qgsmaptoolidentify.h

/***************************************************************************
    qgsmaptoolidentify.h  -  map tool for identifying features
    ---------------------
    begin                : January 2006
    copyright            : (C) 2006 by Martin Dobias
    email                : wonder.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 QGSMAPTOOLIDENTIFY_H
#define QGSMAPTOOLIDENTIFY_H

#include "qgsfeature.h"
#include "qgsfields.h"
#include "qgsmaptool.h"
#include "qgspointxy.h"
#include "qgsunittypes.h"

#include <QObject>
#include <QPointer>
#include "qgis_gui.h"

class QgsRasterLayer;
class QgsVectorLayer;
class QgsMapLayer;
class QgsMapCanvas;
class QgsHighlight;
class QgsIdentifyMenu;
class QgsDistanceArea;

/**
 * \ingroup gui
  \brief Map tool for identifying features in layers

  after selecting a point, performs the identification:
  - for raster layers shows value of underlying pixel
  - for vector layers shows feature attributes within search radius
    (allows editing values when vector layer is in editing mode)
*/
class GUI_EXPORT QgsMapToolIdentify : public QgsMapTool
{
    Q_OBJECT

  public:

    enum IdentifyMode
    {
      DefaultQgsSetting = -1,
      ActiveLayer,
      TopDownStopAtFirst,
      TopDownAll,
      LayerSelection
    };
    Q_ENUM( IdentifyMode )

    enum Type
    {
      VectorLayer = 1,
      RasterLayer = 2,
      AllLayers = VectorLayer | RasterLayer
    };
    Q_DECLARE_FLAGS( LayerType, Type )
    Q_FLAG( LayerType )

    struct IdentifyResult
    {
      //! Constructor for IdentifyResult
      IdentifyResult() = default;

      IdentifyResult( QgsMapLayer *layer, const QgsFeature &feature, const QMap< QString, QString > &derivedAttributes )
        : mLayer( layer ), mFeature( feature ), mDerivedAttributes( derivedAttributes ) {}

      IdentifyResult( QgsMapLayer *layer, const QString &label, const QMap< QString, QString > &attributes, const QMap< QString, QString > &derivedAttributes )
        : mLayer( layer ), mLabel( label ), mAttributes( attributes ), mDerivedAttributes( derivedAttributes ) {}

      IdentifyResult( QgsMapLayer *layer, const QString &label, const QgsFields &fields, const QgsFeature &feature, const QMap< QString, QString > &derivedAttributes )
        : mLayer( layer ), mLabel( label ), mFields( fields ), mFeature( feature ), mDerivedAttributes( derivedAttributes ) {}

      QgsMapLayer *mLayer = nullptr;
      QString mLabel;
      QgsFields mFields;
      QgsFeature mFeature;
      QMap< QString, QString > mAttributes;
      QMap< QString, QString > mDerivedAttributes;
      QMap< QString, QVariant > mParams;
    };

    //! constructor
    QgsMapToolIdentify( QgsMapCanvas *canvas );

    ~QgsMapToolIdentify() override;

    Flags flags() const override { return QgsMapTool::AllowZoomRect; }
    void canvasMoveEvent( QgsMapMouseEvent *e ) override;
    void canvasPressEvent( QgsMapMouseEvent *e ) override;
    void canvasReleaseEvent( QgsMapMouseEvent *e ) override;
    void activate() override;
    void deactivate() override;

    /**
     * Performs the identification.
    \param x x coordinates of mouseEvent
    \param y y coordinates of mouseEvent
    \param layerList Performs the identification within the given list of layers. Default value is an empty list, i.e. uses all the layers.
    \param mode Identification mode. Can use Qgis default settings or a defined mode. Default mode is DefaultQgsSetting.
    \returns a list of IdentifyResult*/
    QList<QgsMapToolIdentify::IdentifyResult> identify( int x, int y, const QList<QgsMapLayer *> &layerList = QList<QgsMapLayer *>(), IdentifyMode mode = DefaultQgsSetting );

    /**
     * Performs the identification.
    To avoid being forced to specify IdentifyMode with a list of layers
    this has been made private and two publics methods are offered
    \param x x coordinates of mouseEvent
    \param y y coordinates of mouseEvent
    \param mode Identification mode. Can use Qgis default settings or a defined mode.
    \param layerType Only performs identification in a certain type of layers (raster, vector). Default value is AllLayers.
    \returns a list of IdentifyResult*/
    QList<QgsMapToolIdentify::IdentifyResult> identify( int x, int y, IdentifyMode mode, LayerType layerType = AllLayers );

    /**
     * return a pointer to the identify menu which will be used in layer selection mode
     * this menu can also be customized
     */
    QgsIdentifyMenu *identifyMenu() {return mIdentifyMenu;}

  public slots:
    void formatChanged( QgsRasterLayer *layer );

  signals:
    void identifyProgress( int, int );
    void identifyMessage( const QString & );
    void changedRasterResults( QList<QgsMapToolIdentify::IdentifyResult> & );

  protected:

    /**
     * Performs the identification.
    To avoid being forced to specify IdentifyMode with a list of layers
    this has been made private and two publics methods are offered
    \param x x coordinates of mouseEvent
    \param y y coordinates of mouseEvent
    \param mode Identification mode. Can use Qgis default settings or a defined mode.
    \param layerList Performs the identification within the given list of layers.
    \param layerType Only performs identification in a certain type of layers (raster, vector).
    \returns a list of IdentifyResult*/
    QList<QgsMapToolIdentify::IdentifyResult> identify( int x, int y, IdentifyMode mode,  const QList<QgsMapLayer *> &layerList, LayerType layerType = AllLayers );

    QgsIdentifyMenu *mIdentifyMenu = nullptr;

    //! Call the right method depending on layer type
    bool identifyLayer( QList<QgsMapToolIdentify::IdentifyResult> *results, QgsMapLayer *layer, const QgsPointXY &point, const QgsRectangle &viewExtent, double mapUnitsPerPixel, QgsMapToolIdentify::LayerType layerType = AllLayers );

    bool identifyRasterLayer( QList<QgsMapToolIdentify::IdentifyResult> *results, QgsRasterLayer *layer, QgsPointXY point, const QgsRectangle &viewExtent, double mapUnitsPerPixel );
    bool identifyVectorLayer( QList<QgsMapToolIdentify::IdentifyResult> *results, QgsVectorLayer *layer, const QgsPointXY &point );

  private:

    /**
     * Desired units for distance display.
     * \since QGIS 2.14
     * \see displayAreaUnits()
     */
    virtual QgsUnitTypes::DistanceUnit displayDistanceUnits() const;

    /**
     * Desired units for area display.
     * \since QGIS 2.14
     * \see displayDistanceUnits()
     */
    virtual QgsUnitTypes::AreaUnit displayAreaUnits() const;

    /**
     * Format a distance into a suitable string for display to the user
     * \since QGIS 2.14
     * \see formatArea()
     */
    QString formatDistance( double distance ) const;

    /**
     * Format a distance into a suitable string for display to the user
     * \since QGIS 2.14
     * \see formatDistance()
     */
    QString formatArea( double area ) const;

    QMap< QString, QString > featureDerivedAttributes( const QgsFeature &feature, QgsMapLayer *layer, const QgsPointXY &layerPoint = QgsPointXY() );

    /**
     * Adds details of the closest vertex to derived attributes
     */
    void closestVertexAttributes( const QgsAbstractGeometry &geometry, QgsVertexId vId, QgsMapLayer *layer, QMap< QString, QString > &derivedAttributes );

    QString formatCoordinate( const QgsPointXY &canvasPoint ) const;
    QString formatXCoordinate( const QgsPointXY &canvasPoint ) const;
    QString formatYCoordinate( const QgsPointXY &canvasPoint ) const;

    // Last point in canvas CRS
    QgsPointXY mLastPoint;

    double mLastMapUnitsPerPixel;

    QgsRectangle mLastExtent;

    int mCoordinatePrecision;
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsMapToolIdentify::LayerType )

#endif