QGIS API Documentation  3.4.3-Madeira (2f64a3c)
qgsrasterrendererregistry.cpp
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1 /***************************************************************************
2  qgsrasterrendererregistry.cpp
3  -----------------------------
4  begin : January 2012
5  copyright : (C) 2012 by Marco Hugentobler
6  email : marco 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 "qgsrasterdataprovider.h"
20 #include "qgsrastershader.h"
21 #include "qgsrastertransparency.h"
27 #include "qgshillshaderenderer.h"
28 #include "qgsapplication.h"
29 #include "qgssettings.h"
30 
31 #include <QIcon>
32 
33 QgsRasterRendererRegistryEntry::QgsRasterRendererRegistryEntry( const QString &name, const QString &visibleName,
34  QgsRasterRendererCreateFunc rendererFunction,
35  QgsRasterRendererWidgetCreateFunc widgetFunction )
36  : name( name )
37  , visibleName( visibleName )
38  , rendererCreateFunction( rendererFunction )
39  , widgetCreateFunction( widgetFunction )
40 {
41 }
42 
44 {
45  return QgsApplication::getThemeIcon( QString( "styleicons/%1.svg" ).arg( name ) );
46 }
47 
49 {
50  // insert items in a particular order, which is returned in renderersList()
51  insert( QgsRasterRendererRegistryEntry( QStringLiteral( "multibandcolor" ), QObject::tr( "Multiband color" ),
53  insert( QgsRasterRendererRegistryEntry( QStringLiteral( "paletted" ), QObject::tr( "Paletted/Unique values" ), QgsPalettedRasterRenderer::create, nullptr ) );
54  insert( QgsRasterRendererRegistryEntry( QStringLiteral( "singlebandgray" ), QObject::tr( "Singleband gray" ),
56  insert( QgsRasterRendererRegistryEntry( QStringLiteral( "singlebandpseudocolor" ), QObject::tr( "Singleband pseudocolor" ),
58  insert( QgsRasterRendererRegistryEntry( QStringLiteral( "singlebandcolordata" ), QObject::tr( "Singleband color data" ),
60  insert( QgsRasterRendererRegistryEntry( QStringLiteral( "hillshade" ), QObject::tr( "Hillshade" ),
61  QgsHillshadeRenderer::create, nullptr ) );
62 }
63 
65 {
66  mEntries.insert( entry.name, entry );
67  mSortedEntries.append( entry.name );
68 }
69 
71 {
72  if ( !mEntries.contains( rendererName ) )
73  {
74  return;
75  }
76  mEntries[rendererName].widgetCreateFunction = func;
77 }
78 
79 bool QgsRasterRendererRegistry::rendererData( const QString &rendererName, QgsRasterRendererRegistryEntry &data ) const
80 {
81  QHash< QString, QgsRasterRendererRegistryEntry >::const_iterator it = mEntries.find( rendererName );
82  if ( it == mEntries.constEnd() )
83  {
84  return false;
85  }
86  data = it.value();
87  return true;
88 }
89 
91 {
92  return mSortedEntries;
93 }
94 
95 QList< QgsRasterRendererRegistryEntry > QgsRasterRendererRegistry::entries() const
96 {
97  QList< QgsRasterRendererRegistryEntry > result;
98 
99  QHash< QString, QgsRasterRendererRegistryEntry >::const_iterator it = mEntries.constBegin();
100  for ( ; it != mEntries.constEnd(); ++it )
101  {
102  result.push_back( it.value() );
103  }
104  return result;
105 }
106 
108 {
109  if ( !provider || provider->bandCount() < 1 )
110  {
111  return nullptr;
112  }
113 
114 
115  QgsRasterRenderer *renderer = nullptr;
116  switch ( drawingStyle )
117  {
119  {
120  int grayBand = 1; //reasonable default
122  renderer = new QgsPalettedRasterRenderer( provider,
123  grayBand,
124  classes );
125  }
126  break;
129  {
130  int grayBand = 1;
131  renderer = new QgsSingleBandGrayRenderer( provider, grayBand );
132 
134  provider->dataType( grayBand ) ) );
135 
136 // Default contrast enhancement is set from QgsRasterLayer, it has already setContrastEnhancementAlgorithm(). Default enhancement must only be set if default style was not loaded (to avoid stats calculation).
137  ( ( QgsSingleBandGrayRenderer * )renderer )->setContrastEnhancement( ce );
138  break;
139  }
141  {
142  int bandNo = 1;
143  double minValue = 0;
144  double maxValue = 0;
145  // TODO: avoid calculating statistics if not necessary (default style loaded)
146  minMaxValuesForBand( bandNo, provider, minValue, maxValue );
147  QgsRasterShader *shader = new QgsRasterShader( minValue, maxValue );
148  renderer = new QgsSingleBandPseudoColorRenderer( provider, bandNo, shader );
149  break;
150  }
152  {
153  QgsSettings s;
154 
155  int redBand = s.value( QStringLiteral( "/Raster/defaultRedBand" ), 1 ).toInt();
156  if ( redBand < 0 || redBand > provider->bandCount() )
157  {
158  redBand = -1;
159  }
160  int greenBand = s.value( QStringLiteral( "/Raster/defaultGreenBand" ), 2 ).toInt();
161  if ( greenBand < 0 || greenBand > provider->bandCount() )
162  {
163  greenBand = -1;
164  }
165  int blueBand = s.value( QStringLiteral( "/Raster/defaultBlueBand" ), 3 ).toInt();
166  if ( blueBand < 0 || blueBand > provider->bandCount() )
167  {
168  blueBand = -1;
169  }
170 
171  renderer = new QgsMultiBandColorRenderer( provider, redBand, greenBand, blueBand );
172  break;
173  }
175  {
176  renderer = new QgsSingleBandColorDataRenderer( provider, 1 );
177  break;
178  }
179  default:
180  return nullptr;
181  }
182 
183  QgsRasterTransparency *tr = new QgsRasterTransparency(); //renderer takes ownership
184  int bandCount = renderer->usesBands().size();
185  if ( bandCount == 1 )
186  {
187  QList<QgsRasterTransparency::TransparentSingleValuePixel> transparentSingleList;
188  tr->setTransparentSingleValuePixelList( transparentSingleList );
189  }
190  else if ( bandCount == 3 )
191  {
192  QList<QgsRasterTransparency::TransparentThreeValuePixel> transparentThreeValueList;
193  tr->setTransparentThreeValuePixelList( transparentThreeValueList );
194  }
195  renderer->setRasterTransparency( tr );
196  return renderer;
197 }
198 
199 bool QgsRasterRendererRegistry::minMaxValuesForBand( int band, QgsRasterDataProvider *provider, double &minValue, double &maxValue ) const
200 {
201  if ( !provider )
202  {
203  return false;
204  }
205 
206  minValue = 0;
207  maxValue = 0;
208 
209  QgsSettings s;
210  if ( s.value( QStringLiteral( "/Raster/useStandardDeviation" ), false ).toBool() )
211  {
213 
214  double stdDevFactor = s.value( QStringLiteral( "/Raster/defaultStandardDeviation" ), 2.0 ).toDouble();
215  double diff = stdDevFactor * stats.stdDev;
216  minValue = stats.mean - diff;
217  maxValue = stats.mean + diff;
218  }
219  else
220  {
222  minValue = stats.minimumValue;
223  maxValue = stats.maximumValue;
224  }
225  return true;
226 }
virtual int bandCount() const =0
Gets number of bands.
Interface for all raster shaders.
static QgsRasterRenderer * create(const QDomElement &elem, QgsRasterInterface *input)
static QgsRasterRenderer * create(const QDomElement &elem, QgsRasterInterface *input)
void setTransparentThreeValuePixelList(const QList< QgsRasterTransparency::TransparentThreeValuePixel > &newList)
Sets the transparent three value pixel list, replacing the whole existing list.
Renderer for paletted raster images.
This class is a composition of two QSettings instances:
Definition: qgssettings.h:58
DrawingStyle
This enumerator describes the different kinds of drawing we can do.
Definition: qgsraster.h:89
static QgsRasterRenderer * create(const QDomElement &elem, QgsRasterInterface *input)
virtual QList< QgsColorRampShader::ColorRampItem > colorTable(int bandNo) const
virtual QList< int > usesBands() const
Returns a list of band numbers used by the renderer.
QVariant value(const QString &key, const QVariant &defaultValue=QVariant(), Section section=NoSection) const
Returns the value for setting key.
QgsRasterRenderer *(* QgsRasterRendererCreateFunc)(const QDomElement &, QgsRasterInterface *input)
DataType
Raster data types.
Definition: qgis.h:92
double maximumValue
The maximum cell value in the raster band.
static QIcon getThemeIcon(const QString &name)
Helper to get a theme icon.
QgsRasterRendererRegistryEntry()=default
Constructor for QgsRasterRendererRegistryEntry.
Raster renderer pipe for single band color.
bool rendererData(const QString &rendererName, QgsRasterRendererRegistryEntry &data) const
double stdDev
The standard deviation of the cell values.
The RasterBandStats struct is a container for statistics about a single raster band.
double mean
The mean cell value for the band. NO_DATA values are excluded.
QList< QgsPalettedRasterRenderer::Class > ClassData
Map of value to class properties.
void insert(const QgsRasterRendererRegistryEntry &entry)
QgsRasterRenderer * defaultRendererForDrawingStyle(QgsRaster::DrawingStyle drawingStyle, QgsRasterDataProvider *provider) const
Creates a default renderer for a raster drawing style (considering user options such as default contr...
Raster renderer pipe for single band pseudocolor.
Raster renderer pipe for single band gray.
QgsRasterRendererWidget *(* QgsRasterRendererWidgetCreateFunc)(QgsRasterLayer *, const QgsRectangle &extent)
static QgsRasterRenderer * create(const QDomElement &elem, QgsRasterInterface *input)
void setTransparentSingleValuePixelList(const QList< QgsRasterTransparency::TransparentSingleValuePixel > &newList)
Sets the transparent single value pixel list, replacing the whole existing list.
Registry for raster renderer entries.
virtual QgsRasterBandStats bandStatistics(int bandNo, int stats=QgsRasterBandStats::All, const QgsRectangle &extent=QgsRectangle(), int sampleSize=0, QgsRasterBlockFeedback *feedback=nullptr)
Returns the band statistics.
static QgsRasterRenderer * create(const QDomElement &elem, QgsRasterInterface *input)
double minimumValue
The minimum cell value in the raster band.
Renderer for multiband images with the color components.
Manipulates raster pixel values so that they enhanceContrast or clip into a specified numerical range...
Defines the list of pixel values to be considered as transparent or semi transparent when rendering r...
QList< QgsRasterRendererRegistryEntry > entries() const
static QgsRasterRenderer * create(const QDomElement &elem, QgsRasterInterface *input)
Factory method to create a new renderer.
void setRasterTransparency(QgsRasterTransparency *t)
static QgsPalettedRasterRenderer::ClassData colorTableToClassData(const QList< QgsColorRampShader::ColorRampItem > &table)
Converts a raster color table to paletted renderer class data.
void insertWidgetFunction(const QString &rendererName, QgsRasterRendererWidgetCreateFunc func)
Raster renderer pipe that applies colors to a raster.
Qgis::DataType dataType(int bandNo) const override=0
Returns data type for the band specified by number.
Base class for raster data providers.