Automatically handle adding data defined button for dynamic properties

Also exposes this capability to modeler - so that model algorithms
can use data defined parameters within their child algorithms.

TODO:
- tests
- setting the associated vector layer

python/gui/auto_generated/processing/qgsprocessingwidgetwrapper.sip.in

@@ -92,22 +92,21 @@ Returns the current wrapped label, if any.
 Returns the parameter definition associated with this wrapper.
 %End
 
-
-    virtual void setWidgetValue( const QVariant &value, const QgsProcessingContext &context ) = 0;
+    void setParameterValue( const QVariant &value, const QgsProcessingContext &context );
 %Docstring
 Sets the current ``value`` for the parameter.
 
 The ``context`` argument is used to specify the wider Processing context which the
 current value is associated with.
 
-.. seealso:: :py:func:`value`
+.. seealso:: :py:func:`parameterValue`
 %End
 
-    virtual QVariant value() const = 0;
+    QVariant parameterValue() const;
 %Docstring
 Returns the current value of the parameter.
 
-.. seealso:: :py:func:`setWidgetValue`
+.. seealso:: :py:func:`setParameterValue`
 %End
 
     virtual void postInitialize( const QList< QgsAbstractProcessingParameterWidgetWrapper * > &wrappers );
@@ -137,6 +136,23 @@ label should be shown for the parameter's widget (i.e. the label is embedded ins
 widget itself).
 
 .. seealso:: :py:func:`createWidget`
+%End
+
+    virtual void setWidgetValue( const QVariant &value, const QgsProcessingContext &context ) = 0;
+%Docstring
+Sets the current ``value`` for the parameter to show in the widget.
+
+The ``context`` argument is used to specify the wider Processing context which the
+current value is associated with.
+
+.. seealso:: :py:func:`widgetValue`
+%End
+
+    virtual QVariant widgetValue() const = 0;
+%Docstring
+Returns the current value of the parameter.
+
+.. seealso:: :py:func:`setWidgetValue`
 %End
 
 };

python/plugins/processing/gui/AlgorithmDialog.py

@@ -110,7 +110,7 @@ class AlgorithmDialog(QgsProcessingAlgorithmDialogBase):
                 if widget is None:
                     continue
 
-                value = wrapper.value()
+                value = wrapper.parameterValue()
                 parameters[param.name()] = value
 
                 if not param.checkValueIsAcceptable(value):

python/plugins/processing/gui/ParametersPanel.py

@@ -219,7 +219,7 @@ class ParametersPanel(BASE, WIDGET):
                 value = parameters[param.name()]
 
                 wrapper = self.wrappers[param.name()]
-                wrapper.setWidgetValue(value, context)
+                wrapper.setParameterValue(value, context)
             else:
                 dest_widget = self.outputWidgets[param.name()]
                 dest_widget.setValue(parameters[param.name()])

python/plugins/processing/gui/wrappers.py

@@ -202,6 +202,12 @@ class WidgetWrapper(QgsAbstractProcessingParameterWidgetWrapper):
     def setValue(self, value):
         pass
 
+    def value(self):
+        return None
+
+    def widgetValue(self):
+        return self.value()
+
     def setWidgetValue(self, value, context):
         self.setValue(value)
 

src/gui/processing/qgsprocessingmodelerwidget.cpp

@@ -145,7 +145,7 @@ QgsProcessingModelChildParameterSource QgsProcessingModelerParameterWidget::valu
   switch ( mStackedWidget->currentIndex() )
   {
     case 0:
-      return QgsProcessingModelChildParameterSource::fromStaticValue( mStaticWidgetWrapper->value() );
+      return QgsProcessingModelChildParameterSource::fromStaticValue( mStaticWidgetWrapper->parameterValue() );
 
     case 1:
       return QgsProcessingModelChildParameterSource::fromExpression( mExpressionWidget->expression() );
@@ -238,7 +238,7 @@ void QgsProcessingModelerParameterWidget::setSourceType( QgsProcessingModelChild
 
 void QgsProcessingModelerParameterWidget::updateUi()
 {
-  mStaticWidgetWrapper->setWidgetValue( mStaticValue, mContext );
+  mStaticWidgetWrapper->setParameterValue( mStaticValue, mContext );
 
   mExpressionWidget->setExpression( mExpression );
 

src/gui/processing/qgsprocessingwidgetwrapper.cpp

@@ -19,8 +19,9 @@
 #include "qgsprocessingwidgetwrapper.h"
 #include "qgsprocessingparameters.h"
 #include "qgsprocessingmodelerwidget.h"
+#include "qgspropertyoverridebutton.h"
 #include <QLabel>
-
+#include <QHBoxLayout>
 
 QgsAbstractProcessingParameterWidgetWrapper::QgsAbstractProcessingParameterWidgetWrapper( const QgsProcessingParameterDefinition *parameter, QgsProcessingGui::WidgetType type, QObject *parent )
   : QObject( parent )
@@ -40,9 +41,25 @@ QWidget *QgsAbstractProcessingParameterWidgetWrapper::createWrappedWidget( const
     return mWidget;
 
   mWidget = createWidget();
+  QWidget *wrappedWidget = mWidget;
+  if ( mType != QgsProcessingGui::Batch && mParameterDefinition->isDynamic() )
+  {
+    QHBoxLayout *hLayout = new QHBoxLayout();
+    hLayout->setMargin( 0 );
+    hLayout->setContentsMargins( 0, 0, 0, 0 );
+    hLayout->addWidget( mWidget, 1 );
+    mPropertyButton = new QgsPropertyOverrideButton();
+    hLayout->addWidget( mPropertyButton );
+    mPropertyButton->init( 0, QgsProperty(), mParameterDefinition->dynamicPropertyDefinition() );
+    mPropertyButton->registerEnabledWidget( mWidget, false );
+
+    wrappedWidget = new QWidget();
+    wrappedWidget->setLayout( hLayout );
+  }
+
   setWidgetValue( mParameterDefinition->defaultValue(), context );
 
-  return mWidget;
+  return wrappedWidget;
 }
 
 QLabel *QgsAbstractProcessingParameterWidgetWrapper::createWrappedLabel()
@@ -69,6 +86,26 @@ const QgsProcessingParameterDefinition *QgsAbstractProcessingParameterWidgetWrap
   return mParameterDefinition;
 }
 
+void QgsAbstractProcessingParameterWidgetWrapper::setParameterValue( const QVariant &value, const QgsProcessingContext &context )
+{
+  if ( mPropertyButton && value.canConvert< QgsProperty >() )
+  {
+    mPropertyButton->setToProperty( value.value< QgsProperty >() );
+  }
+  else
+  {
+    setWidgetValue( value, context );
+  }
+}
+
+QVariant QgsAbstractProcessingParameterWidgetWrapper::parameterValue() const
+{
+  if ( mPropertyButton && mPropertyButton->isActive() )
+    return mPropertyButton->toProperty();
+  else
+    return widgetValue();
+}
+
 QLabel *QgsAbstractProcessingParameterWidgetWrapper::createLabel()
 {
   switch ( mType )

src/gui/processing/qgsprocessingwidgetwrapper.h

@@ -30,6 +30,7 @@ class QgsProcessingContext;
 class QgsProcessingModelerParameterWidget;
 class QgsProcessingModelAlgorithm;
 class QLabel;
+class QgsPropertyOverrideButton;
 
 /**
  * \class QgsAbstractProcessingParameterWidgetWrapper
@@ -111,24 +112,22 @@ class GUI_EXPORT QgsAbstractProcessingParameterWidgetWrapper : public QObject
      */
     const QgsProcessingParameterDefinition *parameterDefinition() const;
 
-    // TODO QGIS 4.0 - rename to setValue, avoid conflict with Python WidgetWrapper method
-
     /**
      * Sets the current \a value for the parameter.
      *
      * The \a context argument is used to specify the wider Processing context which the
      * current value is associated with.
      *
-     * \see value()
+     * \see parameterValue()
      */
-    virtual void setWidgetValue( const QVariant &value, const QgsProcessingContext &context ) = 0;
+    void setParameterValue( const QVariant &value, const QgsProcessingContext &context );
 
     /**
      * Returns the current value of the parameter.
      *
-     * \see setWidgetValue()
+     * \see setParameterValue()
      */
-    virtual QVariant value() const = 0;
+    QVariant parameterValue() const;
 
     /**
      * Called after all wrappers have been created within a particular dialog or context,
@@ -159,12 +158,30 @@ class GUI_EXPORT QgsAbstractProcessingParameterWidgetWrapper : public QObject
      */
     virtual QLabel *createLabel() SIP_FACTORY;
 
+    /**
+     * Sets the current \a value for the parameter to show in the widget.
+     *
+     * The \a context argument is used to specify the wider Processing context which the
+     * current value is associated with.
+     *
+     * \see widgetValue()
+     */
+    virtual void setWidgetValue( const QVariant &value, const QgsProcessingContext &context ) = 0;
+
+    /**
+     * Returns the current value of the parameter.
+     *
+     * \see setWidgetValue()
+     */
+    virtual QVariant widgetValue() const = 0;
+
   private:
 
     QgsProcessingGui::WidgetType mType = QgsProcessingGui::Standard;
     const QgsProcessingParameterDefinition *mParameterDefinition = nullptr;
 
     QPointer< QWidget > mWidget;
+    QPointer< QgsPropertyOverrideButton > mPropertyButton;
     QPointer< QLabel > mLabel;
 
 };

src/gui/processing/qgsprocessingwidgetwrapperimpl.cpp

@@ -92,7 +92,7 @@ void QgsProcessingBooleanWidgetWrapper::setWidgetValue( const QVariant &value, c
   }
 }
 
-QVariant QgsProcessingBooleanWidgetWrapper::value() const
+QVariant QgsProcessingBooleanWidgetWrapper::widgetValue() const
 {
   switch ( type() )
   {

src/gui/processing/qgsprocessingwidgetwrapperimpl.h

@@ -41,12 +41,11 @@ class GUI_EXPORT QgsProcessingBooleanWidgetWrapper : public QgsAbstractProcessin
     // QgsProcessingParameterWidgetWrapper interface
     QWidget *createWidget() override SIP_FACTORY;
     QLabel *createLabel() override SIP_FACTORY;
+
+  protected:
+
     void setWidgetValue( const QVariant &value, const QgsProcessingContext &context ) override;
-    QVariant value() const override;
-
-  protected:
-
-  protected:
+    QVariant widgetValue() const override;
 
     QStringList compatibleParameterTypes() const override;
 
@@ -58,6 +57,8 @@ class GUI_EXPORT QgsProcessingBooleanWidgetWrapper : public QgsAbstractProcessin
 
     QCheckBox *mCheckBox = nullptr;
     QComboBox *mComboBox = nullptr;
+
+    friend class TestProcessingGui;
 };
 
 ///@endcond PRIVATE

tests/src/gui/testprocessinggui.cpp

@@ -79,7 +79,7 @@ class TestWidgetWrapper : public QgsAbstractProcessingParameterWidgetWrapper
     {
     }
 
-    QVariant value() const override
+    QVariant widgetValue() const override
     {
       return QVariant();
     }
@@ -286,12 +286,12 @@ void TestProcessingGui::testWrapperGeneral()
   param = TestParamType( QStringLiteral( "boolean" ), QStringLiteral( "bool" ), true );
   QgsProcessingBooleanWidgetWrapper trueDefault( &param );
   w = trueDefault.createWrappedWidget( context );
-  QVERIFY( trueDefault.value().toBool() );
+  QVERIFY( trueDefault.widgetValue().toBool() );
   delete w;
   param = TestParamType( QStringLiteral( "boolean" ), QStringLiteral( "bool" ), false );
   QgsProcessingBooleanWidgetWrapper falseDefault( &param );
   w = falseDefault.createWrappedWidget( context );
-  QVERIFY( !falseDefault.value().toBool() );
+  QVERIFY( !falseDefault.widgetValue().toBool() );
   delete w;
 }
 
@@ -406,10 +406,10 @@ void TestProcessingGui::testBooleanWrapper()
   QgsProcessingContext context;
   QWidget *w = wrapper.createWrappedWidget( context );
   wrapper.setWidgetValue( true, context );
-  QVERIFY( wrapper.value().toBool() );
+  QVERIFY( wrapper.widgetValue().toBool() );
   QVERIFY( static_cast< QCheckBox * >( wrapper.wrappedWidget() )->isChecked() );
   wrapper.setWidgetValue( false, context );
-  QVERIFY( !wrapper.value().toBool() );
+  QVERIFY( !wrapper.widgetValue().toBool() );
   QVERIFY( !static_cast< QCheckBox * >( wrapper.wrappedWidget() )->isChecked() );
 
   // should be no label in standard mode
@@ -422,10 +422,10 @@ void TestProcessingGui::testBooleanWrapper()
 
   w = wrapperB.createWrappedWidget( context );
   wrapperB.setWidgetValue( true, context );
-  QVERIFY( wrapperB.value().toBool() );
+  QVERIFY( wrapperB.widgetValue().toBool() );
   QVERIFY( static_cast< QComboBox * >( wrapperB.wrappedWidget() )->currentData().toBool() );
   wrapperB.setWidgetValue( false, context );
-  QVERIFY( !wrapperB.value().toBool() );
+  QVERIFY( !wrapperB.widgetValue().toBool() );
   QVERIFY( !static_cast< QComboBox * >( wrapperB.wrappedWidget() )->currentData().toBool() );
 
   // should be no label in batch mode
@@ -437,10 +437,10 @@ void TestProcessingGui::testBooleanWrapper()
 
   w = wrapperM.createWrappedWidget( context );
   wrapperM.setWidgetValue( true, context );
-  QVERIFY( wrapperM.value().toBool() );
+  QVERIFY( wrapperM.widgetValue().toBool() );
   QVERIFY( static_cast< QComboBox * >( wrapperM.wrappedWidget() )->currentData().toBool() );
   wrapperM.setWidgetValue( false, context );
-  QVERIFY( !wrapperM.value().toBool() );
+  QVERIFY( !wrapperM.widgetValue().toBool() );
   QVERIFY( !static_cast< QComboBox * >( wrapperM.wrappedWidget() )->currentData().toBool() );
 
   // should be a label in modeler mode