qgsfeaturepickermodelbase.h

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/***************************************************************************
  qgsfeaturefiltermodel.h - QgsFeatureFilterModel
 ---------------------
 begin                : 10.3.2017
 copyright            : (C) 2017 by Matthias Kuhn
 email                : [email protected]
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
#ifndef QGSFEATUREFILTERMODELBASE_H
#define QGSFEATUREFILTERMODELBASE_H
 
#include "qgsconditionalstyle.h"
#include "qgsfeatureexpressionvaluesgatherer.h"
 
#include <QAbstractItemModel>
#include <QTimer>

class CORE_EXPORT QgsFeaturePickerModelBase : public QAbstractItemModel SIP_ABSTRACT
{
    Q_OBJECT
 
    Q_PROPERTY( QgsVectorLayer *sourceLayer READ sourceLayer WRITE setSourceLayer NOTIFY sourceLayerChanged )
    Q_PROPERTY( QString displayExpression READ displayExpression WRITE setDisplayExpression NOTIFY displayExpressionChanged )
    Q_PROPERTY( QString filterValue READ filterValue WRITE setFilterValue NOTIFY filterValueChanged )
    Q_PROPERTY( QString filterExpression READ filterExpression WRITE setFilterExpression NOTIFY filterExpressionChanged )
    Q_PROPERTY( QString orderExpression READ orderExpression WRITE setOrderExpression NOTIFY orderExpressionChanged )
    Q_PROPERTY( Qt::SortOrder sortOrder READ sortOrder WRITE setSortOrder NOTIFY sortOrderChanged )
    Q_PROPERTY( bool allowNull READ allowNull WRITE setAllowNull NOTIFY allowNullChanged )
    Q_PROPERTY( bool fetchGeometry READ fetchGeometry WRITE setFetchGeometry NOTIFY fetchGeometryChanged )
    Q_PROPERTY( int fetchLimit READ fetchLimit WRITE setFetchLimit NOTIFY fetchLimitChanged )
    Q_PROPERTY( int extraIdentifierValueIndex READ extraIdentifierValueIndex NOTIFY extraIdentifierValueIndexChanged )
 
  public:
 
    // *INDENT-OFF*

    enum class CustomRole SIP_MONKEYPATCH_SCOPEENUM_UNNEST( QgsFeaturePickerModelBase, Role ) : int
    {
      IdentifierValue SIP_MONKEYPATCH_COMPAT_NAME(IdentifierValueRole) = Qt::UserRole, 
      IdentifierValues SIP_MONKEYPATCH_COMPAT_NAME(IdentifierValuesRole), 
      Value SIP_MONKEYPATCH_COMPAT_NAME(ValueRole), 
      Feature SIP_MONKEYPATCH_COMPAT_NAME(FeatureRole), 
      FeatureId SIP_MONKEYPATCH_COMPAT_NAME(FeatureIdRole) 
    };
    Q_ENUM( CustomRole )
    // *INDENT-ON*
 
    
    explicit QgsFeaturePickerModelBase( QObject *parent = nullptr );
    ~QgsFeaturePickerModelBase() override;

    QgsVectorLayer *sourceLayer() const;

    void setSourceLayer( QgsVectorLayer *sourceLayer );

    QString displayExpression() const;

    void setDisplayExpression( const QString &displayExpression );

    QString filterValue() const;

    void setFilterValue( const QString &filterValue );
 
    QModelIndex index( int row, int column, const QModelIndex &parent ) const override;
    QModelIndex parent( const QModelIndex &child ) const override;
    int rowCount( const QModelIndex &parent ) const override;
    int columnCount( const QModelIndex &parent ) const override
    {
      Q_UNUSED( parent )
      return 1;
    }
    QVariant data( const QModelIndex &index, int role ) const override;

    QString filterExpression() const;

    void setFilterExpression( const QString &filterExpression );

    QString orderExpression() const;

    void setOrderExpression( const QString &orderExpression );

    Qt::SortOrder sortOrder() const;

    void setSortOrder( const Qt::SortOrder sortOrder );
 

    QgsFeature formFeature() const;

    void setFormFeature( const QgsFeature &feature );

    QgsFeature parentFormFeature() const;

    void setParentFormFeature( const QgsFeature &feature );

    bool isLoading() const;

    virtual void setExtraIdentifierValueToNull() = 0;

    int extraIdentifierValueIndex() const;

    bool extraValueDoesNotExist() const;

    bool allowNull() const;

    void setAllowNull( bool allowNull );

    bool fetchGeometry() const;

    void setFetchGeometry( bool fetchGeometry );

    int fetchLimit() const;

    void setFetchLimit( int fetchLimit );
 
  signals:

    void currentFeatureChanged();

    void sourceLayerChanged();

    void displayExpressionChanged();

    void filterValueChanged();

    void filterExpressionChanged();

    void orderExpressionChanged();

    void sortOrderChanged();

    void formFeatureChanged();

    void parentFormFeatureChanged();

    void isLoadingChanged();

    void filterJobCompleted();

    void extraIdentifierValueChanged();

    void extraIdentifierValueIndexChanged( int index );

    void extraValueDoesNotExistChanged( bool found );

    void beginUpdate();

    void endUpdate();

    void allowNullChanged();

    void fetchGeometryChanged();

    void fetchLimitChanged();
 
 
  private slots:
    void updateCompleter();
    void scheduledReload();
 
  protected:

    QVariant extraIdentifierValue() const;

    void setExtraIdentifierValue( const QVariant &extraIdentifierValue );

    virtual void requestToReloadCurrentFeature( QgsFeatureRequest &request ) = 0;

    void setExtraIdentifierValueUnguarded( const QVariant &identifierValue );
 
#ifndef SIP_RUN

    virtual QSet<QString> requestedAttributes() const {return {};}

    virtual QgsFeatureExpressionValuesGatherer *createValuesGatherer( const QgsFeatureRequest &request ) const = 0;

    virtual QgsFeatureExpressionValuesGatherer::Entry createEntry( const QVariant &identifier ) const = 0;

    virtual QVariant entryIdentifier( const QgsFeatureExpressionValuesGatherer::Entry &entry ) const = 0;

    virtual bool compareEntries( const QgsFeatureExpressionValuesGatherer::Entry &a, const QgsFeatureExpressionValuesGatherer::Entry &b ) const = 0;

    virtual QVariant nullIdentifier() const = 0;

    virtual bool identifierIsNull( const QVariant &identifier ) const = 0;
 
    QVector<QgsFeatureExpressionValuesGatherer::Entry> mEntries;
#endif

    QVariant mExtraIdentifierValue;

    int mExtraValueIndex = -1;
 
  private:
    void setExtraIdentifierValueIndex( int index, bool force = false );
    void setExtraValueDoesNotExist( bool extraValueDoesNotExist );
    void reload();
    void reloadCurrentFeature();
    QSet<QString> requestedAttributesForStyle() const;
 
    QgsConditionalStyle featureStyle( const QgsFeature &feature ) const;
 
    QgsVectorLayer *mSourceLayer = nullptr;
    QgsExpression mDisplayExpression;
    QString mFilterValue;
    QString mFilterExpression;
    QgsExpression mOrderExpression;
    Qt::SortOrder mSortOrder = Qt::AscendingOrder;
 
    QgsFeature mFormFeature;
    QgsFeature mParentFormFeature;
 
    mutable QgsExpressionContext mExpressionContext;
    mutable QMap< QgsFeatureId, QgsConditionalStyle > mEntryStylesMap;
 
    QgsFeatureExpressionValuesGatherer *mGatherer = nullptr;
    bool mFetchGeometry = true;
    int mFetchLimit = 100;
 
    QTimer mReloadTimer;
    bool mShouldReloadCurrentFeature = false;
    bool mKeepCurrentEntry = false; // need to keep the current value after a reload or if the value does not exist
    bool mExtraValueDoesNotExist = false;
    bool mAllowNull = false;
    bool mIsSettingExtraIdentifierValue = false;
 
    friend class TestQgsFeatureListComboBox;
};
 
#endif // QGSFEATUREFILTERMODELBASE_H