qgsmaplayerstylemanager.h

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/***************************************************************************
  qgsmaplayerstylemanager.h
  --------------------------------------
  Date                 : January 2015
  Copyright            : (C) 2015 by Martin Dobias
  Email                : wonder dot sk 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 QGSMAPLAYERSTYLEMANAGER_H
#define QGSMAPLAYERSTYLEMANAGER_H

#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgsmaplayer.h"

#include <QByteArray>
#include <QMap>
#include <QStringList>
#include <QObject>


class QDomElement;

class CORE_EXPORT QgsMapLayerStyle
{
  public:
    QgsMapLayerStyle() = default;

    explicit QgsMapLayerStyle( const QString &xmlData );

    bool isValid() const;

    void clear();

    QString xmlData() const;

    void readFromLayer( QgsMapLayer *layer );
    void writeToLayer( QgsMapLayer *layer ) const;

    void readXml( const QDomElement &styleElement );
    void writeXml( QDomElement &styleElement ) const;

  private:
    QString mXmlData;
};


class CORE_EXPORT QgsMapLayerStyleManager : public QObject
{
    Q_OBJECT
  public:

    QgsMapLayerStyleManager( QgsMapLayer *layer SIP_TRANSFERTHIS );

    QgsMapLayer *layer() const { return mLayer; }

    void reset();

    void readXml( const QDomElement &mgrElement );
    void writeXml( QDomElement &mgrElement ) const;

    QStringList styles() const;

    QMap<QString, QgsMapLayerStyle> mapLayerStyles() const;

    QgsMapLayerStyle style( const QString &name ) const;

    bool addStyle( const QString &name, const QgsMapLayerStyle &style );

    bool addStyleFromLayer( const QString &name );

    bool removeStyle( const QString &name );

    bool renameStyle( const QString &name, const QString &newName );

    QString currentStyle() const;

    bool setCurrentStyle( const QString &name );

    bool setOverrideStyle( const QString &styleDef );
    bool restoreOverrideStyle();

    bool isDefault( const QString &styleName ) const;

  signals:
    void styleAdded( const QString &name );
    void styleRemoved( const QString &name );
    void styleRenamed( const QString &oldName, const QString &newName );
    void currentStyleChanged( const QString &currentName );

  private:
    QgsMapLayer *mLayer = nullptr;
    QMap<QString, QgsMapLayerStyle> mStyles;
    QString mCurrentStyle;
    QgsMapLayerStyle *mOverriddenOriginalStyle = nullptr;
    QString defaultStyleName() const;
};


class CORE_EXPORT QgsMapLayerStyleOverride
{
  public:

    QgsMapLayerStyleOverride( QgsMapLayer *layer )
      : mLayer( layer )
    {
    }

    ~QgsMapLayerStyleOverride()
    {
      if ( mLayer && mStyleOverridden )
        mLayer->styleManager()->restoreOverrideStyle();
    }

    void setOverrideStyle( const QString &style )
    {
      if ( mLayer )
      {
        if ( mStyleOverridden )
          mLayer->styleManager()->restoreOverrideStyle();

        mLayer->styleManager()->setOverrideStyle( style );
        mStyleOverridden = true;
      }
    }

  private:

    QgsMapLayer *mLayer = nullptr;
    bool mStyleOverridden = false;
};
#endif // QGSMAPLAYERSTYLEMANAGER_H