expressions

Author: signedav

python/gui/auto_generated/editorwidgets/qgsqmlwidgetwrapper.sip.in

@@ -54,6 +54,7 @@ the Free Software Foundation; either version 2 of the License, or     *
 
 };
 
+
 /************************************************************************
  * This file has been generated automatically from                      *
  *                                                                      *

src/app/qgsattributesformproperties.cpp

@@ -1163,45 +1163,43 @@ void DnDTree::onItemDoubleClicked( QTreeWidgetItem *item, int column )
         }
       } );
 
-      //attributes to select
-      QgsFieldComboBox *attributeFieldCombo = new QgsFieldComboBox();
-      attributeFieldCombo->setLayer( mLayer );
-      connect( attributeFieldCombo, &QgsFieldComboBox::fieldChanged, this, [ = ]( QString attributeName )
-      {
-        qmlCode->insertPlainText( QStringLiteral( "feature.attribute(\"%1\")" ).arg( attributeName ) );
-      } );
-
       QgsFieldExpressionWidget *expressionWidget = new QgsFieldExpressionWidget;
       expressionWidget->setLayer( mLayer );
-      expressionWidget->setExpressionDialogTitle( tr( "Expression" ) );
+      QToolButton *addExpressionButton = new QToolButton();
+      addExpressionButton->setIcon( QgsApplication::getThemeIcon( "/symbologyAdd.svg" ) );
 
-      connect( expressionWidget, static_cast < void ( QgsFieldExpressionWidget::* )( const QString & ) > ( &QgsFieldExpressionWidget::fieldChanged ), this, [ = ]( const QString & expressionText )
+      connect( addExpressionButton, &QAbstractButton::clicked, this, [ = ]
       {
-        qmlCode->insertPlainText( QStringLiteral( "expression(%1)" ).arg( expressionText ) );
-        QgsLogger::warning( QStringLiteral( "Do it..." ) );
-        //expression needs to be added here...
+        qmlCode->insertPlainText( QStringLiteral( "expression.evaluate(\"(%1)\")" ).arg( expressionWidget->currentText()) );
       } );
 
+
       QgsQmlWidgetWrapper *qmlWrapper = new QgsQmlWidgetWrapper( mLayer, nullptr, this );
       qmlWrapper->setQmlCode( qmlCode->toPlainText() );
       connect( qmlCode, &QPlainTextEdit::textChanged, this, [ = ]
       {
         qmlWrapper->setQmlCode( qmlCode->toPlainText() );
         qmlWrapper->reinitWidget();
+        QgsFeature f;
+        mLayer->getFeatures().nextFeature(f);
+        qmlWrapper->setFeature( f );
       } );
 
       layout->addRow( tr( "Title" ), title );
-      QGroupBox *qmlCodeBox = new QGroupBox( tr( "QML Code" ) );
+      QScrollArea *qmlCodeBox = new QScrollArea();
       qmlCodeBox->setLayout( new QGridLayout );
       qmlCodeBox->layout()->addWidget( qmlObjectTemplate );
-      qmlCodeBox->layout()->addWidget( attributeFieldCombo );
-      qmlCodeBox->layout()->addWidget( expressionWidget );
+      QGroupBox *expressionWidgetBox = new QGroupBox();
+      qmlCodeBox->layout()->addWidget( expressionWidgetBox );
+      expressionWidgetBox->setLayout( new QGridLayout );
+      expressionWidgetBox->layout()->addWidget( expressionWidget );
+      expressionWidgetBox->layout()->addWidget( addExpressionButton );
       qmlCodeBox->layout()->addWidget( qmlCode );
       layout->addRow( qmlCodeBox );
-      QGroupBox *qmlPreviewBox = new QGroupBox( tr( "Preview") );
+      QScrollArea *qmlPreviewBox = new QScrollArea();
       qmlPreviewBox->setLayout( new QGridLayout );
       qmlPreviewBox->setMinimumWidth( 400 );
-      qmlPreviewBox->layout()->addWidget(qmlWrapper->widget());
+      qmlPreviewBox->layout()->addWidget( qmlWrapper->widget() );
       qmlLayout->addWidget( qmlPreviewBox );
 
       QDialogButtonBox *buttonBox = new QDialogButtonBox( QDialogButtonBox::Ok | QDialogButtonBox::Cancel );

src/gui/editorwidgets/qgsqmlwidgetwrapper.cpp

@@ -91,5 +91,26 @@ void QgsQmlWidgetWrapper::setQmlCode( const QString &qmlCode )
 void QgsQmlWidgetWrapper::setFeature( const QgsFeature &feature )
 {
   if ( mWidget )
-    mWidget->rootContext()->setContextProperty( "feature", feature );
+  {
+    QgsExpressionContext context = layer()->createExpressionContext();
+
+    context.setFeature( feature );
+
+    QmlExpression *qmlExpression = new QmlExpression();
+    qmlExpression->setExpressionContext( context );
+
+    mWidget->rootContext()->setContextProperty( "expression", qmlExpression );
+  }
+}
+
+void QmlExpression::setExpressionContext( const QgsExpressionContext &context )
+{
+  mExpressionContext = context;
+}
+
+QVariant QmlExpression::evaluate( const QString& expression ) const
+{
+  QgsExpression exp = QgsExpression( expression );
+  exp.prepare( &mExpressionContext );
+  return exp.evaluate(&mExpressionContext);
 }

src/gui/editorwidgets/qgsqmlwidgetwrapper.h

@@ -21,7 +21,6 @@
 #include "qgis_gui.h"
 #include <QtQuickWidgets/QQuickWidget>
 
-
 class GUI_EXPORT QgsQmlWidgetWrapper : public QgsWidgetWrapper
 {
     Q_OBJECT
@@ -51,17 +50,18 @@ class GUI_EXPORT QgsQmlWidgetWrapper : public QgsWidgetWrapper
     QgsFeature mFeature;
 };
 
-/*
-class GUI_EXPORT QmlExpression
+
+class GUI_EXPORT QmlExpression : public QObject
 {
-  Q_GADGET
+  Q_OBJECT
 
   public:
-    QgsExpressionContext expressionContext();
-    void setExpressionContext( QgsExpressionContext expressionContext );
+   void setExpressionContext( const QgsExpressionContext &context );
+
+   Q_INVOKABLE QVariant evaluate( const QString &expression) const;
 
-   Q_INVOKABLE evaluate();
-}
-*/
+  private:
+   QgsExpressionContext mExpressionContext;
+};
 
 #endif // QGSQMLWIDGETWRAPPER_H