labelsitem.h

/*
    SPDX-FileCopyrightText: 2016 Artem Fedoskin <afedoskin3@gmail.com>
    SPDX-License-Identifier: GPL-2.0-or-later
*/
 
#pragma once
 
#include "skylabeler.h"
#include "typedef.h"
#include "typedeflite.h"
 
#include "skyopacitynode.h"
 
class StarItem;
class LabelNode;
class GuideLabelNode;
class RootNode;
class TrixelNode;
 
class SkyObject;
 
typedef SkyOpacityNode LabelTypeNode;
 
/**
 * @class LabelsItem
 *
 * This class is in charge of labels in SkyMapLite. Labels can be instantiated by calling addLabel with
 * either SkyObject or plain QString as a name. There are two types of label nodes available - LabelNode
 * that can't be rotated and GuideLabelNode that supports rotation (but it is not used anywhere yet).
 *
 * To prevent labels from overlapping this class uses SkyLabeler. We check LabelNode for overlapping by
 * calling SkyLabeler::markText() (SkyLabeler::markRegion() for GuideLabelNode) and update().
 *
 * Each of SkyItems that uses labels has its own label type in enum label_t (copied from SkyLabeler but
 * was extended). Labels of particular type are reparented to LabelTypeNode(QSGOpacityNode) so
 * to hide all labels of some type you just need to set opacity of LabelTypeNode that corresponds to
 * this type to 0.
 *
 * Order of drawing can be changed in LabelsItem's constructor. Order of labels update can be changed in
 * update().
 *
 * This class is not derived from SkyItem as it doesn't have label type and SkyItem's header needs an
 * inclusion of this header to allow use of label_t enum. (Might be a good idea to fix this)
 *
 * @note font size is set in SkyLabeler::SkyLabeler() by initializing m_stdFont with default font
 *
 * @short Handles labels in SkyMapLite
 * @author Artem Fedoskin
 * @version 1.0
 */
 
class LabelsItem : public SkyOpacityNode
{
  public:
    /**
     * @brief Constructor
     */
    LabelsItem();
 
    /** @short The label_t enum. Holds types of labels */
    enum label_t
    {
        STAR_LABEL,
        ASTEROID_LABEL,
        COMET_LABEL,
        PLANET_LABEL,
        JUPITER_MOON_LABEL,
        SATURN_MOON_LABEL,
        DEEP_SKY_LABEL,
        DSO_MESSIER_LABEL,
        DSO_OTHER_LABEL,
        CONSTEL_NAME_LABEL,
        SATELLITE_LABEL,
        RUDE_LABEL, ///Rude labels block other labels FIXME: find a better solution
        NUM_LABEL_TYPES,
        HORIZON_LABEL,
        EQUATOR_LABEL,
        ECLIPTIC_LABEL,
        TELESCOPE_SYMBOL,
        CATALOG_STAR_LABEL,
        CATALOG_DSO_LABEL,
        NO_LABEL //used in LinesItem
    };
 
    /**
     * Create LabelNode with given skyObject and append it to LabelTypeNode that corresponds
     * to type
     * @param skyObject for which the label is created
     * @param labelType type of LabelTypeNode to which this label has to be reparented
     * @return pointer to newly created LabelNode
     */
    LabelNode *addLabel(SkyObject *skyObject, label_t labelType);
 
    /**
     * Create LabelNode and append it to corresponding TrixelNode so that all labels
     * can be hidden whenever Trixel is not displayed. Use for sky objects that are indexed by SkyMesh
     * @param skyObject for which the label is created
     * @param labelType type of LabelTypeNode to which this label has to be reparented
     * @param trixel id of trixel
     **/
    LabelNode *addLabel(SkyObject *skyObject, label_t labelType, Trixel trixel);
 
    /** @short does the same as above but with QString instead of SkyObject */
    LabelNode *addLabel(QString name, label_t labelType);
 
    /**
     * @short does the same as above but instead creates GuideLabelNode
     * @note currently GuideLabelNode is not used anywhere so it is not fully supported yet
     */
    GuideLabelNode *addGuideLabel(QString name, label_t labelType);
 
    /**
     * The order of labels update can be changed here.
     * @short updates all child labels
     */
    void update();
 
    /**
     * @short updates child labels of LabelTypeNode that corresponds to type in m_labelsLists
     * Labels for stars and DSOs we update labels only if corresponding TrixelNode is visible.
     * @param labelType type of LabelTypeNode (see m_labelsLists)
     */
    void updateChildLabels(label_t labelType);
 
    /** @return LabelTypeNode that holds labels of labelType */
    LabelTypeNode *getLabelNode(label_t labelType) { return m_labelsLists.value(labelType); }
 
    /** @short deletes all labels of type labelType */
    void deleteLabels(label_t labelType);
 
    /** @short deletes particular label */
    void deleteLabel(LabelNode *label);
 
    /** @short hides all labels of type labelType */
    void hideLabels(label_t labelType);
 
    /**
         * @short shows all labels of type labelType
         */
 
    void showLabels(label_t labelType);
 
    /** @short adds trixel to the node corresponding to labelType */
    TrixelNode *addTrixel(label_t labelType, Trixel trixel);
 
    /**
     * @short sets m_rootNode and appends to it this node
     * @param rootNode parent RootNode that instantiates this object
     */
    void setRootNode(RootNode *rootNode);
 
    /** @return pointer to RootNode that instantiated this object */
    RootNode *rootNode() { return m_rootNode; }
 
  private:
    QMap<label_t, LabelTypeNode *> m_labelsLists;
 
    /** @short because this class is not derived from SkyItem it has to store pointer to RootNode */
    RootNode *m_rootNode { nullptr };
    SkyLabeler *skyLabeler { nullptr };
};