[feature][temporal] Add expression variables for frame properties

Adds @frame_number, @frame_rate, @frame_duration, which give the current frame number, frames per second, and length of frames respectively
qgis · May 9, 2020 · 072222d · 072222d
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commit 072222d
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Showing 12 changed files with 78 additions and 5 deletions.
diff --git a/python/core/auto_generated/qgstemporalnavigationobject.sip.in b/python/core/auto_generated/qgstemporalnavigationobject.sip.in
@@ -12,7 +12,7 @@
 
 
 
-class QgsTemporalNavigationObject : QgsTemporalController
+class QgsTemporalNavigationObject : QgsTemporalController, QgsExpressionContextScopeGenerator
 {
 %Docstring
 Implements a temporal controller based on a frame by frame navigation and animation.
@@ -153,6 +153,9 @@ Sets whether the animation should ``loop`` after hitting the end or start frame.
 .. seealso:: :py:func:`isLooping`
 %End
 
+    virtual QgsExpressionContextScope *createExpressionContextScope() const /Factory/;
+
+
   signals:
 
     void stateChanged( AnimationState state );

diff --git a/src/core/expression/qgsexpression.cpp b/src/core/expression/qgsexpression.cpp
@@ -776,6 +776,10 @@ void QgsExpression::initVariableHelp()
   sVariableHelpTexts()->insert( QStringLiteral( "map_end_time" ), QCoreApplication::translate( "variable_help", "End of the map's temporal time range (as a datetime value)" ) );
   sVariableHelpTexts()->insert( QStringLiteral( "map_interval" ), QCoreApplication::translate( "variable_help", "Duration of the map's temporal time range (as an interval value)" ) );
 
+  sVariableHelpTexts()->insert( QStringLiteral( "frame_rate" ), QCoreApplication::translate( "variable_help", "Number of frames per second during animation playback" ) );
+  sVariableHelpTexts()->insert( QStringLiteral( "frame_number" ), QCoreApplication::translate( "variable_help", "Current frame number during animation playback" ) );
+  sVariableHelpTexts()->insert( QStringLiteral( "frame_duration" ), QCoreApplication::translate( "variable_help", "Temporal duration of each animation frame (as an interval value)" ) );
+
   // vector tile layer variables
   sVariableHelpTexts()->insert( QStringLiteral( "zoom_level" ), QCoreApplication::translate( "variable_help", "Zoom level of the tile that is being rendered (derived from the current map scale). Normally in interval [0, 20]." ) );
 

diff --git a/src/core/qgstemporalnavigationobject.cpp b/src/core/qgstemporalnavigationobject.cpp
@@ -69,6 +69,15 @@ void QgsTemporalNavigationObject::setLooping( bool loopAnimation )
   mLoopAnimation = loopAnimation;
 }
 
+QgsExpressionContextScope *QgsTemporalNavigationObject::createExpressionContextScope() const
+{
+  std::unique_ptr< QgsExpressionContextScope > scope = qgis::make_unique< QgsExpressionContextScope >( QStringLiteral( "temporal" ) );
+  scope->setVariable( QStringLiteral( "frame_rate" ), mFramesPerSecond, true );
+  scope->setVariable( QStringLiteral( "frame_number" ), mCurrentFrameNumber, true );
+  scope->setVariable( QStringLiteral( "frame_duration" ), mFrameDuration, true );
+  return scope.release();
+}
+
 QgsDateTimeRange QgsTemporalNavigationObject::dateTimeRangeForFrameNumber( long long frame ) const
 {
   const QDateTime start = mTemporalExtents.begin();

diff --git a/src/core/qgstemporalnavigationobject.h b/src/core/qgstemporalnavigationobject.h
@@ -23,6 +23,7 @@
 #include "qgsrange.h"
 #include "qgsinterval.h"
 #include "qgstemporalcontroller.h"
+#include "qgsexpressioncontextscopegenerator.h"
 
 #include <QList>
 #include <QTimer>
@@ -35,7 +36,7 @@ class QgsMapLayer;
  *
  * \since QGIS 3.14
  */
-class CORE_EXPORT QgsTemporalNavigationObject : public QgsTemporalController
+class CORE_EXPORT QgsTemporalNavigationObject : public QgsTemporalController, public QgsExpressionContextScopeGenerator
 {
     Q_OBJECT
 
@@ -166,6 +167,8 @@ class CORE_EXPORT QgsTemporalNavigationObject : public QgsTemporalController
      */
     void setLooping( bool loop );
 
+    QgsExpressionContextScope *createExpressionContextScope() const override SIP_FACTORY;
+
   signals:
 
     /**

diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -554,8 +554,12 @@ void QgsMapCanvas::refreshMap()
   expressionContext << QgsExpressionContextUtils::globalScope()
                     << QgsExpressionContextUtils::projectScope( QgsProject::instance() )
                     << QgsExpressionContextUtils::atlasScope( nullptr )
-                    << QgsExpressionContextUtils::mapSettingsScope( mSettings )
-                    << defaultExpressionContextScope()
+                    << QgsExpressionContextUtils::mapSettingsScope( mSettings );
+  if ( QgsExpressionContextScopeGenerator *generator = dynamic_cast< QgsExpressionContextScopeGenerator * >( mController ) )
+  {
+    expressionContext << generator->createExpressionContextScope();
+  }
+  expressionContext << defaultExpressionContextScope()
                     << new QgsExpressionContextScope( mExpressionContextScope );
 
   mSettings.setExpressionContext( expressionContext );

diff --git a/src/gui/symbology/qgscategorizedsymbolrendererwidget.cpp b/src/gui/symbology/qgscategorizedsymbolrendererwidget.cpp
@@ -27,6 +27,7 @@
 #include "qgsstyle.h"
 #include "qgslogger.h"
 #include "qgsexpressioncontextutils.h"
+#include "qgstemporalcontroller.h"
 
 #include "qgssymbolselectordialog.h"
 #include "qgsexpressionbuilderdialog.h"
@@ -1211,6 +1212,10 @@ QgsExpressionContext QgsCategorizedSymbolRendererWidget::createExpressionContext
   {
     expContext << QgsExpressionContextUtils::mapSettingsScope( mContext.mapCanvas()->mapSettings() )
                << new QgsExpressionContextScope( mContext.mapCanvas()->expressionContextScope() );
+    if ( const QgsExpressionContextScopeGenerator *generator = dynamic_cast< const QgsExpressionContextScopeGenerator * >( mContext.mapCanvas()->temporalController() ) )
+    {
+      expContext << generator->createExpressionContextScope();
+    }
   }
   else
   {

diff --git a/src/gui/symbology/qgsgraduatedsymbolrendererwidget.cpp b/src/gui/symbology/qgsgraduatedsymbolrendererwidget.cpp
@@ -51,7 +51,7 @@
 #include "qgsprocessingguiregistry.h"
 #include "qgsprocessingcontext.h"
 #include "qgsprocessingwidgetwrapper.h"
-
+#include "qgstemporalcontroller.h"
 
 
 
@@ -423,6 +423,10 @@ QgsExpressionContext QgsGraduatedSymbolRendererWidget::createExpressionContext()
   {
     expContext << QgsExpressionContextUtils::mapSettingsScope( mContext.mapCanvas()->mapSettings() )
                << new QgsExpressionContextScope( mContext.mapCanvas()->expressionContextScope() );
+    if ( const QgsExpressionContextScopeGenerator *generator = dynamic_cast< const QgsExpressionContextScopeGenerator * >( mContext.mapCanvas()->temporalController() ) )
+    {
+      expContext << generator->createExpressionContextScope();
+    }
   }
   else
   {

diff --git a/src/gui/symbology/qgsheatmaprendererwidget.cpp b/src/gui/symbology/qgsheatmaprendererwidget.cpp
@@ -16,6 +16,7 @@
 #include "qgsheatmaprenderer.h"
 #include "qgsrendererregistry.h"
 #include "qgsexpressioncontextutils.h"
+#include "qgstemporalcontroller.h"
 
 #include "qgssymbol.h"
 
@@ -45,6 +46,10 @@ QgsExpressionContext QgsHeatmapRendererWidget::createExpressionContext() const
   {
     expContext << QgsExpressionContextUtils::mapSettingsScope( mContext.mapCanvas()->mapSettings() )
                << new QgsExpressionContextScope( mContext.mapCanvas()->expressionContextScope() );
+    if ( const QgsExpressionContextScopeGenerator *generator = dynamic_cast< const QgsExpressionContextScopeGenerator * >( mContext.mapCanvas()->temporalController() ) )
+    {
+      expContext << generator->createExpressionContextScope();
+    }
   }
   else
   {

diff --git a/src/gui/symbology/qgslayerpropertieswidget.cpp b/src/gui/symbology/qgslayerpropertieswidget.cpp
@@ -40,6 +40,7 @@
 #include "qgsvectorlayer.h"
 #include "qgsexpressioncontextutils.h"
 #include "qgsmasksymbollayerwidget.h"
+#include "qgstemporalcontroller.h"
 
 static bool _initWidgetFunction( const QString &name, QgsSymbolLayerWidgetFunc f )
 {
@@ -238,6 +239,10 @@ QgsExpressionContext QgsLayerPropertiesWidget::createExpressionContext() const
   {
     expContext << QgsExpressionContextUtils::mapSettingsScope( mContext.mapCanvas()->mapSettings() )
                << new QgsExpressionContextScope( mContext.mapCanvas()->expressionContextScope() );
+    if ( const QgsExpressionContextScopeGenerator *generator = dynamic_cast< const QgsExpressionContextScopeGenerator * >( mContext.mapCanvas()->temporalController() ) )
+    {
+      expContext << generator->createExpressionContextScope();
+    }
   }
   else
   {

diff --git a/src/gui/symbology/qgsrendererwidget.cpp b/src/gui/symbology/qgsrendererwidget.cpp
@@ -26,6 +26,7 @@
 #include "qgsproject.h"
 #include "qgsexpressioncontextutils.h"
 #include "qgssymbollayerutils.h"
+#include "qgstemporalcontroller.h"
 
 #include <QMessageBox>
 #include <QInputDialog>
@@ -410,6 +411,11 @@ QgsExpressionContext QgsDataDefinedValueDialog::createExpressionContext() const
   {
     expContext << QgsExpressionContextUtils::mapSettingsScope( mContext.mapCanvas()->mapSettings() )
                << new QgsExpressionContextScope( mContext.mapCanvas()->expressionContextScope() );
+
+    if ( const QgsExpressionContextScopeGenerator *generator = dynamic_cast< const QgsExpressionContextScopeGenerator * >( mContext.mapCanvas()->temporalController() ) )
+    {
+      expContext << generator->createExpressionContextScope();
+    }
   }
   else
   {

diff --git a/src/gui/symbology/qgssymbolwidgetcontext.cpp b/src/gui/symbology/qgssymbolwidgetcontext.cpp
@@ -17,6 +17,7 @@
 #include "qgsmessagebar.h"
 #include "qgsproject.h"
 #include "qgsexpressioncontextutils.h"
+#include "qgstemporalcontroller.h"
 
 QgsSymbolWidgetContext::QgsSymbolWidgetContext( const QgsSymbolWidgetContext &other )
   : mMapCanvas( other.mMapCanvas )
@@ -99,6 +100,11 @@ QList<QgsExpressionContextScope *> QgsSymbolWidgetContext::globalProjectAtlasMap
     scopes << QgsExpressionContextUtils::mapSettingsScope( mMapCanvas->mapSettings() )
            << mMapCanvas->defaultExpressionContextScope()
            << new QgsExpressionContextScope( mMapCanvas->expressionContextScope() );
+
+    if ( const QgsExpressionContextScopeGenerator *generator = dynamic_cast< const QgsExpressionContextScopeGenerator * >( mMapCanvas->temporalController() ) )
+    {
+      scopes << generator->createExpressionContextScope();
+    }
   }
   else
   {

diff --git a/tests/src/core/testqgstemporalnavigationobject.cpp b/tests/src/core/testqgstemporalnavigationobject.cpp
@@ -41,6 +41,7 @@ class TestQgsTemporalNavigationObject : public QObject
     void animationState();
     void temporalExtents();
     void frameSettings();
+    void expressionContext();
 
   private:
     QgsTemporalNavigationObject *navigationObject = nullptr;
@@ -164,5 +165,23 @@ void TestQgsTemporalNavigationObject::frameSettings()
 
 }
 
+void TestQgsTemporalNavigationObject::expressionContext()
+{
+  QgsTemporalNavigationObject object;
+  QgsDateTimeRange range = QgsDateTimeRange(
+                             QDateTime( QDate( 2020, 1, 1 ), QTime( 8, 0, 0 ) ),
+                             QDateTime( QDate( 2020, 1, 1 ), QTime( 12, 0, 0 ) )
+                           );
+  object.setTemporalExtents( range );
+  object.setFrameDuration( QgsInterval( 1, QgsUnitTypes::TemporalHours ) );
+  object.setCurrentFrameNumber( 1 );
+  object.setFramesPerSecond( 30 );
+
+  std::unique_ptr< QgsExpressionContextScope > scope( object.createExpressionContextScope() );
+  QCOMPARE( scope->variable( QStringLiteral( "frame_rate" ) ).toDouble(), 30.0 );
+  QCOMPARE( scope->variable( QStringLiteral( "frame_duration" ) ).value< QgsInterval >().seconds(), 3600.0 );
+  QCOMPARE( scope->variable( QStringLiteral( "frame_number" ) ).toInt(), 1 );
+}
+
 QGSTEST_MAIN( TestQgsTemporalNavigationObject )
 #include "testqgstemporalnavigationobject.moc"