qgslayertreemodellegendnode.h

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/***************************************************************************
  qgslayertreemodellegendnode.h
  --------------------------------------
  Date                 : August 2014
  Copyright            : (C) 2014 by Martin Dobias
  Email                : wonder dot sk at gmail dot com

  QgsWMSLegendNode     : Sandro Santilli < strk at keybit dot net >

 ***************************************************************************
 *                                                                         *
 *   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 QGSLAYERTREEMODELLEGENDNODE_H
#define QGSLAYERTREEMODELLEGENDNODE_H

#include <QIcon>
#include <QObject>


#include "qgis_core.h"
#include "qgis.h"

#include "qgsrasterdataprovider.h" // for QgsImageFetcher dtor visibility

class QgsLayerTreeLayer;
class QgsLayerTreeModel;
class QgsLegendSettings;
class QgsMapSettings;
class QgsSymbol;
class QgsRenderContext;

class CORE_EXPORT QgsLayerTreeModelLegendNode : public QObject
{
    Q_OBJECT
  public:

    enum LegendNodeRoles
    {
      RuleKeyRole = Qt::UserRole,     
      ParentRuleKeyRole               
    };

    QgsLayerTreeLayer *layerNode() const { return mLayerNode; }

    QgsLayerTreeModel *model() const;

    virtual Qt::ItemFlags flags() const;

    virtual QVariant data( int role ) const = 0;

    virtual bool setData( const QVariant &value, int role );

    virtual bool isEmbeddedInParent() const { return mEmbeddedInParent; }
    virtual void setEmbeddedInParent( bool embedded ) { mEmbeddedInParent = embedded; }

    virtual QString userLabel() const { return mUserLabel; }
    virtual void setUserLabel( const QString &userLabel ) { mUserLabel = userLabel; }

    virtual bool isScaleOK( double scale ) const { Q_UNUSED( scale ); return true; }

    virtual void invalidateMapBasedData() {}

    struct ItemContext
    {
      QPainter *painter = nullptr;
      QPointF point;
      double labelXOffset;
    };

    struct ItemMetrics
    {
      QSizeF symbolSize;
      QSizeF labelSize;
    };

    virtual ItemMetrics draw( const QgsLegendSettings &settings, ItemContext *ctx );

    virtual QSizeF drawSymbol( const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight ) const;

    virtual QSizeF drawSymbolText( const QgsLegendSettings &settings, ItemContext *ctx, QSizeF symbolSize ) const;

  signals:
    void dataChanged();

  protected:
    explicit QgsLayerTreeModelLegendNode( QgsLayerTreeLayer *nodeL, QObject *parent SIP_TRANSFERTHIS = nullptr );

    QgsRenderContext *createTemporaryRenderContext() const SIP_FACTORY;

  protected:
    QgsLayerTreeLayer *mLayerNode = nullptr;
    bool mEmbeddedInParent;
    QString mUserLabel;
};

#include "qgslegendsymbolitem.h"

class CORE_EXPORT QgsSymbolLegendNode : public QgsLayerTreeModelLegendNode
{
    Q_OBJECT

  public:

    QgsSymbolLegendNode( QgsLayerTreeLayer *nodeLayer, const QgsLegendSymbolItem &item, QObject *parent SIP_TRANSFERTHIS = nullptr );

    Qt::ItemFlags flags() const override;
    QVariant data( int role ) const override;
    bool setData( const QVariant &value, int role ) override;

    QSizeF drawSymbol( const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight ) const override;

    void setEmbeddedInParent( bool embedded ) override;

    void setUserLabel( const QString &userLabel ) override { mUserLabel = userLabel; updateLabel(); }

    bool isScaleOK( double scale ) const override { return mItem.isScaleOK( scale ); }

    void invalidateMapBasedData() override;

    void setIconSize( QSize sz ) { mIconSize = sz; }
    QSize iconSize() const { return mIconSize; }

    QSize minimumIconSize() const;

    QSize minimumIconSize( QgsRenderContext *context ) const;

    const QgsSymbol *symbol() const;

    void setSymbol( QgsSymbol *symbol );

  public slots:

    void checkAllItems();

    void uncheckAllItems();

  private:
    void updateLabel();

  private:
    QgsLegendSymbolItem mItem;
    mutable QPixmap mPixmap; // cached symbol preview
    QString mLabel;
    bool mSymbolUsesMapUnits;
    QSize mIconSize;

    // ident the symbol icon to make it look like a tree structure
    static const int INDENT_SIZE = 20;

    void checkAll( bool state );
};


class CORE_EXPORT QgsSimpleLegendNode : public QgsLayerTreeModelLegendNode
{
    Q_OBJECT

  public:

    QgsSimpleLegendNode( QgsLayerTreeLayer *nodeLayer, const QString &label, const QIcon &icon = QIcon(), QObject *parent SIP_TRANSFERTHIS = nullptr, const QString &key = QString() );

    QVariant data( int role ) const override;

  private:
    QString mLabel;
    QString mId;
    QIcon mIcon;
    QString mKey;
};


class CORE_EXPORT QgsImageLegendNode : public QgsLayerTreeModelLegendNode
{
    Q_OBJECT

  public:

    QgsImageLegendNode( QgsLayerTreeLayer *nodeLayer, const QImage &img, QObject *parent SIP_TRANSFERTHIS = nullptr );

    QVariant data( int role ) const override;

    QSizeF drawSymbol( const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight ) const override;

  private:
    QImage mImage;
};

class CORE_EXPORT QgsRasterSymbolLegendNode : public QgsLayerTreeModelLegendNode
{
    Q_OBJECT

  public:

    QgsRasterSymbolLegendNode( QgsLayerTreeLayer *nodeLayer, const QColor &color, const QString &label, QObject *parent SIP_TRANSFERTHIS = nullptr );

    QVariant data( int role ) const override;

    QSizeF drawSymbol( const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight ) const override;

  private:
    QColor mColor;
    QString mLabel;
};

class QgsImageFetcher;

class CORE_EXPORT QgsWmsLegendNode : public QgsLayerTreeModelLegendNode
{
    Q_OBJECT

  public:

    QgsWmsLegendNode( QgsLayerTreeLayer *nodeLayer, QObject *parent SIP_TRANSFERTHIS = nullptr );

    QVariant data( int role ) const override;

    QSizeF drawSymbol( const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight ) const override;

    void invalidateMapBasedData() override;

  private slots:

    void getLegendGraphicFinished( const QImage & );
    void getLegendGraphicErrored( const QString & );
    void getLegendGraphicProgress( qint64, qint64 );

  private:

    // Lazily initializes mImage
    QImage getLegendGraphic() const;

    QImage renderMessage( const QString &msg ) const;

    QImage mImage;

    bool mValid;

    mutable std::unique_ptr<QgsImageFetcher> mFetcher;
};


class CORE_EXPORT QgsDataDefinedSizeLegendNode : public QgsLayerTreeModelLegendNode
{
    Q_OBJECT

  public:
    QgsDataDefinedSizeLegendNode( QgsLayerTreeLayer *nodeLayer, const QgsDataDefinedSizeLegend &settings, QObject *parent SIP_TRANSFERTHIS = nullptr );
    ~QgsDataDefinedSizeLegendNode() override;

    QVariant data( int role ) const override;

    ItemMetrics draw( const QgsLegendSettings &settings, ItemContext *ctx ) override;

  private:
    void cacheImage() const;
    QgsDataDefinedSizeLegend *mSettings = nullptr;
    mutable QImage mImage;
};

#endif // QGSLAYERTREEMODELLEGENDNODE_H