[feature] Expose data defined control over raster layer opacity

Allows the opacity of a raster to be varied e.g. on different pages of an atlas, depending on the visibility of another layer, by temporal variables, etc...
qgis · Jun 25, 2021 · 2a9c32b · 2a9c32b
1 parent c013c78
commit 2a9c32b
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Showing 10 changed files with 435 additions and 162 deletions.
diff --git a/python/gui/auto_generated/qgsmaplayerconfigwidget.sip.in b/python/gui/auto_generated/qgsmaplayerconfigwidget.sip.in
@@ -64,6 +64,7 @@ Will be called when live update is enabled.
 
 
   protected:
+
 };
 
 /************************************************************************

diff --git a/python/gui/auto_generated/raster/qgsrasterlayerproperties.sip.in b/python/gui/auto_generated/raster/qgsrasterlayerproperties.sip.in
@@ -43,6 +43,9 @@ Adds a properties page factory to the raster layer properties dialog.
 .. versionadded:: 3.18
 %End
 
+    virtual QgsExpressionContext createExpressionContext() const;
+
+
   protected slots:
 
 };

diff --git a/python/gui/auto_generated/raster/qgsrastertransparencywidget.sip.in b/python/gui/auto_generated/raster/qgsrastertransparencywidget.sip.in
@@ -27,6 +27,16 @@ Widget to control a layers transparency and related options
 Widget to control a layers transparency and related options
 %End
 
+    void setContext( const QgsSymbolWidgetContext &context );
+%Docstring
+Sets the ``context`` in which the dialog is shown, e.g., the associated map canvas and expression contexts.
+
+.. versionadded:: 3.22
+%End
+
+    virtual QgsExpressionContext createExpressionContext() const;
+
+
   public slots:
 
 
@@ -41,6 +51,9 @@ Sync the widget state to the layer set for the widget.
 Apply any changes on the widget to the set layer.
 %End
 
+  protected:
+
+
 };
 /************************************************************************
  * This file has been generated automatically from                      *

diff --git a/src/gui/qgsmaplayerconfigwidget.h b/src/gui/qgsmaplayerconfigwidget.h
@@ -82,6 +82,7 @@ class GUI_EXPORT QgsMapLayerConfigWidget : public QgsPanelWidget
 #endif
 
   protected:
+
     QgsMapLayer *mLayer = nullptr;
     QgsMapCanvas *mMapCanvas = nullptr;
 };

diff --git a/src/gui/raster/qgsrasterlayerproperties.cpp b/src/gui/raster/qgsrasterlayerproperties.cpp
@@ -67,6 +67,7 @@
 
 #include "qgsrasterlayertemporalpropertieswidget.h"
 #include "qgsprojecttimesettings.h"
+#include "qgsexpressioncontextutils.h"
 
 #include <QDesktopServices>
 #include <QTableWidgetItem>
@@ -225,6 +226,13 @@ QgsRasterLayerProperties::QgsRasterLayerProperties( QgsMapLayer *lyr, QgsMapCanv
     return;
   }
 
+  mContext << QgsExpressionContextUtils::globalScope()
+           << QgsExpressionContextUtils::projectScope( QgsProject::instance() )
+           << QgsExpressionContextUtils::atlasScope( nullptr );
+  if ( mMapCanvas )
+    mContext << QgsExpressionContextUtils::mapSettingsScope( mMapCanvas->mapSettings() );
+  mContext << QgsExpressionContextUtils::layerScope( mRasterLayer );
+
   QgsRasterDataProvider *provider = mRasterLayer->dataProvider();
 
   // Only do pyramids if dealing directly with GDAL.
@@ -446,6 +454,8 @@ QgsRasterLayerProperties::QgsRasterLayerProperties( QgsMapLayer *lyr, QgsMapCanv
 
 #endif
 
+  initializeDataDefinedButton( mOpacityDDBtn, QgsRasterPipe::RendererOpacity );
+
   mRenderTypeComboBox_currentIndexChanged( widgetIndex );
 
   // update based on lyr's current state
@@ -516,6 +526,11 @@ void QgsRasterLayerProperties::addPropertiesPageFactory( const QgsMapLayerConfig
   }
 }
 
+QgsExpressionContext QgsRasterLayerProperties::createExpressionContext() const
+{
+  return mContext;
+}
+
 void QgsRasterLayerProperties::setupTransparencyTable( int nBands )
 {
   tableTransparency->clear();
@@ -903,6 +918,9 @@ void QgsRasterLayerProperties::sync()
 
   mTemporalWidget->syncToLayer();
 
+  mPropertyCollection = mRasterLayer->pipe()->dataDefinedProperties();
+  updateDataDefinedButtons();
+
   for ( QgsMapLayerConfigWidget *page : std::as_const( mLayerPropertiesPages ) )
   {
     page->syncToLayer( mRasterLayer );
@@ -1122,6 +1140,8 @@ void QgsRasterLayerProperties::apply()
   mRasterLayer->setCustomProperty( "WMSPublishDataSourceUrl", mPublishDataSourceUrlCheckBox->isChecked() );
   mRasterLayer->setCustomProperty( "WMSBackgroundLayer", mBackgroundLayerCheckBox->isChecked() );
 
+  mRasterLayer->pipe()->setDataDefinedProperties( mPropertyCollection );
+
   // Force a redraw of the legend
   mRasterLayer->setLegend( QgsMapLayerLegend::defaultRasterLegend( mRasterLayer ) );
 
@@ -1582,6 +1602,43 @@ void QgsRasterLayerProperties::optionsStackedWidget_CurrentChanged( int index )
   }
 }
 
+void QgsRasterLayerProperties::initializeDataDefinedButton( QgsPropertyOverrideButton *button, QgsRasterPipe::Property key )
+{
+  button->blockSignals( true );
+  button->init( key, mPropertyCollection, QgsRasterPipe::propertyDefinitions(), nullptr );
+  connect( button, &QgsPropertyOverrideButton::changed, this, &QgsRasterLayerProperties::updateProperty );
+  button->registerExpressionContextGenerator( this );
+  button->blockSignals( false );
+}
+
+void QgsRasterLayerProperties::updateDataDefinedButtons()
+{
+  const auto propertyOverrideButtons { findChildren< QgsPropertyOverrideButton * >() };
+  for ( QgsPropertyOverrideButton *button : propertyOverrideButtons )
+  {
+    updateDataDefinedButton( button );
+  }
+}
+
+void QgsRasterLayerProperties::updateDataDefinedButton( QgsPropertyOverrideButton *button )
+{
+  if ( !button )
+    return;
+
+  if ( button->propertyKey() < 0 )
+    return;
+
+  QgsRasterPipe::Property key = static_cast< QgsRasterPipe::Property >( button->propertyKey() );
+  whileBlocking( button )->setToProperty( mPropertyCollection.property( key ) );
+}
+
+void QgsRasterLayerProperties::updateProperty()
+{
+  QgsPropertyOverrideButton *button = qobject_cast<QgsPropertyOverrideButton *>( sender() );
+  QgsRasterPipe::Property key = static_cast<  QgsRasterPipe::Property >( button->propertyKey() );
+  mPropertyCollection.setProperty( key, button->toProperty() );
+}
+
 void QgsRasterLayerProperties::pbnImportTransparentPixelValues_clicked()
 {
   int myLineCounter = 0;

diff --git a/src/gui/raster/qgsrasterlayerproperties.h b/src/gui/raster/qgsrasterlayerproperties.h
@@ -29,6 +29,7 @@
 #include "qgsmaptoolemitpoint.h"
 #include "qgis_gui.h"
 #include "qgsresamplingutils.h"
+#include "qgsrasterpipe.h"
 
 class QgsPointXY;
 class QgsMapLayer;
@@ -43,6 +44,7 @@ class QgsWebView;
 class QgsProviderSourceWidget;
 class QgsMapLayerConfigWidgetFactory;
 class QgsMapLayerConfigWidget;
+class QgsPropertyOverrideButton;
 
 
 /**
@@ -52,7 +54,7 @@ class QgsMapLayerConfigWidget;
  * \since QGIS 3.12 (in the GUI API)
  */
 
-class GUI_EXPORT QgsRasterLayerProperties : public QgsOptionsDialogBase, private Ui::QgsRasterLayerPropertiesBase
+class GUI_EXPORT QgsRasterLayerProperties : public QgsOptionsDialogBase, private Ui::QgsRasterLayerPropertiesBase, private QgsExpressionContextGenerator
 {
     Q_OBJECT
 
@@ -85,12 +87,40 @@ class GUI_EXPORT QgsRasterLayerProperties : public QgsOptionsDialogBase, private
      */
     void addPropertiesPageFactory( const QgsMapLayerConfigWidgetFactory *factory );
 
+    QgsExpressionContext createExpressionContext() const override;
+
   protected slots:
     //! \brief auto slot executed when the active page in the main widget stack is changed
     void optionsStackedWidget_CurrentChanged( int index ) override SIP_SKIP ;
 
+  private:
+
+    // TODO -- consider moving these to a common raster widget base class
+
+    /**
+     * Registers a property override button, setting up its initial value, connections and description.
+     * \param button button to register
+     * \param key corresponding data defined property key
+     */
+    void initializeDataDefinedButton( QgsPropertyOverrideButton *button, QgsRasterPipe::Property key );
+
+    /**
+     * Updates all property override buttons to reflect the widgets's current properties.
+     */
+    void updateDataDefinedButtons();
+
+    /**
+     * Updates a specific property override \a button to reflect the widgets's current properties.
+     */
+    void updateDataDefinedButton( QgsPropertyOverrideButton *button );
+
+    //! Temporary property collection
+    QgsPropertyCollection mPropertyCollection;
+
   private slots:
 
+    void updateProperty();
+
     //! \brief Applies the settings made in the dialog without closing the box
     void apply();
     //! \brief Called when cancel button is pressed
@@ -277,6 +307,8 @@ class GUI_EXPORT QgsRasterLayerProperties : public QgsOptionsDialogBase, private
 
     QgsWebView *mMetadataViewer = nullptr;
 
+    QgsExpressionContext mContext;
+
     friend class QgsAppScreenShots;
 };
 #endif
diff --git a/src/gui/raster/qgsrastertransparencywidget.cpp b/src/gui/raster/qgsrastertransparencywidget.cpp
@@ -33,7 +33,8 @@
 #include "qgsrasteridentifyresult.h"
 #include "qgsmultibandcolorrenderer.h"
 #include "qgsdoublevalidator.h"
-
+#include "qgsexpressioncontextutils.h"
+#include "qgstemporalcontroller.h"
 
 QgsRasterTransparencyWidget::QgsRasterTransparencyWidget( QgsRasterLayer *layer, QgsMapCanvas *canvas, QWidget *parent )
   : QgsMapLayerConfigWidget( layer, canvas, parent )
@@ -69,6 +70,47 @@ QgsRasterTransparencyWidget::QgsRasterTransparencyWidget( QgsRasterLayer *layer,
   {
     pbnAddValuesFromDisplay->setEnabled( false );
   }
+
+  initializeDataDefinedButton( mOpacityDDBtn, QgsRasterPipe::RendererOpacity );
+}
+
+void QgsRasterTransparencyWidget::setContext( const QgsSymbolWidgetContext &context )
+{
+  mContext = context;
+}
+
+QgsExpressionContext QgsRasterTransparencyWidget::createExpressionContext() const
+{
+  QgsExpressionContext expContext;
+  expContext << QgsExpressionContextUtils::globalScope()
+             << QgsExpressionContextUtils::projectScope( QgsProject::instance() )
+             << QgsExpressionContextUtils::atlasScope( nullptr );
+
+  if ( QgsMapCanvas *canvas = mContext.mapCanvas() )
+  {
+    expContext << QgsExpressionContextUtils::mapSettingsScope( canvas->mapSettings() )
+               << new QgsExpressionContextScope( canvas->expressionContextScope() );
+    if ( const QgsExpressionContextScopeGenerator *generator = dynamic_cast< const QgsExpressionContextScopeGenerator * >( canvas->temporalController() ) )
+    {
+      expContext << generator->createExpressionContextScope();
+    }
+  }
+  else
+  {
+    expContext << QgsExpressionContextUtils::mapSettingsScope( QgsMapSettings() );
+  }
+
+  if ( mRasterLayer )
+    expContext << QgsExpressionContextUtils::layerScope( mRasterLayer );
+
+  // additional scopes
+  const auto constAdditionalExpressionContextScopes = mContext.additionalExpressionContextScopes();
+  for ( const QgsExpressionContextScope &scope : constAdditionalExpressionContextScopes )
+  {
+    expContext.appendScope( new QgsExpressionContextScope( scope ) );
+  }
+
+  return expContext;
 }
 
 void QgsRasterTransparencyWidget::syncToLayer()
@@ -128,6 +170,9 @@ void QgsRasterTransparencyWidget::syncToLayer()
     leNoDataValue->setText( QString() );
   }
 
+  mPropertyCollection = mRasterLayer->pipe()->dataDefinedProperties();
+  updateDataDefinedButtons();
+
   populateTransparencyTable( mRasterLayer->renderer() );
 }
 
@@ -462,6 +507,46 @@ void QgsRasterTransparencyWidget::apply()
     //set global transparency
     rasterRenderer->setOpacity( mOpacityWidget->opacity() );
   }
+
+  mRasterLayer->pipe()->setDataDefinedProperties( mPropertyCollection );
+}
+
+void QgsRasterTransparencyWidget::initializeDataDefinedButton( QgsPropertyOverrideButton *button, QgsRasterPipe::Property key )
+{
+  button->blockSignals( true );
+  button->init( key, mPropertyCollection, QgsRasterPipe::propertyDefinitions(), nullptr );
+  connect( button, &QgsPropertyOverrideButton::changed, this, &QgsRasterTransparencyWidget::updateProperty );
+  button->registerExpressionContextGenerator( this );
+  button->blockSignals( false );
+}
+
+void QgsRasterTransparencyWidget::updateDataDefinedButtons()
+{
+  const auto propertyOverrideButtons { findChildren< QgsPropertyOverrideButton * >() };
+  for ( QgsPropertyOverrideButton *button : propertyOverrideButtons )
+  {
+    updateDataDefinedButton( button );
+  }
+}
+
+void QgsRasterTransparencyWidget::updateDataDefinedButton( QgsPropertyOverrideButton *button )
+{
+  if ( !button )
+    return;
+
+  if ( button->propertyKey() < 0 )
+    return;
+
+  QgsRasterPipe::Property key = static_cast< QgsRasterPipe::Property >( button->propertyKey() );
+  whileBlocking( button )->setToProperty( mPropertyCollection.property( key ) );
+}
+
+void QgsRasterTransparencyWidget::updateProperty()
+{
+  QgsPropertyOverrideButton *button = qobject_cast<QgsPropertyOverrideButton *>( sender() );
+  QgsRasterPipe::Property key = static_cast<  QgsRasterPipe::Property >( button->propertyKey() );
+  mPropertyCollection.setProperty( key, button->toProperty() );
+  emit widgetChanged();
 }
 
 void QgsRasterTransparencyWidget::pixelSelected( const QgsPointXY &canvasPoint )