QGIS API Documentation  3.6.0-Noosa (5873452)
qgsheatmaprendererwidget.cpp
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1 /***************************************************************************
2  qgsheatmaprendererwidget.cpp
3  ----------------------------
4  begin : November 2014
5  copyright : (C) 2014 Nyall Dawson
6  email : nyall dot dawson 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  ***************************************************************************/
16 #include "qgsheatmaprenderer.h"
17 #include "qgsrendererregistry.h"
19 
20 #include "qgssymbol.h"
21 
22 #include "qgslogger.h"
23 #include "qgsvectorlayer.h"
24 #include "qgscolorramp.h"
25 #include "qgscolorrampbutton.h"
26 #include "qgsstyle.h"
27 #include "qgsproject.h"
28 #include "qgsmapcanvas.h"
29 #include <QGridLayout>
30 #include <QLabel>
31 
33 {
34  return new QgsHeatmapRendererWidget( layer, style, renderer );
35 }
36 
37 QgsExpressionContext QgsHeatmapRendererWidget::createExpressionContext() const
38 {
39  QgsExpressionContext expContext;
43 
44  if ( mContext.mapCanvas() )
45  {
48  }
49  else
50  {
52  }
53 
54  if ( vectorLayer() )
56 
57  // additional scopes
59  {
60  expContext.appendScope( new QgsExpressionContextScope( scope ) );
61  }
62 
63  return expContext;
64 }
65 
67  : QgsRendererWidget( layer, style )
68 
69 {
70  if ( !layer )
71  {
72  return;
73  }
74  // the renderer only applies to point vector layers
75  if ( layer->geometryType() != QgsWkbTypes::PointGeometry )
76  {
77  //setup blank dialog
78  mRenderer = nullptr;
79  QLabel *label = new QLabel( tr( "The heatmap renderer only applies to point and multipoint layers. \n"
80  "'%1' is not a point layer and cannot be rendered as a heatmap." )
81  .arg( layer->name() ), this );
82  layout()->addWidget( label );
83  return;
84  }
85 
86  setupUi( this );
87  connect( mRadiusUnitWidget, &QgsUnitSelectionWidget::changed, this, &QgsHeatmapRendererWidget::mRadiusUnitWidget_changed );
88  connect( mRadiusSpinBox, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsHeatmapRendererWidget::mRadiusSpinBox_valueChanged );
89  connect( mMaxSpinBox, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsHeatmapRendererWidget::mMaxSpinBox_valueChanged );
90  connect( mQualitySlider, &QSlider::valueChanged, this, &QgsHeatmapRendererWidget::mQualitySlider_valueChanged );
91  this->layout()->setContentsMargins( 0, 0, 0, 0 );
92 
95  mWeightExpressionWidget->registerExpressionContextGenerator( this );
96 
97  if ( renderer )
98  {
99  mRenderer = QgsHeatmapRenderer::convertFromRenderer( renderer );
100  }
101  if ( !mRenderer )
102  {
103  mRenderer = new QgsHeatmapRenderer();
104  }
105 
106  btnColorRamp->setShowGradientOnly( true );
107 
108  connect( btnColorRamp, &QgsColorRampButton::colorRampChanged, this, &QgsHeatmapRendererWidget::applyColorRamp );
109 
110  if ( mRenderer->colorRamp() )
111  {
112  btnColorRamp->blockSignals( true );
113  btnColorRamp->setColorRamp( mRenderer->colorRamp() );
114  btnColorRamp->blockSignals( false );
115  }
116  mRadiusSpinBox->blockSignals( true );
117  mRadiusSpinBox->setValue( mRenderer->radius() );
118  mRadiusSpinBox->blockSignals( false );
119  mRadiusUnitWidget->blockSignals( true );
120  mRadiusUnitWidget->setUnit( mRenderer->radiusUnit() );
121  mRadiusUnitWidget->setMapUnitScale( mRenderer->radiusMapUnitScale() );
122  mRadiusUnitWidget->blockSignals( false );
123  mMaxSpinBox->blockSignals( true );
124  mMaxSpinBox->setValue( mRenderer->maximumValue() );
125  mMaxSpinBox->blockSignals( false );
126  mQualitySlider->blockSignals( true );
127  mQualitySlider->setValue( mRenderer->renderQuality() );
128  mQualitySlider->blockSignals( false );
129 
130  mWeightExpressionWidget->setLayer( layer );
131  mWeightExpressionWidget->setField( mRenderer->weightExpression() );
132  connect( mWeightExpressionWidget, static_cast < void ( QgsFieldExpressionWidget::* )( const QString & ) >( &QgsFieldExpressionWidget::fieldChanged ), this, &QgsHeatmapRendererWidget::weightExpressionChanged );
133 }
134 
136 {
137  return mRenderer;
138 }
139 
141 {
143  if ( context.mapCanvas() )
144  mRadiusUnitWidget->setMapCanvas( context.mapCanvas() );
145 }
146 
147 void QgsHeatmapRendererWidget::applyColorRamp()
148 {
149  if ( !mRenderer )
150  {
151  return;
152  }
153 
154  QgsColorRamp *ramp = btnColorRamp->colorRamp();
155  if ( !ramp )
156  return;
157 
158  mRenderer->setColorRamp( ramp );
159  emit widgetChanged();
160 }
161 
162 void QgsHeatmapRendererWidget::mRadiusUnitWidget_changed()
163 {
164  if ( !mRenderer )
165  {
166  return;
167  }
168 
169  mRenderer->setRadiusUnit( mRadiusUnitWidget->unit() );
170  mRenderer->setRadiusMapUnitScale( mRadiusUnitWidget->getMapUnitScale() );
171  emit widgetChanged();
172 }
173 
174 void QgsHeatmapRendererWidget::mRadiusSpinBox_valueChanged( double d )
175 {
176  if ( !mRenderer )
177  {
178  return;
179  }
180 
181  mRenderer->setRadius( d );
182  emit widgetChanged();
183 }
184 
185 void QgsHeatmapRendererWidget::mMaxSpinBox_valueChanged( double d )
186 {
187  if ( !mRenderer )
188  {
189  return;
190  }
191 
192  mRenderer->setMaximumValue( d );
193  emit widgetChanged();
194 }
195 
196 void QgsHeatmapRendererWidget::mQualitySlider_valueChanged( int v )
197 {
198  if ( !mRenderer )
199  {
200  return;
201  }
202 
203  mRenderer->setRenderQuality( v );
204  emit widgetChanged();
205 }
206 
207 void QgsHeatmapRendererWidget::weightExpressionChanged( const QString &expression )
208 {
209  mRenderer->setWeightExpression( expression );
210  emit widgetChanged();
211 }
The QgsFieldExpressionWidget class reates a widget to choose fields and edit expressions It contains ...
virtual void setContext(const QgsSymbolWidgetContext &context)
Sets the context in which the renderer widget is shown, e.g., the associated map canvas and expressio...
double renderQuality() const
Returns the render quality used for drawing the heatmap.
void setColorRamp(QgsColorRamp *ramp)
Sets the color ramp to use for shading the heatmap.
QgsSymbolWidgetContext context() const
Returns the context in which the renderer widget is shown, e.g., the associated map canvas and expres...
void colorRampChanged()
Emitted whenever a new color ramp is set for the button.
Base class for renderer settings widgets.
static QgsRendererWidget * create(QgsVectorLayer *layer, QgsStyle *style, QgsFeatureRenderer *renderer)
Static creation method.
Abstract base class for color ramps.
Definition: qgscolorramp.h:31
double maximumValue() const
Returns the maximum value used for shading the heatmap.
QgsWkbTypes::GeometryType geometryType() const
Returns point, line or polygon.
void setWeightExpression(const QString &expression)
Sets the expression used for weighting points when generating the heatmap.
static QgsExpressionContextScope * projectScope(const QgsProject *project)
Creates a new scope which contains variables and functions relating to a QGIS project.
QList< QgsUnitTypes::RenderUnit > RenderUnitList
List of render units.
Definition: qgsunittypes.h:184
The QgsMapSettings class contains configuration for rendering of the map.
QgsHeatmapRendererWidget(QgsVectorLayer *layer, QgsStyle *style, QgsFeatureRenderer *renderer)
Constructor.
static QgsExpressionContextScope * globalScope()
Creates a new scope which contains variables and functions relating to the global QGIS context...
A renderer which draws points as a live heatmap.
Contains settings which reflect the context in which a symbol (or renderer) widget is shown...
void setRadiusMapUnitScale(const QgsMapUnitScale &scale)
Sets the map unit scale used for the heatmap&#39;s radius.
double radius() const
Returns the radius for the heatmap.
const QgsMapUnitScale & radiusMapUnitScale() const
Returns the map unit scale used for the heatmap&#39;s radius.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
const QgsVectorLayer * vectorLayer() const
Returns the vector layer associated with the widget.
points (e.g., for font sizes)
Definition: qgsunittypes.h:118
QgsFeatureRenderer * renderer() override
Returns pointer to the renderer (no transfer of ownership)
QgsColorRamp * colorRamp() const
Returns the color ramp used for shading the heatmap.
Single scope for storing variables and functions for use within a QgsExpressionContext.
void setRenderQuality(const int quality)
Sets the render quality used for drawing the heatmap.
void widgetChanged()
Emitted when the widget state changes.
void setRadiusUnit(const QgsUnitTypes::RenderUnit unit)
Sets the units used for the heatmap&#39;s radius.
void setRadius(const double radius)
Sets the radius for the heatmap.
void fieldChanged(const QString &fieldName)
the signal is emitted when the currently selected field changes
const QgsMapSettings & mapSettings() const
Gets access to properties used for map rendering.
QgsMapCanvas * mapCanvas() const
Returns the map canvas associated with the widget.
static QgsExpressionContextScope * atlasScope(QgsLayoutAtlas *atlas)
Creates a new scope which contains variables and functions relating to a QgsLayoutAtlas.
static QgsExpressionContextScope * mapSettingsScope(const QgsMapSettings &mapSettings)
Creates a new scope which contains variables and functions relating to a QgsMapSettings object...
QgsSymbolWidgetContext mContext
Context in which widget is shown.
QgsExpressionContextScope & expressionContextScope()
Returns a reference to the expression context scope for the map canvas.
Definition: qgsmapcanvas.h:559
void appendScope(QgsExpressionContextScope *scope)
Appends a scope to the end of the context.
static QgsProject * instance()
Returns the QgsProject singleton instance.
Definition: qgsproject.cpp:430
static QgsHeatmapRenderer * convertFromRenderer(const QgsFeatureRenderer *renderer)
QString name
Definition: qgsmaplayer.h:68
static QgsExpressionContextScope * layerScope(const QgsMapLayer *layer)
Creates a new scope which contains variables and functions relating to a QgsMapLayer.
void setContext(const QgsSymbolWidgetContext &context) override
Sets the context in which the renderer widget is shown, e.g., the associated map canvas and expressio...
QString weightExpression() const
Returns the expression used for weighting points when generating the heatmap.
Represents a vector layer which manages a vector based data sets.
void setMaximumValue(const double value)
Sets the maximum value used for shading the heatmap.
QgsUnitTypes::RenderUnit radiusUnit() const
Returns the units used for the heatmap&#39;s radius.
QList< QgsExpressionContextScope > additionalExpressionContextScopes() const
Returns the list of additional expression context scopes to show as available within the layer...