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       1                 :            : /***************************************************************************
       2                 :            :   qgsmaplayerstylemanager.h
       3                 :            :   --------------------------------------
       4                 :            :   Date                 : January 2015
       5                 :            :   Copyright            : (C) 2015 by Martin Dobias
       6                 :            :   Email                : wonder dot sk at gmail dot com
       7                 :            :  ***************************************************************************
       8                 :            :  *                                                                         *
       9                 :            :  *   This program is free software; you can redistribute it and/or modify  *
      10                 :            :  *   it under the terms of the GNU General Public License as published by  *
      11                 :            :  *   the Free Software Foundation; either version 2 of the License, or     *
      12                 :            :  *   (at your option) any later version.                                   *
      13                 :            :  *                                                                         *
      14                 :            :  ***************************************************************************/
      15                 :            : 
      16                 :            : #ifndef QGSMAPLAYERSTYLEMANAGER_H
      17                 :            : #define QGSMAPLAYERSTYLEMANAGER_H
      18                 :            : 
      19                 :            : #include "qgis_core.h"
      20                 :            : #include "qgis_sip.h"
      21                 :            : #include "qgsmaplayerstyle.h"
      22                 :            : 
      23                 :            : #include <QByteArray>
      24                 :            : #include <QMap>
      25                 :            : #include <QStringList>
      26                 :            : #include <QObject>
      27                 :            : 
      28                 :            : 
      29                 :            : class QDomElement;
      30                 :            : 
      31                 :            : class QgsMapLayer;
      32                 :            : 
      33                 :            : /**
      34                 :            :  * \ingroup core
      35                 :            :  * \brief Management of styles for use with one map layer
      36                 :            :  *
      37                 :            :  * Stored styles are identified by their names. The manager
      38                 :            :  * always keep track of which style of the stored ones is currently active. When the current style is changed,
      39                 :            :  * the new style is applied to the associated layer.
      40                 :            :  *
      41                 :            :  * The class takes care of updating itself when the layer's current style configuration changes.
      42                 :            :  * When some of layer style's properties change (e.g. opacity / colors), the style manager will
      43                 :            :  * record them in the currently active style without any extra effort required.
      44                 :            :  *
      45                 :            :  * When an instance is created, it creates "default" style (with empty name) recorded from the associated map layer
      46                 :            :  * and it is set as the current style. The instance must always contain at least one style (which is the current).
      47                 :            :  *
      48                 :            :  * The style which is marked as current has no style data stored in its entry. This is to avoid duplication
      49                 :            :  * of data as all data is stored in map layer and can be retrieved easily. Also when saving, the entry for
      50                 :            :  * the current style will be saved with no data because everything is already saved by the map layer itself.
      51                 :            :  *
      52                 :            :  * The class also features support for temporary change of the layer's style, ideal for short-term use of a custom
      53                 :            :  * style followed by restoration of the original style (for example, when rendering a map with a different than current style).
      54                 :            :  *
      55                 :            :  * \since QGIS 2.8
      56                 :            :  */
      57                 :            : class CORE_EXPORT QgsMapLayerStyleManager : public QObject
      58                 :            : {
      59                 :        166 :     Q_OBJECT
      60                 :            :   public:
      61                 :            : 
      62                 :            :     /**
      63                 :            :      * Construct a style manager associated with a map layer (must not be NULLPTR).
      64                 :            :      * The style manager will be parented to \a layer.
      65                 :            :      */
      66                 :            :     QgsMapLayerStyleManager( QgsMapLayer *layer SIP_TRANSFERTHIS );
      67                 :            : 
      68                 :            :     //! Gets pointer to the associated map layer
      69                 :          0 :     QgsMapLayer *layer() const { return mLayer; }
      70                 :            : 
      71                 :            :     //! Reset the style manager to a basic state - with one default style which is set as current
      72                 :            :     void reset();
      73                 :            : 
      74                 :            :     //! Read configuration (for project loading)
      75                 :            :     void readXml( const QDomElement &mgrElement );
      76                 :            :     //! Write configuration (for project saving)
      77                 :            :     void writeXml( QDomElement &mgrElement ) const;
      78                 :            : 
      79                 :            :     //! Returns list of all defined style names
      80                 :            :     QStringList styles() const;
      81                 :            : 
      82                 :            :     /**
      83                 :            :      * Gets available styles for the associated map layer.
      84                 :            :      * \returns A map of map layer style by style name
      85                 :            :      * \since QGIS 3.0
      86                 :            :      */
      87                 :            :     QMap<QString, QgsMapLayerStyle> mapLayerStyles() const;
      88                 :            : 
      89                 :            :     //! Returns data of a stored style - accessed by its unique name
      90                 :            :     QgsMapLayerStyle style( const QString &name ) const;
      91                 :            : 
      92                 :            :     /**
      93                 :            :      * Add a style with given name and data
      94                 :            :      * \returns TRUE on success (name is unique and style is valid)
      95                 :            :      */
      96                 :            :     bool addStyle( const QString &name, const QgsMapLayerStyle &style );
      97                 :            : 
      98                 :            :     /**
      99                 :            :      * Add style by cloning the current one
     100                 :            :      * \returns TRUE on success
     101                 :            :      */
     102                 :            :     bool addStyleFromLayer( const QString &name );
     103                 :            : 
     104                 :            :     /**
     105                 :            :      * Remove a stored style
     106                 :            :      * \returns TRUE on success (style exists and it is not the last one)
     107                 :            :      */
     108                 :            :     bool removeStyle( const QString &name );
     109                 :            : 
     110                 :            :     /**
     111                 :            :      * Rename a stored style to a different name
     112                 :            :      * \returns TRUE on success (style exists and new name is unique)
     113                 :            :      */
     114                 :            :     bool renameStyle( const QString &name, const QString &newName );
     115                 :            : 
     116                 :            :     //! Returns name of the current style
     117                 :            :     QString currentStyle() const;
     118                 :            : 
     119                 :            :     /**
     120                 :            :      * Set a different style as the current style - will apply it to the layer
     121                 :            :      * \returns TRUE on success
     122                 :            :      */
     123                 :            :     bool setCurrentStyle( const QString &name );
     124                 :            : 
     125                 :            :     /**
     126                 :            :      * Temporarily apply a different style to the layer. The argument
     127                 :            :      * can be either a style name or a full QML style definition.
     128                 :            :      * Each call must be paired with restoreOverrideStyle()
     129                 :            :      */
     130                 :            :     bool setOverrideStyle( const QString &styleDef );
     131                 :            :     //! Restore the original store after a call to setOverrideStyle()
     132                 :            :     bool restoreOverrideStyle();
     133                 :            : 
     134                 :            :     /**
     135                 :            :      * Returns TRUE if this is the default style
     136                 :            :      *
     137                 :            :      * \since QGIS 3.0
     138                 :            :      */
     139                 :            :     bool isDefault( const QString &styleName ) const;
     140                 :            : 
     141                 :            :     /**
     142                 :            :      * Copies all styles from \a other.
     143                 :            :      * In case there is already a style with the same name it will be overwritten.
     144                 :            :      *
     145                 :            :      * \since QGIS 3.14
     146                 :            :      */
     147                 :            :     void copyStylesFrom( QgsMapLayerStyleManager *other );
     148                 :            : 
     149                 :            :   signals:
     150                 :            :     //! Emitted when a new style has been added
     151                 :            :     void styleAdded( const QString &name );
     152                 :            :     //! Emitted when a style has been removed
     153                 :            :     void styleRemoved( const QString &name );
     154                 :            :     //! Emitted when a style has been renamed
     155                 :            :     void styleRenamed( const QString &oldName, const QString &newName );
     156                 :            :     //! Emitted when the current style has been changed
     157                 :            :     void currentStyleChanged( const QString &currentName );
     158                 :            : 
     159                 :            :   private:
     160                 :            :     QgsMapLayer *mLayer = nullptr;
     161                 :            :     QMap<QString, QgsMapLayerStyle> mStyles;
     162                 :            :     QString mCurrentStyle;
     163                 :            :     QgsMapLayerStyle *mOverriddenOriginalStyle = nullptr;
     164                 :            :     QString defaultStyleName() const;
     165                 :            : };
     166                 :            : 
     167                 :            : #endif // QGSMAPLAYERSTYLEMANAGER_H