Add a new QgsRasterBandComboBox widget

And use wherever custom widgets were being created. Reduces
duplicate code and allows specialised handling for raster
band display/selection to be centralized.

Author: nyalldawson

doc/api_break.dox

@@ -1766,11 +1766,18 @@ QgsRasterProjector        {#qgis_api_break_3_0_QgsRasterProjector}
 
 - extentSize() now takes a QgsCoordinateTransform reference, not a pointer. An invalid QgsCoordinateTransform should be used instead of a null pointer if no transformation is required.
 
-QgsRasterRenderer
+QgsRasterRenderer       {#qgis_api_break_3_0_QgsRasterRenderer}
 -----------------
 
 - MinMaxOrigin enum, minMaxOriginName(), minMaxOriginLabel(), minMaxOriginFromName() removed. Use minMaxOrigin() instead
 
+
+QgsRasterRendererWidget       {#qgis_api_break_3_0_QgsRasterRendererWidget}
+-----------------
+
+- displayBandName() was removed.
+
+
 QgsRectangle        {#qgis_api_break_3_0_QgsRectangle}
 ------------
 

python/gui/gui.sip

@@ -212,6 +212,7 @@
 
 %Include raster/qgsmultibandcolorrendererwidget.sip
 %Include raster/qgspalettedrendererwidget.sip
+%Include raster/qgsrasterbandcombobox.sip
 %Include raster/qgsrasterhistogramwidget.sip
 %Include raster/qgsrasterminmaxwidget.sip
 %Include raster/qgsrasterrendererwidget.sip

python/gui/raster/qgsrasterbandcombobox.sip

@@ -0,0 +1,74 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/raster/qgsrasterbandcombobox.h                               *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+class QgsRasterBandComboBox : QComboBox
+{
+%Docstring
+ A combobox widget which displays the bands present in a raster layer.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsrasterbandcombobox.h"
+%End
+  public:
+
+    QgsRasterBandComboBox( QWidget *parent /TransferThis/ = 0 );
+%Docstring
+ Constructor for QgsRasterBandComboBox.
+%End
+
+    QgsRasterLayer *layer() const;
+%Docstring
+ Returns the layer currently associated with the combobox.
+.. seealso:: setLayer()
+ :rtype: QgsRasterLayer
+%End
+
+    int currentBand() const;
+%Docstring
+ Returns the current band number selected in the combobox, or -1
+ if no band is selected.
+.. seealso:: setBand()
+ :rtype: int
+%End
+
+  public slots:
+
+    void setLayer( QgsMapLayer *layer );
+%Docstring
+ Sets the raster ``layer`` for which the bands are listed in the combobox. If no layer is set
+ or a non-raster layer is set then the combobox will be empty.
+.. seealso:: layer()
+%End
+
+    void setBand( int band );
+%Docstring
+ Sets the current ``band`` number selected in the combobox.
+.. seealso:: band()
+%End
+
+  signals:
+
+    void bandChanged( int band );
+%Docstring
+ This signal is emitted when the currently selected band changes.
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/raster/qgsrasterbandcombobox.h                               *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/gui/raster/qgsrasterrendererwidget.sip

@@ -44,8 +44,4 @@ class QgsRasterRendererWidget: QWidget
      */
     void widgetChanged();
 
-
-  protected:
-    /** Returns a band name for display. First choice is color name, otherwise band number*/
-    QString displayBandName( int band ) const;
 };

src/gui/CMakeLists.txt

@@ -1,6 +1,7 @@
 SET(QGIS_GUI_SRCS
   raster/qgsmultibandcolorrendererwidget.cpp
   raster/qgspalettedrendererwidget.cpp
+  raster/qgsrasterbandcombobox.cpp
   raster/qgsrasterhistogramwidget.cpp
   raster/qgsrasterminmaxwidget.cpp
   raster/qgsrasterrendererwidget.cpp
@@ -460,6 +461,7 @@ SET(QGIS_GUI_MOC_HDRS
 
   raster/qgsmultibandcolorrendererwidget.h
   raster/qgspalettedrendererwidget.h
+  raster/qgsrasterbandcombobox.h
   raster/qgsrasterhistogramwidget.h
   raster/qgsrasterminmaxwidget.h
   raster/qgsrasterrendererwidget.h

src/gui/raster/qgshillshaderendererwidget.cpp

@@ -41,23 +41,7 @@ QgsHillshadeRendererWidget::QgsHillshadeRendererWidget( QgsRasterLayer *layer, c
   mZFactor->setClearValue( 1 );
 
   mMultiDirection->setChecked( false );
-
-  if ( mRasterLayer )
-  {
-    QgsRasterDataProvider *provider = mRasterLayer->dataProvider();
-    if ( !provider )
-    {
-      return;
-    }
-
-    //fill available bands into combo box
-    int nBands = provider->bandCount();
-    for ( int i = 1; i <= nBands; ++i ) //band numbering seem to start at 1
-    {
-      mBandsCombo->addItem( displayBandName( i ), i );
-    }
-
-  }
+  mBandsCombo->setLayer( mRasterLayer );
 
   setFromRenderer( layer->renderer() );
 
@@ -66,6 +50,7 @@ QgsHillshadeRendererWidget::QgsHillshadeRendererWidget( QgsRasterLayer *layer, c
   connect( mLightAzimuthDial, &QAbstractSlider::valueChanged, this, &QgsHillshadeRendererWidget::on_mLightAzimuthDail_updated );
   connect( mZFactor, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsRasterRendererWidget::widgetChanged );
   connect( mMultiDirection, &QAbstractButton::toggled, this, &QgsRasterRendererWidget::widgetChanged );
+  connect( mBandsCombo, &QgsRasterBandComboBox::bandChanged, this, &QgsHillshadeRendererWidget::widgetChanged );
 }
 
 QgsRasterRenderer *QgsHillshadeRendererWidget::renderer()
@@ -81,7 +66,7 @@ QgsRasterRenderer *QgsHillshadeRendererWidget::renderer()
     return nullptr;
   }
 
-  int band = mBandsCombo->currentData().toInt();
+  int band = mBandsCombo->currentBand();
   QgsHillshadeRenderer *renderer = new QgsHillshadeRenderer( provider, band, mLightAzimuth->value(), mLightAngle->value() );
   double value = mZFactor->value();
   renderer->setZFactor( value );
@@ -94,7 +79,7 @@ void QgsHillshadeRendererWidget::setFromRenderer( const QgsRasterRenderer *rende
   const QgsHillshadeRenderer *r = dynamic_cast<const QgsHillshadeRenderer *>( renderer );
   if ( r )
   {
-    mBandsCombo->setCurrentIndex( mBandsCombo->findData( r->band() ) );
+    mBandsCombo->setBand( r->band() );
     mLightAngle->setValue( r->altitude() );
     mLightAzimuth->setValue( r->azimuth() );
     mZFactor->setValue( r->zFactor() );

src/gui/raster/qgsmultibandcolorrendererwidget.cpp

@@ -50,33 +50,28 @@ QgsMultiBandColorRendererWidget::QgsMultiBandColorRendererWidget( QgsRasterLayer
     connect( mMinMaxWidget, &QgsRasterMinMaxWidget::load,
              this, &QgsMultiBandColorRendererWidget::loadMinMax );
 
-    connect( mRedBandComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ),
+    connect( mRedBandComboBox, &QgsRasterBandComboBox::bandChanged,
              this, &QgsMultiBandColorRendererWidget::onBandChanged );
-    connect( mGreenBandComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ),
+    connect( mGreenBandComboBox, &QgsRasterBandComboBox::bandChanged,
              this, &QgsMultiBandColorRendererWidget::onBandChanged );
-    connect( mBlueBandComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ),
+    connect( mBlueBandComboBox, &QgsRasterBandComboBox::bandChanged,
              this, &QgsMultiBandColorRendererWidget::onBandChanged );
 
+    mRedBandComboBox->setLayer( mRasterLayer );
+    mGreenBandComboBox->setLayer( mRasterLayer );
+    mBlueBandComboBox->setLayer( mRasterLayer );
+
     //fill available bands into combo boxes
-    mRedBandComboBox->addItem( tr( "Not set" ), -1 );
-    mGreenBandComboBox->addItem( tr( "Not set" ), -1 );
-    mBlueBandComboBox->addItem( tr( "Not set" ), -1 );
+    mRedBandComboBox->insertItem( 0, tr( "Not set" ), -1 );
+    mGreenBandComboBox->insertItem( 0, tr( "Not set" ), -1 );
+    mBlueBandComboBox->insertItem( 0, tr( "Not set" ), -1 );
 
     //contrast enhancement algorithms
     mContrastEnhancementAlgorithmComboBox->addItem( tr( "No enhancement" ), QgsContrastEnhancement::NoEnhancement );
     mContrastEnhancementAlgorithmComboBox->addItem( tr( "Stretch to MinMax" ), QgsContrastEnhancement::StretchToMinimumMaximum );
     mContrastEnhancementAlgorithmComboBox->addItem( tr( "Stretch and clip to MinMax" ), QgsContrastEnhancement::StretchAndClipToMinimumMaximum );
     mContrastEnhancementAlgorithmComboBox->addItem( tr( "Clip to MinMax" ), QgsContrastEnhancement::ClipToMinimumMaximum );
 
-    int nBands = provider->bandCount();
-    for ( int i = 1; i <= nBands; ++i ) //band numbering seem to start at 1
-    {
-      QString bandName = displayBandName( i );
-      mRedBandComboBox->addItem( bandName, i );
-      mGreenBandComboBox->addItem( bandName, i );
-      mBlueBandComboBox->addItem( bandName, i );
-    }
-
     setFromRenderer( mRasterLayer->renderer() );
     onBandChanged( 0 ); // reset mMinMaxWidget bands
 
@@ -96,9 +91,9 @@ QgsRasterRenderer *QgsMultiBandColorRendererWidget::renderer()
     return nullptr;
   }
 
-  int redBand = mRedBandComboBox->currentData().toInt();
-  int greenBand = mGreenBandComboBox->currentData().toInt();
-  int blueBand = mBlueBandComboBox->currentData().toInt();
+  int redBand = mRedBandComboBox->currentBand();
+  int greenBand = mGreenBandComboBox->currentBand();
+  int blueBand = mBlueBandComboBox->currentBand();
 
   QgsMultiBandColorRenderer *r = new QgsMultiBandColorRenderer( provider, redBand, greenBand, blueBand );
   setCustomMinMaxValues( r, provider, redBand, greenBand, blueBand );
@@ -209,9 +204,9 @@ void QgsMultiBandColorRendererWidget::onBandChanged( int index )
   Q_UNUSED( index );
 
   QList<int> myBands;
-  myBands.append( mRedBandComboBox->currentData().toInt() );
-  myBands.append( mGreenBandComboBox->currentData().toInt() );
-  myBands.append( mBlueBandComboBox->currentData().toInt() );
+  myBands.append( mRedBandComboBox->currentBand() );
+  myBands.append( mGreenBandComboBox->currentBand() );
+  myBands.append( mBlueBandComboBox->currentBand() );
   mMinMaxWidget->setBands( myBands );
   emit widgetChanged();
 }
@@ -266,17 +261,17 @@ void QgsMultiBandColorRendererWidget::loadMinMax( int bandNo, double min, double
 
   QLineEdit *myMinLineEdit, *myMaxLineEdit;
 
-  if ( mRedBandComboBox->currentData().toInt() == bandNo )
+  if ( mRedBandComboBox->currentBand() == bandNo )
   {
     myMinLineEdit = mRedMinLineEdit;
     myMaxLineEdit = mRedMaxLineEdit;
   }
-  else if ( mGreenBandComboBox->currentData().toInt() == bandNo )
+  else if ( mGreenBandComboBox->currentBand() == bandNo )
   {
     myMinLineEdit = mGreenMinLineEdit;
     myMaxLineEdit = mGreenMaxLineEdit;
   }
-  else if ( mBlueBandComboBox->currentData().toInt() == bandNo )
+  else if ( mBlueBandComboBox->currentBand() == bandNo )
   {
     myMinLineEdit = mBlueMinLineEdit;
     myMaxLineEdit = mBlueMaxLineEdit;
@@ -336,9 +331,9 @@ void QgsMultiBandColorRendererWidget::setFromRenderer( const QgsRasterRenderer *
   const QgsMultiBandColorRenderer *mbcr = dynamic_cast<const QgsMultiBandColorRenderer *>( r );
   if ( mbcr )
   {
-    mRedBandComboBox->setCurrentIndex( mRedBandComboBox->findData( mbcr->redBand() ) );
-    mGreenBandComboBox->setCurrentIndex( mGreenBandComboBox->findData( mbcr->greenBand() ) );
-    mBlueBandComboBox->setCurrentIndex( mBlueBandComboBox->findData( mbcr->blueBand() ) );
+    mRedBandComboBox->setBand( mbcr->redBand() );
+    mGreenBandComboBox->setBand( mbcr->greenBand() );
+    mBlueBandComboBox->setBand( mbcr->blueBand() );
 
     mDisableMinMaxWidgetRefresh = true;
     setMinMaxValue( mbcr->redContrastEnhancement(), mRedMinLineEdit, mRedMaxLineEdit );
@@ -443,11 +438,11 @@ int QgsMultiBandColorRendererWidget::selectedBand( int index )
   switch ( index )
   {
     case 0:
-      return mRedBandComboBox->currentIndex();
+      return mRedBandComboBox->currentBand();
     case 1:
-      return mGreenBandComboBox->currentIndex();
+      return mGreenBandComboBox->currentBand();
     case 2:
-      return mBlueBandComboBox->currentIndex();
+      return mBlueBandComboBox->currentBand();
     default:
       break;
   }

src/gui/raster/qgspalettedrendererwidget.cpp

@@ -72,25 +72,19 @@ QgsPalettedRendererWidget::QgsPalettedRendererWidget( QgsRasterLayer *layer, con
 
   connect( btnColorRamp, &QgsColorRampButton::colorRampChanged, this, &QgsPalettedRendererWidget::applyColorRamp );
 
+  mBandComboBox->setLayer( mRasterLayer );
+
   if ( mRasterLayer )
   {
     QgsRasterDataProvider *provider = mRasterLayer->dataProvider();
     if ( !provider )
     {
       return;
     }
-
-    //fill available bands into combo box
-    int nBands = provider->bandCount();
-    for ( int i = 1; i <= nBands; ++i ) //band numbering seem to start at 1
-    {
-      mBandComboBox->addItem( displayBandName( i ), i );
-    }
-
     setFromRenderer( mRasterLayer->renderer() );
-    connect( mBandComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsRasterRendererWidget::widgetChanged );
   }
 
+  connect( mBandComboBox, &QgsRasterBandComboBox::bandChanged, this, &QgsRasterRendererWidget::widgetChanged );
   connect( mModel, &QgsPalettedRendererModel::classesChanged, this, &QgsPalettedRendererWidget::widgetChanged );
   connect( mDeleteEntryButton, &QPushButton::clicked, this, &QgsPalettedRendererWidget::deleteEntry );
   connect( mAddEntryButton, &QPushButton::clicked, this, &QgsPalettedRendererWidget::addEntry );
@@ -102,15 +96,15 @@ QgsPalettedRendererWidget::QgsPalettedRendererWidget( QgsRasterLayer *layer, con
   QgsRasterDataProvider *provider = mRasterLayer->dataProvider();
   if ( provider )
   {
-    mButtonLoadFromLayer->setEnabled( !provider->colorTable( mBandComboBox->currentData().toInt() ).isEmpty() );
+    mButtonLoadFromLayer->setEnabled( !provider->colorTable( mBandComboBox->currentBand() ).isEmpty() );
   }
   else
   {
     mButtonLoadFromLayer->setEnabled( false );
   }
 
   connect( QgsProject::instance(), static_cast < void ( QgsProject::* )( QgsMapLayer * ) >( &QgsProject::layerWillBeRemoved ), this, &QgsPalettedRendererWidget::layerWillBeRemoved );
-  connect( mBandComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsPalettedRendererWidget::loadFromLayer );
+  connect( mBandComboBox, &QgsRasterBandComboBox::bandChanged, this, &QgsPalettedRendererWidget::loadFromLayer );
 }
 
 QgsPalettedRendererWidget::~QgsPalettedRendererWidget()
@@ -125,7 +119,7 @@ QgsPalettedRendererWidget::~QgsPalettedRendererWidget()
 QgsRasterRenderer *QgsPalettedRendererWidget::renderer()
 {
   QgsPalettedRasterRenderer::ClassData classes = mModel->classData();
-  int bandNumber = mBandComboBox->currentData().toInt();
+  int bandNumber = mBandComboBox->currentBand();
 
   QgsPalettedRasterRenderer *r = new QgsPalettedRasterRenderer( mRasterLayer->dataProvider(), bandNumber, classes );
   if ( !btnColorRamp->isNull() )
@@ -406,7 +400,7 @@ void QgsPalettedRendererWidget::classify()
       return;
     }
 
-    mGatherer = new QgsPalettedRendererClassGatherer( mRasterLayer,  mBandComboBox->currentData().toInt(), mModel->classData(), btnColorRamp->colorRamp() );
+    mGatherer = new QgsPalettedRendererClassGatherer( mRasterLayer, mBandComboBox->currentBand(), btnColorRamp->colorRamp() );
 
     connect( mGatherer, &QgsPalettedRendererClassGatherer::progressChanged, mCalculatingProgressBar, &QProgressBar::setValue );
     mCalculatingProgressBar->show();
@@ -427,10 +421,10 @@ void QgsPalettedRendererWidget::loadFromLayer()
   QgsRasterDataProvider *provider = mRasterLayer->dataProvider();
   if ( provider )
   {
-    QList<QgsColorRampShader::ColorRampItem> table = provider->colorTable( mBandComboBox->currentData().toInt() );
+    QList<QgsColorRampShader::ColorRampItem> table = provider->colorTable( mBandComboBox->currentBand() );
     if ( !table.isEmpty() )
     {
-      QgsPalettedRasterRenderer::ClassData classes = QgsPalettedRasterRenderer::colorTableToClassData( provider->colorTable( mBandComboBox->currentData().toInt() ) );
+      QgsPalettedRasterRenderer::ClassData classes = QgsPalettedRasterRenderer::colorTableToClassData( provider->colorTable( mBandComboBox->currentBand() ) );
       mModel->setClassData( classes );
       emit widgetChanged();
     }
@@ -450,7 +444,7 @@ void QgsPalettedRendererWidget::gathererThreadFinished()
 {
   mGatherer->deleteLater();
   mGatherer = nullptr;
-  mClassifyButton->setText( tr( "Populate Values" ) );
+  mClassifyButton->setText( tr( "Add Unique Values" ) );
   mClassifyButton->setEnabled( true );
   mCalculatingProgressBar->hide();
   mCancelButton->hide();