOrientation >( properties[QStringLiteral( "angle_orientation" )].toInt() ) );
91  }
92  if ( properties.contains( QStringLiteral( "angle_units" ) ) )
93  {
94  symbolLayer->setAngleUnits( static_cast< AngleUnits >( properties[QStringLiteral( "angle_units" )].toInt() ) );
95  }
96  if ( properties.contains( QStringLiteral( "size" ) ) )
97  {
98  symbolLayer->setSize( properties[QStringLiteral( "size" )].toDouble() );
99  }
100  if ( properties.contains( QStringLiteral( "size_unit" ) ) )
101  {
102  symbolLayer->setSizeUnit( QgsUnitTypes::decodeRenderUnit( properties[QStringLiteral( "size_unit" )].toString() ) );
103  }
104  if ( properties.contains( QStringLiteral( "size_map_unit_scale" ) ) )
105  {
106  symbolLayer->setSizeMapUnitScale( QgsSymbolLayerUtils::decodeMapUnitScale( properties[QStringLiteral( "size_map_unit_scale" )].toString() ) );
107  }
108  if ( properties.contains( QStringLiteral( "offset" ) ) )
109  {
110  symbolLayer->setOffset( QgsSymbolLayerUtils::decodePoint( properties[QStringLiteral( "offset" )].toString() ) );
111  }
112  if ( properties.contains( QStringLiteral( "offset_unit" ) ) )
113  {
114  symbolLayer->setOffsetUnit( QgsUnitTypes::decodeRenderUnit( properties[QStringLiteral( "offset_unit" )].toString() ) );
115  }
116  if ( properties.contains( QStringLiteral( "offset_map_unit_scale" ) ) )
117  {
118  symbolLayer->setOffsetMapUnitScale( QgsSymbolLayerUtils::decodeMapUnitScale( properties[QStringLiteral( "offset_map_unit_scale" )].toString() ) );
119  }
120  return symbolLayer;
121 }
122 
124 {
125  if ( symbol->type() == Qgis::SymbolType::Line )
126  {
127  mLineSymbol.reset( static_cast<QgsLineSymbol *>( symbol ) );
128  return true;
129  }
130  return false;
131 }
132 
134 {
135  return mLineSymbol.get();
136 }
137 
139 {
140  if ( !mLineSymbol )
141  {
142  return;
143  }
144 
145  const QgsRenderContext &ctx = context.renderContext();
146 
147  if ( !context.feature() )
148  {
149  //preview
150  QPolygonF line;
151  line << QPointF( 0, 50 );
152  line << QPointF( 100, 50 );
153  mLineSymbol->renderPolyline( line, nullptr, context.renderContext() );
154  return;
155  }
156 
157  const QgsFeature f( *context.feature() );
158 
159  double xComponent = 0;
160  double yComponent = 0;
161 
162  double xVal = 0;
163  if ( mXIndex != -1 )
164  {
165  xVal = f.attribute( mXIndex ).toDouble();
166  }
167  double yVal = 0;
168  if ( mYIndex != -1 )
169  {
170  yVal = f.attribute( mYIndex ).toDouble();
171  }
172 
173  const QgsMapToPixel &m2p = ctx.mapToPixel();
174  const double mapRotation = m2p.mapRotation();
175 
176  QPolygonF line;
177  line << point;
178 
179  QPointF destPoint;
180  switch ( mVectorFieldType )
181  {
182  case Cartesian:
183  {
184  destPoint = QPointF( point.x() + mScale * ctx.convertToPainterUnits( xVal, mDistanceUnit, mDistanceMapUnitScale ),
185  point.y() - mScale * ctx.convertToPainterUnits( yVal, mDistanceUnit, mDistanceMapUnitScale ) );
186  break;
187  }
188 
189  case Polar:
190  {
191  convertPolarToCartesian( xVal, yVal, xComponent, yComponent );
192  destPoint = QPointF( point.x() + mScale * ctx.convertToPainterUnits( xComponent, mDistanceUnit, mDistanceMapUnitScale ),
193  point.y() - mScale * ctx.convertToPainterUnits( yComponent, mDistanceUnit, mDistanceMapUnitScale ) );
194  break;
195  }
196 
197  case Height:
198  {
199  destPoint = QPointF( point.x(), point.y() - ( mScale * ctx.convertToPainterUnits( yVal, mDistanceUnit, mDistanceMapUnitScale ) ) );
200  break;
201  }
202  }
203 
204  if ( !qgsDoubleNear( mapRotation, 0.0 ) && mVectorFieldType != Height )
205  {
206  const double radians = mapRotation * M_PI / 180.0;
207  destPoint = QPointF( cos( radians ) * ( destPoint.x() - point.x() ) - sin( radians ) * ( destPoint.y() - point.y() ) + point.x(),
208  sin( radians ) * ( destPoint.x() - point.x() ) + cos( radians ) * ( destPoint.y() - point.y() ) + point.y() );
209  }
210 
211  line << destPoint;
212  mLineSymbol->renderPolyline( line, &f, context.renderContext() );
213 }
214 
216 {
217  if ( mLineSymbol )
218  {
219  mLineSymbol->startRender( context.renderContext(), context.fields() );
220  }
221 
222  const QgsFields fields = context.fields();
223  if ( !fields.isEmpty() )
224  {
225  mXIndex = fields.lookupField( mXAttribute );
226  mYIndex = fields.lookupField( mYAttribute );
227  }
228  else
229  {
230  mXIndex = -1;
231  mYIndex = -1;
232  }
233 }
234 
236 {
237  if ( mLineSymbol )
238  {
239  mLineSymbol->stopRender( context.renderContext() );
240  }
241 }
242 
244 {
246  if ( mLineSymbol )
247  {
248  clonedLayer->setSubSymbol( mLineSymbol->clone() );
249  }
250  return static_cast< QgsVectorFieldSymbolLayer * >( clonedLayer );
251 }
252 
254 {
255  QVariantMap properties;
256  properties[QStringLiteral( "x_attribute" )] = mXAttribute;
257  properties[QStringLiteral( "y_attribute" )] = mYAttribute;
258  properties[QStringLiteral( "distance_unit" )] = QgsUnitTypes::encodeUnit( mDistanceUnit );
259  properties[QStringLiteral( "distance_map_unit_scale" )] = QgsSymbolLayerUtils::encodeMapUnitScale( mDistanceMapUnitScale );
260  properties[QStringLiteral( "scale" )] = QString::number( mScale );
261  properties[QStringLiteral( "vector_field_type" )] = QString::number( mVectorFieldType );
262  properties[QStringLiteral( "angle_orientation" )] = QString::number( mAngleOrientation );
263  properties[QStringLiteral( "angle_units" )] = QString::number( mAngleUnits );
264  properties[QStringLiteral( "size" )] = QString::number( mSize );
265  properties[QStringLiteral( "size_unit" )] = QgsUnitTypes::encodeUnit( mSizeUnit );
266  properties[QStringLiteral( "size_map_unit_scale" )] = QgsSymbolLayerUtils::encodeMapUnitScale( mSizeMapUnitScale );
267  properties[QStringLiteral( "offset" )] = QgsSymbolLayerUtils::encodePoint( mOffset );
268  properties[QStringLiteral( "offset_unit" )] = QgsUnitTypes::encodeUnit( mOffsetUnit );
269  properties[QStringLiteral( "offset_map_unit_scale" )] = QgsSymbolLayerUtils::encodeMapUnitScale( mOffsetMapUnitScale );
270  return properties;
271 }
272 
274 {
275  return mDistanceUnit == QgsUnitTypes::RenderMapUnits || mDistanceUnit == QgsUnitTypes::RenderMetersInMapUnits
278 }
279 
280 void QgsVectorFieldSymbolLayer::toSld( QDomDocument &doc, QDomElement &element, const QVariantMap &props ) const
281 {
282  element.appendChild( doc.createComment( QStringLiteral( "VectorField not implemented yet..." ) ) );
283  mLineSymbol->toSld( doc, element, props );
284 }
285 
287 {
288  Q_UNUSED( element )
289  return nullptr;
290 }
291 
293 {
294  if ( mLineSymbol )
295  {
296  mLineSymbol->drawPreviewIcon( context.renderContext().painter(), size );
297  }
298 }
299 
300 QSet<QString> QgsVectorFieldSymbolLayer::usedAttributes( const QgsRenderContext &context ) const
301 {
302  QSet<QString> attributes = QgsMarkerSymbolLayer::usedAttributes( context );
303  if ( !mXAttribute.isEmpty() )
304  {
305  attributes.insert( mXAttribute );
306  }
307  if ( !mYAttribute.isEmpty() )
308  {
309  attributes.insert( mYAttribute );
310  }
311  if ( mLineSymbol )
312  {
313  attributes.unite( mLineSymbol->usedAttributes( context ) );
314  }
315  return attributes;
316 }
317 
319 {
321  return true;
322  if ( mLineSymbol && mLineSymbol->hasDataDefinedProperties() )
323  return true;
324  return false;
325 }
326 
327 void QgsVectorFieldSymbolLayer::convertPolarToCartesian( double length, double angle, double &x, double &y ) const
328 {
329  //convert angle to degree and to north orientation
330  if ( mAngleOrientation == CounterclockwiseFromEast )
331  {
332  if ( angle <= 90 )
333  {
334  angle = 90 - angle;
335  }
336  else
337  {
338  angle = 360 - angle + 90;
339  }
340  }
341 
342  if ( mAngleUnits == Degrees )
343  {
344  angle = angle * M_PI / 180.0;
345  }
346 
347  x = length * std::sin( angle );
348  y = length * std::cos( angle );
349 }
350 
351 void QgsVectorFieldSymbolLayer::setColor( const QColor &color )
352 {
353  if ( mLineSymbol )
354  mLineSymbol->setColor( color );
355 
356  mColor = color;
357 }
358 
360 {
361  return mLineSymbol ? mLineSymbol->color() : mColor;
362 }
363 
364 
@ Line
Line symbol.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
QVariant attribute(const QString &name) const
Lookup attribute value by attribute name.
Definition: qgsfeature.cpp:302
Container of fields for a vector layer.
Definition: qgsfields.h:45
bool isEmpty() const
Checks whether the container is empty.
Definition: qgsfields.cpp:128
int lookupField(const QString &fieldName) const
Looks up field's index from the field name.
Definition: qgsfields.cpp:344
A line symbol type, for rendering LineString and MultiLineString geometries.
Definition: qgslinesymbol.h:30
Perform transforms between map coordinates and device coordinates.
Definition: qgsmaptopixel.h:39
double mapRotation() const
Returns the current map rotation in degrees (clockwise).
Struct for storing maximum and minimum scales for measurements in map units.
double mSize
Marker size.
virtual void setSize(double size)
Sets the symbol size.
QgsUnitTypes::RenderUnit mOffsetUnit
Offset units.
void setSizeUnit(QgsUnitTypes::RenderUnit unit)
Sets the units for the symbol's size.
void setOutputUnit(QgsUnitTypes::RenderUnit unit) override
Sets the units to use for sizes and widths within the symbol layer.
QPointF mOffset
Marker offset.
QgsMapUnitScale mapUnitScale() const override
void setOffset(QPointF offset)
Sets the marker's offset, which is the horizontal and vertical displacement which the rendered marker...
void setSizeMapUnitScale(const QgsMapUnitScale &scale)
Sets the map unit scale for the symbol's size.
double size() const
Returns the symbol size.
QgsMapUnitScale mOffsetMapUnitScale
Offset map unit scale.
QgsMapUnitScale mSizeMapUnitScale
Marker size map unit scale.
QgsUnitTypes::RenderUnit mSizeUnit
Marker size unit.
void setOffsetUnit(QgsUnitTypes::RenderUnit unit)
Sets the units for the symbol's offset.
void setOffsetMapUnitScale(const QgsMapUnitScale &scale)
Sets the map unit scale for the symbol's offset.
QgsUnitTypes::RenderUnit outputUnit() const override
Returns the units to use for sizes and widths within the symbol layer.
double angle() const
Returns the rotation angle for the marker, in degrees clockwise from north.
void setMapUnitScale(const QgsMapUnitScale &scale) override
Contains information about the context of a rendering operation.
QPainter * painter()
Returns the destination QPainter for the render operation.
const QgsMapToPixel & mapToPixel() const
Returns the context's map to pixel transform, which transforms between map coordinates and device coo...
double convertToPainterUnits(double size, QgsUnitTypes::RenderUnit unit, const QgsMapUnitScale &scale=QgsMapUnitScale(), Qgis::RenderSubcomponentProperty property=Qgis::RenderSubcomponentProperty::Generic) const
Converts a size from the specified units to painter units (pixels).
static QString encodeMapUnitScale(const QgsMapUnitScale &mapUnitScale)
static QgsMapUnitScale decodeMapUnitScale(const QString &str)
static QString encodePoint(QPointF point)
Encodes a QPointF to a string.
static QPointF decodePoint(const QString &string)
Decodes a QSizeF from a string.
virtual bool setSubSymbol(QgsSymbol *symbol)
Sets layer's subsymbol. takes ownership of the passed symbol.
virtual QSet< QString > usedAttributes(const QgsRenderContext &context) const
Returns the set of attributes referenced by the layer.
virtual bool hasDataDefinedProperties() const
Returns true if the symbol layer (or any of its sub-symbols) contains data defined properties.
QgsFields fields() const
Fields of the layer.
QgsRenderContext & renderContext()
Returns a reference to the context's render context.
const QgsFeature * feature() const
Returns the current feature being rendered.
Abstract base class for all rendered symbols.
Definition: qgssymbol.h:38
Qgis::SymbolType type() const
Returns the symbol's type.
Definition: qgssymbol.h:97
static Q_INVOKABLE QString encodeUnit(QgsUnitTypes::DistanceUnit unit)
Encodes a distance unit to a string.
static Q_INVOKABLE QgsUnitTypes::RenderUnit decodeRenderUnit(const QString &string, bool *ok=nullptr)
Decodes a render unit from a string.
RenderUnit
Rendering size units.
Definition: qgsunittypes.h:168
@ RenderUnknownUnit
Mixed or unknown units.
Definition: qgsunittypes.h:175
@ RenderMetersInMapUnits
Meters value as Map units.
Definition: qgsunittypes.h:176
@ RenderMapUnits
Map units.
Definition: qgsunittypes.h:170
A symbol layer class for displaying displacement arrows based on point layer attributes.
QSet< QString > usedAttributes(const QgsRenderContext &context) const override
Returns the set of attributes referenced by the layer.
bool setSubSymbol(QgsSymbol *symbol) override
Sets layer's subsymbol. takes ownership of the passed symbol.
QColor color() const override
The fill color.
QgsUnitTypes::RenderUnit outputUnit() const override
Returns the units to use for sizes and widths within the symbol layer.
QgsSymbol * subSymbol() override
Returns the symbol's sub symbol, if present.
void setMapUnitScale(const QgsMapUnitScale &scale) override
void setYAttribute(const QString &attribute)
void setAngleUnits(AngleUnits units)
void setVectorFieldType(VectorFieldType type)
void setDistanceUnit(QgsUnitTypes::RenderUnit unit)
Sets the units for the distance.
~QgsVectorFieldSymbolLayer() override
bool hasDataDefinedProperties() const override
Returns true if the symbol layer (or any of its sub-symbols) contains data defined properties.
void startRender(QgsSymbolRenderContext &context) override
Called before a set of rendering operations commences on the supplied render context.
void setAngleOrientation(AngleOrientation orientation)
QVariantMap properties() const override
Should be reimplemented by subclasses to return a string map that contains the configuration informat...
void stopRender(QgsSymbolRenderContext &context) override
Called after a set of rendering operations has finished on the supplied render context.
QgsVectorFieldSymbolLayer * clone() const override
Shall be reimplemented by subclasses to create a deep copy of the instance.
static QgsSymbolLayer * create(const QVariantMap &properties=QVariantMap())
Creates the symbol layer.
QgsMapUnitScale mapUnitScale() const override
void setXAttribute(const QString &attribute)
void setDistanceMapUnitScale(const QgsMapUnitScale &scale)
bool usesMapUnits() const override
Returns true if the symbol layer has any components which use map unit based sizes.
void setOutputUnit(QgsUnitTypes::RenderUnit unit) override
Sets the units to use for sizes and widths within the symbol layer.
static QgsSymbolLayer * createFromSld(QDomElement &element)
void setColor(const QColor &color) override
The fill color.
void toSld(QDomDocument &doc, QDomElement &element, const QVariantMap &props) const override
Saves the symbol layer as SLD.
void renderPoint(QPointF point, QgsSymbolRenderContext &context) override
Renders a marker at the specified point.
void drawPreviewIcon(QgsSymbolRenderContext &context, QSize size) override
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
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:1234