[search widgets] when selecting _Please select_ find all features

Author: 3nids

src/gui/editorwidgets/core/qgssearchwidgetwrapper.cpp

@@ -33,3 +33,8 @@ void QgsSearchWidgetWrapper::setFeature( const QgsFeature& feature )
   Q_UNUSED( feature )
 }
 
+void QgsSearchWidgetWrapper::clearExpression()
+{
+  mExpression = QString( "TRUE" );
+}
+

src/gui/editorwidgets/core/qgssearchwidgetwrapper.h

@@ -81,6 +81,9 @@ class GUI_EXPORT QgsSearchWidgetWrapper : public QgsWidgetWrapper
     void setFeature( const QgsFeature& feature ) override;
 
   protected:
+    //! clears the expression to search for all features
+    void clearExpression();
+
     QString mExpression;
     int mFieldIdx;
 

src/gui/editorwidgets/qgsvaluemapsearchwidgetwrapper.cpp

@@ -37,7 +37,14 @@ void QgsValueMapSearchWidgetWrapper::comboBoxIndexChanged( int idx )
 {
   if ( mComboBox )
   {
-    setExpression( mComboBox->itemData( idx ).toString() );
+    if ( idx == 0 )
+    {
+      clearExpression();
+    }
+    else
+    {
+      setExpression( mComboBox->itemData( idx ).toString() );
+    }
     emit expressionChanged( mExpression );
   }
 }

src/gui/editorwidgets/qgsvaluerelationsearchwidgetwrapper.cpp

@@ -97,8 +97,15 @@ bool QgsValueRelationSearchWidgetWrapper::valid()
 void QgsValueRelationSearchWidgetWrapper::valueChanged()
 {
   QVariant vl = value();
-  QSettings settings;
-  setExpression( vl.isNull() ? settings.value( "qgis/nullValue", "NULL" ).toString() : vl.toString() );
+  if ( !vl.isValid() )
+  {
+    clearExpression();
+  }
+  else
+  {
+    QSettings settings;
+    setExpression( vl.isNull() ? settings.value( "qgis/nullValue", "NULL" ).toString() : vl.toString() );
+  }
   emit expressionChanged( mExpression );
 }
 
@@ -149,7 +156,7 @@ void QgsValueRelationSearchWidgetWrapper::initWidget( QWidget* editor )
 
   if ( mComboBox )
   {
-    mComboBox->addItem( tr( "Please select" ), QVariant( layer()->fields().at( mFieldIdx ).type() ) );
+    mComboBox->addItem( tr( "Please select" ), QVariant() ); // creates an invalid to allow selecting all features
     if ( config( "AllowNull" ).toBool() )
     {
       mComboBox->addItem( tr( "(no selection)" ), QVariant( layer()->fields().at( mFieldIdx ).type() ) );