qgsfieldmodel.h

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/***************************************************************************
   qgsfieldmodel.h
    --------------------------------------
   Date                 : 01.04.2014
   Copyright            : (C) 2014 Denis Rouzaud
   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 QGSFIELDMODEL_H
#define QGSFIELDMODEL_H

#include <QAbstractItemModel>
#include <QComboBox>
#include <QItemSelectionModel>

#include "qgsfields.h"
#include "qgis_core.h"

#include "qgis_sip.h"

class QgsVectorLayer;

class CORE_EXPORT QgsFieldModel : public QAbstractItemModel
{
    Q_OBJECT

    Q_PROPERTY( bool allowExpression READ allowExpression WRITE setAllowExpression )
    Q_PROPERTY( bool allowEmptyFieldName READ allowEmptyFieldName WRITE setAllowEmptyFieldName )
    Q_PROPERTY( QgsVectorLayer *layer READ layer WRITE setLayer )

  public:

    enum FieldRoles
    {
      FieldNameRole = Qt::UserRole + 1,  
      FieldIndexRole = Qt::UserRole + 2, 
      ExpressionRole = Qt::UserRole + 3, 
      IsExpressionRole = Qt::UserRole + 4, 
      ExpressionValidityRole = Qt::UserRole + 5, 
      FieldTypeRole = Qt::UserRole + 6, 
      FieldOriginRole = Qt::UserRole + 7, 
      IsEmptyRole = Qt::UserRole + 8, 
    };

    explicit QgsFieldModel( QObject *parent SIP_TRANSFERTHIS = nullptr );

    QModelIndex indexFromName( const QString &fieldName );

    void setAllowExpression( bool allowExpression );

    bool allowExpression() { return mAllowExpression; }

    void setAllowEmptyFieldName( bool allowEmpty );

    bool allowEmptyFieldName() const { return mAllowEmpty; }

    bool isField( const QString &expression ) const;

    void setExpression( const QString &expression );

    void removeExpression();

    QgsVectorLayer *layer() { return mLayer; }

    // QAbstractItemModel interface
    QModelIndex index( int row, int column, const QModelIndex &parent = QModelIndex() ) const override;
    QModelIndex parent( const QModelIndex &child ) const override;
    int rowCount( const QModelIndex &parent = QModelIndex() ) const override;
    int columnCount( const QModelIndex &parent ) const override;
    QVariant data( const QModelIndex &index, int role ) const override;

    static QString fieldToolTip( const QgsField &field );

  public slots:

    void setLayer( QgsVectorLayer *layer );

  protected slots:

    virtual void updateModel();

  private slots:
    void layerDeleted();

  protected:
    QgsFields mFields;
    QList<QString> mExpression;

    QgsVectorLayer *mLayer = nullptr;
    bool mAllowExpression = false;
    bool mAllowEmpty = false;

  private:
    void fetchFeature();
};

#endif // QGSFIELDMODEL_H