qgsprojectproperty.h

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/***************************************************************************
                                  qgsproject.h

                      Implements persistent project state.

                              -------------------
  begin                : February 24, 2005
  copyright            : (C) 2005 by Mark Coletti
  email                : mcoletti at gmail.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 QGSPROJECTPROPERTY_H
#define QGSPROJECTPROPERTY_H

#include <QHash>
#include <QVariant>
#include <QStringList>

#include "qgis_core.h"

class QDomNode;
class QDomElement;
class QDomDocument;


class CORE_EXPORT QgsProjectProperty
{
  public:
    QgsProjectProperty();
    virtual ~QgsProjectProperty() = default;

    virtual void dump( int tabs = 0 ) const = 0;

    virtual bool isKey() const = 0;

    virtual bool isValue() const = 0;

    virtual bool isLeaf() const = 0;

    virtual bool readXml( const QDomNode &keyNode ) = 0;

    virtual bool writeXml( const QString &nodeName,
                           QDomElement &element,
                           QDomDocument &document ) = 0;

    virtual QVariant value() const = 0;

};


class CORE_EXPORT QgsProjectPropertyValue : public QgsProjectProperty
{
  public:

    QgsProjectPropertyValue() = default;

    QgsProjectPropertyValue( const QVariant &value )
      : mValue( value )
    {}

    bool isKey() const override { return false; }
    bool isValue() const override { return true; }
    QVariant value() const override { return mValue; }

    //value nodes can also be qualified as leaf nodes even though we only count key nodes.
    bool isLeaf() const override { return true; }

    void dump( int tabs = 0 ) const override;
    bool readXml( const QDomNode &keyNode ) override;
    bool writeXml( const QString &nodeName,
                   QDomElement &element,
                   QDomDocument &document ) override;

  private:

    // We use QVariant as it's very handy to keep multiple types and provides type conversions
    QVariant mValue;

};


class CORE_EXPORT QgsProjectPropertyKey : public QgsProjectProperty
{
  public:

    QgsProjectPropertyKey( const QString &name = QString() );
    ~QgsProjectPropertyKey() override;

    QString name() const { return mName; }

    void setName( const QString &name );

    QVariant value() const override;

    QgsProjectPropertyKey *addKey( const QString &keyName )
    {
      if ( mProperties.contains( keyName ) )
        delete mProperties.take( keyName );

      QgsProjectPropertyKey *p = new QgsProjectPropertyKey( keyName );
      mProperties.insert( keyName, p );

      return p;
    }

    void removeKey( const QString &keyName )
    {
      delete mProperties.take( keyName );
    }

    QgsProjectPropertyValue *setValue( const QString &name, const QVariant &value )
    {
      if ( mProperties.contains( name ) )
        delete mProperties.take( name );

      QgsProjectPropertyValue *p = new QgsProjectPropertyValue( value );
      mProperties.insert( name, p );

      return p;
    }

    QgsProjectPropertyValue *setValue( const QVariant &value )
    {
      return setValue( name(), value );
    }

    void dump( int tabs = 0 ) const override;
    bool readXml( const QDomNode &keyNode ) override;
    bool writeXml( const QString &nodeName, QDomElement &element, QDomDocument &document ) override;

    int count() const { return mProperties.count(); }

    bool isEmpty() const { return mProperties.isEmpty(); }

    bool isKey() const override { return true; }
    bool isValue() const override { return false; }
    bool isLeaf() const override;

    void entryList( QStringList &entries ) const;

    void subkeyList( QStringList &entries ) const;

    virtual void clear()
    {
      mName.clear();
      clearKeys();
    }

    virtual void clearKeys()
    {
      qDeleteAll( mProperties );
      mProperties.clear();
    }

    QgsProjectProperty *find( const QString &propertyName ) const
    {
      return mProperties.value( propertyName );
    }

  private:

    QString mName;

    QHash < QString, QgsProjectProperty * > mProperties;

};

#endif