qgslegendrenderer.h

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/***************************************************************************
  qgslegendrenderer.h
  --------------------------------------
  Date                 : July 2014
  Copyright            : (C) 2014 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 QGSLEGENDRENDERER_H
#define QGSLEGENDRENDERER_H
 
#include "qgis_core.h"
 
#include <QPointF>
 
class QRectF;
class QStandardItem;
class QJsonObject;
 
class QgsLayerTreeGroup;
class QgsLayerTreeLayer;
class QgsLayerTreeModel;
class QgsLayerTreeModelLegendNode;
class QgsLayerTreeNode;
class QgsSymbol;
class QgsRenderContext;
class QgsLayerTreeFilterProxyModel;
 
#include "qgslegendsettings.h"

class CORE_EXPORT QgsLegendRenderer
{
  public:
    QgsLegendRenderer( QgsLayerTreeModel *legendModel, const QgsLegendSettings &settings );
    ~QgsLegendRenderer();
 
#ifndef SIP_RUN
    QgsLegendRenderer( const QgsLegendRenderer &other ) = delete;
    QgsLegendRenderer &operator=( const QgsLegendRenderer &other ) = delete;
    QgsLegendRenderer( QgsLegendRenderer &&other );
#endif

    void setProxyModel( QgsLayerTreeFilterProxyModel *model SIP_TRANSFER );

    QgsLayerTreeFilterProxyModel *proxyModel();

    QSizeF minimumSize( QgsRenderContext *renderContext = nullptr );

    void setLegendSize( QSizeF s ) { mLegendSize = s; }

    QSizeF legendSize() const { return mLegendSize; }

    Q_DECL_DEPRECATED void drawLegend( QPainter *painter ) SIP_DEPRECATED;

    void drawLegend( QgsRenderContext &context );

    QJsonObject exportLegendToJson( const QgsRenderContext &context );

    static void setNodeLegendStyle( QgsLayerTreeNode *node, Qgis::LegendComponent style );

    static Qgis::LegendComponent nodeLegendStyle( QgsLayerTreeNode *node, QgsLayerTreeModel *model );
 
  private:
#ifndef SIP_RUN

    class LegendComponent
    {
      public:
        LegendComponent() = default;
 
        QObject *item = nullptr;

        QSizeF symbolSize;

        QSizeF labelSize;

        QSizeF size;

        double indent = 0;

        double labelXOffset = 0.0;

        double maxSiblingSymbolWidth = 0.0;
    };

    class LegendComponentGroup
    {
      public:
        QList<LegendComponent> components;

        QSizeF size = QSizeF( 0, 0 );

        int column = 0;

        bool placeColumnBreakBeforeGroup = false;
    };

    class ColumnContext
    {
      public:
        ColumnContext() {}

        double left = 0;
        double right = 0;
    };

    QList<LegendComponentGroup> createComponentGroupList( QgsLayerTreeGroup *parentGroup, QgsRenderContext &context, double indent = 0 );

    int setColumns( QList<LegendComponentGroup> &groupList );

    double spaceAboveGroup( const LegendComponentGroup &group );

    QJsonObject exportLegendToJson( const QgsRenderContext &context, QgsLayerTreeGroup *nodeGroup );

    QSizeF paintAndDetermineSize( QgsRenderContext &context );

    QSizeF drawTitle( QgsRenderContext &context, double top, Qt::AlignmentFlag halignment = Qt::AlignLeft, double legendWidth = 0 ) const;

    QSizeF drawGroup( const LegendComponentGroup &group, QgsRenderContext &context, ColumnContext columnContext, double top = 0 );

    LegendComponent drawSymbolItem( QgsLayerTreeModelLegendNode *symbolItem, QgsRenderContext &context, ColumnContext columnContext, double top, double maxSiblingSymbolWidth = 0 );

    QSizeF drawLayerTitle( QgsLayerTreeLayer *nodeLayer, QgsRenderContext &context, ColumnContext columnContext = ColumnContext(), double top = 0 );

    QSizeF drawGroupTitle( QgsLayerTreeGroup *nodeGroup, QgsRenderContext &context, ColumnContext columnContext = ColumnContext(), double top = 0 );

    Qgis::LegendComponent nodeLegendStyle( QgsLayerTreeNode *node );
 
    QgsLayerTreeModel *mLegendModel = nullptr;
    std::unique_ptr< QgsLayerTreeFilterProxyModel > mProxyModel;
 
    QgsLegendSettings mSettings;
 
    QSizeF mLegendSize;
 
#endif
 
#ifdef SIP_RUN
    QgsLegendRenderer( const QgsLegendRenderer &other );
#endif
 
    void widthAndOffsetForTitleText( const Qt::AlignmentFlag halignment, double legendWidth, double &width, double &offset ) const;
};
 
#endif // QGSLEGENDRENDERER_H