qgsexpressionlineedit.h

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/***************************************************************************
   qgsexpressionlineedit.h
    ----------------------
   Date                 : 18.08.2016
   Copyright            : (C) 2016 Nyall Dawson
   Email                : nyall dot dawson at gmail dot com
***************************************************************************
*                                                                         *
*   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 QGSEXPRESSIONLINEEDIT_H
#define QGSEXPRESSIONLINEEDIT_H
 
#include <memory>
 
#include "qgis_gui.h"
#include "qgis_sip.h"
#include "qgsexpressioncontext.h"
 
#include <QWidget>
 
class QgsFilterLineEdit;
class QToolButton;
class QgsDistanceArea;
class QgsExpressionContextGenerator;
class QgsCodeEditorExpression;

class GUI_EXPORT QgsExpressionLineEdit : public QWidget
{
    Q_OBJECT
 
  public:

    explicit QgsExpressionLineEdit( QWidget *parent SIP_TRANSFERTHIS = nullptr );
    ~QgsExpressionLineEdit() override;

    void setExpressionDialogTitle( const QString &title );

    QString expressionDialogTitle() const { return mExpressionDialogTitle; }

    void setMultiLine( bool multiLine );

    QString expectedOutputFormat() const;

    void setExpectedOutputFormat( const QString &expected );

    void setGeomCalculator( const QgsDistanceArea &distanceArea );

    void setLayer( QgsVectorLayer *layer );

    QString expression() const;

    bool isValidExpression( QString *expressionError SIP_OUT = nullptr ) const;

    void registerExpressionContextGenerator( const QgsExpressionContextGenerator *generator );
 
  signals:

    void expressionChanged( const QString &expression );
 
  public slots:

    void setExpression( const QString &expression );
 
  protected:
    void changeEvent( QEvent *event ) override;
 
  private slots:

    void expressionEdited( const QString &expression );
    void expressionEdited();

    void editExpression();

    void updateLineEditStyle( const QString &expression = QString() );
 
  private:
    QgsFilterLineEdit *mLineEdit = nullptr;
    QgsCodeEditorExpression *mCodeEditor = nullptr;
    QToolButton *mButton = nullptr;
    QString mExpressionDialogTitle;
    std::unique_ptr<QgsDistanceArea> mDa;
    QgsExpressionContext mExpressionContext;
    const QgsExpressionContextGenerator *mExpressionContextGenerator = nullptr;
    QgsVectorLayer *mLayer = nullptr;
    QString mExpectedOutputFormat;
 
    bool isExpressionValid( const QString &expressionStr );
 
    friend class TestQgsFieldExpressionWidget;
};
 
#endif // QGSEXPRESSIONLINEEDIT_H