Address comment, optimize and hard-code conditional styling of constr…

…aints

python/core/auto_generated/qgsconditionalstyle.sip.in

@@ -8,8 +8,8 @@
 
 
 
-typedef QList<QgsConditionalStyle> QgsConditionalStyles;
 
+typedef QList<QgsConditionalStyle> QgsConditionalStyles;
 
 class QgsConditionalLayerStyles : QObject
 {
@@ -45,23 +45,11 @@ Each row will check be checked against each rule.
 .. versionadded:: 2.12
 %End
 
-    QgsConditionalStyles constraintStyles() const;
+    QgsConditionalStyle constraintFailureStyles( QgsFieldConstraints::ConstraintStrength strength );
 %Docstring
-Returns a list of row styles associated with layer constraints.
-
-.. seealso:: :py:func:`setConstraintStyles`
-
-.. versionadded:: 3.30
-%End
-
-    void setConstraintStyles( const QgsConditionalStyles &styles );
-%Docstring
-Sets the conditional ``styles`` for fields constraint.
-
-The field name is inserted into a @value variable to conduct
-expressionchecks.
+Returns a style associated to a constraint failure.
 
-.. seealso:: :py:func:`constraintStyles`
+:param strength: the type of constraint
 
 .. versionadded:: 3.30
 %End
@@ -70,7 +58,7 @@ expressionchecks.
 %Docstring
 Set the conditional ``styles`` for a field, with the specified ``fieldName``.
 
-The field value is inserted into a @value variable to conduct
+The field value is inserted into a 'value' variable to conduct
 expression checks.
 
 .. seealso:: :py:func:`fieldStyles`

python/core/auto_generated/vector/qgsvectorlayerutils.sip.in

@@ -168,6 +168,16 @@ be unique within regard to ``existingValues``.
 The optional seed value can be used as a basis for generated values.
 
 .. versionadded:: 3.6
+%End
+
+    static bool attributeHasConstraints( const QgsVectorLayer *layer, int attributeIndex );
+%Docstring
+Returns ``True`` if a feature attribute has active constraints.
+
+:param layer: the vector layer from which field constraints will be checked for
+:param attributeIndex: the attribute index
+
+.. versionadded:: 3.30
 %End
 
     static bool validateAttribute( const QgsVectorLayer *layer, const QgsFeature &feature, int attributeIndex, QStringList &errors /Out/,

src/core/layout/qgslayoutitemattributetable.cpp

@@ -22,6 +22,7 @@
 #include "qgslayoututils.h"
 #include "qgsfeatureiterator.h"
 #include "qgsvectorlayer.h"
+#include "qgsvectorlayerutils.h"
 #include "qgslayoutframe.h"
 #include "qgsproject.h"
 #include "qgsrelationmanager.h"
@@ -575,16 +576,27 @@ bool QgsLayoutItemAttributeTable::getTableContents( QgsLayoutTableContents &cont
 
         if ( mUseConditionalStyling )
         {
-          const QString fieldName = layer->fields().at( idx ).name();
-
-          QList<QgsConditionalStyle> styles = conditionalStyles->constraintStyles();
-          styles = QgsConditionalStyle::matchingConditionalStyles( styles, fieldName, context );
-          const QgsConditionalStyle constraintStyle = QgsConditionalStyle::compressStyles( styles );
+          QgsConditionalStyle constraintstyle;
+          if ( QgsVectorLayerUtils::attributeHasConstraints( layer, idx ) )
+          {
+            QStringList errors;
+            if ( !QgsVectorLayerUtils::validateAttribute( layer, f, idx, errors, QgsFieldConstraints::ConstraintStrengthHard ) )
+            {
+              constraintstyle = layer->conditionalStyles()->constraintFailureStyles( QgsFieldConstraints::ConstraintStrengthHard );
+            }
+            else
+            {
+              if ( !QgsVectorLayerUtils::validateAttribute( layer, f, idx, errors, QgsFieldConstraints::ConstraintStrengthSoft ) )
+              {
+                constraintstyle = layer->conditionalStyles()->constraintFailureStyles( QgsFieldConstraints::ConstraintStrengthSoft );
+              }
+            }
+          }
 
-          styles = conditionalStyles->fieldStyles( fieldName );
+          QList<QgsConditionalStyle> styles = conditionalStyles->fieldStyles( layer->fields().at( idx ).name() );
           styles = QgsConditionalStyle::matchingConditionalStyles( styles, val, context );
           styles.insert( 0, rowStyle );
-          styles.insert( 0, constraintStyle );
+          styles.insert( 0, constraintstyle );
           style = QgsConditionalStyle::compressStyles( styles );
         }
 

src/core/qgsconditionalstyle.cpp

@@ -26,18 +26,33 @@ QgsConditionalLayerStyles::QgsConditionalLayerStyles( QObject *parent )
 {
 }
 
-QgsConditionalStyles QgsConditionalLayerStyles::constraintStyles() const
+QgsConditionalStyle QgsConditionalLayerStyles::constraintFailureStyles( QgsFieldConstraints::ConstraintStrength strength )
 {
-  return mConstraintStyles;
-}
-
-void QgsConditionalLayerStyles::setConstraintStyles( const QgsConditionalStyles &styles )
-{
-  if ( styles == mConstraintStyles )
-    return;
+  switch ( strength )
+  {
+    case QgsFieldConstraints::ConstraintStrengthHard:
+      if ( !mHardConstraintFailureStyle )
+      {
+        mHardConstraintFailureStyle = std::make_unique<QgsConditionalStyle>();
+        mHardConstraintFailureStyle->setBackgroundColor( QColor( 255, 152, 0 ) );
+        mHardConstraintFailureStyle->setTextColor( QColor( 0, 0, 0 ) );
+      }
+      return *mHardConstraintFailureStyle.get();
+
+    case QgsFieldConstraints::ConstraintStrengthSoft:
+      if ( !mSoftConstraintFailureStyle )
+      {
+        mSoftConstraintFailureStyle = std::make_unique<QgsConditionalStyle>();
+        mSoftConstraintFailureStyle->setBackgroundColor( QColor( 255, 191, 12 ) );
+        mSoftConstraintFailureStyle->setTextColor( QColor( 0, 0, 0 ) );
+      }
+      return *mSoftConstraintFailureStyle.get();
+
+    case QgsFieldConstraints::ConstraintStrengthNotSet:
+      return QgsConditionalStyle();
+  }
 
-  mConstraintStyles = styles;
-  emit changed();
+  return QgsConditionalStyle();
 }
 
 QgsConditionalStyles QgsConditionalLayerStyles::rowStyles() const
@@ -72,14 +87,6 @@ bool QgsConditionalLayerStyles::writeXml( QDomNode &node, QDomDocument &doc, con
 {
   QDomElement stylesel = doc.createElement( QStringLiteral( "conditionalstyles" ) );
 
-  QDomElement constraintel = doc.createElement( QStringLiteral( "constraintstyles" ) );
-  const auto constMConstraintStyles = mConstraintStyles;
-  for ( const QgsConditionalStyle &style : constMConstraintStyles )
-  {
-    style.writeXml( constraintel, doc, context );
-  }
-  stylesel.appendChild( constraintel );
-
   QDomElement rowel = doc.createElement( QStringLiteral( "rowstyles" ) );
   const auto constMRowStyles = mRowStyles;
   for ( const QgsConditionalStyle &style : constMRowStyles )
@@ -122,24 +129,13 @@ bool QgsConditionalLayerStyles::rulesNeedGeometry() const
 
 bool QgsConditionalLayerStyles::readXml( const QDomNode &node, const QgsReadWriteContext &context )
 {
-  mConstraintStyles.clear();
   mRowStyles.clear();
   mFieldStyles.clear();
 
   const QDomElement condel = node.firstChildElement( QStringLiteral( "conditionalstyles" ) );
 
-  const QDomElement constraintstylesel = condel.firstChildElement( QStringLiteral( "constraintstyles" ) );
-  QDomNodeList nodelist = constraintstylesel.toElement().elementsByTagName( QStringLiteral( "style" ) );
-  for ( int i = 0; i < nodelist.count(); i++ )
-  {
-    const QDomElement styleElm = nodelist.at( i ).toElement();
-    QgsConditionalStyle style = QgsConditionalStyle();
-    style.readXml( styleElm, context );
-    mConstraintStyles.append( style );
-  }
-
   const QDomElement rowstylesel = condel.firstChildElement( QStringLiteral( "rowstyles" ) );
-  nodelist = rowstylesel.toElement().elementsByTagName( QStringLiteral( "style" ) );
+  QDomNodeList nodelist = rowstylesel.toElement().elementsByTagName( QStringLiteral( "style" ) );
   for ( int i = 0; i < nodelist.count(); i++ )
   {
     const QDomElement styleElm = nodelist.at( i ).toElement();

src/core/qgsconditionalstyle.h

@@ -16,6 +16,8 @@
 #define QGSCONDITIONALSTYLE_H
 
 #include "qgis_core.h"
+#include "qgsfield.h"
+
 #include <QObject>
 #include <QFont>
 #include <QColor>
@@ -32,7 +34,6 @@ class QgsSymbol;
 
 typedef QList<QgsConditionalStyle> QgsConditionalStyles;
 
-
 /**
  * \ingroup core
  * \brief The QgsConditionalLayerStyles class holds conditional style information
@@ -66,28 +67,16 @@ class CORE_EXPORT QgsConditionalLayerStyles : public QObject
     void setRowStyles( const QgsConditionalStyles &styles );
 
     /**
-     * Returns a list of row styles associated with layer constraints.
-     *
-     * \see setConstraintStyles()
-     * \since QGIS 3.30
-     */
-    QgsConditionalStyles constraintStyles() const;
-
-    /**
-     * Sets the conditional \a styles for fields constraint.
-     *
-     * The field name is inserted into a @value variable to conduct
-     * expressionchecks.
-     *
-     * \see constraintStyles()
+     * Returns a style associated to a constraint failure.
+     * \param strength the type of constraint
      * \since QGIS 3.30
      */
-    void setConstraintStyles( const QgsConditionalStyles &styles );
+    QgsConditionalStyle constraintFailureStyles( QgsFieldConstraints::ConstraintStrength strength );
 
     /**
      * Set the conditional \a styles for a field, with the specified \a fieldName.
      *
-     * The field value is inserted into a @value variable to conduct
+     * The field value is inserted into a 'value' variable to conduct
      * expression checks.
      *
      * \see fieldStyles()
@@ -133,7 +122,8 @@ class CORE_EXPORT QgsConditionalLayerStyles : public QObject
   private:
     QHash<QString, QgsConditionalStyles> mFieldStyles;
     QgsConditionalStyles mRowStyles;
-    QgsConditionalStyles mConstraintStyles;
+    std::unique_ptr<QgsConditionalStyle> mHardConstraintFailureStyle;
+    std::unique_ptr<QgsConditionalStyle> mSoftConstraintFailureStyle;
 };
 
 /**

src/core/vector/qgsvectorlayerutils.cpp

@@ -367,6 +367,20 @@ QVariant QgsVectorLayerUtils::createUniqueValueFromCache( const QgsVectorLayer *
 
 }
 
+bool QgsVectorLayerUtils::attributeHasConstraints( const QgsVectorLayer *layer, int attributeIndex )
+{
+  if ( !layer )
+    return false;
+
+  if ( attributeIndex < 0 || attributeIndex >= layer->fields().count() )
+    return false;
+
+  const QgsFieldConstraints constraints = layer->fields().at( attributeIndex ).constraints();
+  return ( constraints.constraints() & QgsFieldConstraints::ConstraintNotNull ||
+           constraints.constraints() & QgsFieldConstraints::ConstraintUnique ||
+           constraints.constraints() & QgsFieldConstraints::ConstraintExpression );
+}
+
 bool QgsVectorLayerUtils::validateAttribute( const QgsVectorLayer *layer, const QgsFeature &feature, int attributeIndex, QStringList &errors,
     QgsFieldConstraints::ConstraintStrength strength, QgsFieldConstraints::ConstraintOrigin origin )
 {

src/core/vector/qgsvectorlayerutils.h

@@ -183,6 +183,14 @@ class CORE_EXPORT QgsVectorLayerUtils
      */
     static QVariant createUniqueValueFromCache( const QgsVectorLayer *layer, int fieldIndex, const QSet<QVariant> &existingValues, const QVariant &seed = QVariant() );
 
+    /**
+     * Returns TRUE if a feature attribute has active constraints.
+     * \param layer the vector layer from which field constraints will be checked for
+     * \param attributeIndex the attribute index
+     * \since QGIS 3.30
+     */
+    static bool attributeHasConstraints( const QgsVectorLayer *layer, int attributeIndex );
+
     /**
      * Tests a feature attribute value to check whether it passes all constraints which are present on the corresponding field.
      * Returns TRUE if the attribute value is valid for the field. Any constraint failures will be reported in the errors argument.

src/gui/attributetable/qgsattributetablemodel.cpp

@@ -529,6 +529,7 @@ void QgsAttributeTableModel::fieldConditionalStyleChanged( const QString &fieldN
   if ( fieldName.isNull() )
   {
     mRowStylesMap.clear();
+    mConstraintStylesMap.clear();
     emit dataChanged( index( 0, 0 ), index( rowCount() - 1, columnCount() - 1 ) );
     return;
   }
@@ -772,8 +773,31 @@ QVariant QgsAttributeTableModel::data( const QModelIndex &index, int role ) cons
       }
       const QgsConditionalStyle rowstyle = QgsConditionalStyle::compressStyles( styles );
 
-      styles = QgsConditionalStyle::matchingConditionalStyles( mLayer->conditionalStyles()->constraintStyles(), field.name(),  mExpressionContext );
-      const QgsConditionalStyle constraintstyle = QgsConditionalStyle::compressStyles( styles );
+      QgsConditionalStyle constraintstyle;
+      if ( QgsVectorLayerUtils::attributeHasConstraints( mLayer, fieldId ) )
+      {
+        if ( mConstraintStylesMap.contains( mFeat.id() ) &&
+             mConstraintStylesMap[mFeat.id()].contains( fieldId ) )
+        {
+          constraintstyle = mConstraintStylesMap[mFeat.id()][fieldId];
+        }
+        else
+        {
+          QStringList errors;
+          if ( !QgsVectorLayerUtils::validateAttribute( mLayer, mFeat, fieldId, errors, QgsFieldConstraints::ConstraintStrengthHard ) )
+          {
+            constraintstyle = mLayer->conditionalStyles()->constraintFailureStyles( QgsFieldConstraints::ConstraintStrengthHard );
+          }
+          else
+          {
+            if ( !QgsVectorLayerUtils::validateAttribute( mLayer, mFeat, fieldId, errors, QgsFieldConstraints::ConstraintStrengthSoft ) )
+            {
+              constraintstyle = mLayer->conditionalStyles()->constraintFailureStyles( QgsFieldConstraints::ConstraintStrengthSoft );
+            }
+          }
+          mConstraintStylesMap[mFeat.id()].insert( fieldId, constraintstyle );
+        }
+      }
 
       styles = mLayer->conditionalStyles()->fieldStyles( field.name() );
       styles = QgsConditionalStyle::matchingConditionalStyles( styles, val,  mExpressionContext );
@@ -821,6 +845,7 @@ bool QgsAttributeTableModel::setData( const QModelIndex &index, const QVariant &
     return false;
 
   mRowStylesMap.remove( mFeat.id() );
+  mConstraintStylesMap.remove( mFeat.id() );
 
   if ( !mLayer->isModified() )
     return false;

src/gui/attributetable/qgsattributetablemodel.h

@@ -345,6 +345,7 @@ class GUI_EXPORT QgsAttributeTableModel: public QAbstractTableModel
     QHash<QgsFeatureId, int> mIdRowMap;
     QHash<int, QgsFeatureId> mRowIdMap;
     mutable QHash<QgsFeatureId, QList<QgsConditionalStyle> > mRowStylesMap;
+    mutable QHash<QgsFeatureId, QHash<int, QgsConditionalStyle> > mConstraintStylesMap;
 
     mutable QgsExpressionContext mExpressionContext;