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       1                 :            : /***************************************************************************
       2                 :            :   qgsdatadefinedsizelegend.h
       3                 :            :   --------------------------------------
       4                 :            :   Date                 : June 2017
       5                 :            :   Copyright            : (C) 2017 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 QGSDATADEFINEDSIZELEGEND_H
      17                 :            : #define QGSDATADEFINEDSIZELEGEND_H
      18                 :            : 
      19                 :            : #include "qgslegendsymbolitem.h"
      20                 :            : 
      21                 :            : #include <QColor>
      22                 :            : #include <QFont>
      23                 :            : 
      24                 :            : class QDomElement;
      25                 :            : class QgsMarkerSymbol;
      26                 :            : class QgsProperty;
      27                 :            : class QgsReadWriteContext;
      28                 :            : class QgsRenderContext;
      29                 :            : class QgsSizeScaleTransformer;
      30                 :            : class QgsLineSymbol;
      31                 :            : 
      32                 :            : 
      33                 :            : /**
      34                 :            :  * \ingroup core
      35                 :            :  * \brief Object that keeps configuration of appearance of marker symbol's data-defined size in legend.
      36                 :            :  *
      37                 :            :  * For example: the list of classes (size values), whether the classes should appear in separate
      38                 :            :  * legend nodes or whether to collapse them into one legend node.
      39                 :            :  *
      40                 :            :  * \since QGIS 3.0
      41                 :            :  */
      42                 :            : class CORE_EXPORT QgsDataDefinedSizeLegend
      43                 :            : {
      44                 :            :   public:
      45                 :            : 
      46                 :            :     /**
      47                 :            :      * Constructor for QgsDataDefinedSizeLegend.
      48                 :            :      */
      49                 :            :     QgsDataDefinedSizeLegend();
      50                 :            : 
      51                 :            :     ~QgsDataDefinedSizeLegend();
      52                 :            : 
      53                 :            :     //! Copy constructor
      54                 :            :     QgsDataDefinedSizeLegend( const QgsDataDefinedSizeLegend &other );
      55                 :            :     QgsDataDefinedSizeLegend &operator=( const QgsDataDefinedSizeLegend &other );
      56                 :            : 
      57                 :            :     //! Determines how to display data-defined size legend
      58                 :            :     enum LegendType
      59                 :            :     {
      60                 :            :       LegendSeparated,   //!< Each class (size value) has a separate legend node
      61                 :            :       LegendCollapsed,   //!< All classes are rendered within one legend node
      62                 :            :     };
      63                 :            : 
      64                 :            :     //! How to vertically align symbols when all classes go into one node
      65                 :            :     enum VerticalAlignment
      66                 :            :     {
      67                 :            :       AlignCenter,      //!< Symbols are aligned to the center
      68                 :            :       AlignBottom,      //!< Symbols are aligned to the bottom
      69                 :            :     };
      70                 :            : 
      71                 :            :     //! Definition of one class for the legend
      72                 :          0 :     struct SizeClass
      73                 :            :     {
      74                 :          0 :       SizeClass( double size, const QString &label ): size( size ), label( label ) {}
      75                 :            : 
      76                 :            :       double size;    //!< Marker size in units used by the symbol (usually millimeters). May be further scaled before rendering if size scale transformer is enabled.
      77                 :            :       QString label;  //!< Label to be shown with the particular symbol size
      78                 :            :     };
      79                 :            : 
      80                 :            :     //! Sets how the legend should be rendered
      81                 :          0 :     void setLegendType( LegendType type ) { mType = type; }
      82                 :            :     //! Returns how the legend should be rendered
      83                 :            :     LegendType legendType() const { return mType; }
      84                 :            : 
      85                 :            :     //! Sets marker symbol that will be used to draw markers in legend
      86                 :            :     void setSymbol( QgsMarkerSymbol *symbol SIP_TRANSFER );
      87                 :            :     //! Returns marker symbol that will be used to draw markers in legend
      88                 :            :     QgsMarkerSymbol *symbol() const;
      89                 :            : 
      90                 :            :     /**
      91                 :            :      * Sets the line \a symbol that will be used to draw callout lines in legend.
      92                 :            :      *
      93                 :            :      * Ownership of \a symbol is transferred.
      94                 :            :      *
      95                 :            :      * \see lineSymbol()
      96                 :            :      * \since QGIS 3.14
      97                 :            :      */
      98                 :            :     void setLineSymbol( QgsLineSymbol *symbol SIP_TRANSFER );
      99                 :            : 
     100                 :            :     /**
     101                 :            :     * Returns the line symbol that will be used to draw callout lines in legend.
     102                 :            :     * \see setLineSymbol()
     103                 :            :     * \since QGIS 3.14
     104                 :            :     */
     105                 :            :     QgsLineSymbol *lineSymbol() const;
     106                 :            : 
     107                 :            :     //! Sets transformer for scaling of symbol sizes. Takes ownership of the object. Accepts NULLPTR to set no transformer.
     108                 :            :     void setSizeScaleTransformer( QgsSizeScaleTransformer *transformer SIP_TRANSFER );
     109                 :            :     //! Returns transformer for scaling of symbol sizes. Returns NULLPTR if no transformer is defined.
     110                 :            :     QgsSizeScaleTransformer *sizeScaleTransformer() const;
     111                 :            : 
     112                 :            :     //! Sets list of classes: each class is a pair of symbol size (in units used by the symbol) and label
     113                 :          0 :     void setClasses( const QList< QgsDataDefinedSizeLegend::SizeClass > &classes ) { mSizeClasses = classes; }
     114                 :            :     //! Returns list of classes: each class is a pair of symbol size (in units used by the symbol) and label
     115                 :          0 :     QList< QgsDataDefinedSizeLegend::SizeClass > classes() const { return mSizeClasses; }
     116                 :            : 
     117                 :            :     //! Sets title label for data-defined size legend
     118                 :          0 :     void setTitle( const QString &title ) { mTitleLabel = title; }
     119                 :            :     //! Returns title label for data-defined size legend
     120                 :            :     QString title() const { return mTitleLabel; }
     121                 :            : 
     122                 :            :     //! Sets vertical alignment of symbols - only valid for collapsed legend
     123                 :          0 :     void setVerticalAlignment( VerticalAlignment vAlign ) { mVAlign = vAlign; }
     124                 :            :     //! Returns vertical alignment of symbols - only valid for collapsed legend
     125                 :            :     VerticalAlignment verticalAlignment() const { return mVAlign; }
     126                 :            : 
     127                 :            :     //! Sets font used for rendering of labels - only valid for collapsed legend
     128                 :          0 :     void setFont( const QFont &font ) { mFont = font; }
     129                 :            :     //! Returns font used for rendering of labels - only valid for collapsed legend
     130                 :            :     QFont font() const { return mFont; }
     131                 :            : 
     132                 :            :     //! Sets text color for rendering of labels - only valid for collapsed legend
     133                 :          0 :     void setTextColor( const QColor &color ) { mTextColor = color; }
     134                 :            :     //! Returns text color for rendering of labels - only valid for collapsed legend
     135                 :            :     QColor textColor() const { return mTextColor; }
     136                 :            : 
     137                 :            :     //! Sets horizontal text alignment for rendering of labels - only valid for collapsed legend
     138                 :          0 :     void setTextAlignment( Qt::AlignmentFlag flag ) { mTextAlignment = flag; }
     139                 :            :     //! Returns horizontal text alignment for rendering of labels - only valid for collapsed legend
     140                 :            :     Qt::AlignmentFlag textAlignment() const { return mTextAlignment; }
     141                 :            : 
     142                 :            :     //
     143                 :            : 
     144                 :            :     //! Updates the list of classes, source symbol and title label from given symbol and property
     145                 :            :     void updateFromSymbolAndProperty( const QgsMarkerSymbol *symbol, const QgsProperty &ddSize );
     146                 :            : 
     147                 :            :     //! Generates legend symbol items according to the configuration
     148                 :            :     QgsLegendSymbolList legendSymbolList() const;
     149                 :            : 
     150                 :            :     /**
     151                 :            :      * Draw the legend if using LegendOneNodeForAll and optionally output size of the legend and x offset of labels (in painter units).
     152                 :            :      * If the painter in context is NULLPTR, it only does size calculation without actual rendering.
     153                 :            :      * Does nothing if legend is not configured as collapsed.
     154                 :            :      */
     155                 :            :     void drawCollapsedLegend( QgsRenderContext &context, QSizeF *outputSize SIP_OUT = nullptr, double *labelXOffset SIP_OUT = nullptr ) const;
     156                 :            : 
     157                 :            :     //! Returns output image that would be shown in the legend. Returns invalid image if legend is not configured as collapsed.
     158                 :            :     QImage collapsedLegendImage( QgsRenderContext &context, const QColor &backgroundColor = Qt::transparent, double paddingMM = 1 ) const;
     159                 :            : 
     160                 :            :     //! Creates instance from given element and returns it (caller takes ownership). Returns NULLPTR on error.
     161                 :            :     static QgsDataDefinedSizeLegend *readXml( const QDomElement &elem, const QgsReadWriteContext &context ) SIP_FACTORY;
     162                 :            : 
     163                 :            :     //! Writes configuration to the given XML element.
     164                 :            :     void writeXml( QDomElement &elem, const QgsReadWriteContext &context ) const;
     165                 :            : 
     166                 :            :   private:
     167                 :            :     LegendType mType = LegendSeparated;
     168                 :            :     QString mTitleLabel;  //!< Title label for the following size-based item(s)
     169                 :            :     QList< SizeClass > mSizeClasses;  //!< List of classes: symbol size (in whatever units symbol uses) + label
     170                 :            :     std::unique_ptr<QgsMarkerSymbol> mSymbol;
     171                 :            :     std::unique_ptr<QgsLineSymbol> mLineSymbol;
     172                 :            :     std::unique_ptr<QgsSizeScaleTransformer> mSizeScaleTransformer;  //!< Optional transformer for classes
     173                 :            :     VerticalAlignment mVAlign = AlignBottom;
     174                 :            :     QFont mFont;
     175                 :            :     QColor mTextColor = Qt::black;
     176                 :            :     Qt::AlignmentFlag mTextAlignment = Qt::AlignLeft;
     177                 :            : };
     178                 :            : 
     179                 :            : #endif // QGSDATADEFINEDSIZELEGEND_H